Muribaculaceae Genomes Assembled from Metagenomes Suggest Genetic Drivers of Differential Response to Acarbose Treatment in Mice

Correlation between the structures of natural polysaccharides and their properties in regulating gut microbiota: Current understanding and beyond

Natural polysaccharides have complex structural properties and a wide range of health-promoting effects. Accumulating evidence suggests that the effects are significantly mediated through fermentation by gut microbiota. In recent years, the relationship between the structures of natural polysaccharides and their properties in regulating gut microbiota has garnered significant research attention as researchers attempt to precisely understand the role of gut microbiota in the bioactivities of natural polysaccharides. Progress in this niche, however, remains limited. In this review, we first provide an overview of current research investigating this structure-property relationship. We then present a detailed correlation analysis between the structural characteristics of 159 purified natural polysaccharides and their effects on gut microbiota reported over the past two decades. The analysis revealed that diverse gut bacteria show specific correlations with the molecular weight, glycosidic linkages, and monosaccharide composition of natural polysaccharides. Multifaceted molecular mechanisms, including carbohydrate binding, enzymatic degradation, and cross-feeding, were proposed to be collectively involved in these correlations. Finally, we offer our perspective on future studies to further improve our understanding of the relationship between polysaccharide structure and gut microbiota regulation.

Glycosylation of oyster peptides by COS ameliorates zinc deficiency-induced syndromes: intestinal inflammation and imbalance of the gut microbiota in vivo

Zinc is essential for maintaining the integrity and repair of small intestinal epithelial cells while zinc deficiency could induce the inflammatory infiltration and imbalance of intestinal flora in the intestine. In this study, glycosylation between oyster protein hydrolysate (OPH) and chitosan oligosaccharide (COS) was conducted and used as the carrier of zinc ions (OCZn). The results of zeta potential and particle size distribution showed that the OPH-COS successfully bound to zinc ions to form OCZn with a surface zinc content of 0.56% (scanning electron microscopy). In addition, OCZn was found to exhibit good intestinal digestion by in vitro simulated digestion microscopy, while TSQ fluorescence staining revealed the presence of free zinc ions released from OCZn in the intestinal cells. In the zinc deficiency-induced mouse model, a moderate dose of OCZn (zinc: 6.96 mg kg-1) showed significant restorative effects on colonic inflammation (IL-1β: 28.20 pg per mg·protein, IL-6: 27.73 pg per mg·protein), protein expressions of HO-1 and ZO-1, oxidative stress (the liver and kidneys), and imbalance of the gut microbiota, increasing microbial diversity and abundance (ratio of Firmicutes/Bacteroides). Zinc deficiency triggered the abundance of Proteobacteria (risk of diseases), while the dominant bacteria were mainly restored to Bacteroides, Parabacteroides, Alistipes, Alloprevotella, and Muribaculaceae following the administration of OCZn. This study provided a theoretical basis for improving the inflammatory infiltration of the colon and the imbalance of intestinal flora caused by zinc deficiency.

Meconium Influences Pulmonary Short-Chain Fatty Acid Concentration in Porcine Meconium Aspiration Model

Introduction

The factors influencing meconium aspiration syndrome (MAS) severity remain poorly understood. In a piglet model of MAS, we hypothesized the respiratory microbiome would reflect the bacterial signature of meconium with short-chain fatty acid (SCFA) accumulation as a byproduct of bacterial fermentation.

Methods

Cesarean section at approximately 115-day term was performed on two sows. Male (9) and female (3) piglets were delivered, instrumented, anesthetized, and randomized into a Control (n = 6) or MAS group (n = 6). MAS received a meconium slurry (3 mL/kg) aspiration injury. Experimental animals were monitored continuously, ventilated, and resuscitated for 24 h. BALF was collected for 16S microbiome sequencing and SCFA analysis by gas chromatography. Effects of SCFAs on A549 alveolar pulmonary epithelial in vitro cell viability and inflammation were assessed.

Results

The MAS group had significantly higher fluid and vasopressor requirements than the Control group (p < 0.05) though both groups developed lung injury. The meconium microbiome demonstrated a difference in genus proportions as compared with the BALF of the Control and MAS groups. The MAS group had a relative increase in propionic acid-forming bacteria and higher BALF concentrations of propionic acid (0.6 ± 0.2 mmol/kg) than the Control group (0.2 ± 0.2 mmol/kg; p > 0.05). Propionic acid was associated with decreased pulmonary epithelial cell viability and an upregulated pro-inflammatory response.

Conclusions

Meconium may host a microbiome with byproducts that interact with the pulmonary epithelium and influence lung injury severity in MAS.

Daily intake of household-produced milk kefir on Salmonella Typhimurium infection in C57BL/6 mice: mortality, microbiota modulation, and immunological implications

AIMS

Salmonellosis, a major global cause of diarrheal diseases, significantly impacts the intestinal microbiome. Probiotic-rich beverages, such as kefir, are increasingly utilized as alternative health-promoting beverages associated with various microbiota benefits. This study investigated the repercussions of daily consumption of household-produced milk kefir on Salmonella enterica serovar Typhimurium infection in C57BL-6 mice.

METHODS AND RESULTS

Kefir consumption pre-infection reduced the presence of inflammatory cells in the colon and altered the cytokine profile by reducing IL-10 and increasing IFN-γ. Despite reducing intestinal inflammation, kefir intake did not yield a prompt response to an acute infection caused by the aggressive pathogen Salmonella. This contributed to increased mortality in the mice, evidenced by higher fecal Salmonella counts post-infection. Metabarcoding analysis demonstrated that the use of kefir before infection increases butyric acid by the higher abundance of Lachnospiraceae and Prevotellaceae families and genus in feces, coupled with an increase in Muribaculaceae family and Bacteroides genus among infected kefir-treated mice. While kefir hinted at microbiota alterations reducing enterobacteria (Helicobacter), decrease IL-10, and increased IFN-γ, butyric acid on pre-infection, the beverage potentially facilitated the systemic translocation of pathogens, intensifying the infection's severity by altering the immune response.

CONCLUSIONS

The use of kefir in the dosage of 10% w/v (109 CFU), for acute infections with Salmonella Typhimurium, may not be enough to combat the infection and worsen the prognosis, leaving the intestine less inflamed, favoring the replication and translocation of the pathogen. These findings underscore the importance of prudently evaluating the widespread use of probiotics and probiotic-rich beverages, especially during acute infections, given their potential association with adverse effects during these diseases.

Structural elucidation of a Acanthopanax senticosus polysaccharide CQ-1 and its hepatoprotective activity via gut health regulation and antioxidative defense

Acanthopanax senticosus has proven health benefits, particularly for liver damage. The objective of this study was to elucidate the protective effects and the underlying mechanisms of action of A. senticosus against metabolic dysfunction-associated fatty liver disease (MAFLD). A novel homogeneous water-soluble polysaccharide, CQ-1, was successfully isolated and purified from A. senticosus root. The main chain structure of CQ-1 was identified as →2)-α-L-Rha-(1 → 4)-α-D-GalAp-(1 → 6)-β-D-Galp-(1→. Additionally, branched chains comprising an arabinosyl residue, galactosyl residue, and galacturonic acidic residue were identified as being attached to →2,4)-α-L-Rha-(1→, →3,6)-β-D-Galp-(1→, and →3,4)-α-D-GalAp-(1→, respectively. CQ-1 exhibited antioxidant and prebiotic activities in vitro. CQ-1 increased antioxidant capacity and reduced serum pro-inflammatory cytokines in mice. Additionally, CQ-1 has been shown to enhance the diversity and composition of the gut microbiota, thereby facilitating the restoration of gut function. These include improving intestinal barrier function and increasing short-chain fatty acid levels in mice. Our study has shown that CQ-1 has a hepatoprotective effect in MAFLD mice, and we have proposed that CQ-1 may be a promising strategy for the treatment of MAFLD.

Dietary soy protein reverses obesity-induced liver steatosis and alters fecal microbial composition independent of isoflavone level

Introduction

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major public health concern that is exacerbated by the obesity pandemic. Dietary interventions have the potential to alleviate obesity-associated MASLD through variable mechanisms, including optimizing the gut microbiota. Previously, we reported that soy protein concentrate (SPC) with low or high levels of isoflavone (LIF or HIF) protected young obese Zucker rats from developing liver steatosis. The current study was designed to test whether SPC-LIF and SPC-HIF diets would reverse liver steatosis and alter fecal microbial composition in adult obese Zucker rats with existing steatosis.

Methods

Six-week-old male obese Zucker rats (n = 26) were fed a casein control diet (CAS) for 8 weeks and 7 rats were randomly selected and sacrificed to confirm liver steatosis. The remaining rats were randomly assigned to receive CAS, SPC-LIF, or SPC-HIF diet (n = 6-7/group) for an additional 10 weeks.

Results

Compared to CAS diet, feeding SPC-LIF and SPC-HIF diets resulted in significantly lower liver weight, liver steatosis score, and liver microvesicular score (p < 0.05), but did not lead to difference in body weight, liver macrovesicular score, serum ALT, or serum AST. Isoflavone levels (e.g., LIF vs. HIF) did not affect any of these measurements except in the SPC-HIF group, which had an additional decrease in liver weight (p < 0.05) compared to the SPC-LIF group. The SPC-HIF group also had significantly higher levels of the aglycone forms of daidzein, genistein, and equol as well as the total levels of daidzein, genistein, and equol compared to SPC-LIF or CAS diet fed rats (p < 0.05). The distribution of microbial communities based on measures of beta diversity of both SPC-LIF and SPC-HIF groups were significantly different to that of the CAS group (p ≤ 0.005). Alpha-diversity did not differ between any of the groups.

Conclusion

Taken together, dietary soy protein can reverse liver steatosis in adult Zucker rats, and the reversal of steatosis is accompanied by alterations in gut microbial composition.

Antidiabetic Effect of Bifidobacterium animalis TISTR 2591 in a Rat Model of Type 2 Diabetes

This study investigated the beneficial effects of probiotic Bifidobacterium animalis TISTR 2591 on the regulation of blood glucose and its possible mechanisms in a rat model of type 2 diabetes. The type 2 diabetic-Sprague Dawley rats were established by the combination of a high-fat diet and a low dose of streptozotocin. After 4 weeks of treatment with 2 × 108 CFU/ml of B. animalis TISTR 2591, fasting blood glucose (FBG), oral glucose tolerance, serum insulin, and pancreatic and hepatic histopathology were determined. Liver lipid accumulation, glycogen content, and gluconeogenic protein expression were evaluated. Oxidative stress and inflammatory status were determined. B. animalis TISTR 2591 significantly reduced FBG levels and improved glucose tolerance and serum insulin in the diabetic rats. Structural damage of the pancreas and liver was ameliorated in the B. animalis TISTR 2591-treated diabetic rats. In addition, significant decreases in hepatic fat accumulation, glycogen content, and phosphoenolpyruvate carboxykinase-1 protein expression were found in the diabetic rats treated with B. animalis TISTR 2591. The diabetic rats showed a significant reduction of inflammation following B. animalis TISTR 2591 supplementation, as demonstrated by decreasing hepatic NF-κB protein expression and serum and liver TNF-α levels. The B. animalis TISTR 2591 significantly decreased MDA levels and increased antioxidant SOD and GPx activities in the diabetic rats. In conclusion, B. animalis TISTR 2591 was shown to be effective in controlling glucose homeostasis and improving glucose tolerance in the diabetic rats. These beneficial activities were attributed to reducing oxidative and inflammatory status and modulating hepatic glucose metabolism.

Acarbose enhances the efficacy of immunotherapy against solid tumours by modulating the gut microbiota

The crucial role of gut microbiota in shaping immunotherapy outcomes has prompted investigations into potential modulators. Here we show that oral administration of acarbose significantly increases the anti-tumour response to anti-PD-1 therapy in female tumour-bearing mice. Acarbose modulates the gut microbiota composition and tryptophan metabolism, thereby contributing to changes in chemokine expression and increased T cell infiltration within tumours. We identify CD8+ T cells as pivotal components determining the efficacy of the combined therapy. Further experiments reveal that acarbose promotes CD8+ T cell recruitment through the CXCL10-CXCR3 pathway. Faecal microbiota transplantation and gut microbiota depletion assays indicate that the effects of acarbose are dependent on the gut microbiota. Specifically, acarbose enhances the efficacy of anti-PD-1 therapy via the tryptophan catabolite indoleacetate, which promotes CXCL10 expression and thus facilitates CD8+ T cell recruitment, sensitizing tumours to anti-PD-1 therapy. The bacterial species Bifidobacterium infantis, which is enriched by acarbose, also improves response to anti-PD-1 therapy. Together, our study endorses the potential combination of acarbose and anti-PD-1 for cancer immunotherapy.

Modulatory Effects of Isolated Lactobacillus paracasei from Malaysian Water Kefir Grains on the Intestinal Barrier and Gut Microbiota in Diabetic Mice

Type 2 diabetes (T2DM) is one of the four major types of non-communicable diseases that have become a global health concern. Water kefir is a product of a brown sugar solution fermented with kefir grains which comprises around 30 microbial species in its grains. Water kefir possesses a wide range of health benefits, including anti-hyperlipidemic effects, and reduces hypertension and blood glucose levels in animal models. Reportedly, consuming water kefir containing probiotics may enhance the intestinal barrier and positively influence the composition of the intestinal microflora. The present study aimed to evaluate the regulatory effects of Lactobacillus paracasei isolated from Malaysian water kefir grains (MWKG) on the alterations of intestinal barrier and gut microbiota in diabetic mice via histopathological analysis of the distal colon and 16S rRNA gene sequencing on fecal microbiome. Results indicated that the administration of isolated Lactobacillus paracasei from MWKG to diabetic mice ameliorated the dominant probiotic phyla in the gut microbiota. Results showed that lower dose (LD) and high dose (HD) treatments of the isolated Lactobacillus paracasei could significantly reduce inflammatory cell infiltration in the distal colon of diabetic mice. The treatments revealed a significant decrease in the relative abundance of Firmicutes in the gut, 0.27 ± 0.06% for LD and 0.34 ± 0.04% for HD, compared to untreated (UN) diabetic mice, 0.40 ± 0.02%. These results suggest that L. paracasei isolated from MWKG could serve as a potential dietary supplement against intestinal inflammation and modify gut microbiota composition in patients with T2DM.

Microbiome alterations are associated with apolipoprotein E mutation in Octodon degus and humans with Alzheimer's disease

Gut microbiome dysbiosis is linked to many neurological disorders including Alzheimer's disease (AD). A major risk factor for AD is polymorphism in the apolipoprotein E (APOE) gene, which affects gut microbiome composition. To explore the gut-brain axis in AD, long-lived animal models of naturally developing AD-like pathologies are needed. Octodon degus (degu) exhibit spontaneous AD-like symptoms and ApoE mutations, making them suitable for studying the interplay between AD genetic determinants and gut microbiome. We analyzed the association between APOE genotype and gut microbiome in 50 humans and 32 degu using16S rRNA gene amplicon sequencing. Significant associations were found between the degu ApoE mutation and gut microbial changes in degu, notably a depletion of Ruminococcaceae and Akkermansiaceae and an enrichment of Prevotellaceae, mirroring patterns seen in people with AD. The altered taxa were previously suggested to be involved in AD, validating the degu as an unconventional model for studying the AD/microbiome crosstalk.

Diminished representation of vitamin-B12-producing bacteria in constipated elders with frailty

Constipation and frailty are associated with intestinal dysbiosis. This study aims to identify intestinal microbial signatures that can differentiate between constipated elders accompanied by frailty and those without frailty. We collected stool samples from 61 participants and conducted 16S rRNA gene sequencing. Constipated patients with frailty (Constipation_F) exhibited reduced gut microbial diversities compared to constipated patients without frailty (Constipation_NF) and healthy individuals (C). From differential genera, random forest models identified 14, 8, and 5 biomarkers for distinguishing Constipation_F from Constipation_NF, Constipation_F from C, and Constipation_NF from C, respectively. Functional analysis revealed that pathways (P381-PWY and PWY-5507) related to vitamin B12 synthesis were reduced in Constipation_F, which aligns with the decreased abundances of vitamin-B12-producing Actinomyces and Akkermansia in this group. Our study unveils substantial differences in gut microbiota between constipated elders with frailty and those without, underscoring the diagnostic and therapeutic potential of genera involved in vitamin B12 synthesis.

Exploration of the Muribaculaceae Family in the Gut Microbiota: Diversity, Metabolism, and Function

The gut microbiota are mainly composed of Bacteroidetes and Firmicutes and are crucial for metabolism and immunity. Muribaculaceae are a family of bacteria within the order Bacteroidetes. Muribaculaceae produce short-chain fatty acids via endogenous (mucin glycans) and exogenous polysaccharides (dietary fibres). The family exhibits a cross-feeding relationship with probiotics, such as Bifidobacterium and Lactobacillus. The alleviating effects of a plant-based diet on inflammatory bowel disease, obesity, and type 2 diabetes are associated with an increased abundance of Muribaculaceae, a potential probiotic bacterial family. This study reviews the current findings related to Muribaculaceae and systematically introduces their diversity, metabolism, and function. Additionally, the mechanisms of Muribaculaceae in the alleviation of chronic diseases and the limitations in this field of research are introduced.

Review: Mechanism of herbivores synergistically metabolizing toxic plants through liver and intestinal microbiota

Interspecific interactions are central to ecological research. Plants produce toxic plant secondary metabolites (PSMs) as a defense mechanism against herbivore overgrazing, prompting their gradual adaptation to toxic substances for tolerance or detoxification. P450 enzymes in herbivore livers bind to PSMs, whereas UDP-glucuronosyltransferase and glutathione S-transferase increase the hydrophobicity of the bound PSMs for detoxification. Intestinal microorganisms such as Bacteroidetes metabolize cellulase and other macromolecules to break down toxic components. However, detoxification is an overall response of the animal body, necessitating coordination among various organs to detoxify ingested PSMs. PSMs undergo detoxification metabolism through the liver and gut microbiota, evidenced by increased signaling processes of bile acids, inflammatory signaling molecules, and aromatic hydrocarbon receptors. In this context, we offer a succinct overview of how metabolites from the liver and gut microbiota of herbivores contribute to enhancing metabolic PSMs. We focused mainly on elucidating the molecular communication between the liver and gut microbiota involving endocrine, immune, and metabolic processes in detoxification. We have also discussed the potential for future alterations in the gut of herbivores to enhance the metabolic effects of the liver and boost the detoxification and metabolic abilities of PSMs.

Benzyl Isothiocyanate and Resveratrol Synergistically Alleviate Dextran Sulfate Sodium-Induced Colitis in Mice

The aim of our study was to investigate whether the combination of benzyl isothiocyanate (BITC) and resveratrol (RES) has a synergistic effect on the inhibition of inflammation in colitis. The results revealed that the BITC and RES combination (BITC_RES) was more effective than either substance alone at significantly alleviating the symptoms of dextran sodium sulfate (DSS)-induced colitis in mice, including the prevention of colon shortening and loss of body weight, a reduction in the disease activity index, and prevention of colon damage. Similarly, compared with the DSS group, BITC_RES reduced myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) levels in the mouse colon by 1.4-3.0-fold and 1.4-fold, respectively. In addition, the combination of BITC and RES upregulated the inflammatory factor IL-10 by 1.3- and 107.4-fold, respectively, compared to the individual BITC and RES groups, whereas the proinflammatory factors, including TNF-α, IL-1β, and IL-6, were downregulated by 1.1-7.4-, 0.7-3.6-, and 0.6-2.6-fold, respectively, in the BITC_RES group compared with the individual groups. Gut microbiome analysis indicated that BITC_RES remodeled the structure of gut bacteria at the phylum, family, and genus levels, upregulating the abundance of the phylum Bacteroidetes and the family Muribaculaceae and the genus norank_f_Muribaculaceae and downregulating the abundance of the phylum Firmicutes. Significant correlations between the relative levels of these proinflammatory cytokines and changes in the gut microbiota were found using Pearson's correlation analysis. BITC and RES exhibited synergistic effects by reshaping the gut microbiota and modulating the level of serum cellular inflammatory factors, thus exerting a protective effect against colitis.

Effect of Probiotic Bacteria on the Gut Microbiome of Mice with Lipopolysaccharide-Induced Inflammation

The role of lipopolysaccharide (LPS) in the development of diseases is clear, but the specific mechanisms remain poorly understood. This study aimed to investigate the microbiome aberrations in the guts of mice against the background of LPS, as well as the anti-inflammatory effect of probiotic supplementation with Lactobacillus plantarum from the gut, a mix of commercial probiotic lactic acid bacteria, and Weissella confusa isolated from milk using next-generation sequencing. LPS injections were found to induce inflammatory changes in the intestinal mucosa. These morphological changes were accompanied by a shift in the microbiota. We found no significant changes in the microbiome with probiotic supplementation compared to the LPS group. However, when Lactobacillus plantarum and a mix of commercial probiotic lactic acid bacteria were used, the intestinal mucosa was restored. Weissella confusa did not contribute to the morphological changes of the intestinal wall or the microbiome. Changes in the microbiome were observed with probiotic supplementation of Lactobacillus plantarum and a mix of commercial probiotic lactic acid bacteria compared to the control group. In addition, when Lactobacillus plantarum was used, we observed a decrease in the enrichment of the homocysteine and cysteine interconversion pathways with an increase in the L-histidine degradation pathway.

Meta-analysis of the Microbial Diversity Cultured in Bioreactors Simulating the Gut Microbiome

Understanding the intricate ecological interactions within the gut microbiome and unravelling its impact on human health is a challenging task. Bioreactors are valuable tools that have contributed to our understanding of gut microbial ecology. However, there is a lack of studies describing and comparing the microbial diversity cultivated in these models. This knowledge is crucial for refining current models to reflect the gastrointestinal microbiome accurately. In this study, we analysed the microbial diversity of 1512 samples from 18 studies available in public repositories that employed cultures performed in batches and various bioreactor models to cultivate faecal microbiota. Community structure comparison between samples using t-distributed stochastic neighbour embedding and the Hellinger distance revealed a high variation between projects. The main driver of these differences was the inter-individual variation between the donor faecal inocula. Moreover, there was no overlap in the structure of the microbial communities between studies using the same bioreactor platform. In addition, α-diversity analysis using Hill numbers showed that highly complex bioreactors did not exhibit higher diversities than simpler designs. However, analyses of five projects in which the samples from the faecal inoculum were also provided revealed an amplicon sequence variants enrichment in bioreactors compared to the inoculum. Finally, a comparative analysis of the taxonomy of the families detected in the projects and the GMRepo database revealed bacterial families exclusively found in the bioreactor models. These findings highlight the potential of bioreactors to enrich low-abundance microorganisms from faecal samples, contributing to uncovering the gut microbial "dark matter".

Gut microbiome changes in mouse, Mongolian gerbil, and hamster models following Clostridioides difficile challenge

Introduction

Clostridioides difficile infection (CDI), as well as its etiology and pathogenesis, have been extensively investigated. However, the absence of suitable CDI animal models that reflect CDI symptoms and the associated gut microbiome changes in humans has limited research progress in this field. Thus, we aimed to investigate whether Mongolian gerbils, which present a range of human pathological conditions, can been used in studies on CDI. Methods: In this study, we infected Mongolian gerbils and two existing CDI model animals, mice and hamsters, with the hypervirulent ribotype 027 C. difficile strain, and comparatively analyzed changes in their gut microbiome composition via 16S rRNA gene sequencing.

Methods

In this study, we infected Mongolian gerbils and two existing CDI model animals, mice and hamsters, with the hypervirulent ribotype 027 C. difficile strain, and comparatively analyzed changes in their gut microbiome composition via 16S rRNA gene sequencing.

Results

The results obtained showed that C. difficile colonized the gastrointestinal tracts of the three rodents, and after the C. difficile challenge, C57BL/6J mice did not manifest CDI symptoms and their intestines showed no significant pathological changes. However, the hamsters showed explosive intestinal bleeding and inflammation and the Mongolian gerbils presented diarrhea as well as increased infiltration of inflammatory cells, mucus secretion, and epithelial cell shedding in their intestinal tissue. Further, intestinal microbiome analysis revealed significant differences with respect to intestinal flora abundance and diversity. Specifically, after C. difficile challenge, the Firmicutes/Bacteroidetes ratio decreased for C57BL/6J mice, but increased significantly for Mongolian gerbils and hamsters. Furthermore, the abundance of Proteobacteria increased in all three models, especially in hamsters, while that of Verrucomicrobia only increased significantly in C57BL/6J mice and Mongolian gerbils. Our results also indicated that differences in the relative abundances of Lactobacillaceae and Akkermansia were primarily responsible for the observed differences in response to C. difficile challenge.

Conclusion

Based on the observed responses to C. difficile challenge, we concluded for the first time that the Mongolian gerbil could be used as an animal model for CDI. Additionally, the taxa identified in this study may be used as biomarkers for further studies on CDI and to improve understanding regarding changes in gut microbiome in CDI-related diseases.

Intestinal microbial diversity of swines fed with different sources of lithium

A drug that is widely used in the treatment of psychiatric disorder is lithium (Li) salts. The people who make therapeutic use of this drug develop a series of side effects. Through metataxonomic data, this study assessed the impacts of lithium, as Li carbonate or Li-enriched mushrooms, on the microbial composition of the ileum, colon, and feces of piglets. Employing Bray-Curtis metric, no differences were observed among the treatments evaluated. Nevertheless, the alpha diversity indices showed differences in the Simpson, Shannon, and Chao-1 indices in the colon and Chao-1 in the feces in the diets with Li compared with the diets without Li. The taxa with the highest relative abundance varied among the ileum, colon, and feces, with a predominance of the phyla Firmicutes, Bacteroidota, and Proteobacteria in diets with Li. Many groups of microorganisms that are important for the health of the host (e.g., Lactobacillus, Ruminococcaceae, Enterorhabdus, Muribaculaceae, and Coprococcus) had their relative abundance increased in animals that received diets with the recommended dose of lithium. Furthermore, there was an increase in the abundance of Prevotellaceae and Bacteroidales (in the diet with Li-enriched mushroom) and Clostridia, Ruminococcus, Burkholderia, and Bacteroidales (diets with Li carbonate) at the recommended dosages. This is the first study to show the effects of Li carbonate and Li-enriched mushrooms on the intestinal microbiota of piglets. Thus, the effects of lithium on the body may be related to its ability to change the composition of the intestinal microbiota.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03938-3.

Bioactives and metabolites of Tetrastigma hemsleyanum root extract alleviate DSS-induced ulcerative colitis by targeting the SYK protein in the B cell receptor signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Tetrastigma hemsleyanum is an endemic Chinese herb with a wide range of pharmacological activities, including anti-inflammatory, antiviral, antioxidant, antitumor, and immunomodulatory activities. However, the effect and mechanisms of the anti-inflammatory activity of T. hemsleyanum root extract against dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) have not yet been fully investigated.

AIM OF THE STUDY

This study aimed to explore the therapeutic effect and molecular mechanisms of T. hemsleyanum root extract in DSS-induced UC mice and knockdown cells.

MATERIALS AND METHODS

T. hemsleyanum root extract was obtained and analyzed by high-performance liquid chromatography (HPLC). The therapeutic effects of T. hemsleyanum root extract on DSS-induced UC mice were evaluated by the disease activity index (DAI) score, colon length, serum inflammatory cytokines and oxidant/antioxidant levels, and histopathological features of the ileum and colon. Genome-wide gene expression profiles of ileal and colonic tissues were collected by transcriptomics, and signaling pathways were analyzed by the KEGG database. UC-related pathways were uploaded to the STRING database, then the protein-protein interactions (PPIs) were determined by Cytoscape, and the enriched genes were evaluated by real-time quantitative PCR (qPCR). The protein-ligand complexes were docked by AutoDock, and the genes were knocked down in Caco-2 cells by shRNA. The non-targeted metabolomic profiling of ileal contents was analyzed by ultra-high-performance liquid chromatography (UHPLC), and gut microflora were sequenced by an Illumina MiSeq System.

RESULTS

Ten components that alleviated UC symptoms in mice by decreasing the DAI and serum inflammatory cytokines and oxidant levels, promoting intestinal development, and increasing serum antioxidant levels were identified in T. hemsleyanum root extract. T. hemsleyanum root extract activated the B cell receptor signaling pathway in the colon tissue of UC mice, in which two components, rutin and astragaline, bound to the spleen tyrosine kinase (SYK) protein but also restored gut microflora diversity and increased the proportion of probiotics. Furthermore, metabolites of T. hemsleyanum root extract were involved in vitamin metabolism, fatty acid metabolism, and ferroptosis.

CONCLUSIONS

The rutin and astragaline components of T. hemsleyanum root extract, by binding to SYK protein, activated the B cell receptor signaling pathway and restored gut microflora diversity to alleviate UC symptoms in mice.

Gut microbiota composition is associated with the efficacy of Delta-24-RGDOX in malignant gliomas

Glioblastoma, the most common primary brain tumor, has a 6.8% survival rate 5 years post diagnosis. Our team developed an oncolytic adenovirus with an OX-40L expression cassette named Delta-24-RGDOX. While studies have revealed the interaction between the gut microbiota and immunotherapy agents, there are no studies linking the gut microbiota with viroimmunotherapy efficacy. We hypothesize that gut bacterial signatures will be associated with oncolytic viral therapy efficacy. To test this hypothesis, we evaluated the changes in gut microbiota in two mouse cohorts: (1) GSC-005 glioblastoma-bearing mice treated orally with indoximod, an immunotherapeutic agent, or with Delta-24-RGDOX by intratumoral injection and (2) a mouse cohort harboring GL261-5 tumors used to mechanistically evaluate the importance of CD4+ T cells in relation to viroimmunotherapy efficacy. Microbiota assessment indicated significant differences in the structure of the gut bacterial communities in viroimmunotherapy-treated animals with higher survival compared with control or indoximod-treated animals. Moreover, viroimmunotherapy-treated mice with prolonged survival had a higher abundance of Bifidobacterium. The CD4+ T cell depletion was associated with gut dysbiosis, lower mouse survival, and lower antitumor efficacy of the therapy. These findings suggest that microbiota modulation along the gut-glioma axis contributes to the clinical efficacy and patient survival of viroimmunotherapy treated animals.

Dahuang zhechong pill ameliorates hepatic fibrosis by regulating gut microbiota and metabolites

ETHNOPHARMACOLOGICAL RELEVANCE

DHZCP is a traditional Chinese medicinal formula in "The Synopsis of Prescriptions of the Golden Chamber" that has been often used in the treatment of hepatic disorders, gynecopathy and atherosclerosis. However, its underlying mechanisms in preventing hepatic fibrosis remain incompletely understood.

AIM OF THE STUDY

This study aims to explore the therapeutic efficacy and potential mechanism of DHZCP in a CCL4-induced experimental hepatic fibrosis rat model.

MATERIALS AND METHODS

DHZCP was orally administered at doses of 0.168, 0.084 and 0.042 g⋅kg-1⋅d-1 in a CCL4-induced hepatic fibrosis model using SD rats. Histopathology, immunohistochemistry and biochemical analysis, ELISA, Flow cytometry, WB, RT-PCR, 16 S rRNA, and untargeted metabolomic analysis were used to determine the therapeutic effects and mechanisms of DHZCP in the treatment of CCL4-induced hepatic fibrosis.

RESULTS

Pharmacodynamically, DHZCP inhibited ALT and AST, improved liver function, decreased NF-κB, TNF-α and IL-6 in liver tissue, indicating its role in inhibiting CCL4-induced liver inflammation. Most importantly, it reduces the level of fibrosis in serum and liver tissue. Histological analysis also showed that DHZCP could effectively inhibit inflammatory cytokine infiltration and excessive collagen deposition. Mechanistically, DHZCP regulates gut microbiota, improves the proportion of firmicutes and bacteroidota at the phylum level, and increases the abundance of beneficial bacteria at the genus level, such as muribagulaceae unclassified, prevotella, alloprevotella, closteriales unclassified, lachnospiraceae unclassified and phascolarctobacterium. Instead, it reduced the abundance of two harmful bacteria, desulfovibrio and colidextribacter. Four types of metabolites such as hydrocarbons, organic nitrogen compounds, organic oxygen compounds, and organosulfur compounds were added. Furthermore, DHZCP was found to reduce the damage of intestinal barrier caused by changes in gut microbiota and metabolites.

CONCLUSION

DHZCP is an effective inhibitor of hepatic fibrosis by regulating gut microbiota and metabolites, improving the integrity of the intestinal barrier.

Serine protease inhibitor from the muscle larval Trichinella spiralis ameliorates non-alcoholic fatty liver disease in mice via anti-inflammatory properties and gut-liver crosstalk

Trichinella spiralis is recognized for its ability to regulate host immune responses. The serine protease inhibitor of T. spiralis (Ts-SPI) participates in T. spiralis-mediated immunoregulatory effects. Studies have shown that helminth therapy exhibits therapeutic effects on metabolic diseases. In addition, we previously found that T. spiralis-derived crude antigens could alleviate diet-induced obesity. Thus, Ts-SPI was hypothesized to alleviate non-alcoholic fatty liver disease (NAFLD). Herein, recombinant Ts-SPI (rTs-SPI) was prepared from the muscle larvae T. spiralis. The relative molecular mass of rTs-SPI was approximately 35,000 Da, and western blot analysis indicated good immunoreactivity. rTs-SPI ameliorated hepatic steatosis, inflammation, and pyroptosis in NAFLD mice, which validated the hypothesis. rTs-SPI also reduced macrophage infiltration, significantly expanded Foxp3+ Treg population, and inactivated TLR4/NF-κB/NLRP3 signaling in the liver. Furthermore, rTs-SPI treatment significantly shifted the gut microbiome structure, with a remarkable increase in beneficial bacteria and reduction in harmful bacteria to improve gut barrier integrity. Finally, Abx-treated mice and FMT confirmed that gut-liver crosstalk contributed to NAFLD improvement after rTs-SPI treatment. Taken together, Taken together, these findings suggest that rTs-SPI exerts therapeutic effects in NAFLD via anti-inflammatory activity and gut-liver crosstalk.

Novel primers to identify a wider diversity of butyrate-producing bacteria

Butyrate-producing bacteria are a functionally important part of the intestinal tract flora, and the resulting butyric acid is essential for maintaining host intestinal health, regulating the immune system, and influencing energy metabolism. However, butyrate-producing bacteria have not been defined as a coherent phylogenetic group. They are primarily identified using primers for key genes in the butyrate-producing pathway, and their use has been limited to the Bacillota and Bacteroidetes phyla. To overcome this limitation, we developed functional gene primers able to identify butyrate-producing bacteria through the butyrate kinase gene, which encodes the enzyme involved in the final step of the butyrate-producing pathway. Genomes extracted from human and rat feces were used to amplify the target genes through PCR. The obtained sequences were analyzed using BLASTX to construct a developmental tree using the MEGA software. The newly designed butyrate kinase gene primers allowed to recognize a wider diversity of butyrate-producing bacteria than that recognized using currently available primers. Specifically, butyrate-producing bacteria from the Synergistota and Spirochaetota phyla were identified for the first time using these primers. Thus, the developed primers provide a more accurate method for researchers and doctors to identify potential butyrate-producing bacteria and deepen our understanding of butyrate-producing bacterial species.

A polyphenol-rich plant extract prevents hypercholesterolemia and modulates gut microbiota in western diet-fed mice

Introduction

Totum-070 is a combination of five plant extracts enriched in polyphenols to target hypercholesterolemia, one of the main risk factors for cardiovascular diseases. The aim of this study was to investigate the effects of Totum-070 on cholesterol levels in an animal model of diet-induced hypercholesterolemia.

Methods

C57BL/6JOlaHsd male mice were fed a Western diet and received Totum-070, or not, by daily gavage (1g/kg and 3g/kg body weight) for 6 weeks.

Results

The Western diet induced obesity, fat accumulation, hepatic steatosis and increased plasma cholesterol compared with the control group. All these metabolic perturbations were alleviated by Totum-070 supplementation in a dose-dependent manner. Lipid excretion in feces was higher in mice supplemented with Totum-070, suggesting inhibition of intestinal lipid absorption. Totum-070 also increased the fecal concentration of short chain fatty acids, demonstrating a direct effect on intestinal microbiota.

Discussion

The characterization of fecal microbiota by 16S amplicon sequencing showed that Totum-070 supplementation modulated the dysbiosis associated with metabolic disorders. Specifically, Totum-070 increased the relative abundance of Muribaculum (a beneficial bacterium) and reduced that of Lactococcus (a genus positively correlated with increased plasma cholesterol level). Together, these findings indicate that the cholesterol-lowering effect of Totum-070 bioactive molecules could be mediated through multiple actions on the intestine and gut microbiota.

Gut Biogeography Accentuates Sex-Related Differences in the Murine Microbiome

Recent studies have highlighted the influence of factors such as sex and sex-linked hormones on microbiome composition, raising concerns about the generalizability of findings. Here, we explore whether gut geography, specifically the upper and lower gastrointestinal tract (GI), contributes to sex-linked microbiome differences in mice. We collected microbial samples throughout the length of the GI from male and female C57B6/J mice at 6- and 8-weeks old, and conducted 16S rRNA sequencing. Our findings revealed significant sex-related differences, with Clostridium_sensu_stricto_1 more abundant in the male colon, while females exhibited higher levels of Dubosiella newyorkensis across all organs at 6 weeks. We also observed decreased Shannon alpha diversity in the small intestine compared to the lower GI, and this diversity decreased further at 8 weeks. Interestingly, our results suggest that age mitigates sex-related, but not gut geography-related differences in beta diversity, with implications for experimental outcomes and treatment strategies. This study underscores the dynamic nature of microbial diversity, influenced by sex, age, and GI localization, emphasizing the need for a more comprehensive understanding of microbiome dynamics in experimental research and clinical interventions.

Integrated Microbiome and Metabolomics Analysis of the Effects of Dietary Supplementation with Corn-Steep-Liquor-Derived Candida utilis Feed on Black Pigs

In this experiment, glucose master liquor and corn steep liquor were used as carbon and nitrogen sources, and Candida utilis was used as a strain to ferment yeast feed. The OD value and number of yeast cells were used as response values to optimize the medium components of the yeast feed through a response surface methodology. The optimal medium components were a glucose master liquor concentration of 8.3%, a corn steep liquor concentration of 1.2%, and a KH2PO4 concentration of 0.14%. Under this condition of fermentation, the OD value was 0.670 and the number of yeast cells was 2.72 × 108/mL. Then, we fed Candida utilis feed to Dongliao black piglets, and the effects of the yeast feed on the piglets' growth performance, fecal microbiota, and plasma metabolic levels were investigated through 16S rDNA sequencing and metabolomics. In total, 120 black piglets with an average initial weight of 6.90 ± 1.28 kg were randomly divided into two groups. One group was fed the basic diet (the CON group), and the other was supplemented with 2.5% Candida utilis add to the basic diet (the 2.5% CU group). After a pre-feeding period, the formal experiments were performed for 21 days. The results showed that the addition of Candida utilis to the diet did not affect growth performance compared with the control group. Meanwhile, no significant differences were observed in the serum biochemical indices. However, piglets in the 2.5% CU group had a significantly altered fecal microbiota, with an increased abundance of Clostridium_sensu_stricto_1, Lactobacillus, and Muribaculaceae_unclassified. Regarding the plasma metabolome, the 12 differential metabolites detected were mainly enriched in the histidine, tryptophan, primary bile acid, and caffeine metabolic pathways. Regarding the integrated microbiome-metabolome analysis, differential metabolites correlated with fecal flora to variable degrees, but most of them were beneficial bacteria of Firmicutes. Collectively, dietary Candida utilis feed had no adverse effect on growth performance; however, it played an important role in regulating fecal flora and maintaining metabolic levels.

Central blockage of sympathetic nerves inhibits the abnormal vital signs and disturbance of the gut microbiota caused by continuous light exposure

Background

Continuous light exposure increases sympathetic excitation in rats, leading to hypertension, left ventricular hypertrophy, and fibrosis. This study was aimed to investigate whether continuous light exposure causes destabilization of vital signs and gut microbiota (GM) in Sprague Dawley (SD) rats and whether clonidine hydrochloride (CH), a central sympathetic depressant drug, could prevent these changes.

Methods

Eight-week-old male SD rats were divided into three groups with different interventions for 14 weeks: control group (CG), 2-mL pure water gavaged daily while on a normal 12-h light/dark cycle; continuous illumination group (CI), 2-mL pure water gavaged daily while receiving continuous exposure to light (300 lx); and drug administration group (DA), CH (10 μg/kg) gavaged daily while receiving continuous exposure to light (300 lx).

Results

The results showed that blood pressure, heart rate, and body weight were significantly higher in the CI group than in the CG and DA groups (P < 0.05). Moreover, the Shannon index was higher in the DA group than in the CI group (P = 0.012). The beta diversity index in the CG group was significantly higher in the CI group (P = 0.039). The pairwise comparison results of the linear discriminant analysis effect size showed that Oscillospirales were enriched in the DA group, whereas the Prevotellaceae lineage (family level) > Prevotella (genus level) > Prevotellaceae_bacterium (species level) were enriched in the CI group. The Muribaculaceae family was more abundant in the CG group than in the CI group.

Conclusion

Sympathetic nerve inhibition restored the abnormal vital signs and GM changes under continuous light exposure.

Effect of Intertidal Vegetation (Suaeda salsa) Restoration on Microbial Diversity in the Offshore Areas of the Yellow River Delta

The coastal wetlands in the Yellow River Delta play a vital role in the ecological function of the area. However, the impact of primary restoration on microbial communities is not yet fully understood. Hence, this study aimed to analyze the bacterial and archaeal communities in the soil. The results indicated that Marinobacter and Halomonas were predominant in the bacterial community during spring and winter. On the other hand, Muribaculaceae and Helicobacter were prevalent during the core remediation of soil, while Inhella and Halanaerobium were predominant in non-vegetation-covered high-salinity soil. The bacterial Shannon index showed significant differences in vegetation-covered areas. For archaea, Salinigranum, Halorubrum, and Halogranum were dominant in vegetation areas, while Halolamina, Halogranum, and Halorubrum were prevalent in non-vegetation areas. The colonization of Suaeda salsa led to differences in the composition of bacteria (22.6%) and archaea (29.5%), and salt was one of the significant reasons for this difference. The microflora was more diverse, and the elements circulated after vegetation grounding, while the microbial composition in non-vegetation areas was similar, but there was potential competition. Therefore, vegetation restoration can effectively restore soil ecological function, while the microorganisms in the soil before restoration provide germplasm resources for pollutant degradation and antimicrobial development.

The effects of hydrolyzed protein on macronutrient digestibility, fecal metabolites and microbiota, oxidative stress and inflammatory biomarkers, and skin and coat quality in adult dogs

Research on protein hydrolysates has observed various properties and functionalities on ingredients depending on the type of hydrolysate. The objective of this study was to evaluate the effects of hydrolyzed chicken protein that was incorporated into diets on digestibility, gut health, skin and coat health, oxidative stress, and intestinal inflammation markers in healthy adult dogs. Five complete and balanced diets were manufactured: (1) CONd: 25% chicken meal diet; (2) 5% CLHd: 5% chicken liver and heart hydrolysate plus 20% chicken meal diet; (3) CLHd: 25% chicken liver and heart hydrolysate diet; (4) 5% CHd: 5% chicken hydrolysate plus 20% chicken meal diet; (5) CHd: 25% chicken hydrolysate diet. A replicated 5 × 5 Latin square design was used which included 10 neutered adult Beagles. Each of the 5 periods consisted of a 7-d washout time and a 28-d treatment period. All diets were well accepted by the dogs. Fecal butyrate concentration was higher while fecal isovalerate and total phenol/indole were lower in dogs fed CLHd than CONd (P < 0.05). Dogs fed CHd had higher fecal immunoglobulin A concentration when compared with CLHd (P < 0.05); however, both groups were comparable to the CONd. There was no difference among groups in serum cytokine concentrations, serum oxidative stress biomarkers, or skin and coat health analyses (P > 0.05). Fecal microbiota was shifted by CLHd with higher abundance in Ruminococcus gauvreauii group as well as lower Clostridium sensu stricto 1, Sutterella, Fusobacterium, and Bacteroides when compared with CONd (P < 0.05). There was also a difference in beta diversity of fecal microbiota between CLHd and CHd (P < 0.05). In conclusion, chicken protein hydrolysate could be incorporated into canine extruded diets as a comparable source of protein to traditional chicken meal. The test chicken protein hydrolysates showed the potential to support gut health by modulating immune response and microbiota; however, functional properties of protein hydrolysates are dependent on inclusion level and source.

Efficacy of an inulin-based treatment on intestinal colonization by multidrug-resistant E. coli: insight into the mechanism of action

Inulin, an increasingly studied dietary fiber, alters intestinal microbiota. The aim of this study was to assess whether inulin decreases intestinal colonization by multidrug resistant E. coli and to investigate its potential mechanisms of action. Mice with amoxicillin-induced intestinal dysbiosis mice were inoculated with extended spectrum beta-lactamase producing E. coli (ESBL-E. coli). The combination of inulin and pantoprazole (IP) significantly reduced ESBL-E. coli fecal titers, whereas pantoprazole alone did not and inulin had a delayed and limited effect. Fecal microbiome was assessed using shotgun metagenomic sequencing and qPCR. The efficacy of IP was predicted by increased abundance of 74 taxa, including two species of Adlercreutzia. Preventive treatments with A. caecimuris or A. muris also reduced ESBL-E. coli fecal titers. Fecal microbiota of mice effectively treated by IP was enriched in genes involved in inulin catabolism, production of propionate and expression of beta-lactamases. They also had increased beta-lactamase activity and decreased amoxicillin concentration. These results suggest that IP act through production of propionate and degradation of amoxicillin by the microbiota. The combination of pantoprazole and inulin is a potential treatment of intestinal colonization by multidrug-resistant E. coli. The ability of prebiotics to promote propionate and/or beta-lactamase producing bacteria may be used as a screening tool to identify potential treatments of intestinal colonization by multidrug resistant Enterobacterales.

Giardia spp.-induced microbiota dysbiosis disrupts intestinal mucin glycosylation

Infection with the protozoan parasite Giardia duodenalis (syn. intestinalis, lamblia) has been associated with intestinal mucus disruptions and microbiota dysbiosis. The mechanisms remain incompletely understood. Mucus consists primarily of densely glycosylated mucin glycoproteins. Mucin O-glycans influence mucus barrier properties and mucin-microbe interactions and are frequently altered during disease. In this study, we observed time-dependent and regiospecific alterations to intestinal mucin glycosylation patterns and the expression of mucin-associated glycosyltransferase genes during Giardia infection. Glycosylation alterations were observed in Giardia-infected mice in the upper small intestine, the site of parasite colonization, and in the distal colon, where active trophozoites were absent. Alterations occurred as early as day 2 post-infection and persisted in mice after parasite clearance. We also observed small intestinal goblet cell hyperplasia and thinning of the distal colon mucus barrier during early infection, and microbiota alterations and altered production of cecal SCFAs. Giardia-induced alterations to mucin glycosylation were at least in part dependent on microbiota dysbiosis, as transplantation of a dysbiotic mucosal microbiota collected from Giardia-infected mice recapitulated some alterations. This study describes a novel mechanism by which Giardia alters intestinal mucin glycosylation, and implicates the small intestinal microbiota in regulation of mucin glycosylation patterns throughout the gastrointestinal tract.

Emerging role of the crosstalk between gut microbiota and liver metabolome of subterranean herbivores in response to toxic plants

Plant secondary metabolites (PSMs) are a defense mechanism against herbivores, which in turn use detoxification metabolism to process ingested and absorbed PSMs. The feeding environment can cause changes in liver metabolism patterns and the gut microbiota. Here, we compared gut microbiota and liver metabolome to investigate the response mechanism of plateau zokors (Eospalax baileyi) to toxic plant Stellera chamaejasme (SC) in non-SC and SC grassland (-SCG and +SCG). Our results indicated that exposure to SC in the -SCG population increased liver inflammatory markers including prostaglandin (PG) in the Arachidonic acid pathway, while exposure to SC in the +SCG population exhibited a significant downregulation of PGs. Secondary bile acids were significantly downregulated in +SCG plateau zokors after SC treatment. Of note, the microbial taxa Veillonella in the -SCG group was significantly correlated with liver inflammation markers, while Clostridium innocum in the +SCG group had a significant positive correlation with secondary bile acids. The increase in bile acids and PGs can lead to liver inflammatory reactions, suggesting that +SCG plateau zokors may mitigate the toxicity of SC plants by reducing liver inflammatory markers including PGs and secondary bile acids, thereby avoiding liver damage. This provides new insight into mechanisms of toxicity by PSMs and counter-mechanisms for toxin tolerance by herbivores.

Association of intestinal bacteria with immune activation in a cohort of healthy adults

IMPORTANCE

Chronic inflammation may develop over time in healthy adults as a result of a variety of factors, such as poor diet directly affecting the composition of the intestinal microbiome, or by causing obesity, which may also affect the intestinal microbiome. These effects may trigger the activation of an immune response that could eventually lead to an inflammation-related disease, such as colon cancer. Before disease develops it may be possible to identify subclinical inflammation or immune activation attributable to specific intestinal bacteria normally found in the gut that could result in future adverse health impacts. In the present study, we examined a group of healthy men and women across a wide age range with and without obesity to determine which bacteria were associated with particular types of immune activation to identify potential preclinical markers of inflammatory disease risk. Several associations were found that may help develop dietary interventions to lower disease risk.

Effect of Cichorium glandulosum on intestinal microbiota and bile acid metabolism in db/db mice

This study aims to investigate the effects of Chorum glandulosum Boiss. et Huet (CG) on the intestinal microbiota and serum bile acid (BA) in db/db mice. A total of 12 db/db mice were randomly divided into model (MOD), high-dose CG (CGH), and control (CON) groups. The CON and MOD groups received distilled water by gavage for 8 weeks. Whereas, the CGH group received an alcohol extract of CG at a dose of 200 mg/kg/day. Results showed that CG can reduce blood lipid levels. It change the composition of the intestinal microbiota, and increase the relative abundances of Muribaculaceae, Prevotellaceae, Bifidobacterium_pseudolongum, Bacteroidaceae in db/db mice as well. LC-MS metabolomics results showed that CG adjusted the serum BA levels. The results reduced the levels of primary BAs, such as cholic acid (CA) and chenodeoxycholic acid (CDCA). The results decreased the primary BA/secondary BA (PSA/SBA) ratio in db/db mice. Correlation analysis showed that the abundances of Bifidobacterium_pseudolongum and Bacteroidaceae were positively correlated with acetic acid level and negatively correlated with ursocholic acid (UCA), α-muricholic acid (αMCA), triglyceride (TG), and total cholesterol levels (TC), indicating an interaction between the intestinal microbiota and serum BAs. CG may play a positive role in the interaction between the intestinal microbiota and BAs in lipid metabolism.

Hepatobiliary and pancreatic: Multi-donor fecal microbiota transplantation attenuated high-fat diet-induced hepatic steatosis in mice by remodeling the gut microbiota

BACKGROUND AND AIMS

Fecal microbiota transplantation (FMT) can improve the symptoms of nonalcoholic fatty liver disease (NAFLD) by restoring the gut microbiota. This study was aimed to evaluate the therapeutic effects of single-donor (SD) or multi-donor (MD) FMT in a mouse model of hepatic steatosis and explore the underlying mechanisms.

METHODS

Fecal samples were collected from NAFLD patients and healthy controls with similar baseline characteristics, with gut microbiota analyzed. Mice were fed either a normal-chow diet (NCD) or a high-fat diet (HFD) for 3 weeks and then administered fecal microbiota collected from healthy SDs or MDs for 12 weeks.

RESULTS

Fecal samples from NAFLD patients showed significantly lower microbial diversity than those from healthy controls. MD-FMT reduced liver fat accumulation and body weight and significantly improved serum and liver biochemical indices in HFD-fed mice. Compared to untreated HFD-fed mice, MD-FMT significantly decreased the relative expression of IL-1β, IL-6, TNF-α, IFN-γ, and IL-1β mRNAs in the liver. The relative protein level of intestinal barrier components, including claudin-1, occludin, and E-cadherin, as well as serum lipopolysaccharide (LPS) level in mice, were found to be improved following MD-FMT intervention. Furthermore, FMT reversed HFD-induced gut dysbiosis and increased the abundance of beneficial bacteria such as Blautia and Akkermansia.

CONCLUSION

NAFLD patients and healthy controls showed distinct gut microbiota. Likewise, HFD altered gut microbiota in mice compared to NCD-fed controls. MD-FMT restored gut dysbiosis in HFD-fed mice and attenuated liver steatosis, and should be considered as an effective treatment option for NAFLD.

Profile of Pancreatic and Ileal Microbiota in Experimental Acute Pancreatitis

Acute pancreatitis (AP) is accompanied by gut microbiota dysbiosis. However, the composition of the pancreatic and ileal microbiota associated with AP is still unknown. This study aims to examine the alterations in the microbial composition of the pancreas and ileum in the context of experimental acute pancreatitis, as well as explore the potential interplay between these two regions. Methods: Caerulein (CAE), caerulein+lipopolysaccharide (CAE+LPS), and L-arginine (ARG) were used to induce AP in mice. The pancreas and ileum were collected for histological study and bacterial 16S rRNA gene sequencing. The results showed microbial structural segregation between the AP and control groups and between ARG and the two CAE groups (CAE, CAE+LPS) in the pancreas and ileum. Taxonomic analysis at the genus level and linear discriminant analysis effect size (LEfSe) at the operational taxonomic units (OTUs) level illustrated that AP mice exhibited a marked increase in the relative abundance of Muribaculaceae and a decrease in that of Dietzia both in the pancreas and ileum, and a reduction in Bifidobacterium only in the ileum; in addition, Roseburia was enriched in the two CAE groups in the pancreas and/or ileum, while Escherichia-Shigella expanded in the pancreas of the ARG group. Spearman correlation analysis between pancreatic and ileal microbiota revealed that the abundance of Muribaculaceae and Dietzia in the pancreas was related to that in the ileum. These findings demonstrated that caerulein and L-arginine differentially disturbed the pancreatic and ileal microbiota when inducing AP. Furthermore, these findings provide preliminary support for an association between the microbiota of the pancreas and ileum, which could be caused by AP-induced microbial translocation.

Dietary Inclusion of Yellow Mealworms (T. molitor) and Lesser Mealworms (A. diaperinus) Modifies Intestinal Microbiota Populations of Diet-Induced Obesity Mice

BACKGROUND

Insect-based proteins are high-quality alternatives to support the shift toward more sustainable and healthy diets. Additionally, insects contain chitin and have unique fatty acid profiles. Studies have shown that mealworms may beneficially affect metabolism, but limited information is known regarding their effects on gut microbiota.

OBJECTIVES

We determined the effects of defatted yellow mealworm (Tenebrio molitor) and whole lesser mealworm (Alphitobius diaperinus) meals on the intestinal microbiota of diet-induced obesity mice.

METHODS

Male C57BL/6J mice were fed a high-fat diet (HFD; 46% kcal) to induce obesity. Obese mice were then randomly assigned to treatments (n = 10/group) and fed for 8 wk: HFD, HFD with casein protein; B50, HFD with 50% protein from whole lesser mealworm; B100, HFD with 100% protein from whole lesser mealworm; Y50, HFD with 50% protein from defatted yellow mealworm; Y100, HFD with 100% protein from defatted yellow mealworm. Lean mice (n = 10) fed a low-fat-diet (10% kcal) were included. Fresh feces were collected at baseline and every 2 wk, with cecal digesta collected at kill. Fecal and cecal DNA was analyzed for microbiota using 16S rRNA MiSeq Illumina sequencing.

RESULTS

In feces and cecal digesta, mice fed mealworms had greater (P < 0.05) bacterial alpha diversity, with changes occurring in a time-dependent manner (P < 0.05). Beta diversity analyses of cecal samples showed a clear separation of treatments, with a time-based separation shown in fecal samples. Widespread microbial differences were observed, with over 45 genera altered (P < 0.05) by diet in cecal digesta. In feces, over 50 genera and 40 genera were altered (P < 0.05) by diet and time, respectively.

CONCLUSION

Mealworm consumption changes the intestinal microbiota of obese mice, increasing alpha diversity measures and shifting bacterial taxa. More investigation is required to determine what mealworm components are responsible and how they may be linked with the metabolic benefits observed in mealworm-fed mice.

The potential links between human gut microbiota and cardiovascular health and disease - is there a gut-cardiovascular axis?

The gut-heart axis is an emerging concept highlighting the crucial link between gut microbiota and cardiovascular diseases (CVDs). Recent studies have demonstrated that gut microbiota is pivotal in regulating host metabolism, inflammation, and immune function, critical drivers of CVD pathophysiology. Despite a strong link between gut microbiota and CVDs, this ecosystem’s complexity still needs to be fully understood. The short-chain fatty acids, trimethylamine N-oxide, bile acids, and polyamines are directly or indirectly involved in the development and prognosis of CVDs. This review explores the relationship between gut microbiota metabolites and CVDs, focusing on atherosclerosis and hypertension, and analyzes personalized microbiota-based modulation interventions, such as physical activity, diet, probiotics, prebiotics, and fecal microbiota transplantation, as a promising strategy for CVD prevention and treatment.

Lactobacillus sp. participated in the adaptation of Rongchang piglets to cold stress

Rongchang piglets were easily induced to cold stress and diarrhoea in the winter when raised in an open hog house. However, they also gradually recovered under mid-cold stress. Other studies have suggested gut microbiome might be involved in the host energy metabolism to relieve stress. To study how to adapt Rongchang piglets to cold stress by gut microbiome, thirty Rongchang piglets were randomly divided into a mild cold stress group and a control group for 30 consecutive days. The findings revealed that the piglets had low growth performance and a high diarrhoea rate and mortality rate during the first half of the cold treatment, but subsequently stabilised. The level of cortisol (COR) also displayed a similar trend. In the mild cold stress group, the relative abundance of Muribaculaceae significantly increased on day 15, and the predominant bacterial on day 30 was Lactobacillus sp. Our results indicated that the Rongchang piglet's production performance and health were impaired at the start of the mild cold stress. However, as time passed, the body could progressively adapt to the low temperature, and Lactobacillus sp. participated in this process. This study provides new insight into how to alleviate health damage caused by cold stress.

Alterations of gut microbiota in a mouse model with partial small intestinal obstruction

Introduction

Changes in the gut microbiota of patients with partial small intestinal obstruction (PSIO) have not been widely clarified. We aimed to explore bacterial diversity in a PSIO mouse model.

Methods

A PSIO mouse model was established using male C57BL/6 mice, and feces samples from the distal ileum and ileum epithelium tissues were collected. MiSeq sequencing of the 16S rRNA gene was conducted to characterize microbiota diversity and composition. RNA sequencing for differences in transcriptomic programming of the ileum tissue was performed between the PSIO and (Control) Ctrl groups.

Results

Bacterial diversity in the PSIO group was significantly lower than that in the controls. Pseudomonadota was predominant in the feces of the PSIO group. Unclassified_Muribaculaceae (p = 0.008) and Akkermansia (p = 0.007) were more abundant in the Ctrl group than those in the PSIO group. Furthermore, Escherichia_Shigella (p = 0.008) was more predominant in the feces of the PSIO group. The Kyoto Encyclopedia of Genes and Genomes pathways related to metabolism were depleted in the PSIO group. Pathways associated with intestinal fibrosis, including extracellular matrix-receptor interaction, focal adhesion, phosphoinositide 3-kinase (PI3K)-Akt signaling pathway and transforming growth factor (TGF)-beta signaling pathway, which were enriched in ileum epithelial tissue in the PSIO group.

Conclusion

PSIO can lead to changes in the predominant intestinal bacterial groups. Depleted functional profiles of the gut microbiota were identified in the PSIO group. Functional pathways associated with intestinal fibrosis were activated by PSIO. The potential regulation by the microbiota needs to be explored in the future.

OLED catheters for inner-body phototherapy: A case of type 2 diabetes mellitus improved via duodenal photobiomodulation

Phototherapeutics has shown promise in treating various diseases without surgical or drug interventions. However, it is challenging to use it in inner-body applications due to the limited light penetration depth through the skin. Therefore, we propose an organic light-emitting diode (OLED) catheter as an effective photobiomodulation (PBM) platform useful for tubular organs such as duodenums. A fully encapsulated highly flexible OLED is mounted over a round columnar structure, producing axially uniform illumination without local hotspots. The biocompatible and airtight OLED catheter can operate in aqueous environments for extended periods, meeting the essential requirements for inner-body medical applications. In a diabetic Goto-Kakizaki (GK) rat model, the red OLED catheter delivering 798 mJ of energy is shown to reduce hyperglycemia and insulin resistance compared to the sham group. Results are further supported by the subdued liver fibrosis, illustrating the immense potential of the OLED-catheter-based internal PBM for the treatment of type 2 diabetes and other diseases yet to be identified.

Beneficial Effects of Dietary Flaxseed Oil through Inflammation Pathways and Gut Microbiota in Streptozotocin-Induced Diabetic Mice

Flaxseed oil (FO) has displayed potential anti-diabetes properties by providing a high content of α-linolenic acid. However, the effects and mechanisms of FO on type 1 diabetes are still unclear. The present study aims to explore the effects of different doses of FO feeding on hepatic inflammation and gut microbiota in streptozotocin-induced diabetic mice. Forty-eight six-week-old C57BL/6J male mice were divided into a control group (CON), a diabetic group (MOD), a diabetes with 7.0% w/w FO feeding group (FO-L), and a diabetes with 10.5% w/w FO feeding group (FO-H) for six weeks. The 7.0% w/w and 10.5% w/w FO feeding groups exhibited potential recovery of the number and size of pancreas tissues. The fasting blood glucose level was significantly decreased only after 4 weeks of feeding with 10.5% w/w FO in diabetic mice. The 10.5% w/w FO feeding group significantly decreased the postprandial blood glucose level of mice in the OGTT test. Hepatic glycogen levels were dramatically upregulated in the mice fed with both 7.0% w/w and 10.5% w/w FO. FO feeding significantly attenuated hepatic LPS, TNF-α, and IL-1β levels. In addition, we observed that 7.0% w/w and 10.5% w/w FO feedings notably downregulated hepatic gene and protein expressions of TLR4, MyD88, and P65. Furthermore, only 10.5% FO regulated fecal microbiota by increasing the relative abundance of the Bacteroidetes phylum, Lactococcus family, and Muribaculaceae and Streptococcaceae family and genus in streptozotocin-induced diabetic mice. Therefore, we conclude that FO feeding plays a role in anti-inflammation via the regulation of hepatic LPS/TLR4/MyD88 pathways and gut microbiota. In addition, different doses of FO supplementation may exhibit varying mechanisms in streptozotocin-induced mice.

The Immunomodulatory Effect of β-Glucan Depends on the Composition of the Gut Microbiota

This study aimed to elucidate the relationship between the immunomodulatory effects of β-glucan and the composition of gut microbiota in mice. The mice were fed a diet containing β-glucan for 3 weeks, and feces, blood, and tissues were then collected to analyze the immunomodulatory effect and gut microbiota composition. Based on the results of the analysis of the expression level of immune-associated proteins, the high immunomodulatory effect group (HIE) and low immunomodulatory effect group (LIE) were categorized. Before the β-glucan diet, the proportions of the phylum Bacteroidota, family Muribaculaceae, and family Lactobacillaceae were significantly higher in HIE than in LIE. Furthermore, the genus Akkermansia was absent before the β-glucan diet and increased after β-glucan diet. These microbes had the ability to metabolize β-glucan or were beneficial to health. In conclusion, our findings demonstrate that variation in the composition of gut microbiota among individuals can result in varying expressions of β-glucan functionality. This outcome supports the notion that β-glucan may be metabolized through diverse pathways by gut microbes originally possessed by mice, subsequently producing various metabolites, such as short-chain fatty acids. Alternatively, the viscosity of the intestinal mucosa could be enhanced by β-glucan, potentially promoting the growth of certain bacteria (e.g., the genus Akkermansia). This study provides insights into the intricate interplay between β-glucan, gut microbiota, and immunomodulation.

Diet effects on colonic health influence the efficacy of Bin1 mAb immunotherapy for ulcerative colitis

Ulcerative colitis (UC) is an idiopathic disease of the large intestine linked to high fat-high protein diets, a dysbiotic microbiome, and a metabolome linked to diet and/or aberrant circadian rhythms associated with poor sleeping patterns. Understanding diet-affected factors that negatively influence colonic health may offer new insights into how to prevent UC and enhance the efficacy of UC immunotherapy. In this preclinical study, we found that standard or high fiber diets in mice positively influenced their colonic health, whereas a high fat-high protein diet negatively influenced colonic health, consistent with clinical findings. Animals fed a high fat/high protein diet experienced obesity and a reduced colon length, illustrating a phenotype we suggest calling peinosis [hunger-like-condition; Greek, peina: hunger; osis: condition], as marked by a lack of nutrient energy remaining in fecal pellets. Notably, a high fat/high protein diet also led to signs of muscle weakness that could not be explained fully by weight gain. In contrast, mice on a high fiber diet ranked highest compared to other diets in terms of colon length and lack of muscle weakness. That said, mice on a high fiber diet were more prone to UC and toxic responses to immunotherapy, consistent with clinical observations. Recent studies have suggested that a standard diet may be needed to support the efficacy of immunotherapeutic drugs used to prevent and treat UC. Here we observed that protection against UC by Bin1 mAb, a passive UC immunotherapy that acts by coordinately enforcing intestinal barrier function, protecting enteric neurons, and normalizing the microbiome, was associated with increased colonic levels of healthful short-chain fatty acids (SCFA), particularly butyric acid and propionic acid, which help enforce intestinal barrier function. This work offers a preclinical platform to investigate how diet affects UC immunotherapy and the potential of dietary SCFA supplements to enhance it. Further, it suggests that the beneficial effects of passive immunotherapy by Bin1 mAb in UC treatment may be mediated to some extent by promoting increased levels of healthful SCFA.

Multispecies probiotic supplementation in diet with reduced crude protein levels altered the composition and function of gut microbiome and restored microbiome-derived metabolites in growing pigs

Both crude protein (CP) and probiotics can modulate the gut microbiome of the host, thus conferring beneficial effects. However, the benefits of low CP diet supplemented with multispecies probiotics on gut microbiome and its metabolites have not been investigated in pigs. Thus, we investigated the combinatory effects of low CP diet supplemented with multispecies probiotics on gut microbiome composition, function, and microbial metabolites in growing pigs. In total, 140 6 week-old piglets (Landrace × Yorkshire × Duroc) were used in this study. The pigs were divided into four groups with a 2 × 2 factorial design based on their diets: normal-level protein diet (16% CP; NP), low-level protein diet (14% CP; LP), NP with multispecies probiotics (NP-P), and LP with multispecies probiotics (LP-P). After the feeding trial, the fecal samples of the pigs were analyzed. The fecal scores were improved by the probiotic supplementation, especially in LP-P group. We also observed a probiotic-mediated alteration in the gut microbiome of pigs. In addition, LP-P group showed higher species richness and diversity compared with other groups. The addition of multispecies probiotics in low CP diet also enhanced gut microbiota metabolites production, such as short-chain fatty acids (SCFAs) and polyamines. Correlation analysis revealed that Oscillospiraceae UCG-002, Eubacterium coprostanoligenes, Lachnospiraceae NK4A136 group, and Muribaculaceae were positively associated with SCFAs; and Prevotella, Eubacterium ruminantium, Catenibacterium, Alloprevotella, Prevotellaceae NK3B31 group, Roseburia, Butyrivibrio, and Dialister were positively correlated with polyamines. Supplementation with multispecies probiotics modulated the function of the gut microbiome by upregulating the pathways for protein digestion and utilization, potentially contributing to enriched metabolite production in the gut. The results of this study demonstrate that supplementation with multispecies probiotics may complement the beneficial effects of low CP levels in pig feed. These findings may help formulate sustainable feeding strategies for swine production.

Melatonin improves the homeostasis of mice gut microbiota rhythm caused by sleep restriction

Insufficient sleep is regarded as a disruptor of circadian rhythm, and it also contributes to the occurrence of intestinal diseases. The physiological functions of the gut depend on the normal circadian rhythm of the intestinal microbiota. However, how lack of sleep affects intestinal circadian homeostasis is unclear. Therefore, we subjected mice to sleep restriction and found that chronic sleep loss disrupts the pattern of colonic microbial communities and reduces the proportion of gut microbiota with a circadian rhythm, with concomitant changes in the peak phase of the KEGG pathway. We then found that exogenous melatonin supplementation restored the proportion of gut microbiota with a circadian rhythm and increased the KEGG pathway with a circadian rhythm. And we screened for possible circadian oscillation families, Muribaculaceae and Lachnospiraceae, that are sensitive to sleep restriction and can be rescued by melatonin. Our results suggest that sleep restriction disrupts the circadian rhythm of the colonic microbiota. In contrast, melatonin ameliorates disturbances in the circadian rhythm homeostasis of the gut microbiota due to sleep restriction.

An analysis of the cecum microbiome of three breeds of the guinea pig: Andina, Inti, and Peru

This study investigated the effect of host genetics on the structure and composition of the cecum microbiota of three breeds of guinea pigs: Andina, Inti, and Peru. Fifteen guinea pigs were distributed into three groups according to their breed: Andina (5), Inti (5), and Peru (5). We discovered that four main phyla were shared between the three breeds: Bacteroidota, Firmicutes, Spirochaetota, and Synergistota. Although there were no significant differences in the alpha and beta diversity analysis, we found that the Linear discriminant analysis effect size and the heat tree analysis showed significant differences between the abundance of several taxa present in the cecum microbiome of the three breeds. These results suggest that host genetics could be a factor in the structure and composition of the guinea pig cecum microbiome. In addition, we found unique genera for each breed that have fermentation capacity and, therefore can be analyzed in further studies to determine if there is a functional relationship between them and the breed and its industrial profile.

Probiotic characteristics and whole-genome sequence analysis of Pediococcus acidilactici isolated from the feces of adult beagles

The beneficial effects of lactic acid bacteria are well known and recognized as functional foods that are health benefits for companion animals. This study, for the first time, reports the probiotic properties, safety, and whole-genome sequence of Pediococcus acidilactici GLP06 isolated from feces of beagles. In this study, candidate probiotic bacteria P. acidilactici GLP02 and GLP06 were morphologically characterized and tested for their antimicrobial capacity, tolerance to different conditions (low pH, bile salts, an artificial gastrointestinal model, and high temperature), antibiotic sensitivity, hemolytic activity, cell surface hydrophobicity, autoaggregation activity, and adhesion to Caco-2 cells. P. acidilactici GLP06 showed better probiotic potential. Therefore, P. acidilactici GLP06 was evaluated for in vivo safety in mice and whole-genome sequencing. The results showed, that the supplemented MG06 group (1010 cfu/mL), GLP06 was not only nontoxic to mice, but also promoted the development of the immune system, improved resistance to oxidative stress, and increased the diversity of intestinal microorganisms and the abundance of Lactobacillus. Whole-genome sequencing showed that P. acidilactici GLP06 was 2,014,515 bp and contained 1,976 coding sequences, accounting for 86.12% of the genome, with no drug resistance genes and eight CRISPR sequences. In conclusion, the newly isolated canine-derived P. acidilactici GLP06 had good probiotic potential, was nontoxic to mice and promoted the development of immune organs, improved the biodiversity of the intestinal flora, and had no risk of drug-resistant gene transfer, indicating that P. acidilactici GLP06 can be used as a potential probiotic for the prevention and treatment of gastrointestinal diseases in companion animals.

Dextran-Sulfate-Sodium-Induced Colitis-Ameliorating Effect of Aqueous Phyllanthus emblica L. Extract through Regulating Colonic Cell Gene Expression and Gut Microbiomes

The anti-inflammation effect of aqueous Phyllanthus emblica L. extract (APE) and its possible underlying mechanism in dextran sulfate sodium (DSS)-induced mice chronic colonic inflammation were studied. APE treatment significantly improved the colitic symptoms, including ameliorating the shortening of the colon, increasing the DSS-induced body weight loss, reducing the disease activity index, and reversing the condition of colon tissue damage of mucus lost and goblet cell reduction. Overproduction of serum pro-inflammatory cytokines were suppressed by the treatment of APE. Gut microbiome analysis showed that APE remodeled the structure of gut bacteria in phylum and genus levels, upregulating the abundance of phylum Bacteroidetes, family Muribaculaceae, and genus Bacteroides and downregulating the abundance of phylum Firmicutes. The reshaped gut microbiome caused metabolic functions and pathway change with enhanced queuosine biosynthesis and reduced polyamine synthesis pathway. Colon tissue transcriptome analysis further elucidated APE-inhibited mitogen-activated protein kinase (MAPK), cytokine-cytokine receptor interaction, and tumor necrosis factor (TNF) signaling pathways and the expressions of the genes that promote the progress of colorectal cancer. It turned out that APE reshaped the gut microbiome and inhibited MAPK, cytokine-cytokine receptor interaction, and TNF signaling pathways as well as the colorectal-cancer-related genes to exert its colitis protective effect.