Tilapia head glycolipids reduce inflammation by regulating the gut microbiota in dextran sulphate sodium-induced colitis mice

Synergistic effects of tilapia head protein hydrolysate and walnut protein hydrolysate on the amelioration of cognitive impairment in mice

BACKGROUND

Cognitive impairment (CI) is a significant public health concern, and bioactive peptides have shown potential as therapeutic agents. However, information about their synergistic effects on cognitive function is still limited. Here, we investigated the synergistic effects of tilapia head protein hydrolysate (THPH) and walnut protein hydrolysate (WPH) in mitigating CI induced by scopolamine in mice.

RESULTS

The results showed that the combined supplementation of THPH and WPH (mass ratio, 1:1) was superior to either individual supplement in enhancing spatial memory and object recognition abilities in CI mice, and significantly lessened brain injury in CI mice by alleviating neuronal damage, reducing oxidative stress and stabilizing the cholinergic system. In addition, the combined supplementation was found to be more conducive to remodeling the gut microbiota structure in CI mice by not only remarkably reducing the ratio of Firmicutes to Bacteroidota, but also specifically enriching the genus Roseburia. On the other hand, the combined supplementation regulated the disorders of sphingolipid and amino acid metabolism in CI mice, particularly upregulating glutathione and histidine metabolism, and displayed a stronger ability to increase the expression of genes and proteins related to the brain-derived neurotrophic factor (BDNF)/TrkB/CrEB signaling pathway in the brain.

CONCLUSION

These findings demonstrate that tilapia head and walnut-derived protein hydrolysates exerted synergistic effects in ameliorating CI, which was achieved through modulation of gut microbiota, serum metabolic pathways and BDNF signaling pathways. © 2024 Society of Chemical Industry.

Soluble dietary fibers from solid-state fermentation of wheat bran by the fungus Cordyceps cicadae and their effects on colitis mice

Ulcerative colitis is a chronic inflammatory disease with a complex pathogenesis for which there is no definitive therapeutic agent. Fermentation, as a green and efficient bioprocessing technique, has been shown to enhance the biological activity of food ingredients. Soluble dietary fiber isolated from plants is thought to have the potential to prevent and alleviate ulcerative colitis. This work was designed to study the differences in the chemical properties of the soluble dietary fiber from wheat bran fermented by Isaria cicadae Miq. (FSDF) and the unfermented soluble dietary fiber from wheat bran (UFSDF) and their effects on colitis mice. The results showed that FSDF and UFSDF differed in molecular weight, monosaccharide compositions, and surface morphology. In addition, supplementation with UFSDF and FSDF ameliorated the symptoms of DSS-induced colitis in mice by attenuating body weight loss, decreasing the disease activity index and splenic index, shortening the length of the colon, and attenuating colonic tissue damage. UFSDF and FSDF also increased the production of the anti-inflammatory cytokine IL-10 and inhibited the expression of IL-6, IL-1β, and TNF-α. The results of gut flora and short-chain fatty acid analyses showed that UFSDF and FSDF improved the diversity of gut microbiota, up-regulated the abundance of some beneficial bacteria such as Akkermansia and Muribaculaceae, increased the levels of acetic acid, propionic acid, and butyric acid, and restored dextran sodium sulfate (DSS)-induced dysbiosis of the intestinal flora in mice. These findings provide guidance for the development of FSDF and UFSDF as functional foods for the relief of ulcerative colitis.

Microbial dysbiosis index for assessing colitis status in mouse models: A systematic review and meta-analysis

Although countless gut microbiome studies on colitis using mouse models have been carried out, experiments with small sample sizes have encountered reproducibility limitations because of batch effects and statistical errors. In this study, dextran-sodium-sulfate-induced microbial dysbiosis index (DiMDI) was introduced as a reliable dysbiosis index that can be used to assess the state of microbial dysbiosis in DSS-induced mouse models. Meta-analysis of 189 datasets from 11 independent studies was performed to construct the DiMDI. Microbial dysbiosis biomarkers, Muribaculaceae, Alistipes, Turicibacter, and Bacteroides, were selected through four different feature selection methods and used to construct the DiMDI. This index demonstrated a high accuracy of 82.3% and showed strong robustness (88.9%) in the independent cohort. Therefore, DiMDI may be used as a standard for assessing microbial imbalance in DSS-induced mouse models and may contribute to the development of reliable colitis microbiome studies in mouse experiments.

Early life stress induces irritable bowel syndrome from childhood to adulthood in mice

Background

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorder. Traditionally, early life stress (ELS) is predisposed to IBS in adult. However, whether ELS induces IBS in early life remains unclear.

Methods

Separated cohort studies were conducted in neonatal male pups of C57BL/6 mice by maternal separation (MS) model. MS and non-separation mice were scheduled to be evaluated for prime IBS-phenotypes, including visceral hypersensitivity, intestinal motility, intestinal permeability, and anxiety-like behavior. Ileal contents and fecal samples were collected and analyzed by 16S rRNA gene sequencing and bacterial community analyses. Subcellular structures of intestinal epithelial, such as epithelial tight junctions and mitochondria, were observed under transmission electron microscopy.

Results

MS induced visceral hypersensitivity and decreased total intestinal transit time from childhood to adulthood. In addition, MS induced intestinal hyperpermeability and anxiety-like behavior from adolescence to adulthood. Besides, MS affected intestinal microbial composition from childhood to adulthood. Moreover, MS disrupted intestinal mitochondrial structure from childhood to adulthood.

Conclusion

The study showed for the first time that MS induced IBS from early life to adulthood in mice. The disrupted intestinal mitochondrial structure and the significant dysbiosis of intestinal microbiota in early life may contribute to the initiation and progress of IBS from early life to adulthood.

Glycolipids improve the stability of liposomes: The perspective of bilayer membrane structure

The storage and thermal stability of liposomes, which are amphiphilic carriers, cause very large challenges. However, glycolipid modification may be a potential method to improve the stability of liposomes. In this study, the mechanism by which tilapia head glycolipids improve the stability of liposomes was studied. The head groups of glycolipids and liposomes have a strong interaction (K_a = 633.650 M^-1), mainly due to hydrogen bonds, which promote the formation of microstructure domains between glycolipids and liposomes. In addition, glycolipids caused the bilayer structure of liposomes to rearrange, resulting in an increase in the phase transition temperature, tight arrangement of membrane molecules, and increase in membrane thickness (from 2.4 nm to 3.5 nm). Novelty, the formation of microstructure domains helped prevent the liposomes membrane structure from being disrupted during storage and heat. Therefore, glycolipid modification improved the stability of liposomes. This study can provide new insights into the development of high-stability liposomes.

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.

Probiotics (Lactobacillus plantarum HNU082) Supplementation Relieves Ulcerative Colitis by Affecting Intestinal Barrier Functions, Immunity-Related Gene Expression, Gut Microbiota, and Metabolic Pathways in Mice

Probiotics can effectively improve ulcerative colitis (UC), but the mechanism is still unclear. Here, shotgun metagenome and transcriptome analyses were performed to explore the therapeutic effect and the mechanism of the probiotic Lactobacillus plantarum HNU082 (Lp082) on UC. The results showed that Lp082 treatment significantly ameliorated dextran sulfate sodium (DSS)-induced UC in mice, which was manifested as increases in body weight, water intake, food intake, and colon length and decreases in disease activity index (DAI), immune organ index, inflammatory factors, and histopathological scores after Lp082 intake. An in-depth study discovered that Lp082 could improve the intestinal mucosal barrier and relieve inflammation by cooptimizing the biological barrier, chemical barrier, mechanical barrier, and immune barrier. Specifically, Lp082 rebuilt the biological barrier by regulating the intestinal microbiome and increasing the production of short-chain fatty acids (SCFAs). Lp082 improved the chemical barrier by reducing intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM) and increasing goblet cells and mucin2. Lp082 ameliorated the mechanical barrier by increasing zonula occludens-1 (ZO-1), zonula occludens-2 (ZO-2), and occludin while decreasing claudin-1 and claudin-2. Lp082 optimized the immune barrier by reducing the content of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), myeloperoxidase (MPO), and interferon-γ (IFN-γ) and increasing IL-10, transforming growth factor-β1 (TGF-β1), and TGF-β2, inhibiting the NF-κB signaling pathway. Taken together, probiotic Lp082 can play a protective role in a DSS-induced colitis mouse model by protecting the intestinal mucosal barrier, attenuating the inflammatory response, and regulating microbial imbalance. This study provides support for the development of probiotic-based microbial products as an alternative treatment strategy for UC. IMPORTANCE Many studies have focused on the therapeutic effect of probiotics on ulcerative colitis (UC), but few studies have paid attention to the mechanism of probiotics, especially the therapeutic effect. This study suggests that Lp082 has a therapeutic effect on colitis in mice. Its mechanisms of action include protecting the mucosal barrier and actively modulating the gut microbiome, modulating inflammatory pathways, and reducing neutrophil infiltration. Our study enriches the mechanism and provides a new prospect for probiotics in the treatment of colitis, helps to deepen the understanding of the intestinal mucosal barrier, and provides guidance for the future probiotic treatment of human colitis.

Lactobacillus plantarum HNU082 alleviates dextran sulfate sodium-induced ulcerative colitis in mice through regulating gut microbiome

Probiotics have shown good efficacy in the prevention of ulcerative colitis (UC), but the specific mechanism remains unclear. Therefore, shotgun metagenomic and transcriptome analyses were performed to explore the preventive effect of a potential probiotic Lactobacillus plantarum HNU082 (Lp082) on UC and its specific mechanism. The results showed that Lp082 intervention ameliorated dextran sulfate sodium (DSS)-induced UC in mice, which was manifested in the increase in body weight, water intake, food intake, and colon length and the decrease in the DAI index, immune organ index, inflammatory factors and histopathological scores after Lp082 intake. The mechanism is deeply studied and it is discovered that Lp082 improves the intestinal mucosal barrier by co-optimizing biological barriers, chemical barriers, mechanical barriers, and immune barriers. Specifically, Lp082 improved the biological barrier by increasing the diversity, optimizing the species composition and the structure of the gut microbiota, increasing bacteria producing short chain fatty acids (SCFAs), and activating microbial metabolic pathways producing SCFAs so as to enhance the content of SCFAs. Lp082 optimized the chemical barrier by decreasing the mRNA expression of ICAM-1 and VCAM and by increasing the content of goblet cells and the mRNA expression and immunofluorescent protein content of mucin2. Lp082 ameliorated the mechanical barrier by decreasing the mRNA expression of claudin-1 and claudin-2, and by increasing the mRNA expression of ZO-1 and ZO-2 and the immunofluorescent protein content of ZO-1. Lp082 also optimized the immune barrier by increasing the mRNA expression of IL-10, TGF-β1, and TGF-β2 and by decreasing the mRNA expression and protein contents of IL-6, tumour necrosis factor-alpha (TNF-α) and myeloperoxidase (MPO). In addition, Lp082 can also regulate the metabolic pathways of inflammation and disease in mice, and notably, Lp082 inhibits the NF-κB signaling pathway by inhibiting NF-κB signaling molecules to alleviate UC. In conclusion, improving gut microbiota dysbiosis, protecting the intestinal mucosal barrier, regulating inflammatory and disease pathways, and affecting neutrophil infiltration are the potential mechanisms of probiotic Lp082 in alleviating UC. Our study enriches the mechanism and provides a new prospect for Lactobacillus plantarum HNU082 in the prevention of colitis, provides support for the development of probiotic-based microbial products as an alternative prevention strategy for UC, and provides guidance for the future probiotic prevention of human colitis.

Tilapia skin peptides, a by-product of fish processing, ameliorate DSS-induced colitis by regulating inflammation and inhibiting apoptosis

Intestinal bowel disease (IBD) has always been tough to treat, therefore researchers are struggle to look for treatments that are safe, low cost, and effective. Food-derived peptides are thought to have anti-inflammatory and antioxidant properties, but they have not been studied in depth in the treatment of IBD. Based on this, we explored the effect of tilapia skin peptides (TSPs) on the remission of colitis in the present study. Colonic epithelial cell lines CT-26 and HT-29 were co-treated with lipopolysaccharide (LPS) and TSPs for 12 h. Cell viability was assessed by CCK8 assay. Dextran sulfate sodium (DSS)-induced colitis model was established and 100 mg/kg TSPs were oral administered at the same time as DSS intervention. Colonic mucosal barrier function was assessed by western blotting. The inflammatory responses were evaluated by quantitative real-time PCR along with ELISA, respectively. Apoptosis was investigated by TUNEL and flow cytometry. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to characterize peptides composition of TSPs. It was found that TSPs significantly inhibit LPS-induced inflammation and apoptosis in vitro without affecting cell viability. Moreover, the upregulation and activation of Caspase-3 and Caspase-8 were also reversed by TSPs. Subsequently, in vivo experiments demonstrated that TSPs can attenuate DSS induced colitis, manifested by a decrease in weight loss and colon shortening. The expression of ZO-1 and occluding were significantly increased, and the pro-inflammatory cytokines were down-regulated. Meanwhile, TSPs alleviated DSS-induced apoptosis and reduced the expressions of Caspase-3 and Caspase-8. Finally, we found that TSPs were composed of 51 short peptides, and 12 of them were predicted to have significant biological activity. Collectively, this study suggested that TSPs can alleviate colon damage caused by foreign stimuli via inhibiting inflammation and apoptosis which indicated that it has great potential value for the treatment of IBD.

Anti-inflammatory effect of Bifidobacterium animalis subsp. lactis A6 on DSS-induced colitis in mice

AIMS

This study aimed to investigate the protective effect of Bifidobacterium animalis subsp. lactis A6 on dextran sodium sulphate (DSS)-induced colitis in C57BL/6J mice.

METHODS AND RESULTS

Mice were randomly divided into three groups (n = 8 per group). Each group was administered with PBS (Control and DSS group) or B. lactis A6 with a dosage of ~4.0 × 109  CFU day-1 (DSS + A6 group) for 21 consecutive days. The DSS and DSS + A6 group mice were ad libitum drinking 2.5% DSS water during day 15-21, while the Control group mice were given normal water. The administration of B. lactis A6 significantly inhibited DSS-induced bodyweight loss and colon shortening (p < 0.001), but showed no significant influence on the spleen enlargement (p > 0.05). The intestinal barrier integrity was improved by reducing colonic damage, recovering mucus layer loss and enhancing tight junction expression including ZO-1, occludin and claudin-1. In addition, B. lactis A6 attenuated the oxidative stress by decreasing MDA and increasing SOD and GSH levels in colon tissues. Moreover, B. lactis A6 suppressed DSS-induced inflammatory responses via downregulating TNF-α, IL-1β and IL-6 levels and upregulating IL-10 level in colon tissues.

CONCLUSION

B. lactis A6 effectively alleviated DSS-induced colitis by maintaining intestinal barrier integrity, reducing oxidative stress and inhibiting inflammatory responses.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study suggests that B. lactis A6 could act as a candidate probiotic for UC treatment.

Black bean husk and black rice anthocyanin extracts modulated gut microbiota and serum metabolites for improvement in type 2 diabetic rats

Black rice and black bean have not yet been fully investigated as healthy foods for their therapeutic effects on type 2 diabetes mellitus (T2DM). In this study, we aimed to evaluate the antidiabetic effects of black rice, black bean husk anthocyanin extracts, and their combination on glycolipid metabolism, gut microbiota, and serum metabolites in T2DM rats. Black bean husk and black rice anthocyanin extracts were administered to T2DM rats by gavage for 4 weeks. The results showed that black rice and black bean husk anthocyanin extracts significantly improved blood glucose, insulin resistance, serum oxidative stress state, lipid metabolism and inflammatory cytokines levels in rats, and alleviated liver damage. Black rice and black bean husk anthocyanin extracts increased the abundance of short-chain fatty acid (SCFA) producing bacteria Akkermansia spp., Phascolarctobacterium spp., Bacteroides spp., and Coprococcus spp., changed the gut microbiota structure; activated AMPK, PI3K, and AKT; inhibited HMGCR, G6pase and PEPCK expression; and inhibited hepatic gluconeogenesis. Moreover, by adjusting the levels of urea, deoxycytidine, L-citrulline, pseudouridine, and other serum metabolites in T2DM rats, the arginine biosynthesis and pyrimidine metabolism pathways were downregulated. The above results indicated that black rice and black bean husk anthocyanin extracts had a significant impact on the development of T2DM.

Methamphetamine induces intestinal injury by altering gut microbiota and promoting inflammation in mice

Methamphetamine (METH) is a psychostimulant abused worldwide. Its abuse induces intestinal toxicity. Moreover, the gut microbiota is altered by drugs, which induces intestinal injury. Whether gut microbiota mediates METH-induced intestinal toxicity remains to be validated. In the present study, wild-type and TLR4^-/- mice were treated with METH. Gut microbiota was determined using 16S rRNA gene sequencing. Transcriptomics of the intestinal mucosa was performed by RNA-Sequencing. Blood levels of pro-inflammatory cytokines and lipopolysaccharide (LPS), the intestinal barrier, and inflammation were also assessed. METH treatment weakened the intestinal barrier and increased pro-inflammatory cytokines and LPS levels in the blood. Moreover, METH treatment significantly decreased the diversity of probiotics but increased the abundance of pathogenic gut microbiota, contributing to the over-production of LPS and disruption of intestinal barrier. Inflammatory pathways were enriched in the intestinal mucosa of METH-treated mice by KEGG analysis. Consistently, activation of the TLR4 pathway was determined in METH-treated mice, which confirmed intestinal inflammation. However, pretreatment with antibiotics or Tlr4 silencing significantly alleviated METH-induced gut microbiota dysbiosis, LPS over-production, intestinal inflammation, and disruption of the intestinal barrier. These findings suggested that the gut microbiota and LPS-mediated inflammation took an important role in METH-induced intestinal injury. Taken together, these findings suggest that METH-induced intestinal injury is mediated by gut microbiota dysbiosis and LPS-associated inflammation.

Tilapia nilotica Head Lipids Improved Bone Loss by Regulating Inflammation and Serum Metabolism Through Gut Microbiota in Ovariectomized Rats

Osteoporosis is a global health problem, and it is of great significance to replace the drugs with natural functional factors. In this study, we investigated the antiosteoporotic activity of lipids prepared from Tilapia nilotica fish head lipids (THLs) in the ovariectomized osteoporosis rats. THLs are composed of neutral lipids (NL, 77.84%), phospholipids (PL, 11.86%), and glycolipids (GL, 6.47%). There were apparent differences in the fatty acid composition of disparate components, and PL contains the most abundant Ω-3 polyunsaturated fatty acids. The results proved that THLs could improve bone microstructure, increase bone mineral density, and decrease bone resorption. To illustrate the antiosteoporotic mechanism, we analyzed the changes in gut microbial communities, proinflammation factors, serum metabolites, and metabolic pathways. Further study on gut microbiota showed that THLs significantly decreased the content of Alistipes in the gut and dramatically increased the beneficial bacteria such as Oscillospira, Roseburia, and Dubosiella. Meanwhile, proinflammation factors of serum in OVX rats decreased significantly, and metabolites were changed. Therefore, we speculated that THLs improved bone loss through reducing inflammation and changing the metabolites and metabolic pathways such as arachidonic acid metabolism and primary bile acid metabolism, etc., by altering gut microbiota. The results indicated that THLs could be a functional factor with antiosteoporotic activity.

Protective and restorative effects of sophorolipid on intestinal dystrophy in dextran sulfate sodium-induced colitis mouse model

The public has gradually begun to regard inflammatory bowel disease (IBD) as a crucial health issue; however, its mode of action has not been fully elucidated. Sophorolipid (SPL), a glycolipid-type biosurfactant, could be used as a potential treatment in physical intestinal dystrophy. We conducted a 2 × 2 factorial experiment to investigate the protective effect of SPL in a dextran sulfate sodium (DSS)-induced colitis mouse model (first factor, presence of SPL in feed; second factor, presence of DSS in water). Forty C57BL/6 mice (8-week-old) were used, and they were allocated to treatments according to their initial body weight. After a 7 d adjustment period, the DSS treatment was initiated in specific groups. At day 14, DSS was withdrawn from mice, and half of the mice were randomly selected and euthanized to collect colon and colon content samples. Three days after the end of DSS treatment, the rest of the mice were euthanized to investigate the therapeutic effect of SPL. Dietary SPL improved the growth performance in 3 d after DSS treatment, and the histopathological score was lower in the DSS-treated SPL group than in the DSS-treated control group. Mucosal thickness and goblet cell numbers significantly increased in the SPL-supplemented groups compared to in the control group. Similarly, SPL supplementation upregulated the gene expression levels of mucin-2, interleukin-10, and transforming growth factor-β, and increased the concentration of short chain fatty acid compared to the control groups. In conclusion, dietary supplementation with SPL attenuated the pathological response against acute and chronic inflammation by the maintenance of the mucosal barrier and wound healing capacity.

Tilapia Head Protein Hydrolysate Attenuates Scopolamine-Induced Cognitive Impairment through the Gut-Brain Axis in Mice

The destruction of the homeostasis in the gut-brain axis can lead to cognitive impairment and memory decline. Dietary intervention with bioactive peptides from aquatic products is an innovative strategy to prevent cognitive deficits. The present study aimed to determine the neuroprotective effect of tilapia head protein hydrolysate (THPH) on scopolamine-induced cognitive impairment in mice, and to further explore its mechanism through the microbiota–gut-brain axis. The results showed that THPH administration significantly improved the cognitive behavior of mice, and normalized the cholinergic system and oxidative stress system of the mice brain. The histopathological observation showed that THPH administration significantly reduced the pathological damage of hippocampal neurons, increased the number of mature neurons marked by NeuN and delayed the activation of astrocytes in the hippocampus of mice. In addition, THPH administration maintained the stability of cholinergic system, alleviated oxidative stress and further improved the cognitive impairment by reshaping the gut microbiota structure of scopolamine-induced mice and alleviating the disorder of lipid metabolism and amino acid metabolism in serum. In conclusion, our research shows that THPH supplementation is a nutritional strategy to alleviate cognitive impairment through the gut-brain axis.

Effects and Mechanisms of Probiotics, Prebiotics, Synbiotics, and Postbiotics on Metabolic Diseases Targeting Gut Microbiota: A Narrative Review

Metabolic diseases are serious threats to public health and related to gut microbiota. Probiotics, prebiotics, synbiotics, and postbiotics (PPSP) are powerful regulators of gut microbiota, thus possessing prospects for preventing metabolic diseases. Therefore, the effects and mechanisms of PPSP on metabolic diseases targeting gut microbiota are worth discussing and clarifying. Generally, PPSP benefit metabolic diseases management, especially obesity and type 2 diabetes mellitus. The underlying gut microbial-related mechanisms are mainly the modulation of gut microbiota composition, regulation of gut microbial metabolites, and improvement of intestinal barrier function. Moreover, clinical trials showed the benefits of PPSP on patients with metabolic diseases, while the clinical strategies for gestational diabetes mellitus, optimal formula of synbiotics and health benefits of postbiotics need further study. This review fully summarizes the relationship between probiotics, prebiotics, synbiotics, postbiotics, and metabolic diseases, presents promising results and the one in dispute, and especially attention is paid to illustrates potential mechanisms and clinical effects, which could contribute to the next research and development of PPSP.

Flaxseed oligosaccharides alleviate DSS-induced colitis through modulation of gut microbiota and repair of the intestinal barrier in mice

Intestinal epithelial barrier dysfunction with dysbiosis of gut microbiota contributes to the occurrence and acceleration of colitis. This study aimed to evaluate the effect of flaxseed oligosaccharides (FOSs) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice and to elucidate the underlying mechanisms. UC was induced in mice by administering 2% DSS in drinking water for 8 days. Then, FOS (50 mg kg-1 d-1, 100 mg kg-1 d-1 and 200 mg kg-1 d-1) was administered by gavage for 14 days. The results showed that FOS treatment (200 mg kg-1 d-1) significantly ameliorated colitis by decreasing disease activity index (DAI), increasing colon length and improving colonic histology. FOS treatment (200 mg kg-1 d-1) down-regulated the critical markers of oxidative stresses, including malondialdehyde (MDA) and myeloperoxidase (MPO). Furthermore, FOS (200 mg kg-1 d-1) significantly suppressed the levels of pro-inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-6 and interleukin (IL)-1β but increased that of anti-inflammatory cytokine interleukin (IL)-10. The 16S rDNA gene high-throughput sequencing results indicated that FOS treatment increased the gut microbial diversity and inhibited the proliferation of inflammation-related bacteria such as unidentified_Clostridiales. An increase in total short-chain fatty acids (SCFAs), propionic acid and butyric acid, was also observed by FOS supplementation. FOS (200 mg kg-1d-1) also protected the intestinal barrier by increasing the protein levels of Claudin1 and Occludin. In conclusion, FOS attenuated DSS-induced colitis by modulating the gut microbiota and repairing the intestinal barrier.

Administration with Quinoa Protein Reduces the Blood Pressure in Spontaneously Hypertensive Rats and Modifies the Fecal Microbiota

Despite the well-established role of quinoa protein as the source of antihypertensive peptides through in vitro enzymolysis, there is little evidence supporting the in vivo antihypertensive effect of intact quinoa protein. In this study, in vivo study on spontaneously hypertensive rats (SHRs) was conducted by administering quinoa protein for five weeks. Gastrointestinal content identification indicated that many promising precursors of bioactive peptides were released from quinoa protein under gastrointestinal processing. Quinoa protein administration on SHRs resulted in a significant decrease in blood pressure, a significant increase in alpha diversity, and microbial structure alternation towards that in non-hypertension rats. Furthermore, blood pressure was highly negatively correlated with the elevated abundance of genera in quinoa protein-treated SHRs, such as Turicibacter and Allobaculum. Interestingly, the fecal microbiota in quinoa protein-treated SHRs shared more features in the composition of genera with non-hypertension rats than that of the captopril-treated group. These results indicate that quinoa protein may serve as a potential candidate to lower blood pressure and ameliorate hypertension-related gut dysbiosis.

Tilapia head glycolipids protect mice against dextran sulfate sodium-induced colitis by ameliorating the gut barrier and suppressing NF-kappa B signaling pathway

The purpose of this study was to evaluate the relieving effect of tilapia head glycolipids (TH-GLs) on dextran sulfate sodium (DSS)-induced colitis in mice and to further explore its mechanism. Mice were orally administered 3% (w/v) DSS to establish a model of ulcerative colitis (UC), and subsequently treated with TH-GLs or sulfasalazine. In addition, the expression of key targets in the intestinal mucosal barrier and the inflammatory signal pathway were studied by combining immunochemical analysis techniques. The results showed that varying doses of TH-GLs can significantly improve colon lesions caused by DSS, reduce histological scores, increase mucus secretion, extend colon length, increase weight, and inhibit the occurrence of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), Interleukin-1β (IL-1β), and Interleukin- 6 (IL-6). Further, studies have shown that TH-GLs increase the secretion of MUC2 and up-regulate the expression of tight junction related proteins, such as ZO-1 and Occludin. In addition, TH-GLs significantly down-regulated the protein expression levels of TNF-α, IKK-β, and nuclear factor-κB (NF-κB). Here, we have elucidated the potential mechanism of TH-GLs in protecting mice with colitis. In general, this study shows that TH-GLs could improve the symptoms of UC by improving the gut barrier and inhibiting inflammatory signals, which provides a scientific basis for future clinical applications.

Fecal microbiota transplantation ameliorates experimental colitis via gut microbiota and T-cell modulation

BACKGROUND

Emerging evidence has demonstrated that fecal microbiota transplantation (FMT) has a promising therapeutic effect on mice with experimental colitis and patients with ulcerative colitis (UC), although the mechanism of FMT is unclear.

AIM

To evaluate the protective effect of FMT on UC and clarify its potential dependence on the gut microbiota, through association analysis of gut microbiota with colon transcriptome in mice.

METHODS

Dextran sodium sulfate (DSS)-induced experimental colitis was established and fecal microbiota was transplanted by gavage. Severity of colon inflammation was measured by body weight, disease activity index, colon length and histological score. Gut microbiota alteration was analyzed through 16S ribosomal ribonucleic acid sequencing. The differentially expressed genes (DEGs) in the colon were obtained by transcriptome sequencing. The activation status of colonic T lymphocytes in the lamina propria was evaluated by flow cytometry.

RESULTS

Compared with the DSS group, the weight loss, colon length shortening and inflammation were significantly alleviated in the FMT group. The scores of disease activity index and colon histology decreased obviously after FMT. FMT restored the balance of gut microbiota, especially by upregulating the relative abundance of Lactobacillus and downregulating the relative abundance of Clostridium_sensu_stricto_1 and Turicibacter. In the transcriptomic analysis, 128 DEGs intersected after DSS treatment and FMT. Functional annotation analysis suggested that these DEGs were mainly involved in T-lymphocyte activation. In the DSS group, there was an increase in colonic T helper CD4⁺ and T cytotoxic CD8⁺ cells by flow cytometry. FMT selectively downregulated the ratio of colonic CD4⁺ and CD8⁺ T cells to maintain intestinal homeostasis. Furthermore, Clostri dium_sensu_stricto_1 was significantly related to inflammation-related genes including REG3G, CCL8 and IDO1.

CONCLUSION

FMT ameliorated DSS-induced colitis in mice via regulating the gut microbiota and T-cell modulation.

Sulfasalazine maintains blood-brain barrier integrity and relieves lipopolysaccharide-induced inflammation in hCMEC/D3 cells

Sulfasalazine is a recognized therapy for inflammatory bowel disease and is of paramount importance for maintaining intestinal barrier homeostasis. However, its effects on blood-brain barrier (BBB) function and inflammation have not yet been explored. We sought to examine whether sulfasalazine has anti-inflammatory and antiapoptotic effects on the BBB. hCMEC/D3 cells are a well-established BBB in vitro model, were treated with 1 μg/mL Escherichia coli O111:B4 lipopolysaccharide for 12 h. The cell counting kit-8 assay was used to assess cell viability. The cells were also treated with gradient concentrations of sulfasalazine for 12 h. The levels of apoptosis-related proteins and inflammatory factors (IL-1χ and TNF-α IL-6) were measured by western blotting. ZO-1 and F-actin expression was measured by immunofluorescence staining. This study confirmed that 5 mM sulfasalazine improved the maintenance of BBB integrity and relieved lipopolysaccharide-induced inflammatory apoptosis and showed that sulfasalazine might be an effective treatment for BBB disruption.

Characterization of lipid profiling in three parts (muscle, head and viscera) of tilapia (Oreochromis niloticus) using lipidomics with UPLC-ESI-Q-TOF-MS

A lipidomic evaluation was performed on the tilapia muscle, head and viscera, including studying the composition, distribution and stereospecific characteristics of fatty acids and lipid species. The head and viscera lipids were significantly richer than the muscle lipids. Triacylglycerols were the predominant fraction (over 80% of total lipid in the muscle and head). Additionally, polyunsaturated fatty acids had higher percentages in phospholipids (30.35-52.05% of total fatty acids) than in triacylglycerols (18.11-25.15%). The C52:2 and C52:3 were the most abundant triacylglycerols, which indicates the potential application in infant food. Moreover, 622, 530 and 513 lipids were identified using ultraperformance liquid chromatography-quadrupole time-of-flight-mass spectrometry in the muscle, head and viscera, respectively. The three tilapia parts were distinguished using multivariate analysis. Five fatty acids and 33 lipid species were considered as the potential biomarkers. This comprehensive analysis will help to evaluate the lipid nutritional values and facilitate exploitation in tilapia consumption and processing.

Fish Oil, Cannabidiol and the Gut Microbiota: An Investigation in a Murine Model of Colitis

Inflammatory bowel disorders can be associated with alterations in gut microbiota (dysbiosis) and behavioral disturbances. In experimental colitis, administration of fish oil (FO) or cannabinoids, such as cannabidiol (CBD), reduce inflammation. We investigated the effect of combined FO/CBD administration on inflammation and dysbiosis in the dextran sulphate sodium (DSS) model of mouse colitis, which also causes behavioral disturbances. Colitis was induced in CD1 mice by 4% w/v DSS in drinking water for five consecutive days followed by normal drinking water. FO (20–75 mg/mouse) was administered once a day starting two days after DSS, whereas CBD (0.3–30 mg/kg), alone or after FO administration, was administered once a day starting 3 days after DSS, until day 8 (d8) or day 14 (d14). Inflammation was assessed at d8 and d14 (resolution phase; RP) by measuring the Disease Activity Index (DAI) score, change in body weight, colon weight/length ratio, myeloperoxidase activity and colonic interleukin (IL)-1β (IL-1β), IL-10, and IL-6 concentrations. Intestinal permeability was measured with the fluorescein isothiocyanate-dextran. Behavioral tests (novel object recognition (NOR) and light/dark box test) were performed at d8. Fecal microbiota composition was determined by ribosomal 16S DNA sequencing of faecal pellets at d8 and d14. DSS-induced inflammation was stronger at d8 and accompanied by anxiety-like behavior and impaired recognition memory. FO (35, 50, 75 mg/mouse) alone reduced inflammation at d8, whereas CBD alone produced no effect at any of the doses tested; however, when CBD (3, 10 mg/kg) was co-administered with FO (75 mg/mouse) inflammation was attenuated. FO (20 mg/mouse) and CBD (1 mg/kg) were ineffective when given alone, but when co-administered reduced all inflammatory markers and the increased intestinal permeability at both d8 and d14, but not the behavioral impairments. FO, CBD, and their combination affected gut bacteria taxa that were not affected by DSS per se. Akkermansia muciniphila, a species suggested to afford anti-inflammatory action in colitis, was increased by DSS only at d14, but its levels were significantly elevated by all treatments at d8. FO and CBD co-administered at per se ineffective doses reduce colon inflammation, in a manner potentially strengthened by their independent elevation of Akkermansia muciniphila.

Identification of the core active structure of a Dendrobium officinale polysaccharide and its protective effect against dextran sulfate sodium-induced colitis via alleviating gut microbiota dysbiosis

It has been claimed that Dendrobium officinale applied as a functional food in China for centuries derived from the excellent anti-inflammatory activities. Herein, we aim to investigate the core structure of a Dendrobium officinale polysaccharide (DOP) based on the linear structural features by a specific endo-β-1,4-mannanase which was required for the protective effect against dextran sulfate sodium (DSS)-induced colitis in mice. Structure characterization revealed that enzymatic fragment contained the core domain (EDOP) which was composed of glucose and mannose in the molar ratio of 1.00:4.76, and consisted of (1 → 4)-β-D-Glcp and (1 → 4)-β-D-Manp with some attached 2-O-acetylated groups. In colitis mice, both DOP and EDOP could dramatically attenuate the clinical signs via blocking pro-inflammatory cytokines (TNF-α, IL-6, IL-1β, and their related mRNA), restoring the levels of short-chain fatty acids (SCFAs), activating the G-protein coupled receptors (GPRs) and modulating the gut microbiota. Gut microbiota dysbiosis is currently considered to be an important factor affecting colitis. The treatment of DOP and EDOP could recall the diversity of gut microbiota and modulate the abundance of the gut microbiota, including increasing the abundance of Bacteroides, Lactobacillus and Ruminococcaceae and reducing the abundance of Proteobacteria. Our findings have suggested that EDOP, as a core domain of DOP, retained similar structural features together with anti-inflammatory activity with DOP, and they could be potentially applied as natural candidates in the treatment of inflammatory bowel disease (IBD).