Role of dietary tea polyphenols on growth performance and gut health benefits in juvenile hybrid sturgeon (Acipenser baerii ♀ × A. schrenckii ♂)

The present study aimed to evaluate the effects of dietary TPs on growth performance, intestinal digestion, microflora and immunity in juvenile hybrid sturgeon. A total of 450 fish (97.20 ± 0.18 g) were randomly divided into a standard diet (TP-0) or four treatments consisting of a standard diet supplemented with four concentrations of TPs (mg/kg): 100 (TP-100), 300 (TP-300), 500 (TP-500), and 1000 (TP-1000) for 56 days. The TP-300 significantly increased weight gain rate (WGR) and specific growth rate (SGR) (p < 0.05), and TP-1000 significantly increased the feed conversion ratio (FCR) (p < 0.05). TP-300 and TP-500 significantly increased intestinal trypsin, amylase, and lipase activities (p < 0.05). Besides, TP-300 significantly enhanced total antioxidant capacity (T-AOC) and the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) and decreased malondialdehyde (MDA) content (p < 0.05). Moreover, TP-300 decreased the expression levels of tumor necrosis factor-alpha (TNF-α), interleukin 8 (IL-8), and interleukin 1β(IL-1β) compared with TP-0 and TP-1000 (p < 0.05). In addition, the intestinal microbiota diversity in the TP-300 group was observably higher, the dominant microbiota was Bacteroidota, Cyanobacteria, Proteobacteria and Firmicutes at the phylum level, Enterobacteriaceae, Nostocaceae and Clostridiaceae at the family level. The relative abundances of potential probiotics including Rhodobacteraceae and potential pathogens especially Clostridiaceae were the highest, and lowest, respectively. In conclusion, TP-300 altered the abundance of microbial taxa, resulting in enhancing the intestinal digestion, antioxidant status and non-specific immunity to improve the growth performance in juvenile hybrid sturgeon.

Study of anti-fatigue activity of polysaccharide from fruiting bodies of Armillaria gallica

Fatigue is a common physiological response that is closely related to energy metabolism. Polysaccharides, as excellent dietary supplements, have been proven to have a variety of pharmacological activities. In this study, A 23.007 kDa polysaccharide from Armillaria gallica (AGP) was purified and performed structural characterization, including analysis of homogeneity, molecular weight and monosaccharide composition. Methylation analysis is used to analyze the glycosidic bond composition of AGP. The mouse model of acute fatigue was used to evaluate the anti-fatigue effect of AGP. AGP-treatment improved exercise endurance in mice and reduced fatigue symptoms caused by acute exercise. AGP regulated the levels of adenosine triphosphate, lactic acid, blood urea nitrogen and lactate dehydrogenase, muscle glycogen and liver glycogen of acute fatigue mice. AGP affected the composition of intestinal microbiota, the changes of some intestinal microorganisms are correlated with fatigue and oxidative stress indicators. Meanwhile, AGP reduced oxidative stress levels, increased antioxidant enzyme activity and regulated the AMP-dependent protein kinase/nuclear factor erythroid 2-related factor 2 signaling pathway. AGP exerted an anti-fatigue effect through modulation of oxidative stress, which is related to intestinal microbiota.

Clostridioides difficile infection in infants: a case report and literature review

BACKGROUND

Clostridioides difficile (C. difficile) is the major pathogen causing antibiotic-associated diarrhea. There are a variety of symptoms associated with C. difficile infection (CDI) in adults, including self-limiting diarrhea, pseudomembranous colitis, toxic megacolon, septic shock, and even death from the infection. However, the infant's intestine appears to be completely resistant to the effects of C. difficile toxins A and B with rare development of clinical symptoms.

CASE PRESENTATION

In this study, we reported a 1-month-old girl with CDI who was born with neonatal hypoglycemia and necrotizing enterocolitis. Her symptom of diarrhea occurred after extensive use of broad-spectrum antibiotics during hospitalization and was accompanied by elevated white blood cell, platelet, and C-reactive protein levels, and repeated routine stool examinations were abnormal. She was recovered by norvancomycin (an analogue of vancomycin) and probiotic treatment. The results of 16 S rRNA gene sequencing also demonstrated the recovery of intestinal microbiota with the enrichment of Firmicutes and Lactobacillus.

CONCLUSIONS

Based on the literature review and this case report, clinicians should also pay attention to diarrhea caused by C. difficile in infants and young children. More strong evidence is needed to explain the true prevalence of CDI in this population and to better understand the C. difficile-associated diarrhea in infants.

Effects of different steaming times on the composition, structure and immune activity of Polygonatum Polysaccharide

ETHNOPHARMACOLOGICAL RELEVANCE

As a commonly used traditional Chinese herbal medicine, Polygonati Rhizoma has high medicinal value, it can enhance the immune capacity of the body, regulate the metabolism of blood glucose and lipids, treat weakness of the stomach and intestines and physical fatigue, and so on. There are three plant varieties of Polygonati Rhizoma recorded in Chinese Pharmacopoeia, including Polygonatum sibiricum Red., Polygonatum kingianum Coll. et Hemsl. and Polygonatum cyrtonema Hua, compared with the first two, Polygonatum cyrtonema Hua is less studied. Polygonatum cyrtonema Hua is one of the basal plants of the Chinese herb Polygonati Rhizoma, that strengthens the spleen, moistens the lungs, and benefits the kidneys. Polygonatum polysaccharide is the main active substance of Polygonatum cyrtonema Hua, which has various biological effects of regulating immune system, anti-inflammatory, anti-antidepressant, antioxidant and other effects.

AIM OF THE STUDY

In order to analyze the necessity and scientificity of multiple cycles of steaming during the traditional nine-steaming and nine-drying process of the concoction of Polygonatum, we investigated the changes in the composition and structure of polysaccharides, and explored its immunomodulatory activity and molecular biological mechanism.

METHODS

The structural characterization and molecular weight of polysaccharides were studied by scanning electron microscope (SEM), high-performance size exclusion chromatography-evaporative light scattering detector (HPSEC-ELSD) and Matrix.assisted laser resolutionu ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The composition and proportion of monosaccharides were determined by PMP-HPLC method. A mouse immunosuppression model was established by intraperitoneal injection of cyclophosphamide to compare the immunomodulatory effects and mechanisms of different steaming times of Polygonatum, The changes of body mass and immune organ indices of mice were measured; the secretion levels of interleukin-2 (IL-2), interferon γ (IFN-γ) and the expression levels of immunoglobulin M (IgM) and immunoglobulin A (IgA) in serum were determined by enzyme-linked immunosorbent assay; and then flow cytometry was used to detect T-lymphocyte subpopulations to evaluate the differences of immunomodulatory effects of polysaccharides during the processing and preparation of Polygonatum. Finally, the Illumina MiSeq high-throughput sequencing platform was used to analyze short-chain fatty acids and to investigate the effects of different steaming times of Polygonatum polysaccharides on immune function and intestinal flora in immunosuppressed mice.

RESULTS

The structure of the Polygonatum polysaccharide with different steaming times changed significantly, the relative molecular weight of Polygonatum polysaccharide decreased significantly, and the monosaccharide composition of Polygonatum cyrtonema Hua with different steaming times was the same but the content was different. The immunomodulatory activity of the Polygonatum polysaccharide was enhanced after concoction, which significantly increased the spleen index and thymus index, and increased the expression of IL-2, IFN-γ, IgA and IgM. The CD4+/CD8+ ratio of Polygonatum polysaccharide also increased gradually with different steaming times, indicating enhanced immune function and significant immunomodulatory effect. The content of short-chain fatty acids in the feces of mice in both six steaming six sun-drying of Polygonatum polysaccharides (SYWPP) and nine steaming nine sun-drying of Polygonatum polysaccharides (NYWPP) groups increased significantly, including the content of propionic acid, isobutyric acid, valeric acid, and isovaleric acid, and also had a good effect on the regulation and improvement of microbial community abundance and diversity, SYWPP and NYWPP increased the relative abundance of Bacteroides and the ratio of Bacteroides and Firmicutes (B:F), while SYWPP significantly increased the abundance of Bacteroides, Alistipes and norank_f__Lachnospiraceae, but the effect of raw Polygonatum polysaccharides (RPP) and NYWPP was not significant than SYWPP.

CONCLUSION

Overall, both SYWPP and NYWPP could significantly enhance the immune activity of the organism, improve the imbalance of intestinal flora in immunosuppressed mice, and increase the content of intestinal short chain fatty acids (SCFAs), it is noteworthy that SYWPP has a better effect on the improvement of the immune activity of the organism. These findings can explore the stage of the concoction process of Polygonatum cyrtonema Hua to achieve the best effect, provide a reference basis for the development of quality standards, and at the same time promote the application of new therapeutic agents and health foods in raw and different steaming times of Polygonatum polysaccharide.

Alteration of intestinal microbiota is associated with diabetic retinopathy and its severity: Samples collected from southeast coast Chinese

BACKGROUND

Current approaches for the therapy of diabetic retinopathy (DR), which was one of leading causes of visual impairment, have their limitations. Animal experiments revealed that restructuring of intestinal microbiota can prevent retinopathy.

AIM

To explore the relationship between intestinal microbiota and DR among patients in the southeast coast of China, and provide clues for novel ways to prevention and treatment methods of DR.

METHODS

The fecal samples of non-diabetics (Group C, n = 15) and diabetics (Group DM, n = 30), including 15 samples with DR (Group DR) and 15 samples without DR (Group D), were analyzed by 16S rRNA sequencing. Intestinal microbiota compositions were compared between Group C and Group DM, Group DR and Group D, as well as patients with proliferative diabetic retinopathy (PDR) (Group PDR, n = 8) and patients without PDR (Group NPDR, n = 7). Spearman correlation analyses were performed to explore the associations between intestinal microbiota and clinical indicators.

RESULTS

The alpha and beta diversity did not differ significantly between Group DR and Group D as well as Group PDR and Group NPDR. At the family level, Fusobacteriaceae, Desulfovibrionaceae and Pseudomonadaceae were significantly increased in Group DR than in Group D (P < 0.05, respectively). At the genera level, Fusobacterium, Pseudomonas, and Adlercreutzia were increased in Group DR than Group D while Senegalimassilia was decreased (P < 0.05, respectively). Pseudomonas was negatively correlated with NK cell count (r = -0.39, P = 0.03). Further, the abundance of genera Eubacterium (P < 0.01), Peptococcus, Desulfovibrio, Acetanaerobacterium and Negativibacillus (P < 0.05, respectively) were higher in Group PDR compared to Group NPDR, while Pseudomonas, Alloprevotella and Tyzzerella (P < 0.05, respectively) were lower. Acetanaerobacterium and Desulfovibrio were positively correlated with fasting insulin (r = 0.53 and 0.61, respectively, P < 0.05), when Negativibacillus was negatively correlated with B cell count (r = -0.67, P < 0.01).

CONCLUSION

Our findings indicated that the alteration of gut microbiota was associated with DR and its severity among patients in the southeast coast of China, probably by multiple mechanisms such as producing short-chain fatty acids, influencing permeability of blood vessels, affecting levels of vascular cell adhesion molecule-1, hypoxia-inducible factor-1, B cell and insulin. Modulating gut microbiota composition might be a novel strategy for prevention of DR, particularly PDR in population above.

Combined impacts of microplastics and cadmium on the liver function, immune response, and intestinal microbiota of crucian carp (Carassius carassius)

Microplastics (MPs) and the heavy metal cadmium (Cd) have attracted global attention for their toxicological interactions in aquatic organisms. The purpose of this investigation was evaluating the effect of MPs (1 mg L^-1) and Cd (5 mg L^-1) on the liver function, immune response of crucian carp (Carassius carassius) after 96 h exposure, and intestinal microbiota after 21 days, respectively. Co-exposure to MPs and Cd significantly enhanced MP accumulation in the liver of the crucian carp compared to the accumulation with exposure to MPs alone. Co-exposure to MPs and Cd triggered notable histopathological alterations accompanied by increased hepatic cell necrosis and inflammation, and was associated with higher aspartate aminotransferase and alanine aminotransferase levels, lower superoxide dismutase and catalase activity levels, but higher malondialdehyde content and total antioxidant capacity in the liver. Moreover, the combined treatment of MPs and Cd led to the up-regulated transcription of genes related to immune response, such as interleukin 8 (il-8), il-10, il-1β, tumor necrosis factor-α, and heat shock protein 70, both in the liver and spleen. Co-exposure to MPs and Cd reduced the variety and abundance of the intestinal microbiota in the crucian carp. Our research indicates that the combined exposure to MPs and Cd may exert synergistic toxic effects on crucian carp, which could impede the sustainable growth of the aquaculture industry and pose potential risks to food safety.

Pectin alleviates the pulmonary inflammatory response induced by PM2.5 from a pig house by modulating intestinal microbiota

This study aimed to investigate whether dietary fiber pectin can alleviate PM_2.5-induced pulmonary inflammation and the potential mechanism. PM_2.5 samples were collected from a nursery pig house. The mice were divided into three groups: the control group, PM_2.5 group and PM_2.5 + pectin group. The mice in the PM_2.5 group were intratracheally instilled with PM_2.5 suspension twice a week for four consecutive weeks, and those in the PM_2.5 + pectin group were subject to the same PM_2.5 exposure, but fed with a basal diet supplemented with 5% pectin. The results showed that body weight and feed intake were not different among the treatments (p > 0.05). However, supplementation with pectin relieved PM_2.5-induced pulmonary inflammation, presenting as slightly restored lung morphology, decreased mRNA expression levels of IL-1β, IL-6 and IL-17 in the lung, decreased MPO content in bronchoalveolar lavage fluid (BLAF), and even decreased protein levels of IL-1β and IL-6 in the serum (p < 0.05). Dietary pectin altered the composition of the intestinal microbiota, increasing the relative abundance of Bacteroidetes and decreasing the ratio of Firmicutes/Bacteroidetes. At the genus level, short-chain fatty acid (SCFA)-producing bacteria, such as Bacteroides, Anaerotruncus, Prevotella 2, Parabacteroides, Ruminococcus 2 and Butyricimonas, were enriched in the PM_2.5 +pectin group. Accordingly, dietary pectin increased the concentrations of SCFAs, including acetate, propionate, butyrate and valerate, in mice. In conclusion, dietary fermentable fiber pectin can relieve PM_2.5-induced pulmonary inflammation via alteration of intestinal microbiota composition and SCFA production. This study provides a new insight into reducing the health risk associated with PM_2.5 exposure.

Dietary administration of a postbiotic, heat-killed Pediococcus pentosaceus PP4012 enhances growth performance, immune response and modulates intestinal microbiota of white shrimp, Penaeus vannamei

The efficacy of postbiotics on the immune-related gene expression and gut microbiota of white shrimp (Penaeus vannamei) remains unexplored. A commercial heat-killed postbiotic Pediococcus pentosaceus PP4012 was used to evaluate the growth performance, intestinal morphology, immunological status, and microbial community of white shrimp after dietary administration in this study. White shrimp (0.040 ± 0.003 g) were divided into three treatments; a control, inanimate P. pentosaceus (10⁵ CFU g feed^-1) at low concentration (IPL) and inanimate P. pentosaceus (10⁶ CFU g feed^-1) at high concentrations (IPH). The diets of IPL and IPH significantly increased final weight, specific growth rate and production compared to the control group. Shrimp fed with IPL and IPH significantly utilized feed more efficiently than those fed the control diet. The IPH treatment significantly lowered the cumulative mortality rate compared to the control and IPL diet following Vibrio parahaemolyticus infection. No significant difference was observed for Vibrio-like and lactic acid bacteria in intestine of shrimp fed with the control diet and the experimental diets. Adding inanimate P. pentosaceus significantly improved immune responses such as lysozyme and phagocytic activity compared to the control group. However, the total hemocyte count, phenoloxidase activity, respiratory burst, and superoxide dismutase were not significantly different among treatments. The immune-related genes alf, pen3a, and pen4 expression were significantly higher in shrimp fed IPL diet compared with control and IPH. Taxonomic identification of bacterial genera in all dietary groups belonged to two predominant phyla, Proteobacteria and Bacteroidota. An abundance of Photobacterium, Motilimonas, Litorilituus, and Firmicutes bacterium ZOR0006 were identified in the intestine of shrimp fed postbiotic diets. Unique microbes such as Cohaesibacter was discovered in the shrimp fed IPL while Candidatus Campbellbacteria, uncultured Verrucomicrobium DEV114 and Paenalcaligenes were discovered in the intestines of shrimp fed IPH diet. Collectively, these data suggest that including heat-killed P. pentosaceus, particularly IPH, can enhance growth performance, promote microbial diversity, elevate immune responses, and increase shrimp's resistance to V. parahaemolyticus.

Effects of Pu-erh and Dian Hong tea polyphenols on the gut-liver axis in mice

Tea polyphenols (TP) are the most biologically active components in tea, with antioxidant, antiobesity, and antitumor properties, as well as the ability to modulate the composition and function of intestinal microbiota. This experimental study evaluated the chemical constituents of polyphenols in Pu-erh (PTP) and Dian Hong tea (DHTP). It also investigated the co-regulatory effects of PTP and DHTP on intestinal flora and liver tissues in mice using 16 S rRNA gene and transcriptome sequencing. The results revealed that DHT had higher concentrations of EGC (epigallocatechin), C (catechin), EC (epicatechin), and EGCG (epigallocatechin gallate). In contrast, PT had higher concentrations of GA (gallic acid), ECG (epicatechin-3-gallate), TF (theaflavin), and TB (theabrownin). PTP and DHTP consumption significantly reduced the rates of weight gain in mice. Microbial community diversity was significantly higher in PTP and DHTP-treated mice than in the control group. Notably, beneficial microbes such as Lactobacillus increased significantly in PTP-treated mice, whereas Lachnospiraceae increased significantly in DHTP-treated mice. Both PTP and DHTP improved the activity of the antioxidant enzymes (SOD) and total antioxidant capacity (T-AOC) in the liver. The transcriptome analysis revealed that the beneficial effects of PTP and DHTP were due to changes in various metabolic pathways, the majority of which were related to antioxidant and lipid metabolism. This study discovered that PTP and DHTP had beneficial effects in mice via the gut-liver axis.

Long-term consumption of different doses of Grifola frondosa affects immunity and metabolism: correlation with intestinal mucosal microbiota and blood lipids

Grifola frondosa (GF) is an edible mushroom with hypoglycemic and hypolipidemic effects. In this study, the specific pathogen-free male mice were randomized into the normal (NM), low-dose GF (LGF), medium-dose GF (MGF), and high-dose GF (HGF) groups. The LGF, MGF, and HGF groups were fed with 1.425 g/(kg d), 2.85 g/(kg d), and 5.735 g/(kg d) of GF solution for 8 weeks. After feeding with GF solution, compared with the NM group, the thymus index was significantly increased in the LGF group, and TC, TG, and LDL of mice were significantly increased in the HGF group, while HDL was significantly decreased. Compared with the NM group, the uncultured Bacteroidales bacterium, Ligilactobacillus increased in the LGF group, and Candidatus Arthromitus increased in the MGF group. The characteristic bacteria of the HGF group included Christensenellaceae R7, unclassified Clostridia UCG 014, unclassified Eubacteria coprostanoligenes, and Prevotellaceae Ga6A1. Among them, Ligilactobacillus showed a negative correlation with HDL. Unclassified Eubacterium coprostanoligenes group and Ligilactobacillus showed a positive correlation with TG. In summary, our experiments evidenced that GF improves lipid metabolism disorders by regulating the intestinal microbiota, providing a new pathway for hypolipidemic using GF dietary.

The preventive effect of Glycyrrhiza polysaccharide on lipopolysaccharide-induced acute colitis in mice by modulating gut microbial communities

Acute colitis is characterised by an unpredictable onset and causes intestinal flora imbalance together with microbial migration, which leads to complex parenteral diseases. Dexamethasone, a classic drug, has side effects, so it is necessary to use natural products without side effects to prevent enteritis. Glycyrrhiza polysaccharide (GPS) is an α-d-pyranoid polysaccharide with anti-inflammatory effects; however, its anti-inflammatory mechanism in the colon remains unknown. This study investigated whether GPS reduces the lipopolysaccharide (LPS)-induced inflammatory response in acute colitis. The results revealed that GPS attenuated the upregulation of tumour necrosis factor-α, interleukin (IL)-1β, and IL-6 in the serum and colon tissues and significantly reduced the malondialdehyde content in colon tissues. In addition, the 400 mg/kg GPS group showed higher relative expressions of occludin, claudin-1, and zona occludens-1 in colon tissues and lower concentrations of diamine oxidase, D-lactate, and endotoxin in the serum than the LPS group did, indicating that GPS improved the physical and chemical barrier functions of colon tissues. GPS increased the abundance of beneficial bacteria, such as Lactobacillus, Bacteroides, and Akkermansia, whereas pathogenic bacteria, such as Oscillospira and Ruminococcus were inhibited. Our findings indicate that GPS can effectively prevent LPS-induced acute colitis and exert beneficial effects on the intestinal health.

Effects of weaning American glass eels (Anguilla rostrata) with the formula diet on intestinal microbiota and inflammatory cytokines genes expression

This study aimed to investigate the effects of weaning American glass eels (Anguilla rostrata) with the formula diet on intestinal microbiota and the expression of inflammatory cytokines genes. During the feeding trial, the control group (termed IF group) was fed with initial feed for 34 days, and the experimental group (termed FF group) was fed with initial feed for 30 days, and then weaned with the formula diet for 4 days. After feeding trial, intestines were subjected to microbiota analysis using 16S rDNA high-throughput sequencing, and expression of three inflammatory cytokines genes in gut were examined by qPCR. The results indicated that the species richness and diversity of intestinal microbiota exhibited significantly higher in FF group than that in IF group (P < 0.05). At the phylum level, the core intestinal microflora was the same for two groups. The most abundant phylum was Firmicutes in IF group, while it was Proteobacteria in FF group. Five genera were significantly higher in the IF group compared with the FF group, and Bacillus was the most major enriched biomarker at genus level. Nine genera were significantly higher in the FF group compared with the IF group, and Acidovorax was the most major enriched biomarker. Weaning from initial feeding diet to formula feeding diet enhanced the expression levels of TNF-α and IL-8, and there was no significant change in IL-1β expression between the two groups. These findings would be very useful to improve the diet formulation for weaning stage of American glass eels.

Combined effect of salinity and hypoxia on digestive enzymes and intestinal microbiota in the oyster Crassostrea hongkongensis

Anthropologic activities caused frequent eutrophication in coastal and estuarine waters, resulting in diel-cycling hypoxia. Given global climate change, extreme weather events often occur, thus salinity fluctuation frequently breaks out in these waters. This study aimed to evaluate the combined effects of salinity and hypoxia on intestinal microbiota and digestive enzymes of Crassostrea hongkongensis. Specifically, we sequenced 16 S rRNA of intestinal microbiota and measured the digestive enzymes trypsin (TRS), lipase (LPS) and amylase (AMY) in oysters exposed for 28 days to three salinities (10, 25 and 35) and two dissolved oxygen conditions, normoxia (6 mg/L) and hypoxia (6 mg/L for 12 h, 2 mg/L for 12 h). Oysters in normoxia and salinity of 25 were treated as control. After 28-day exposure, for microbial components, Fusobacteriota, Firmicutes, Bacteroidota, Proteobacteria and Actinobacteriota comprised the majority for all experimental groups. Compared with the control group, the diversity and structure of intestinal microbiota tended to change in all treated groups. The species richness in C. hongkongensis intestine also changed. It was the most significant that high salinity increased Proteobacteria proportion while low salinity and hypoxia increased Fusobacteriota but decreased Proteobacteria, respectively. Additionally, Actinobacteriota was sensitive and changed under environmental stressor (P < 0.01). The prediction results on intestinal microbiota showed that, all functions of oysters were up-regulated to distinct degrees under low/high salinity with hypoxia. According to the KEGG prediction, cellular processes were more active and energy metabolism upregulated, indicating the adaptation of C. hongkongensis to environmental change. Periodical hypoxia and low/high salinity had complex effect on the digestive enzymes, in which the activity of TRS and LPS decreased while AMY increased. High/low salinity and periodical hypoxia can change the secretion of digestive enzymes and influence intestinal microbial diversity and species richness of C. hongkongensis, deducing the chronic adverse effects on the digestive physiology in long-term exposure.

Diarrhea accompanies intestinal inflammation and intestinal mucosal microbiota dysbiosis during fatigue combined with a high-fat diet

OBJECTIVE

It was reported fatigue or a high-fat diet triggers diarrhea, and intestinal microbiota may play central roles in diarrhea. Therefore, we investigated the association between the intestinal mucosal microbiota and the intestinal mucosal barrier from fatigue combined with a high-fat diet.

METHOD

This study divided the Specific pathogen-free (SPF) male mice into the normal group (MCN) and the standing united lard group (MSLD). The MSLD group stood on water environment platform box for 4 h/day for 14 days, and 0.4 mL lard was gavaged from day 8, twice daily for 7 days.

RESULT

After 14 days, Mice in the MSLD group showed diarrhea symptoms. The pathological analysis showed structural damage to the small intestine in the MSLD group, with an increasing trend of interleukin-6 (IL-6) and IL-17, and inflammation accompanied by structural damage to the intestine. Fatigue combined with a high-fat diet considerably decreased Limosilactobacillus vaginalis and Limosilactobacillus reuteri, and among them, Limosilactobacillus reuteri positively associated with Muc2 and negatively with IL-6.

CONCLUSION

The interactions between Limosilactobacillus reuteri and intestinal inflammation might be involved in the process of intestinal mucosal barrier impairment in fatigue combined with high-fat diet-induced diarrhea.

Combined exposure to polystyrene nanoplastics and bisphenol A induces hepato- and intestinal-toxicity and disturbs gut microbiota in channel catfish (Ictalurus punctatus)

The widespread consumption of nanoplastics (NPs) and bisphenol A (BPA) affected the aquatic ecosystem and imposed risks to the safety of aquatic organisms. This study was aimed at assessing the ecotoxicological effects of single and combined exposure to BPA and polystyrene nanoplastics (PSNPs) on the channel catfish (Ictalurus punctatus). A total of 120 channel catfish were separated into four groups with triplicate (each contains 10 fish) and exposed to chlorinated tap water (control group), PSNP single exposure (0.3 mg/L), BPA single exposure (500 μg/L) and PSNPs (0.3 mg/L) + BPA (500 μg/L) co-exposure for 7 days. Our results showed a relatively higher intestinal accumulation of PSNPs in co-exposure group, compared to PSNP single exposure group. Histopathological analysis showed that single exposure to PSNPs and BPA caused breakage of intestinal villi and swelling of hepatocytes in channel catfish, while the co-exposure exacerbated the histopathological damage. In addition, co-exposure significantly increased SOD, CAT activities and MDA contents in the intestine and liver, inducing oxidative stress. In terms of immune function, the activities of ACP and AKP were significantly decreased. The expressions of immune-related genes such as IL-1β, TLR3, TLR5, hepcidin and β-defensin were significantly up-regulated, and the expression of IL-10 was down-regulated. Additionally, the co-exposure significantly altered the composition of the intestinal microbiota, leading to an increase in the Shannon index and a decrease in the Simpson index. In summary, this study revealed that mixture exposure to PSNPs and BPA exacerbated toxic effects on histopathology, oxidative stress, immune function and intestinal microbiota in channel catfish. It emphasized the threat of NPs and BPA to the health of aquatic organisms and human food safety, with a call for effective ways to regulate the consumption of these anthropogenic chemicals.

Dietary Supplementation of Brevibacillus laterosporus S62-9 Improves Broiler Growth and Immunity by Regulating Cecal Microbiota and Metabolites

Brevibacillus laterosporus has been added as a direct-fed microbiota to chicken. Yet, few studies have reported the effects of B. laterosporus on broiler growth and gut microbiota. The aim of this study was to evaluate the effects of B. laterosporus S62-9 on growth performance, immunity, cecal microbiota, and metabolites in broilers. A total of 160 1-day-old broilers were randomly divided into S62-9 and control groups, with or without 10⁶ CFU/g B. laterosporus S62-9 supplementation, respectively. During the 42 days feeding, body weight and feed intake were recorded weekly. Serum was collected for immunoglobulin determination, and cecal contents were taken for 16S rDNA analysis and metabolome at Day 42. Results indicated that the broilers in S62-9 group showed an increase in body weight of 7.2% and 5.19% improvement in feed conversion ratio compared to the control group. The B. laterosporus S62-9 supplementation promoted the maturation of immune organs and increased the concentration of serum immunoglobulins. Furthermore, the α-diversity of cecal microbiota was improved in the S62-9 group. B. laterosporus S62-9 supplementation increased the relative abundance of beneficial bacteria including Akkermansia, Bifidobacterium, and Lactobacillus, while decreased the relative abundance of pathogens including Klebsiella and Pseudomonas. Untargeted metabolomics revealed that 53 differential metabolites between the two groups. The differential metabolites were enriched in 4 amino acid metabolic pathways, including arginine biosynthesis and glutathione metabolism. In summary, B. laterosporus S62-9 supplementation could improve the growth performance and immunity through the regulation of gut microbiota and metabolome in broilers.

Sex different effect of antibiotic and probiotic treatment on intestinal microbiota composition in chemically induced liver injury rats

Differences in the gut microbiota and metabolic processes between males and females may explain differences in the risk of liver injury; however, the sex-specific effects of antibiotics and probiotics on these relationships are not clear. We evaluated differences in the gut microbiota and the risk of liver injury between male and female rats after the oral administration of antibiotics or probiotics followed by a period of diethylnitrosamine treatment to chemically induce liver injuryusing high-throughput sequencing of fecal microbiota combined with histological analyses of liver and colon tissues. Our results suggest that the ratio of gram-positive to gram-negative bacteria in kanamycin-treated rats was significantly higher than that of other groups, and this difference persisted for the duration of the experiment. Antibiotics significantly changed the composition of the gut microbiota of experimental rats. Clindamycin caused more diethylnitrosamine-induced damage to livers of male rats. Probiotics did not influencethe gut microbiota; however, they hadprotective effects against liver injury induced by diethylnitrosamine, especially in female rats. These results strengthen our understanding of sex differences in the indirect effects of antibiotics or probiotics on metabolism and liver injury in hosts via the gut microbiota.

Polystyrene micro- and nanoparticles exposure induced anxiety-like behaviors, gut microbiota dysbiosis and metabolism disorder in adult mice

Plastics have been proven to be a potential threat to the ecosystem, and their toxicity mechanism is still uncertain. In the ecological environment, plastics can be degraded into microplastics (MPs) and nanoplastics (NPs), which can be contaminated and ingested through the food chain. MPs and NPs are associated with severe intestinal injury, intestinal microbiota disorder, and neurotoxicity, but it is still unclear whether MPs- and NPs-induced intestinal microbiota dysbiosis will affect the brain through the gut-brain axis. In the current study, we determined the effects of exposure to polystyrene (PS)-MPs and PS-NPs on anxiety-like behaviors and explored the underlying mechanisms. This study explored the behavioral effects of 30-day and 60-day exposure to PS-NPs and PS-MPs using the open field test (OFT) and elevated plus maze (EPM) test. Behavioral tests showed PS-NPs and PS-MPs treatment remarkedly induced anxiety-like behaviors compared with the control group. Using 16 S rRNA gene sequencing and untargeted metabolomics analyses, we observed that PS-MPs and PS-NPs exposure reduced the beneficial gut microbiota expression level, such as Lachnoclostridium and Lactobacillus, and increased the conditionally pathogenic bacteria expressions level, such as Proteobacteria, Actinobacteria, and Desulfovibrio. In addition, PS-NPs and PS-MPs reduce intestinal mucus secretion and increase intestinal permeability. The results of serum metabonomics suggested that the metabolic pathways, such as ABC transporter pathways, aminoacyl-tRNA biosynthesis, biosynthesis of amino acids, and bile secretion were enriched after PS-NPs and PS-MPs treatment. Besides, neurotransmitter metabolites were also altered by PS-NPs and PS-MPs. It is noteworthy that the correlation analysis showed that the disorder of intestinal microbiota was related to anxiety-like behaviors and neurotransmitter metabolites disorder. The regulation of intestinal microbiota may be a promising treatment strategy for PS-MPs- and PS-NPs-induced anxiety disorder.

Hydrogen gas ameliorates acute alcoholic liver injury via anti-inflammatory and antioxidant effects and regulation of intestinal microbiota

Alcoholic liver disease (ALD) is a globally prevalent liver-related disorder characterized by severe oxidative stress and inflammatory liver damage, for which no effective treatment is currently available. Hydrogen gas (H₂) has been demonstrated to be an efficient antioxidant in various diseases in animals as well as humans. However, the protective effects of H₂ on ALD and its underlying mechanisms remain to be elucidated. The present study demonstrated that H₂ inhalation ameliorated liver injury, and attenuated liver oxidative stress, inflammation, and steatosis in an ALD mouse model. Moreover, H₂ inhalation improved gut microbiota, including increasing the abundance of Lachnospiraceae and Clostridia, and decreasing the abundance of Prevotellaceae and Muribaculaceae, and also improved intestinal barrier integrity. Mechanistically, H₂ inhalation blocked activation of the LPS/TLR4/NF-κB pathway in liver. Notably, it was further demonstrated that the reshaped gut microbiota may accelerate alcohol metabolism, regulate lipid homeostasis and maintain immune balance by bacterial functional potential prediction (PICRUSt). Fecal microbiota transplantation from mice that had undergone H₂ inhalation significantly alleviated acute alcoholic liver injury. In summary, the present study showed that H₂ inhalation alleviated liver injury by reducing oxidative stress and inflammation, while also improving intestinal flora and enhancing the intestinal barrier. H₂ inhalation may serve as an effective intervention for preventing and treating ALD in a clinical context.

[Intestinal and pharyngeal microbiota in early neonates: an analysis based on high-throughput sequencing]

OBJECTIVES

To investigate the distribution characteristics and correlation of intestinal and pharyngeal microbiota in early neonates.

METHODS

Full-term healthy neonates who were born in Shanghai Pudong New Area Maternal and Child Health Hospital from September 2021 to January 2022 and were given mixed feeding were enrolled. The 16S rRNA sequencing technique was used to analyze the stool and pharyngeal swab samples collected on the day of birth and days 5-7 after birth, and the composition and function of intestinal and pharyngeal microbiota were analyzed and compared.

RESULTS

The diversity analysis showed that the diversity of pharyngeal microbiota was higher than that of intestinal microbiota in early neonates, but the difference was not statistically significant (P>0.05). On the day of birth, the relative abundance of Proteobacteria in the intestine was significantly higher than that in the pharynx (P<0.05). On days 5-7 after birth, the relative abundance of Actinobacteria and Proteobacteria in the intestine was significantly higher than that in the pharynx (P<0.05), and the relative abundance of Firmicutes in the intestine was significantly lower than that in the pharynx (P<0.05). At the genus level, there was no significant difference in the composition of dominant bacteria between the intestine and the pharynx on the day of birth (P>0.05), while on days 5-7 after birth, there were significant differences in the symbiotic bacteria of Streptococcus, Staphylococcus, Rothia, Bifidobacterium, and Escherichia-Shigella between the intestine and the pharynx (P<0.05). The analysis based on the database of Clusters of Orthologous Groups of proteins showed that pharyngeal microbiota was more concentrated on chromatin structure and dynamics and cytoskeleton, while intestinal microbiota was more abundant in RNA processing and modification, energy production and conversion, amino acid transport and metabolism, carbohydrate transport and metabolism, coenzyme transport and metabolism, and others (P<0.05). The Kyoto Encyclopedia of Genes and Genomes analysis showed that compared with pharyngeal microbiota, intestinal microbiota was more predictive of cell motility, cellular processes and signal transduction, endocrine system, excretory system, immune system, metabolic diseases, nervous system, and transcription parameters (P<0.05).

CONCLUSIONS

The composition and diversity of intestinal and pharyngeal microbiota of neonates are not significantly different at birth. The microbiota of these two ecological niches begin to differentiate and gradually exhibit distinct functions over time.

[Clinical study of 19 cases of steroid-refractory gastrointestinal acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation with fecal microbiota transplantation]

Objective: To investigate the clinical efficacy of fecal microbiota transplantation (FMT) for treating steroid-refractory gastrointestinal acute graft-versus-host disease (GI-aGVHD) . Methods: This analysis included 29 patients with hematology who developed steroid-refractory GI-aGVHD after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in Huaian Hospital Affiliated to Xuzhou Medical University from March 2017 to March 2022. Among them, 19 patients underwent FMT treatment (the FMT group) and 10 patients did not (the control group). The efficacy and safety of FMT were assessed, as well as the changes in intestinal microbiota abundance, lymphocyte subpopulation ratio, peripheral blood inflammatory cytokines, and GVHD biomarkers before and after FMT treatment. Results: ① Complete remission of clinical symptoms after FMT was achieved by 13 (68.4%) patients and 2 (20.0%) controls, with a statistically significant difference (P<0.05). Intestinal microbiota diversity increased and gradually recovered to normal levels after FMT and FMT-related infections did not occur. ②The proportion of CD3(+) and CD8(+) cells in the FMT group after treatment decreased compared with the control group, and the ratio of CD4(+), regulatory T cells (Treg), and CD4(+)/CD8(+) cells increased (all P< 0.05). The interleukin (IL) -6 concentration in the FMT group was lower than that in the control group [4.15 (1.91-5.71) ng/L vs 6.82 (2.40-8.91) ng/L, P=0.040], and the IL-10 concentration in the FMT group was higher than that in the control group [12.11 (5.69-20.36) ng/L vs 7.51 (4.10-9.58) ng/L, P=0.024]. Islet-derived protein 3α (REG3α) was significantly increased in patients with GI-aGVHD, and the REG3α level in the FMT group was lower than that in the control group after treatment [30.70 (10.50-105.00) μg/L vs 74.35 (33.50-139.50) μg/L, P=0.021]. Conclusion: FMT is a safe and effective method for the treatment of steroid-refractory GI-aGVHD by restoring intestinal microbiota diversity, regulating inflammatory cytokines, and upregulating Treg cells.

Dysregulation along the gut microbiota-immune system axis after oral exposure to titanium dioxide nanoparticles: A possible environmental factor promoting obesity-related metabolic disorders

Food additives are one major hallmark of ultra-processed food in the Western-diet, a food habit often associated with metabolic disorders. Among these additives, the whitener and opacifying agent titanium dioxide (TiO₂) raises public health issues due to the ability of TiO₂ nanoparticles (NPs) to cross biological barriers and accumulate in different systemic organs like spleen, liver and pancreas. However before their systemic passage, the biocidal properties of TiO₂ NPs may alter the composition and activity of the gut microbiota, which play a crucial role for the development and maintenance of immune functions. Once absorbed, TiO₂ NPs may further interact with immune intestinal cells involved in gut microbiota regulation. Since obesity-related metabolic diseases such as diabetes are associated with alterations in the microbiota-immune system axis, this raises questions about the possible involvement of long-term exposure to food-grade TiO₂ in the development or worsening of these diseases. The current purpose is to review the dysregulations along the gut microbiota-immune system axis after oral TiO₂ exposure compared to those reported in obese or diabetic patients, and to highlight potential mechanisms by which foodborne TiO₂ NPs may increase the susceptibility to develop obesity-related metabolic disorders.

Study effect and mechanism of levofloxacin on the neurotoxicity of Rana nigromaculata tadpoles exposed to imidacloprid based on the microbe-gut-brain axis

Aquatic organisms may be simultaneously exposed to antibiotics and pesticides. After levofloxacin (LVFX), imidacloprid (IMI) exposure and co-exposure at environmental levels, we found LVFX and IMI had antagonistic effect on the neurotoxicity of tadpoles. IMI-induced neurotoxicity on tadpoles can be explained by oxidative stress and hormone levels in some degree. By regulating ornithine, l-asparagine, putrescine and tryptamine in the intestine, LVFX affected glutathione metabolism, arginine and proline metabolism, alanine, aspartate and glutamate metabolism, tyrosine metabolism and aminoacyl tRNA biosynthesis, so then eased the neurotoxicity caused by IMI. More interestingly, Fusobacteriota and Cetobacterium might play an important role on easing the neurotoxicity caused by IMI. In addition, LVFX might have a laxation effect on the increased relative abundance of Bacteroidota caused by IMI. In conclusion, IMI not only affected oxidative stress and hormone levels in the brain, but also affected the synthesis of neurotransmitters in the intestine by regulating intestinal microbiota. In LVFX and IMI co-exposed groups, LVFX alleviated the neurotoxicity caused by IMI through regulating the intestinal microbiota, showing as an antagonistic effect. Our results provided a new perspective for aquatic ecological risk assessment under co-exposure of antibiotics and pesticides.

coli strains with distinct in-vitro adherent/invasive properties establish their own co-colonization niche and shape the intestinal microbiota in inflammation-susceptible mice

Background

Inflammatory bowel disease (IBD) patients experience recurrent episodes of intestinal inflammation and often follow an unpredictable disease course. Mucosal colonization with adherent-invasive Escherichia coli (AIEC) are believed to perpetuate intestinal inflammation. However, it remains unclear if the 24-year-old AIEC in-vitro definition fully predicts mucosal colonization in-vivo. To fill this gap, we have developed a novel molecular barcoding approach to distinguish strain variants in the gut and have integrated this approach to explore mucosal colonization of distinct patient-derived E. coli isolates in gnotobiotic mouse models of colitis.

Results

Germ-free inflammation-susceptible interleukin-10-deficient (Il10-/-) and inflammation-resistant WT mice were colonized with a consortia of AIEC and non-AIEC strains, then given a murine fecal transplant to provide niche competition. E. coli strains isolated from human intestinal tissue were each marked with a unique molecular barcode that permits identification and quantification by barcode-targeted sequencing. 16S rRNA sequencing was used to evaluate the microbiome response to E. coli colonization. Our data reveal that specific AIEC and non-AIEC strains reproducibly colonize the intestinal mucosa of WT and Il10-/- mice. These E. coli expand in Il10-/- mice during inflammation and induce compositional dysbiosis to the microbiome in an inflammation-dependent manner. In turn, specific microbes co-evolve in inflamed mice, potentially diversifying E. coli colonization patterns. We observed no selectivity in E. coli colonization patterns in the fecal contents, indicating minimal selective pressure in this niche from host-microbe and interbacterial interactions. Because select AIEC and non-AIEC strains colonize the mucosa, this suggests the in vitro AIEC definition may not fully predict in vivo colonization potential. Further comparison of seven E. coli genomes pinpointed unique genomic features contained only in highly colonizing strains (two AIEC and two non-AIEC). Those colonization-associated features may convey metabolic advantages (e.g., iron acquisition and carbohydrate consumption) to promote efficient mucosal colonization.

Conclusions

Our findings establish the in-vivo mucosal colonizer, not necessarily AIEC, as a principal dysbiosis driver through crosstalk with host and associated microbes. Furthermore, we highlight the utility of high-throughput screens to decode the in-vivo colonization dynamics of patient-derived bacteria in murine models.

Structure characterization and Anti-Rheumatoid arthritis activity of a polysaccharide from Notopterygium incisum

SCOPE

Notopterygium incisum is a traditional Chinese medicine that is commonly used to treat rheumatoid arthritis. Polysaccharide from N. incisum could be one of its main active components. However, there have been little investigations on N. incisum polysaccharides.

METHODS AND RESULTS

A novel polysaccharide named NIP was extracted from Notopterygium incisum with a molecular weight of 2.34×10⁶  Da. NIP, composed of arabinose, galactose, glucose, and galacturonic acid, was linked by methyl esterified 1,4-linked α-galacturonic acid, 1,6-linked β-galactose, 1,5-linked α-arabinose, and 1,4,6-linked β- glucose. In vitro, NIP could inhibit the NO production of LPS-stimulated RAW264.7 cells. In vivo, NIP relieved toe redness and swelling of AIA rats, reduced the release of inflammatory factors in the serum, and inhibited the activation of NF-κB and JAK/STAT3 signaling pathways. In addition, NIP could effectively decrease oxidative stress, reverse intestinal flora imbalance, and promote butyric acid-producing bacteria's proliferation to exert anti-RA activity.

CONCLUSION

NIP might be recommended as a functional food that can alleviate the damage of rheumatoid arthritis. This article is protected by copyright. All rights reserved.

A comparative study on effects of dietary three strains of lactic acid bacteria on the growth performance, immune responses, disease resistance and intestinal microbiota of Pacific white shrimp, Penaeus vannamei

The present study evaluated the growth performance, immune responses, disease resistance and intestinal microbiota in Penaeus vannamei fed diets supplemented with three strains of lactic acid bacteria (LAB). The basal diet (control, CO) supplemented with Lactobacillus plantarum W2 (LA), Pediococcus acidilactici Nj (PE), Enterococcus faecium LYB (EN) and florfenicol (FL), respectively, formed three LAB diets (1 × 10¹⁰ cfu kg^-1) and a florfenicol diet (15 mg kg^-1, positive control), were fed to shrimp for 42 days. Results indicated that specific growth rate, feed efficiency rate, and disease resistance of shrimp against Vibrio parahaemolyticus in the treatment groups were significantly improved versus the control (P < 0.05). Compared with the control, acid phosphatase, alkaline phosphatase, phenonoloxidase, total nitric oxide synthase, peroxidase, superoxide dismutase activities, total antioxidant capacity, and lysozyme content in the serum and the relative expression levels of SOD, LZM, proPO, LGBP, HSP70, Imd, Toll, Relish, TOR, 4E-BP, eIF4E1α and eIF4E2 genes in the hepatopancreas of LAB groups were enhanced to various extents. Intestinal microbiota analysis showed that the LA and EN groups significantly improved microbial diversity and richness, and LAB groups significantly altered intestinal microbial structure of shrimp. At the phylum level, the Verrucomicrobiota in the LA and PE groups, the Firmicutes in the EN group, and the Actinobacteriota in the PE and EN groups were enriched. Moreover, the CO group increased the proportion of potential pathogens (Vibrionaceae and Flavobacteriaceae). The potential pathogen (Vibrio) was reduced, and potential beneficial bacteria (Tenacibaculum, Ruegeria and Bdellovibrio) were enriched in response to dietary three strains of LAB. When the intestinal microbiota homeostasis of shrimp is considered, L. plantarum and E. faecium showed better effects than P. acidilactici. However, due to the concerns on the possible potential risks of E. faecium strains to human health, L. plantarum W2 is more suitable for application in aquaculture than E. faecium LYB. Considering collectively the above, Lactobacillus plantarum W2 could be applied as better probiotic to improve the growth performance, non-specific immunity, disease resistance and promote intestinal health of P. vannamei.

Exposure to nitrate induced growth, intestinal histology and microbiota alterations of Bufo raddei Strauch tadpoles

Nitrate (NO₃^-) is one of the ubiquitous environmental chemicals which multiplies negative impacts on aquatic life such as amphibian larvae. However, the data involving the dynamics of amphibians in response to NO₃-N are scarce. This study investigated the effects of NO₃-N on locomotor ability, growth performance, oxidative stress parameters, intestinal histology, and intestinal microbiota of Bufo raddei Strauch tadpoles. The tadpoles were chronically exposed to different concentrations of NO₃-N (10, 50, 100, and 200 mg/L) from Gosner stage 26 to 38. Our results revealed that NO₃-N exposure caused significantly reduced body weight and length, impaired locomotor activity, and severe oxidative damage to liver tissue. Moreover, the high NO₃-N (50, 100, and 200 mg/L) exposure caused irregular arrangement and indistinct cell borders of mucosal epithelial cells in the tadpoles intestine. The NO₃-N exposure significantly changed the structure of the intestinal microbiota. The phylum Cyanobacteria occupy the main niche of intestinal microbes and have a certain negative correlation with the growth and motility of tadpoles. In addition, the functional prediction revealed that NO₃-N exposure obviously downregulated the metabolism of enzyme families in tadpoles. Our comprehensive research shows the toxicity of NO₃-N exposure in B. raddei Strauch, explores the potential links between development and intestinal microbiota of tadpole, and provides a new framework for the potential health risk of nitrate in amphibians.

Effects of Aspergillus-meal prebiotic diet on the growth performance, health status and gut microbiota of Asian seabass, Lates calcarifer

In this study, the growth performance, health status and intestinal microbiota of juvenile Asian seabass, Lates calcarifer, were assessed after dietary administration of a prebiotic product obtained from fermented Aspergillus orizae, Fermacto®. Asian seabass were fed three diets; control (without Aspergillus-meal prebiotic), 0.2% and 0.3% Aspergillus-meal prebiotic for 56 days. Fish were raised in freshwater with acceptable water quality. No significant differences were found in the growth performance and composition of dorsal fish muscle among all groups. Fish fed diets supplemented with 0.3% of Aspergillus-meal prebiotic had a significantly higher survival rate after being challenged with V. alginolyticus than fish fed with the control diet. Supplementation of the Aspergillus-meal prebiotic significantly improved immune responses by inducing higher respiratory burst, superoxide dismutase, phagocytic and lysozyme activity compared to the control group. In addition, prebiotic doses significantly induced an up-regulation of heat shock cognate 70 kDa protein (hsp70) in the liver compared to the control group. Signaling pathways were also affected with significantly higher gene expression of complement c-3 (c3), mechanistic target of rapamycin (mtor), and mammalian lethal with SEC13 protein 8 (mlst-8) in the liver of fish fed 0.3% Aspergillus prebiotic. The pro-inflammatory gene, tumor necrosis factor (tnf) and anti-inflammatory gene, transforming growth factor beta-1 (tfg-β1) were significantly higher in the head kidney of fish offered prebiotic diets. Fish receiving Aspergillus-meal prebiotic revealed significantly higher expression of Mx gene 24 h post nervous necrosis virus injection compared to the control. Additionally, the α-diversity of gut microbiota, including genus, Pielou's evenness, Shannon diversity index, and Margalef's species richness were significantly higher in fish fed 0.3% Aspergillus-meal prebiotic than the control group. The principal component analysis eigenvector plots showed that a high abundance of beneficial bacteria, such as Entercoccus faecium, Lactococcus lactis, Macrococcus caseolyticus and Vagococcus fluvialis, along with potentially pathogenic bacteria, such as Staphylococcus sciuri and L. garvieae subsp. garvieae were present in fish treated with Aspergillus-meal prebiotic. Although dietary Aspergillus-meal prebiotic did not improve the growth performance of Asian seabass, 0.3% of Aspergillus-meal prebiotic is recommended to elevate the immunological status of fish.

Intestinal microbiota analyses of five economic fishery resources in the South China Sea

The investigation of intestinal microbiota can provide evidence for revealing the growth and development regulation, feeding habits, environmental adaptability and pollutant indication of marine organisms. To data, the intestinal microbiota of marine organisms in the South China Sea is relatively lacking. To supplement these information, we sequenced intestinal microbiota from five fishery resources (including Auxis rochei, A. thazard, Symplectoteuthis oualaniensis, Thunnus albacores, and Coryphaena equiselis) in the South China Sea using high-throughput Illumina sequencing technology. After filtering, a total of 18,706,729 reads were finally produced and then clustered into OTUs. The mean number of OTUs detected in A. rochei, A. thazard, C. equiselis, S. oualaniensis, and T. albacores was 127, 137, 52, 136, and 142, respectively. Although the Actinobacteria, Bacteroidetes, Cyanobacteria, Deferribacteres, Firmicutes, Proteobacteria, Spirochaetes, Tenericutes, [Thermi], and unclassified_Bacteria were the most abundant in the five species, Photobacterium is the most abundant microbiota. Meanwhile, intestinal microbiota showed species- and sampling sites- specificity, thus only 84 microbiota species were common to all species. Additionally, the potential functions of OTUs in the five species is mainly involved in the synthesis and metabolism of carbohydrate, amino acid, fatty acid and vitamin. This study can provide basic data for clarifying the diversity and species- specificity of intestinal microbiota of five species in the South China Sea, and help to improve the intestinal microbiota database of marine organisms.

Protective effect and mechanism insight of purified Antarctic kill phospholipids against mice ulcerative colitis combined with bioinformatics

Antarctic krill oil is functional oil and has a complex phospholipids composition that poses difficulties in elucidating its effect mechanism on ulcerative colitis (UC). The mechanism of UC action was studied by bioinformatics, and the therapeutic effect of Antarctic krill phospholipids (APL) on dextran sulfate sodium (DSS)-induced colitis mice was verified. GO functional enrichment analysis uncovered an enrichment of these genes in the regulation of cell-cell adhesion, membrane region, signaling receptor activator activity, and cytokine activity. Meanwhile, the KEGG results revealed the genes were enriched in the TNF signaling pathway, pathogenic Escherichia coli infection, inflammatory bowel disease and tight junction. Animal experiments showed that APL treatment alleviated the UC symptoms and reduced inflammatory damage. Meanwhile, the expressions of the tight junction (TJ) proteins, ZO-1 and occludin, were restored, and the levels of IL-6 and TNF-α were reduced. Moreover, Firmicutes/Bacteroidetes ratio in the intestinal microbiota was regulated, and the contents of short-chain fatty acids metabolites were raised. These findings would provide an insight for the beneficial effects of APL and dietary therapy strategies for UC.

Increased abundances of potential pathogenic bacteria and expressions of inflammatory cytokines in the intestine of oyster Crassostrea gigas after high temperature stress

High temperature stress is a significant threat to the health of oysters, but the effects on their intestinal performances are not well understood. In this study, the effects of high temperature stress on the intestinal histology, immune response and associated microbiota were investigated in Crassostrea gigas after rearing at 20, 25 and 28 °C for 21 days. With the increase of temperature, shortened and shed microvilli as well as increased goblet cells were observed in the intestines of oysters. The transcripts of cytokines CgIL17-5, CgTNF-2 and CgTGF-β and apoptosis-related gene CgCaspase-3 in intestine increased with the increasing temperature. Further, the diversity and composition of the oyster intestinal microbiota changed after high temperature stress. The 16S rRNA gene copy number per ng of DNA in the T25 (5.16 × 10⁵) and T28 (1.63 × 10⁵) groups were higher than that in the control group (8.62 × 10⁴). The Chao 1 index in the T25 (238.00) and T28 (240.17) groups was lower than that in the control group (279.00). The Shannon index decreased progressively with the increasing temperature, with the value in the T28 group (4.44) significantly lower than that in the control group (5.40) (p < 0.05). The abundances of potential pathogenic bacteria such as Acinetobacter, Pseudomonas, Vibrio and Endozoicomonas increased while that of probiotic bacteria Bacillus decreased after high temperature exposure. Functional prediction indicated that the pathways associated with bacterial proliferation were enriched at 25 °C, while those involved in protein synthesis were blocked at 28 °C. Collectively, these results suggested that high temperature stress led to an increased abundances of potential pathogenic bacteria and expressions of inflammatory cytokines in the intestine, which may consequently affect the functional integrity of the intestinal barrier in oysters.

Dietary glutamate enhances intestinal immunity by modulating microbiota and Th17/Treg balance-related immune signaling in piglets after lipopolysaccharide challenge

The purpose of this study was to explore the effects of glutamate on piglet growth performance and intestinal immunity function, and to further elucidate its mechanism. In a 2 × 2 factorial design involving immunological challenge (lipopolysaccharide (LPS) or saline) and diet (with or without glutamate), twenty-four piglets were randomly assigned to four groups, each with 6 replicates. Piglets were fed with a basal or glutamate diet for 21 d before being injected intraperitoneally with LPS or saline. Piglet's intestinal samples were collected 4 h after injection. Results showed that glutamate increased daily feed intake, average daily gain, villus length, villus area, and villus length to crypt depth ratio (V/C), and decreased the crypt depth (P < 0.05). Furthermore, glutamate increased the mRNA expression of forkhead box P3 (FOXP3), a signal transducer and activator of transcription 5 (STAT5) and transforming growth factor beta, while decreasing the mRNA expression of RAR-related orphan receptor c and STAT3. Glutamate increased interleukin-10 (IL-10) mRNA expression while decreasing the mRNA expression of IL-1β, IL-6, IL-8, IL-17, IL-21, and tumor necrosis factor-α. At the phylum level, glutamate increased the Actinobacteriota abundance and Firmicutes-to-Bacteroidetes ratio while decreasing Firmicutes abundance. At the genus level, glutamate improved the abundance of beneficial bacteria (e.g., Lactobacillus, Prevotellaceae-NK3B31-group, and UCG-005). Furthermore, glutamate increased the concentrations of short-chain fatty acids (SCFAs). Correlation analysis revealed that the intestinal microbiota is closely related to Th17/Treg balance-related index and SCFAs. Collectively, glutamate can improve piglet growth performance and intestinal immunity by modulating gut microbiota and Th17/Treg balance-related signaling pathways.

Bacteriophage-based techniques for elucidating the function of zebrafish gut microbiota

Bacteriophages (or phages) are unique viruses that can specifically infect bacteria. Since their discovery by Twort and d'Herelle, phages with bacterial specificity have played important roles in microbial regulation. The intestinal microbiota and host health are intimately linked with nutrient, metabolism, development, and immunity aspects. However, the mechanism of interactions between the composition of the microbiota and their functions in maintaining host health still needs to be further explored. To address the lack of methodology and functions of intestinal microbiota in the host, we first proposed that, with the regulations of special intestinal microbiota and applications of germ-free (GF) zebrafish model, phages would be used to infect and reduce/eliminate the defined gut bacteria in the conventionally raised (CR) zebrafish and compared with the GF zebrafish colonized with defined bacterial strains. Thus, this review highlighted the background and roles of phages and their functional characteristics, and we also summarized the phage-specific infection of target microorganisms, methods to improve the phage specificity, and their regulation within the zebrafish model and gut microbial functional study. Moreover, the primary protocol of phage therapy to control the intestinal microbiota in zebrafish models from larvae to adults was recommended including phage screening from natural sources, identification of host ranges, and experimental design in the animal. A well understanding of the interaction and mechanism between phages and gut bacteria in the host can potentially provide powerful strategies or techniques for preventing bacteria-related human diseases by precisely regulating in vitro and in vivo, which will provide novel insights for phages' application and combined research in the future. KEY POINTS: • Zebrafish models for clarifying the microbial and phages' functions were discussed • Phages infect host bacteria with exquisite specificity and efficacy • Phages can reduce/eliminate the defined gut bacteria to clarify their function.

Effects of compound prebiotics as prophylactic and therapeutic supplementation in a mouse model of acute colitis

Compound prebiotics (CP) have been explored in modulation of intestinal microbiota and remission of inflammatory responses in the acute colitis (AC). Yet, research on the roles of simultaneous prophylactic and therapeutic CP intervention in relation to AC remains lacking. Here, CP were pre-fed to examine preventive effects. CP, CP combined with mesalazine (5-aminosalicylic acid) (CPM), and mesalazine were used to evaluate therapeutic effects on the dextran sulfate sodium (DSS)-induced AC. Results showed that prophylactic CP and therapeutic CPM alleviated AC, evidenced by variations of body weight, colon length, spleen index, disease activity index score, histological score, and intestinal mucosa. Ruminococcus and Bifidobacterium were detected in significant abundance in the prophylactic CP and therapeutic CPM groups, respectively. Phylogenetic ecological network analysis revealed that therapeutic CPM probably had the strongest coupling between microbes in changing intestinal microbiota to influence treatment. However, changes in short-chain fatty acids (SCFAs) seemed to have no persuasive results, probably due to reduced SCFA level in feces and variability in transit, absorption, and utilization. Furthermore, therapeutic CP exerted higher value in terms of observed species and Shannon diversity, as well as a more concentrated distribution by principal coordinates analysis. Together, the favorable roles of CP in colitis provide directions for prebiotics in designing effective prophylactic functional diets and treatment strategies. KEY POINTS: • Prebiotics as prophylactic intervention effectively inhibited acute colitis. • Prebiotics as prophylactic and therapeutic interventions had distinct effects on gut microbiota. • Prebiotics combined with drug intervention had higher efficacy in treating acute colitis.

Intestinal microbiome in crayfish: Its role upon growth and disease presentation

The intestine-associated microbiota in crustaceans are considered a key element for maintaining homeostasis and health within the organisms. Recently, efforts have been made to characterize bacterial communities of freshwater crustaceans, including crayfish, and their interplay with the host's physiology and the aquatic environments. As a result, it has become evident that crayfish intestinal microbial communities display high plasticity, which is strongly influenced by both the diet, especially in aquaculture, and the environment. Moreover, studies regarding the characterization and distribution of the microbiota along the gut portions led to the discovery of bacteria with probiotic potential. The addition of these microorganisms to their food has shown a limited positive correlation with the growth and development of crayfish freshwater species. Finally, there is evidence that infections, particularly those from viral etiology, lead to low diversity and abundance of the intestinal microbial communities. In the present article, we have reviewed data on the crayfish' intestinal microbiota, highlighting the most frequently observed taxa and emphasizing the dominance of phylum within this community. In addition, we have also searched for evidence of microbiome manipulation and its potential impact on productive parameters, and discussed the role of the microbiome in the regulation of diseases presentation, and environmental perturbations.

Lactobacillus rhamnosus and L. plantarum combination treatment ameliorated colitis symptoms in a mouse model by altering intestinal microbial composition and suppressing inflammatory response

SCOPE

Changes in composition of intestinal microbes may disrupt the balance of their interaction with a susceptible host, resulting in development of inflammatory bowel disease (IBD).

METHODS AND RESULTS

We applied in combination two Lactobacillus strains (L. rhamnosus BY-02, L. plantarum BY-05) ("LS treatment"), previously isolated from feces of healthy human infants, in a mouse model of dextran sodium sulfate (DSS)-induced colitis, and evaluated their ameliorative effect and its possible mechanism. LS treatment suppressed weight loss and colon shortening, and reduced disease activity index in the mice. It also had several additional beneficial effects: (i) maintained goblet cell numbers and ameliorated intestinal barrier damage in colonic tissue; (ii) altered intestinal microbial composition close to normal by increasing abundances of Muribaculaceae, Akkermansia, Clostridia, Oscillospiraceae and Lachnospiraceae, and decreasing abundance of Escherichia-Shigella; (iii) increased content of short-chain fatty acids; (iv) reduced content of pro-inflammatory lipopolysaccharides; (v) suppressed overactivation of TLR4/NF-κB inflammatory signaling pathway.

CONCLUSION

Combination treatment with two Lactobacillus strains strongly ameliorated colitis symptoms in our mouse model by favorably altering intestinal microbial composition and suppressing inflammatory response. This article is protected by copyright. All rights reserved.

Fecal Immunoglobulin Levels as a Modifier of the Gut Microbiome in Patients with Common Variable Immunodeficiency

OBJECTIVE

Common variable immunodeficiency (CVID) is the most common clinically relevant entity of inborn errors of immunity. In these patients, an altered gut microbiome composition with reduced diversity has been described. We sought to investigate the fecal immunoglobulin levels and their impact on the gut microflora in patients with CVID.

METHODS

We analyzed the gut microbiome of 28 CVID patients and 42 healthy donors (HDs), including 21 healthy household controls, by sequencing the V3 and V4 regions of the bacterial 16S rRNA gene extracted from stool samples. The fecal levels of immunoglobulin A, M, and G of 27 CVID patients and 41 HDs were measured in the supernatant by ELISA and normalized for protein concentration.

RESULTS

We measured decreased IgA and increased IgG in stool samples from CVID patients compared to HDs. Decreased levels of fecal IgA and IgM were associated with reduced microbial diversity and increased dysbiosis. We identified a large number of significantly differentially abundant taxa, especially in patients with decreased IgA levels, but also in patients with decreased IgM levels compared to their counterparts.

CONCLUSIONS

CVID patients have an altered gut microbiota composition, which is most prevalent in patients with decreased fecal IgA and IgM levels. In this study, we identify fecal immunoglobulins as a potential modifier of the gut microbiome in CVID patients.

Gut microbiota and host cytochrome P450 characteristics in the pseudo germ-free model: co-contributors to a diverse metabolic landscape

BACKGROUND

The pseudo germ-free (PGF) model has been widely used to research the role of intestinal microbiota in drug metabolism and efficacy, while the modelling methods and the utilization of the PGF model are still not standardized and unified. A comprehensive and systematic research of the PGF model on the composition and function of the intestinal microbiota, changes in host cytochrome P450 (CYP450) enzymes expression and intestinal mucosal permeability in four different modelling cycles of the PGF groups are provided in this paper.

RESULTS

16S rRNA gene amplicon sequencing was employed to compare and analyze the alpha and beta diversity, taxonomic composition, taxonomic indicators and predicted function of gut microbiota in the control and PGF groups. Bacterial richness and diversity decreased significantly in the PGF group beginning after the first week of establishment of the PGF model with antibiotic exposure. The PGF group exposed to antibiotics for 4-week-modelling possessed the fewest indicator genera. Moreover, increased intestinal mucosal permeability occurred in the second week of PGF model establishment, indicating that one week of antibiotic exposure is an appropriate time to establish the PGF model. The results of immunoblots revealed that CYP1A2, CYP2C19 and CYP2E1 expression was significantly upregulated in the PGF group compared with the control group, implying that the metabolic clearance of related drugs would change accordingly. The abundance of functional pathways predicted in the gut microbiota changed dramatically between the control and PGF groups.

CONCLUSIONS

This study provides information concerning the microbial and CYP450 enzyme expression profiles as a reference for evaluating drug metabolism differences co-affected by gut microbiota and host CYP450 enzymes in the PGF model.

Exposure to cadmium induced gut antibiotic resistance genes (ARGs) and microbiota alternations of Babylonia areolata

Cadmium (Cd) is widely distributed in aquatic environments and has multiple adverse effects on aquatic organisms such as the ivory shell (Babylonia areolata). However, its effects on antibiotic resistance genes (ARGs) and gut microbiota of B. areolata remain unclear. In this study, we explored the effects of different concentrations (0, 0.03, 0.18 and 1.08 mg/L) of Cd on intestinal microbial communities and ARGs in B. areolata through 16S rRNA gene sequencing and high-throughput quantitative PCR. The results showed that the structure and diversity of ARGs and microbiota in B. areolata gut were altered upon Cd exposure. Tetracycline, Vancomycin and Macrolide-Lincosamide-Streptogramin B (MLSB) resistance genes were identified as the major ARGs in B. areolata gut. The absolute abundance and alpha diversity of ARGs in B. areolata gut increased with the rise of cadmium concentration. The microbial communities at genus level were enriched in the low and medium Cd concentration groups, while decreased in the high Cd concentration group compared to the control groups. In addition, the influence of microbiota on the ARG profile was more significant than that of Cd concentration and MGEs in B. areolata gut. Null model analysis demonstrated that stochastic processes dominated ARG assembly in the Cd-exposed groups and were enhanced with the increasing Cd concentrations. Four opportunistic bacterial pathogens (Bacteroides, Legionella, Acinetobacter and Escherichia) detected in B. areolata gut maybe the potential hosts of ARGs. Our findings provide references for the hazards assessment of environmental Cd exposure of gut microbiome in aquatic animals.

Short-Chain Fatty Acids in the Microbiota-Gut-Brain Axis: Role in Neurodegenerative Disorders and Viral Infections

The gut-brain axis (GBA) is the umbrella term to include all bidirectional communication between the brain and gastrointestinal (GI) tract in the mammalian body. Evidence from over two centuries describes a significant role of GI microbiome in health and disease states of the host organism. Short-chain fatty acids (SCFAs), mainly acetate, butyrate, and propionate that are the physiological forms of acetic acid, butyric acid, and propionic acid respectively, are GI bacteria derived metabolites. SCFAs have been reported to influence cellular function in multiple neurodegenerative diseases (NDDs). In addition, the inflammation modulating properties of SCFAs make them suitable therapeutic candidates in neuroinflammatory conditions. This review provides a historical background of the GBA and current knowledge of the GI microbiome and role of individual SCFAs in central nervous system (CNS) disorders. Recently, a few reports have also identified the effects of GI metabolites in the case of viral infections. Among these viruses, the flaviviridae family is associated with neuroinflammation and deterioration of CNS functions. In this context, we additionally introduce SCFA based mechanisms in different viral pathogenesis to understand the former's potential as agents against flaviviral disease.

Predictive value of gut microbiota in long-term blood pressure control: a cross-sectional study

OBJECTIVES

To investigate the prediction of long-term blood pressure control using the intestinal flora of patients with hypertension.

METHODS

A total of 125 patients with primary grade-2 hypertension who attended the cardiovascular department of Hebei Province Hospital of Chinese Medicine between April 2021 and April 2022 were enrolled; these included 65 patients with substandard long-term blood pressure control (the uncontrolled group) and 60 patients with standard long-term blood pressure control (the controlled group). General clinical data and data on morning stools and diet were recorded for all the enrolled patients. The 16 s rDNA sequencing of faecal intestinal flora was also performed to analyse the differences in intestinal flora between the two groups of patients and to investigate the relationship between blood pressure compliance and the presence of flora.

RESULTS

The intestinal flora of the two groups of patients differed in terms of the Firmicutes-Bacteroidetes ratio (F/B), α-diversity analysis (Chao1, ACE and Shannon) results and β-diversity analysis results. At the genus level, the number of Streptococcus and Paraprevotella in patients in the uncontrolled group was greater than that of the controlled group, and the level of Akkermansia and Bifidobacterium was lower than that in the controlled group. A logistic regression analysis of the difference factors found differences in ACE, F/B, Streptococcus, Paraprevotella and Akkermansia in the two groups; these differences remained after correcting for age, gender and body mass index. The receiver operating characteristic curves revealed the following: ACE (area under the curve [AUC] = 85.282), Streptococcus (AUC = 82.705), Akkermansia (AUC = 77.333), Paraprevotella (AUC = 66.154) and F/B (AUC = 60.436).

CONCLUSIONS

There were significant differences in the intestinal flora of the patients in the controlled blood group compared with that of the uncontrolled group. Therefore, the ACE, genus levels of Streptococcus and Akkermansia could provide some prediction of late blood pressure compliance or non-compliance in patients with hypertension.

Lead and copper influenced bile acid metabolism by changing intestinal microbiota and activating farnesoid X receptor in Bufo gargarizans

Lead (Pb) and copper (Cu) are ubiquitous metal contaminants and can pose a threat to ecosystem and human health. Bile acids have recently received considerable attention for their role in the maintenance of health. However, there were few studies on whether Pb and Cu affect bile acid metabolism in amphibians. In this study, a combination approach of histological analysis, targeted metabolomics, 16S rDNA sequencing and qPCR was used to explore the impacts of Pb, Cu and their mixture (Mix) on bile acid in Bufo gargarizans tadpoles. The results showed that Pb, Cu, and Mix resulted in intestinal damage and altered the bile acid profiles. Specifically, Pb and Mix exposure decreased total bile acid concentrations while increased toxic bile acid levels; in contrast, Cu exposure increased total bile acid levels. And hydrophilic bile acids were reduced in all treated tadpoles. Moreover, Pb and/or Cu changed the composition of intestinal microbiota, especially Clostridia, Bacteroides and Eubacterium involved in bile acid biotransformation. qPCR revealed that the decreased total bile acid concentrations in Pb- and Mix-treated tadpoles were most likely attributed to the activation of intestinal farnesoid X receptor (Fxr), which suppressed bile acid synthesis and reabsorption. While activated fxr in the Cu treatment group may be a regulatory mechanism in response to increased bile excretion, which is a detoxification route of tadpoles under Cu stress. Collectively, Pb, Cu and Mix changed bile acid profiles by affecting intestinal microbial composition and activating Fxr signaling. This study provided insight into the impacts of Pb and Cu on bile acid metabolism and contributed to the assessment of the potential ecotoxicity of heavy metals on amphibians.

Defecation status, intestinal microbiota, and habitual diet are associated with the fecal bile acid composition: a cross-sectional study in community-dwelling young participants

PURPOSE

Bile acid (BA) metabolism by intestinal bacteria is associated with the risk of gastrointestinal diseases; additionally, its control has become a modern strategy for treating metabolic diseases. This cross-sectional study investigated the influence of defecation status, intestinal microbiota, and habitual diet on fecal BA composition in 67 community-dwelling young participants.

METHODS

Feces were collected for intestinal microbiota and BA analyses; data about defecation status and dietary habits were collected using the Bristol stool form scales and a brief-type self-administered diet history questionnaire, respectively. The participants were categorized into four clusters based on their fecal BA composition, according to cluster analysis, and tertiles based on deoxycholic acid (DCA) and lithocholic acid (LCA) levels.

RESULTS

The high primary BA (priBA) cluster with high fecal cholic acid (CA) and chenodeoxycholic acid (CDCA) levels had the highest frequency of normal feces, whereas the second BA (secBA) cluster with high levels of fecal DCA and LCA had the lowest. Alternately, the high-priBA cluster had a distinct intestinal microbiota, with higher Clostridium subcluster XIVa and lower Clostridium cluster IV and Bacteroides. The low-secBA cluster with low fecal DCA and LCA levels had the lowest animal fat intake. Nevertheless, the insoluble fiber intake of the high-priBA cluster was significantly higher than that of the high-secBA cluster.

CONCLUSION

High fecal CA and CDCA levels were associated with distinct intestinal microbiota. Conversely, high levels of cytotoxic DCA and LCA were associated with increased animal fat intake and decreased frequency of normal feces and insoluble fiber intake.

CLINICAL TRIAL REGISTRY

University Hospital Medical Information Network (UMIN) Center system (UMIN000045639); date of registration: 15/11/2019.

Exploring the mechanism of Xingpi Capsule in diarrhea predominant-irritable bowel syndrome treatment based on multiomics technology

BACKGROUND

Xingpi Capsule (XP), a commercially available over-the-counter herbal medicine in China, plays a prominent role in treating diarrhea-predominant irritable bowel syndrome (IBS-D). Nevertheless, the potential mechanisms remain unclear.

PURPOSE

This study aimed to investigate XP efficacy in IBS-D and elucidate the underlying molecular mechanisms.

METHODS

A rat IBS-D model was established by senna decoction gavage combined with restraint stress and swimming exhaustion. The changes in rat body weight and stool were recorded daily. Colon pathological changes and the number of colonic goblet cells of rats were observed by hematoxylin-eosin (HE) staining and Alcian blue plus periodic acid-Schiff (AB-PAS) staining, respectively. The expression of Occludin, a tight-junction-associated protein, was examined via immunohistochemistry. Images of colonic microvilli were obtained by TEM. Western blotting (WB) was used to analyze the protein expression of the ASK1/P38 MAPK pathway. The composition of the rat intestinal microbiota was detected by 16S rRNA sequencing. Changes in colonic metabolites were evaluated by liquid chromatography-mass spectrometry (LC-MS). Changes in colon RNA expression were assessed by RNA sequencing (RNA-Seq). The nontoxic range of hypoxanthine (HPX) was screened by Cell Counting Kit-8 (CCK8), the cell model of human colonic epithelial cells (NCM460) induced by lipopolysaccharide (LPS) was established, and the effective concentration of HPX was screened by CCK8. After transfection of pcDNA3.1-MAP3K5, Hoechst 33,342 staining, flow cytometry to detect cell apoptosis, and immunofluorescence to detect the fluorescence changes of ASK1 and ZO-1. WB detection of ASK1/P38 MAPK pathway protein expression changes.

RESULTS

XP increased the body weight of IBS-D patients and reduced the loose stool rate, loose stool index, and Bristo score. In addition, XP mitigated colon lesions, increased the number of goblet cells and the expression of Occludin, and prevented severe distortion and effacement of the microvillous structure. Specifically, 16S rRNA gene sequence analysis showed that XP decreased the abundance of Desulfurium and Prevotella 9 at the phylum and genus levels while increasing the abundance of Bacteroides at the genus level. RNA-Seq combined with WB validation showed that XP exerted antidiarrheal effects by inhibiting the ASK1/P38 MAPK signaling pathway. Additionally, XP also increased the relative expression level of the metabolite HPX, as revealed by untargeted metabolomics analysis. Impressively, the correlation analysis between 16S rRNA sequencing and LC-MS suggested that HPX and Prevotella 9 are negatively correlated, which indicated that XP might increase the content of HPX by reducing the abundance of Prevotella 9. Meanwhile, a negative correlation between HPX and ASK1 was indicated through RNA-Seq and LC-MS, which suggested that the inhibition of ASK1 (Map3k5) may be ascribed to the increase in HPX after XP treatment. In vitro experiments have proven that HPX can alleviate LPS-induced NCM460 damage, specifically manifested as enhancing cell viability, reducing cell apoptosis, increasing ZO-1 expression, reducing the fluorescence intensity of MAP3K5 in the model group, and inhibiting the expression of ASK1/P38 MAPK pathway proteins. The protective effect of HPX was reversed after transfection with pcDNA 3.1-MAP3K5, which fully demonstrated that the protective mechanism of HPX was achieved by inhibiting MAP3K5 and its downstream pathways.

CONCLUSION

XP displayed multifaceted protection against IBS-D in rats by regulating the intestinal microbiota, increasing the relative expression level of HPX, a metabolite of the microbiota, and inhibiting the ASK1/P38 MAPK signaling pathway.

Omics analysis revealed the possible mechanism of streptococcus disease outbreak in tilapia under high temperature

High temperature is a main cause to result in the outbreak of tilapia streptococcal disease. However, the underlying mechanisms are not well understood. In this study, we first confirmed that tilapia infected with Streptococcus agalactiae (S. agalactiae) had a higher mortality at high temperature (35 °C) than that at normal temperature (28 °C). Subsequently, the effects of high temperature on gene expression pattern of S. agalactiae and intestinal microbiota of tilapia were respectively detected by RNA-seq and 16S rDNA sequencing. RNA-seq identified 357 differentially expressed genes (DEGs) in S. agalactiae cultured at 28 °C and 35 °C. GO and KEGG analysis showed that these DEGs were highly involved in metabolic processes, including glucose, lipid and amino acid metabolisms, which indicates that S. agalactiae have stronger vitality and are likely to be more infectious under high temperature. Microbiota analysis revealed that high temperature could influence the bacterial community composition of tilapia intestine, accompanied by changes in intestinal structure. Compared to feed at 28 °C, the total bacterial species as well as pathogens, such as norank_f__Rhizobiales_Incertae_Sedis, Pseudorhodoplanes, Ancylobacter, in tilapia intestine were significantly increased at 35 °C, which may weaken the immune resistance of tilapia. Taken together, our results suggest that high temperature evoked tilapia susceptible to S. agalactiae should be the combined effect of enhanced S. agalactiae metabolism and dysregulated tilapia intestinal microbiota.

Fructooligosaccharides attenuate non-alcoholic fatty liver disease by remodeling gut microbiota and association with lipid metabolism

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common liver disease highly associated with metabolic diseases and gut dysbiosis. Several clinical trials have confirmed that fructooligosaccharides (FOSs) are a viable alternative treatment for NAFLD. However, the mechanisms underlying the activities of FOSs remain unclear.

METHODS

In this study, the effects of FOSs were investigated with the use of two C57BL/6 J mouse models of NAFLD induced by a high-fat, high-cholesterol (HFHC) diet and a methionine- and choline-deficient (MCD) diet, respectively. The measured metabolic parameters included body, fat, and liver weights; and blood glucose, glucose tolerance, and serum levels of glutamate transaminase, aspartate transaminase, and triglycerides. Liver tissues were collected for histological analysis. In addition, 16 S rRNA sequencing was conducted to investigate the effects of FOSs on the composition of the gut microbiota of mice in the HFHC and MCD groups and treated with FOSs.

RESULTS

FOS treatment attenuated severe metabolic changes and hepatic steatosis caused by the HFHC and MCD diets. In addition, FOSs remodeled the structure of gut microbiota in mice fed the HFHC and MCD diets, as demonstrated by increased abundances of Bacteroidetes (phylum level), Klebsiella variicola, Lactobacillus gasseri, and Clostridium perfringens (species level); and decreased abundances of Verrucomicrobia (phylum level) and the Fissicatena group (genus level). Moreover, the expression levels of genes associated with lipid metabolism and inflammation (i.e., ACC1, PPARγ, CD36, MTTP, APOC3, IL-6, and IL-1β) were down-regulated after FOS treatment.

CONCLUSION

FOSs alleviated the pathological phenotype of NAFLD via remodeling of the gut microbiota composition and decreasing hepatic lipid metabolism, suggesting that FOSs as functional dietary supplements can potentially reduce the risk of NAFLD.

Immunity orchestrates a bridge in gut-brain axis of neurodegenerative diseases

Neurodegenerative diseases, in particular for Alzheimer's disease (AD), Parkinson's disease (PD) and Multiple sclerosis (MS), are a category of diseases with progressive loss of neuronal structure or function (encompassing neuronal death) leading to neuronal dysfunction, whereas the underlying pathogenesis remains to be clarified. As the microbiological ecosystem of the intestinal microbiome serves as the second genome of the human body, it is strongly implicated as an essential element in the initiation and/or progression of neurodegenerative diseases. Nevertheless, the precise underlying principles of how the intestinal microflora impact on neurodegenerative diseases via gut-brain axis by modulating the immune function are still poorly characterized. Consequently, an overview of initiating the development of neurodegenerative diseases and the contribution of intestinal microflora on immune function is discussed in this review.

Trimethylamine N-oxide: role in cell senescence and age-related diseases

INTRODUCTION

Hayflick and Moorhead first demonstrated cell senescence as the irreversible growth arrest of cells after prolonged cultivation. Telomere shortening and oxidative stress are the fundamental mechanisms that drive cell senescence. Increasing studies have shown that TMAO is closely associated with cellular aging and age-related diseases. An emerging body of evidence from animal models, especially mice, has identified that TMAO contributes to senescence from multiple pathways and appears to accelerate many neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. However, the specific mechanism of how TMAO speeds aging is still not completely clear.

MATERIAL AND METHODS

In this review, we summarize some key findings in TMAO, cell senescence, and age-related diseases. We focused particular attention on the potential mechanisms for clinical transformation to find ways to interfere with the aging process.

CONCLUSION

TMAO can accelerate cell senescence by causing mitochondrial damage, superoxide formation, and promoting the generation of pro-inflammatory factors.

Novel studies on Drosophila melanogaster model reveal the roles of JNK-Jak/STAT axis and intestinal microbiota in insulin resistance

The JNK pathway play a critical role in insulin resistance induced by a long-term high-sugar diet. However, the roles of up- and downstream molecules of the JNK pathway in insulin resistance are less known in vertebrates and invertebrates. As a classical organism in biological research, Drosophila melanogaster (D. melanogaster) has been widely applied to the studies of mechanism of insulin resistance. Based on previous studies, we found a novel predictive mechanism of the formation of insulin resistance in D. melanogaster. We found that JNK activated by high-sugar diet and dysregulated intestinal microbiota could mediate inflammation, and then the activated JNK released Upd3, which in turn stimulated Jak/STAT pathway to release ImpL2. ImpL2 can compete with Drosophila insulin-like peptides (Dilps) for binding with the insulin receptor and inhibit the activation of insulin pathway. In this study, we reviewed novel studies on the insulin signalling pathway based on the D. melanogaster model. The findings support our hypothesis. We, therefore, described how a long-term high-sugar diet disrupts intestinal microbiota to induce inflammation and the disruption of JNK-Jak/STAT axis. This description may offer some new clues to the formation of insulin resistance.

Intestinal homeostasis disruption in mice chronically exposed to arsenite-contaminated drinking water

Chronic exposure to inorganic arsenic [As(III) and As(V)] affects about 200 million people, and is linked to a greater incidence of certain types of cancer. Drinking water is the main route of exposure, so, in endemic areas, the intestinal mucosa is constantly exposed to the metalloid. However, studies on the intestinal toxicity of inorganic As are scarce. The objective of this study was to evaluate the toxicity of a chronic exposure to As(III) on the intestinal mucosa and its associated microbiota. For this purpose, BALB/c mice were exposed during 6 months through drinking water to As(III) (15 and 30 mg/L). Treatment with As(III) increased reactive oxygen species (43-64%) and lipid peroxidation (8-51%). A pro-inflammatory response was also observed, evidenced by an increase in fecal lactoferrin (23-29%) and mucosal neutrophil infiltration. As(III) also induced an increase in the colonic levels of pro-inflammatory cytokines (24-201%) and the activation of some pro-inflammatory signaling pathways. Reductions in the number of goblet cells and mucus production were also observed. Moreover, As(III) exposure resulted in changes in gut microbial alpha diversity but no differences in beta diversity. This suggested that the abundance of some taxa was significantly affected by As(III), although the composition of the population did not show significant alterations. Analysis of differential taxa agreed with this, 21 ASVs were affected in abundance or variability, especially ASVs from the family Muribaculaceae. Intestinal microbiota metabolism was also affected, as reductions in fecal concentration of short-chain fatty acids were observed. The effects observed on different components of the intestinal barrier may be responsible of the increased permeability in As(III) treated mice, evidenced by an increase in fecal albumin (48-66%). Moreover, serum levels of Lipopolysaccharide binding proteins and TNF-α were increased in animals treated with 30 mg/L of As(III), suggesting a low-level systemic inflammation.