Intestinal alterations and mild glucose homeostasis impairments in the offspring born to overweight rats

The gut plays a crucial role in metabolism by regulating the passage of nutrients, water and microbial-derived substances to the portal circulation. Additionally, it produces incretins, such as glucose-insulinotropic releasing peptide (GIP) and glucagon-like derived peptide 1 (GLP1, encoded by gcg gene) in response to nutrient uptake. We aimed to investigate whether offspring from overweight rats develop anomalies in the barrier function and incretin transcription. We observed pro-inflammatory related changes along with a reduction in Claudin-3 levels resulting in increased gut-permeability in fetuses and offspring from overweight rats. Importantly, we found decreased gip mRNA levels in both fetuses and offspring from overweight rats. Differently, gcg mRNA levels were upregulated in fetuses, downregulated in female offspring and unchanged in male offspring from overweight rats. When cultured with high glucose, intestinal explants showed an increase in gip and gcg mRNA levels in control offspring. In contrast, offspring from overweight rats did not exhibit any response in gip mRNA levels. Additionally, while females showed no response, male offspring from overweight rats did exhibit an upregulation in gcg mRNA levels. Furthermore, female and male offspring from overweight rats showed sex-dependent anomalies when orally challenged with a glucose overload, returning to baseline glucose levels after 120 min. These results open new research questions about the role of the adverse maternal metabolic condition in the programming of impairments in glucose homeostasis, enteroendocrine function and gut barrier function in the offspring from overweight mothers and highlight the importance of a perinatal maternal healthy metabolism.

hUC-MSCs therapy for Crohn's disease: efficacy in TNBS-induced colitis in rats and pilot clinical study

BACKGROUND

The use of mesenchymal stem cells (MSCs) has recently emerged as a promising new therapeutic strategy for many diseases including perianal fistulizing Crohn's disease (CD). Whether hUC-MSCs can promote the healing of luminal ulcer in CD has not been studied so far.

METHODS

The model of TNBS-induced colitis in rats was used to confirm the efficacy of hUC-MSCs in the treatment of CD. Then, seventeen CD patients refractory to or unsuitable for currently available therapies were enrolled and received once submucosal local injection through colonoscopy combined with once intravenous drip on the next day. All patients received a 24-week follow-up. Clinical and laboratory assessments were monitored at baseline, week 4, 8, 12, and 24. Endoscopic evaluations were conducted at baseline and week 12. Mucosal specimens were obtained at the margin of lesions by endoscopy biopsies and used for RNA sequencing. Two hUC-MSCs co-culture systems were established in vitro, one with the mucosa specimens and the other with M1 macrophages induced from THP1. The expressions of genes representing inflammation (TNFα, IL-6, and IL-1β) and intestinal barrier function (ZO1, CLAUDIN1, and CDH1) were tested by RT-PCR.

FINDINGS

hUC-MSCs treatment increased body weight and decreased disease activity index (DAI), colon macroscopic damage index (CMDI), and histopathological score (HPS) of rats with TNBS-induced colitis. The results of the clinical study also showed that this mode of hUC-MSCs application was associated with regression of intestinal ulceration. Eight patients (47%) got endoscopic responses (SES-CD improvement of ≥50% from baseline) and three patients (17.65%) got mucosal healing (SES-CD is zero), with a parallel improvement of clinical and laboratory parameters without serious adverse events. RNA sequencing showed hUC-MSCs therapy was associated with an upregulation of transcripts linked to intestinal epithelial barrier integrity and a downregulation of inflammatory signaling pathways in the intestinal mucosa, especially the TNF signaling pathway, IL-17 signaling pathway, and TLR signaling pathway. RNA expression of intestinal epithelial tight junction protein (ZO1, CLAUDIN1, and CDH1), and the RNA expression of major intestinal inflammatory factors in CD (IL-1β, IL-6, and TNFα, p < 0.001 for all) were improved significantly. Moreover, hUC-MSCs could attenuate the polarization of M1 macrophage induced from THP1, thereby decreasing the mRNA expression of IL-1β, IL-6, and TNFα significantly (p < 0.05 for all). TSG-6 expression was evaluated in hUC-MSCs culture supernatant after treatment with TNFα, IFNγ, and LPS for 48 h. And hUC-MSCs could inhibit the phosphorylation of JAK/STAT1 in the intestinal mucosa of CD patients.

INTERPRETATION

hUC-MSCs transplantation alleviated TNBS-induced colitis in rats. In this pilot clinical study, preliminary data suggested that this approach to administering hUC-MSCs might have potential for clinical efficacy and manageable safety in treating refractory CD, potentially providing hope for better outcomes. No serious adverse events were observed.

FUNDING

This work was funded by General Program of National Natural Science Foundation of China (Grant No. 82270639), the Scientific research project of Shanghai Municipal Health Committee (Grant No. 202240001), Specialty Feature Construction Project of Shanghai Pudong New Area Health Commission (Grant No. PWZzb2022-05), Shanghai East Hospital Youth Research and Cultivation Foundation program (Grant No. DFPY2022015), Peak Disciplines (Type IV) of Institutions of Higher Learning in Shanghai and Technology Development Project of Pudong Science, Technology and Economic Commission of Shanghai (Grant No. PKJ2021-Y08).

Probiotics may alleviate intestinal damage induced by cardiopulmonary bypass in children

OBJECTIVES

Intestinal ischemia-reperfusion injury induced by cardiopulmonary bypass causes intestinal epithelial barrier dysfunction, leading to dysbiosis and bacterial translocation. We conducted a randomized prospective study with two objectives: (1) to investigate epithelial barrier dysfunction and bacterial translocation induced by cardiopulmonary bypass and changes in the gut microbiota and (2) to verify whether probiotics can improve these conditions.

METHODS

Between 2019 and 2020, patients 0-15 years old scheduled to undergo cardiac surgery using cardiopulmonary bypass were enrolled and randomly allocated to 2 groups: the intervention group received probiotics, and the control group did not receive probiotics. We analyzed the microbiota in feces and blood, organic acid concentrations in feces, plasma intestinal fatty-acid binding protein, and immunological responses.

RESULTS

Eighty-two patients were enrolled in this study. The characteristics of the patients were similar in both groups. The total number of obligate anaerobes was higher in the intervention group than in the control group after postoperative day 7. We identified four clusters within the perioperative gut microbiota, and cluster changes showed a corrective effect of probiotics on dysbiosis after postoperative day 7. Organic acid concentrations in feces, incidence of bacterial translocation, Intestinal fatty-acid binding protein levels, and immunological responses, except for Interleukin -17A, were not markedly different between the two groups.

CONCLUSIONS

Administration of probiotics was able to correct dysbiosis but did not sufficiently alleviate the intestinal damage induced by cardiopulmonary bypass. More effective methods should be examined to prevent disturbances induced by cardiac surgery using cardiopulmonary bypass.

Supplementation of citrus pectin with whole-cell pectinase PG5 on Pichia pastoris promotes recovery of colitis and enhances intestinal barrier function in DSS-treated mice

A whole-cell biocatalyst was developed by genetically engineering pectinase PG5 onto the cell surface of Pichia pastoris using Gcw12 as the anchoring protein. Whole-cell PG5 eliminated the need for enzyme extraction and purification, while also exhibiting enhanced thermal stability, pH stability, and resistance to proteases in vitro compared to free PG5. Magnetic resonance mass spectrometry analysis revealed that whole-cell PG5 efficiently degraded citrus pectin, resulting in the production of a mixture of pectin oligosaccharides. The primary components of the mixture were trigalacturonic acid, followed by digalacturonic acid and tetragalacturonic acid. Supplementation of citrus pectin with whole-cell PG5 resulted in a more pronounced protective effect compared to free PG5 in alleviating colitis symptoms and promoting the integrity of the colonic epithelial barrier in a mouse model of dextran sulfate sodium-induced colitis. Hence, this study demonstrates the potential of utilizing whole-cell pectinase as an effective biocatalyst to promote intestinal homeostasis in vivo.

Electroacupuncture Improving Intestinal Barrier Function in Rats with Irritable Bowel Syndrome Through Regulating Aquaporins

BACKGROUND

Intestinal mucosal barrier dysfunction plays a crucial role in the pathogenesis of irritable bowel syndrome with diarrhea (IBS-D). In order to explore the mechanism of electroacupuncture (EA) treatment on intestinal mucosal barrier, this study observed the effect of EA on aquaporins (AQPs), tight junctions (TJs), NF-κB pathway and the gut microbiota in IBS-D rats.

METHODS

The IBS-D model was established by acetic acid enema combined with chronic restraint method. The effects of EA on the treatment of IBS-D were examined by the abdominal withdrawal reflex score, Bristol's fecal character score, fecal water content, small intestine propulsion rate and HE staining. AQPs, TJs and inflammation-related molecular mechanisms were explored. The fecal samples were applied for 16S rRNA sequencing to assess the effect of EA intervention to the intestinal bacterial abundance.

RESULTS

EA reduced intestinal sensitization, restored intestinal motility and improved inflammatory cell infiltration. Furthermore, EA improved intestinal inflammation and flora environment significantly, inhibited NF-κB signaling and inflammatory factors (IL-1β and TNF-α). It can also increase the gene and protein expression of AQPs (AQP1, AQP3, and AQP8) and the gene levels of TJs (ZO-1 and Occludin).

CONCLUSION

EA has an inhibitory effect on the NF-κB signaling pathway, and regulates the proteins of AQP1, AQP3, AQP8, and TJs to restore the balance of water metabolism and intestinal permeability in IBS-D, which also restored the function of the intestinal mucosa by regulating the intestinal flora.

An Updated View of the Effect of Probiotic Supplement on Sports Performance: A Detailed Review

PURPOSE OF REVIEW

Modulation of the host microbiota through probiotics has been shown to have beneficial effects on health in the growing body of research. Exercise increases the amount and diversity of beneficial microorganisms in the host microbiome. Although low- and moderate-intensity exercise has been shown to reduce physiological stress and improve immune function, high-intensity prolonged exercise can suppress immune function and reduce microbial diversity due to intestinal hypoperfusion. The effect of probiotic supplementation on sports performance is still being studied; however, questions remain regarding the mechanisms of action, strain used, and dose. In this review, the aim was to investigate the effects of probiotic supplements on exercise performance through modulation of gut microbiota and alleviation of GI symptoms, promotion of the immune system, bioavailability of nutrients, and aerobic metabolism.

RECENT FINDINGS

Probiotic supplementation may improve sports performance by reducing the adverse effects of prolonged high-intensity exercise. Although probiotics have been reported to have positive effects on sports performance, information about the microbiome and nutrition of athletes has not been considered in most current studies. This may have limited the evaluation of the effects of probiotic supplementation on sports performance.

Mitigation effect of hesperidin on X-ray radiation-induced intestinal barrier dysfunction in Caco-2 cell monolayers

The tight junctions (TJs) and barrier function of the intestinal epithelium are highly sensitive to radiation. However, polyphenols can be used to reverse the effects of radiation. Here, we investigated the effects of hesperidin (hesperetin-7-rhamnoglucoside) on X-ray-induced intestinal barrier dysfunction in human epithelial Caco-2 monolayers. To examine whether hesperidin mitigated the effects of X-ray exposure (2 Gy), cell survival was evaluated and intestinal barrier function was assessed by measuring the transepithelial flux, apparent permeability coefficient (Papp), and barrier integrity. Hesperidin improved the survival of Caco-2 cell monolayers and attenuated X-ray exposure-induced intestinal barrier dysfunction. For fluorescein transport experiments, transepithelial flux and Papp of fluorescein in control group were significantly elevated by X-ray, but were restored to near control by 10 μM hesperidin pretreatment. Further, X-ray exposure decreased the barrier integrity and TJ interruption by reducing TJ-related proteins occludin and claudin-4, whereas cell monolayers pretreated with hesperidin before X-ray exposure were reinstated to control level. It was concluded that hesperidin treatment before X-ray exposure alleviated X-ray-induced intestinal barrier dysfunction through regulation of TJ-related proteins. These results indicate that hesperidin prevents and mitigates X-ray-induced intestinal barrier dysfunction.

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.

Salvia miltiorrhiza polysaccharide promotes the health of crayfish (Procambarus clarkii) by promoting hemocyte phagocytosis, protecting hepatopancreas and enhancing intestinal barrier function

Plant polysaccharides as immunomodulators are considered one of the effective measures to reduce antibiotic therapy in aquaculture. The immunomodulatory function of Salvia miltiorrhiza polysaccharides (SMP) has been demonstrated and begun to be applied in vertebrates, but its potential effect on crustaceans is unclear. In this study, crayfish (Procambarus clarkii) was fed with 0 %, 0.3 %, 0.7 %, 1.1 %, and 1.5 % SMP for 4 weeks to investigate the effects of SMP on hemocytes phagocytosis, hepatopancreatic function, and intestinal barrier function. The results revealed that hemocyte phagocytic activity was increased in all SMP groups. During the process of hemocytes phagocytic recognition and formation of phagosomes and phagolysosomes, the mRNA expression levels of mas, hem, rab3, ctsb, and lamp-1 were up-regulated mainly in the 0.3 % SMP group. During the clearance phase of phagocytosis, respiratory burst activity, ROS level, T-SOD, CAT, GST, and LZM activities were mainly increased in the 1.5 % SMP group. Hepatopancreas AKP and GOT activity were no significant change in all SMP groups. ACP activity was significantly enhanced in the 1.1 % SMP group. The GPT activity of 0.3-0.7 % SMP group was significantly decreased. The 0.7 % SMP group had the highest intestinal fold height. The highest index values of OTUs, Ace, Chao, and Shannon were in the 0.3 % SMP group. The dietary addition of 0.3 % SMP led to a tendency of increased relative abundance of Firmicutes and Bacteroidota at the phylum level, while the relative abundance of Proteobacteria at the phylum level decreased. In conclusion, dietary SMP could promote crayfish health by enhancing phagocytosis, protecting hepatopancreas and enhancing intestinal barrier function. This study contributes to the theoretical foundation for exploring the potential application of plant polysaccharides in crustaceans.

MUC13 negatively regulates tight junction proteins and intestinal epithelial barrier integrity via protein kinase C

Glycosylated mucin proteins contribute to the essential barrier function of the intestinal epithelium. The transmembrane mucin MUC13 is an abundant intestinal glycoprotein with important functions for mucosal maintenance that are not yet completely understood. We demonstrate that in human intestinal epithelial monolayers, MUC13 localized to both the apical surface and the tight junction (TJ) region on the lateral membrane. MUC13 deletion resulted in increased transepithelial resistance (TEER) and reduced translocation of small solutes. TEER buildup in ΔMUC13 cells could be prevented by addition of MLCK, ROCK or protein kinase C (PKC) inhibitors. The levels of TJ proteins including claudins and occludin were highly increased in membrane fractions of MUC13 knockout cells. Removal of the MUC13 cytoplasmic tail (CT) also altered TJ composition but did not affect TEER. The increased buildup of TJ complexes in ΔMUC13 and MUC13-ΔCT cells was dependent on PKC. The responsible PKC member might be PKCδ (or PRKCD) based on elevated protein levels in the absence of full-length MUC13. Our results demonstrate for the first time that a mucin protein can negatively regulate TJ function and stimulate intestinal barrier permeability.

Development of small intestinal barrier function and underlying mechanism in Chinese indigenous and Duroc piglets during suckling and weaning periods

This study explored the developmental changes in small intestinal barrier function and the potential regulatory roles of intestinal microbiota and metabolites in different breeds of piglets during suckling and weaning periods. Taoyuan black (TB), Xiangcun black (XB), and Duroc (DR) piglets (10 litters per breed; half male and half female) were selected for sampling to evaluate the intestinal barrier-related indexes and intestinal microbiota and metabolites at 1, 10, 21 (weaned), and 24 (3 d after weaning) d old. The results showed that weaning led to severe shedding of small intestinal microvilli and sparse microvilli arrangement. D-lactate level in the ileum of TB and XB piglets during suckling and weaning periods was lower (P < 0.01) than that of DR piglets, as well as the ileal diamine oxidase level at 1 d old. The expression level of mucin 1 was higher (P < 0.05) in the ileum of TB and XB piglets than that of DR piglets, and it was the highest in the ileum of TB piglets at 21 d old. The expression levels of mucin 2 and mucin 13 were higher (P < 0.10) in TB and XB piglets than those of DR piglets at 21 d old, whereas mucin 2 and mucin 13 in the ileum of TB and XB piglets were higher (P < 0.05) than those of DR piglets at 24 d old. TB and XB piglets had a lower relative abundance of Escherichia_Shigella at 21 and 24 d old, but they had higher Streptococcus at 1 and 24 d old than DR piglets (P < 0.01). Differential metabolites between the three breeds of piglets were mainly related to oxidative phosphorylation, steroid biosynthesis, and bile acid synthesis. Collectively, these findings suggest that different pig breeds present differences in the development of the small intestinal barrier function. Compared with DR piglets, TB and XB piglets had higher intestinal permeability during the suckling period and a stronger intestinal mechanical barrier after weaning. Moreover, intestinal microbiota and metabolites are the key factors for developing small intestinal barrier functions in different breeds of piglets.

Amelioration of obesity and inflammation by polysaccharide from unripe fruits of raspberry via gut microbiota regulation

Raspberry, a traditional medicine food homology species, has important benefits in patients with metabolic syndrome. However, the mechanism of raspberry polysaccharides (RP) on obesity remains unclear. In our study, we showed that RP intervention is negatively associated with body weight gain, hyperlipidemia, inflammation, and fat accumulation in obese mice. RP ameliorated HFD-induced gut microbiota dysbiosis, produced short-chain fatty acids, maintained intestinal barrier integrity, and prevented metabolic endotoxemia, manifested by decreased host lipopolysaccharide level, and increased colon expression of tight junction proteins. These effects might be related with driven by a SCFAs-producing bacterium and downregulation of TLR4/NF-κB signaling transduction. Notably, the abundance of Ruminococcaceae_UCG - 014, Lactobacillus taiwanensis, Bifidobacterium pseudolongum, and Turicibacter are markedly correlated with enhanced intestinal barrier function induced by RP treatment. Thus, we believe that RP could be as a potential health supplement or prebiotic for obesity therapy.

Autoinducer-2 promotes the colonization of Lactobacillus rhamnosus GG to improve the intestinal barrier function in a neonatal mouse model of antibiotic-induced intestinal dysbiosis

BACKGROUND

Human health is seriously threatened by antibiotic-induced intestinal disorders. Herein, we aimed to determine the effects of Autoinducer-2 (AI-2) combined with Lactobacillus rhamnosus GG (LGG) on the intestinal barrier function of antibiotic-induced intestinal dysbiosis neonatal mice.

METHODS

An antibiotic-induced intestinal dysbiosis neonatal mouse model was created using antibiotic cocktails, and the model mice were randomized into the control, AI-2, LGG, and LGG + AI-2 groups. Intestinal short-chain fatty acids and AI-2 concentrations were detected by mass spectrometry and chemiluminescence, respectively. The community composition of the gut microbiota was analyzed using 16S rDNA sequencing, and biofilm thickness and bacterial adhesion in the colon were assessed using scanning electron microscopy. Transcriptome RNA sequencing of intestinal tissues was performed, and the mRNA and protein levels of HCAR2 (hydroxycarboxylic acid receptor 2), claudin3, and claudin4 in intestinal tissues were determined using quantitative real-time reverse transcription PCR and western blotting. The levels of inflammatory factors in intestinal tissues were evaluated using enzyme-linked immunosorbent assays (ELISAs). D-ribose, an inhibitor of AI-2, was used to treat Caco-2 cells in vitro.

RESULTS

Compared with the control, AI-2, and LGG groups, the LGG + AI-2 group showed increased levels of intestinal AI-2 and proportions of Firmicutes and Lacticaseibacillus, but a reduced fraction of Proteobacteria. Specifically, the LGG + AI-2 group had considerably more biofilms and LGG on the colon surface than those of other three groups. Meanwhile, the combination of AI-2 and LGG markedly increased the concentration of butyric acid and promoted Hcar2, claudin3 and claudin4 expression levels compared with supplementation with LGG or AI-2 alone. The ELISAs revealed a significantly higher tumor necrosis factor alpha (TNF-α) level in the control group than in the LGG and LGG + AI-2 groups, whereas the interleukin 10 (IL-10) level was significantly higher in the LGG + AI-2 group than in the other three groups. In vitro, D-ribose treatment dramatically suppressed the increased levels of Hcar2, claudin3, and claudin4 in Caco-2 cells induced by AI-2 + LGG.

CONCLUSIONS

AI-2 promotes the colonization of LGG and biofilm formation to improve intestinal barrier function in an antibiotic-induced intestinal dysbiosis neonatal mouse model.

Washed microbiota transplantation improves symptoms and intestinal barrier function in patients with functional bowel disorders: a propensity-score matching analysis

BACKGROUND

Alterations in the intestinal microbiota may play a role in the pathogenesis of functional bowel disorders (FBDs). Probiotics are widely used to improve intestinal dysbacteriosis in FBDs. In the context of FBDs, washed microbiota transplantation (WMT) appear to be a promising therapeutic option. We aimed to compare probiotics with WMT by using a propensity-score matching analysis (PSMA).

METHODS

We conducted a retrospective investigation of 103 patients with FBDs, including irritable bowel syndrome (IBS), functional constipation (FC), functional diarrhea (FDr), functional abdominal bloating (FAB). Patients were divided into the WMT group or probiotics group (taking probiotics capsules). Data on the following parameters were matched for PSMA: age; sex; disease course; body mass index; anxiety; insomnia; tobacco smoking; alcohol consumption; and levels of D-lactate, diamine oxidase, and lipopolysaccharide. Intestinal barrier function (IBF) and symptoms were evaluated both before and after treatment initiation. Prognostic factors were assessed by Cox proportional hazards regression analysis.

RESULTS

PSMA identified in 34 matched pairs (11 IBS, 12 FC, 7 FDr, and 4 FAB in the probiotics group and 14 IBS, 13 FC, 5 FDr, and 2 FAB in the WMT group. Improvement of FBD symptoms was greater with WMT than probiotics (P = 0.002). The WMT group had significantly fewer patients with intestinal barrier damage than the probiotics group (38.2% vs. 67.6%, P = 0.041). This improvement of FBD with WMT was further reflected as a reduction in D-lactate levels (P = 0.031). Increased D-lactate levels which were identified as a prognostic factor for FBDs (HR = 0.248, 95%CI 0.093-0.666, P = 0.006) in multivariate Cox regression analysis.

CONCLUSION

WMT could improve symptoms and IBF in patients with FBDs. Increased D-lactate levels in patients with FBDs may predict a favorable response to WMT treatment.

Structural elucidation of a highly branched α-D-glucan from Huangjiu and its hepatoprotective activity via gut microbiome regulation and intestinal barrier repairment

Polysaccharides in Huangjiu, a traditional fermented food, are expected to be potentially effective ingredients in protecting against alcoholic liver disease (ALD). Elucidating their precise structural and functional characteristics is essential for in-depth understanding of structure-activity relationships of hepatoprotective polysaccharides. Herein, a major polysaccharide component HJPS1-2 was purified from Huangjiu with an average molecular weight of 3.49 kDa. Structural analyses inferred that HJPS1-2 backbone was composed of (1 → 4)-linked α-D-Glcp and a single α(1 → 6)-D-Glcp-α(1 → 6)-D-Glcp branched unit for every three α(1 → 4)-D-Glcp. An ALD mouse model was further established to clarify the underlying effect of HJPS1-2 on ALD alleviation. Biochemical detection and histopathological assessment revealed that HJPS1-2 intervention remarkably improved ethanol-induced hepatic dysfunction and steatosis. HJPS1-2 treatment ameliorated gut microbiota dysbiosis of ALD mice in a dose-dependent manner, mainly manifested as restoration of microbial diversities, community structure and bacterial interaction patterns. Compared with ethanol group, the strikingly elevated intestinal short-chain fatty acids' levels and enhanced intestinal barrier function after HJPS1-2 intake might contribute to reduced serum and liver lipopolysaccharide levels and subsequently suppressed release of hepatic inflammatory cytokines, thus mitigating ALD. Collectively, this research supports the potential of food-derived polysaccharides to hinder the early formation and progression of ALD through maintaining intestinal homeostasis.

Antibiotics attenuate diet-induced nonalcoholic fatty liver disease without altering intestinal barrier dysfunction

To date the role of the alterations of intestinal microbiota in the development of intestinal barrier dysfunction in settings of nonalcoholic fatty liver disease (NAFLD) has not been fully understood. Here, we assessed the effect of antibiotics on development of NAFLD and their impact on intestinal barrier dysfunction. Male C57BL/6J mice were either pair-fed a liquid control diet (C) or fat- and fructose-rich diet (FFr) +/- antibiotics (AB, ampicillin/vancomycin/metronidazole/gentamycin) for 7 weeks. Fasting blood glucose was determined and markers of liver damage, inflammation, intestinal barrier function, and microbiota composition were assessed. The development of hepatic steatosis with early signs of inflammation found in FFr-fed mice was significantly abolished in FFr+AB-fed mice. Also, while prevalence of bacteria in feces was not detectable and TLR4 ligand levels in portal plasma were at the level of controls in FFr+AB-fed mice, impairments of intestinal barrier function like an increased permeation of xylose and iNOS protein levels persisted to a similar extent in both FFr-fed groups irrespective of AB use. Exposure of everted small intestinal tissue sacs of naïve mice to fructose resulted in a significant increase in tissue permeability and loss of tight junction proteins, being not affected by the presence of AB, whereas the concomitant treatment of tissue sacs with the NOS inhibitor aminoguanidine attenuated these alterations. Taken together, our data suggest that intestinal barrier dysfunction in diet-induced NAFLD in mice may not be predominantly dependent on changes in intestinal microbiota but rather that fructose-induced alterations of intestinal NO-homeostasis might be critically involved.

Exposure to triphenyltin impairs gut integrity, disturbs gut microbiota, and alters fecal metabolites

Triphenyltin is an environmental contaminant widely used in antifouling paints and can cause toxicity in various organs in living organisms. However, its effects on intestinal function and the microbiome of the gut remain unknown. The objective of this study was to explore the intestinal toxicity of triphenyltin in mice by orally administering 0, 1.875, 3.75, and 7.5 mg/Kg to adult male mice for 8 weeks. Results showed that triphenyltin caused ileum tissue damage, induced oxidative stress, upregulated inflammation-related gene expression and increased serum tumor-necrosis factor α (TNF-α) levels in mice. Triphenyltin impaired ileum barrier function by downregulating Muc2, ZO-1, Occludin and their protein levels at 3.75 and 7.5 mg/Kg. TPT exposure led to partial inflammation and decreased mucin mRNA expression in the colon. Triphenyltin altered intestinal micro-ecological balance and fecal metabolome in mice. In conclusion, triphenyltin alters the mouse gut microbiota and fecal metabolome.

Modulation of gut microbiota ecosystem by a glucan-rich snail mucin heteropolysaccharide attenuates loperamide-induced constipation

The present study aimed to investigate the effect of oral administration of snail-derived mucin extract (SM) on ameliorating constipation symptoms of loperamide-induced constipated rats (n = 6). The analytical results indicated that SM mainly contains a glucan-rich snail mucin heteropolysaccharide with high molecular weights (108.5-267.9 kDa), comprising primarily of glucose (64.9 %) and galactose (22.4 %) with some deoxyhexoses (5.0 %) and hexosamines (4.9 %). Daily SM administration at doses of 10-40 mg/kg/day to the loperamide-induced constipated rats significantly (p < 0.05) ameliorated the deterioration in fecal parameters, such as numbers and weight of feces, fecal water contents, and gastrointestinal transit ratio. The histomorphometric results showed that the loperamide-induced decreases in the thickness of mucosal and muscularis mucosae layers as well as the distribution of mucin and c-KIT-positive areas were significantly (p < 0.05) improved via SM consumption at all doses tested. SM administration at all doses significantly increased the expression of genes encoding tryptophan hydroxylases (TPH1 and TPH2; p < 0.05), tight junction molecules (OCLN, CLDN1, and TJP1; p < 0.05), and mucin (MUC2 and MUC4; p < 0.05), but significantly decreased the aquaporin-encoding genes (AQP3 and AQP8; p < 0.05). Gut microbial community analysis indicated that SM administration could modulate loperamide-induced dysbiosis by increasing the phyla Actinobacteria (11.72-12.64 % at 10-40 mg/kg doses; p < 0.05) and Firmicutes (79.33 % and 74.24 % at 20 and 40 mg/kg doses; p < 0.05) and decreasing the phyla Bacteroidetes (5.98-12.47 % at 10-40 mg/kg doses; p < 0.05) and Verrucomicrobia (2.21 % and 2.78 % at 20 and 40 mg/kg doses; p < 0.05), suggesting that SM administration is effective in ameliorating constipation by controlling gut microbial communities. These findings can be utilized as fundamental data for developing novel functional materials using SM to prevent or treat constipation.

Lactiplantibacillus plantarum fermentation enhanced the protective effect of kiwifruit on intestinal injury in rats: Based on mitochondrial morphology and function

Fermented foods have protective effects on body health. In our previously study, we found Lactiplantibacillus plantarum fermentation enhanced antioxidant activity of kiwifruit in vitro digestion. Then, in this work we explored the protective effect of fermented kiwi on intestinal injury induced by acute lipopolysaccharide (LPS) stress. Compared to non-fermented kiwi pulp (KP), Lactiplantibacillus plantarum fermented kiwi pulp (FKP-LP) contained more peptides, hormones and vitamins contents, lesser nucleic acid and carbohydrate contents. FKP-LP could relieve the intestinal injury by improving morphological of tight junction and upregulating tight junction proteins mRNA expression. Fermented kiwi maintained the mitochondrial morphology, mitochondrial respiratory function, and mitochondrial homeostasis, and relieved the LPS induced injury by regulating the contents of energy substances, and the respiratory chain complex enzyme activity through the pathway of AMPK and its downstream factors including PGC-1α, NRF1, NRF2, TFAM, and ULK2.

Effect of ultrasound-guided lumbar square muscle block on stress response in patients undergoing radical gastric cancer surgery

BACKGROUND

Radical surgery is a common treatment for patients with gastric cancer; however, it can lead to postoperative complications and intestinal barrier dysfunction. Ultrasound-guided quadratus lumborum block is often used for postoperative analgesia, but its effects on stress response and intestinal barrier function are not well understood.

AIM

To investigate the effects of an ultrasound-guided quadratus lumborum block on stress response and intestinal barrier function in patients undergoing radical surgery for gastric cancer.

METHODS

A total of 100 patients undergoing radical surgery for gastric cancer were randomly categorized into observation and control groups. Plasma adrenaline and cortisol levels, intestinal mucosal barrier indexes, and complication rates were compared between the two groups before, during, and 1 day after surgery.

RESULTS

The observation group had significantly lower plasma adrenaline and cortisol levels during surgery and at 1 day postoperatively than that of the control group (P < 0.05). Additionally, intestinal barrier indexes (endotoxin and D-dimer) at 1 day postoperatively were significantly lower in the observation group than in the control group (P < 0.05).

CONCLUSION

Ultrasound-guided quadratus lumborum block could reduce stress response, protect intestinal barrier function, and decrease the incidence of complications in patients undergoing radical surgery for gastric cancer. This technique has the potential for clinical applications.

Dietary pectin attenuates Salmonella typhimurium-induced colitis by modulating the TLR2-NF-κB pathway and intestinal microbiota in mice

The role of dietary pectin on microbial-induced colitis, oxidative status, barrier function, and microbial composition, as well as the underlying mechanisms, is scarce. In this study, we aimed to investigate whether dietary pectin alleviates Salmonella typhimurium-induced colitis in mice. Male C57BL/6J mice fed an isocaloric and isofibrous diet with 7% pectin or cellulose were administered sterile water or Salmonella typhimurium to induce colitis, which is equal to a human food dose of 0.57% (5.68 g/kg). Dietary pectin alleviated Salmonella typhimurium-induced colitis and oxidative stress as shown by the reduced disease activity index score, decreased colon shortening and histological damage score, colonic hydrogen peroxide, malondialdehyde concentrations, and relative mRNA expressions of coenzyme Q-binding protein COQ10 homologue B (Coq10b), Ccl-2, Ccl-3, Ccl-8, Tnf-α, Il-1β, Ifn-γ, Ifn-β, and serum TNF-α protein level. Moreover, pectin administration ameliorated the downregulated colonic abundances of occludin, zonula occludens-1, zonula occludens-2, and the upregulated abundances of TLR2 and p-NF-κB in Salmonella-infected mice. Additionally, 16S rRNA analysis demonstrated that pectin altered the microbial beta-diversity and reduced Salmonella levels. Collectively, pectin ameliorated Salmonella typhimurium-induced colitis, oxidative stress, and tight junction, which may be related to the inactivation of TLR2-NF-κB signalling and reduced abundance of Salmonella.

New insights into the unfolded protein response (UPR)-anterior gradient 2 (AGR2) pathway in the regulation of intestinal barrier function in weaned piglets

Sustained dysfunction of the intestinal barrier caused by early weaning is a major factor that induces postweaning diarrhea in weaned piglets. In both healthy and diseased states, the intestinal barrier is regulated by goblet cells. Alterations in the characteristics of goblet cells are linked to intestinal barrier dysfunction and inflammatory conditions during pathogenic infections. In this review, we summarize the current understanding of the mechanisms of the unfolded protein response (UPR) and anterior gradient 2 (AGR2) in maintaining intestinal barrier function and how modifications to these systems affect mucus barrier characteristics and goblet cell dysregulation. We highlight a novel mechanism underlying the UPR-AGR2 pathway, which affects goblet cell differentiation and maturation and the synthesis and secretion of mucin by regulating epidermal growth factor receptor and mucin 2. This study provides a theoretical basis and new insights into the regulation of intestinal health in weaned piglets.

Gut microbiota in pre-clinical rheumatoid arthritis: From pathogenesis to preventing progression

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by progressive polyarthritis that leads to cartilage and bone damage. Pre-clinical RA is a prolonged state before clinical arthritis and RA develop, in which autoantibodies (antibodies against citrullinated proteins, rheumatoid factors) can be present due to the breakdown of immunologic self-tolerance. As early treatment initiation before the onset of polyarthritis may achieve sustained remission, optimize clinical outcomes, and even prevent RA progression, the pre-clinical RA stage is showing the prospect to be the window of opportunity for RA treatment. Growing evidence has shown the role of the gut microbiota in inducing systemic inflammation and polyarthritis via multiple mechanisms, which may involve molecular mimicry, impaired intestinal barrier function, gut microbiota-derived metabolites mediated immune regulation, modulation of the gut microbiota's effect on immune cells, intestinal epithelial cells autophagy, and the interaction between the microbiome and human leukocyte antigen alleles as well as microRNAs. Since gut microbiota alterations in pre-clinical RA have been reported, potential therapies for modifying the gut microbiota in pre-clinical RA, including natural products, antibiotic therapy, fecal microbiota transplantation, probiotics, microRNAs therapy, vitamin D supplementation, autophagy inducer-based treatment, prebiotics, and diet, holds great promise for the successful treatment and even prevention of RA via altering ongoing inflammation. In this review, we summarized current studies that include pathogenesis of gut microbiota in RA progression and promising therapeutic strategies to provide novel ideas for the management of pre-clinical RA and possibly preventing arthritis progression.

Da-Cheng-Qi decoction improves severe acute pancreatitis-associated acute lung injury by interfering with intestinal lymphatic pathway and reducing HMGB1-induced inflammatory response in rats

CONTEXT

Da-Cheng-Qi Decoction (DCQD) has a significant effect on Severe Acute Pancreatitis-Associated Acute Lung Injury (SAP-ALI).

OBJECTIVE

To explore the mechanism of DCQD in the treatment of SAP-ALI based on intestinal barrier function and intestinal lymphatic pathway.

MATERIALS AND METHODS

Forty-five Sprague-Dawley rats were divided into three groups: sham operation, model, and DCQD. The SAP model was induced by a retrograde infusion of 5.0% sodium taurocholate solution (1 mg/kg) at a constant rate of 12 mL/h using an infusion pump into the bile-pancreatic duct. Sham operation and model group were given 0.9% normal saline, while DCQD group was given DCQD (5.99 g/kg/d) by gavage 1 h before operation and 1, 11 and 23 h after operation. The levels of HMGB1, RAGE, TNF-α, IL-6, ICAM-1, d-LA, DAO in blood and MPO in lung were detected using ELISA. The expression of HMGB1, RAGE, NF-κB p65 in mesenteric lymph nodes and lung were determined.

RESULTS

Compared with SAP group, DCQD significantly reduced the histopathological scoring of pancreatic tissue (SAP, 2.80 ± 0.42; DCQD, 2.58 ± 0.52), intestine (SAP, 3.30 ± 0.68; DCQD, 2.50 ± 0.80) and lung (SAP, 3.30 ± 0.68; DCQD, 2.42 ± 0.52). DCQD reduced serum HMGB1 level (SAP, 134.09 ± 19.79; DCQD, 88.05 ± 9.19), RAGE level (SAP, 5.05 ± 1.44; DCQD, 2.13 ± 0.54). WB and RT-PCR showed HMGB1-RAGE pathway was inhibited by DCQD (p < 0.01).

DISCUSSION AND CONCLUSIONS

DCQD improves SAP-ALI in rats by interfering with intestinal lymphatic pathway and reducing HMGB1-induced inflammatory response.

PE (0:0/14:0), an endogenous metabolite of the gut microbiota, exerts protective effects against sepsis-induced intestinal injury by modulating the AHR/CYP1A1 pathway

Sepsis is known to cause damage to the intestinal mucosa, leading to bacterial translocation, and exacerbation of both local and remote organ impairments. In the present study, fecal samples were collected from both septic and healthy individuals. Analysis through 16s rRNA sequencing of the fecal microbiota revealed that sepsis disrupts the balance of the gut microbial community. Recent research has highlighted the association of lipid metabolism with disease. By analyzing the fecal metabolome, four lipid metabolites that showed significant differences between the two groups were identified: PE (O-16:0/0:0), PE (17:0/0:0), PE (0:0/14:0), and PE (12:0/20:5 (5Z, 8Z, 11Z, 14Z, 17Z)). Notably, the serum levels of PE (0:0/14:0) were higher in the healthy group. Subsequent in vitro and in vivo experiments demonstrated the protective effects of this compound against sepsis-induced intestinal barrier damage. Label-free proteomic analysis showed significant differences in the expression levels of the aryl hydrocarbon receptor (AHR), a protein implicated in sepsis pathogenesis, between the LPS-Caco-2 and LPS-Caco-2 + PE (0:0/14:0) groups. Further analysis, with the help of Discovery Studio 3.5 software and co-immunoprecipitation assays, confirmed the direct interaction between AHR and PE (0:0/14:0). In the cecal ligation and puncture (CLP) model, treatment with PE (0:0 /14:0) was found to up-regulate the expression of tight junction proteins through the AHR/Cytochrome P450, family 1, subfamily A, and polypeptide 1 (CYP1A1) pathway. This highlights the potential therapeutic use of PE (0:0/14:0) in addressing sepsis-induced intestinal barrier damage.

Perinatal foodborne titanium dioxide exposure-mediated dysbiosis predisposes mice to develop colitis through life

BACKGROUND

Perinatal exposure to titanium dioxide (TiO2), as a foodborne particle, may influence the intestinal barrier function and the susceptibility to develop inflammatory bowel disease (IBD) later in life. Here, we investigate the impact of perinatal foodborne TiO2 exposure on the intestinal mucosal function and the susceptibility to develop IBD-associated colitis. Pregnant and lactating mother mice were exposed to TiO2 until pups weaning and the gut microbiota and intestinal barrier function of their offspring was assessed at day 30 post-birth (weaning) and at adult age (50 days). Epigenetic marks was studied by DNA methylation profile measuring the level of 5-methyl-2'-deoxycytosine (5-Me-dC) in DNA from colic epithelial cells. The susceptibility to develop IBD has been monitored using dextran-sulfate sodium (DSS)-induced colitis model. Germ-free mice were used to define whether microbial transfer influence the mucosal homeostasis and subsequent exacerbation of DSS-induced colitis.

RESULTS

In pregnant and lactating mice, foodborne TiO2 was able to translocate across the host barriers including gut, placenta and mammary gland to reach embryos and pups, respectively. This passage modified the chemical element composition of foetus, and spleen and liver of mothers and their offspring. We showed that perinatal exposure to TiO2 early in life alters the gut microbiota composition, increases the intestinal epithelial permeability and enhances the colonic cytokines and myosin light chain kinase expression. Moreover, perinatal exposure to TiO2 also modifies the abilities of intestinal stem cells to survive, grow and generate a functional epithelium. Maternal TiO2 exposure increases the susceptibility of offspring mice to develop severe DSS-induced colitis later in life. Finally, transfer of TiO2-induced microbiota dysbiosis to pregnant germ-free mice affects the homeostasis of the intestinal mucosal barrier early in life and confers an increased susceptibility to develop colitis in adult offspring.

CONCLUSIONS

Our findings indicate that foodborne TiO2 consumption during the perinatal period has negative long-lasting consequences on the development of the intestinal mucosal barrier toward higher colitis susceptibility. This demonstrates to which extent environmental factors influence the microbial-host interplay and impact the long-term mucosal homeostasis.

Microbial influence on triggering and treatment of host cancer: An intestinal barrier perspective

Inflammatory bowel disease (IBD) is associated with complex complications that may lead to tumors. However, research on the mechanisms underlying susceptibility to chronic immune diseases and cancer pathogenesis triggered by the inflammatory environment remains limited. An imbalance in the host gut microbiota often accompanies intestinal inflammation. The delayed recovery of the dysregulated intestinal microbiota may exacerbate systemic inflammatory responses, multiorgan pathology, and metabolic disorders. This delay may also facilitate bacterial translocation. This review examined the relationship between gut barrier disruption and unbalanced microbial translocation and their impact on the brain, liver, and lungs. We also explored their potential roles in tumor initiation. Notably, the role of the intestinal microbiota in the development of inflammation is linked to the immune surveillance function of the small intestine and the repair status of the intestinal barrier. Moreover, adherence to a partially anti-inflammatory diet can aid in preventing the malignant transformation of inflammation by repairing the intestinal barrier and significantly reducing inflammation. In conclusion, enhancing intestinal barrier function may be a novel strategy for preventing and treating chronic malignancies in the intestine and other body areas.

Analgesic effect of ultrasound-guided bilateral transversus abdominis plane block in laparoscopic gastric cancer

BACKGROUND

Postoperative complications are important factors affecting the survival time and quality of life of patients undergoing radical gastrectomy.

AIM

To investigate and compare the anesthetic effects of intravenous general anesthesia combined with epidural anesthesia or ultrasound-guided bilateral transversus abdominal plane block (TAPB) in gastric cancer patients undergoing laparoscopic radical gastrectomy.

METHODS

The clinical data of 85 patients who underwent laparoscopic radical gastrectomy in our hospital from December 2020 to January 2023 were retrospectively collected and divided into a TAPB group (n = 45) and epidural anesthesia group (n = 40) according to the different anesthesia and analgesia programs used. The TAPB group received general anesthesia combined with TAPB, and the epidural anesthesia group received general anesthesia combined with epidural anesthesia. The pain status, cognitive status, intestinal barrier indicators, recovery quality, and incidence of complications were compared between the two groups.

RESULTS

Compared with the epidural anesthesia group, the TAPB group's visual analog scale scores were significantly lower 6 h, 12 h, 24 h and 48 h after surgery (P < 0.05). The incidence of postoperative cognitive dysfunction (POCD) in the TAPB group was significantly lower than that in the epidural anesthesia group, and the Mini-mental State Examination score 24 h after surgery was significantly higher in the TAPB group than the epidural anesthesia group (P < 0.05). The levels of diamine oxidase and plasma D-lactate were significantly lower in the TAPB group than the epidural anesthesia group 24 h after surgery (P < 0.05). The agitation score and the incidence of agitation during recovery were significantly lower in the TAPB group than epidural anesthesia group (P < 0.05). The total incidence of postoperative complications in the TAPB group was 4.44%, significantly lower than the 20.00% in the epidural anesthesia group (P < 0.05).

CONCLUSION

Compared with epidural anesthesia combined with general anesthesia, TAPB combined with general anesthesia had a good analgesic effect in laparoscopic radical gastrectomy and can further reduce the incidence of POCD and postoperative complications, improve the levels of intestinal barrier indicators, and improve postoperative recovery quality.

Effects of Enteromorpha prolifera polysaccharides on growth performance, intestinal barrier function and cecal microbiota in yellow-feathered broilers under heat stress

BACKGROUND

Global warming leading to heat stress (HS) is becoming a major challenge for broiler production. This study aimed to explore the protective effects of seaweed (Enteromorpha prolifera) polysaccharides (EPS) on the intestinal barrier function, microbial ecology, and performance of broilers under HS. A total of 144 yellow-feathered broilers (male, 56 days old) with 682.59 ± 7.38 g were randomly assigned to 3 groups: 1) TN (thermal neutral zone, 23.6 ± 1.8 °C), 2) HS (heat stress, 33.2 ± 1.5 °C for 10 h/d), and 3) HSE (HS + 0.1% EPS). Each group contained 6 replicates with 8 broilers per replicate. The study was conducted for 4 weeks; feed intake and body weights were measured at the end of weeks 2 and 4. At the end of the feeding trial, small intestine samples were collected for histomorphology, antioxidant, secretory immunoglobulin A (sIgA) content, apoptosis, gene and protein expression analysis; cecal contents were also collected for microbiota analysis based on 16S rDNA sequencing.

RESULTS

Dietary EPS promoted the average daily gain (ADG) of broilers during 3-4 weeks of HS (P < 0.05). At the end of HS on broilers, the activity of total superoxide dismutase (T-SOD), glutathione S-transferase (GST), and the content of sIgA in jejunum were improved by EPS supplementation (P < 0.05). Besides, dietary EPS reduced the epithelial cell apoptosis of jejunum and ileum in heat-stressed broilers (P < 0.05). Addition of EPS in HS group broilers' diet upregulated the relative mRNA expression of Occludin, ZO-1, γ-GCLc and IL-10 of the jejunum (P < 0.05), whereas downregulated the relative mRNA expression of NF-κB p65, TNF-α and IL-1β of the jejunum (P < 0.05). Dietary EPS increased the protein expression of Occludin and ZO-1, whereas it reduced the protein expression of NF-κB p65 and MLCK (P < 0.01) and tended to decrease the protein expression of TNF-α (P = 0.094) in heat-stressed broilers. Furthermore, the proportions of Bacteroides and Oscillospira among the three groups were positively associated with jejunal apoptosis and pro-inflammatory cytokine expression (P < 0.05) and negatively correlated with jejunal Occludin level (P < 0.05). However, the proportions of Lactobacillus, Barnesiella, Subdoligranulum, Megasphaera, Collinsella, and Blautia among the three groups were positively related to ADG (P < 0.05).

CONCLUSIONS

EPS can be used as a feed additive in yellow-feathered broilers. It effectively improves growth performance and alleviates HS-induced intestinal injury by relieving inflammatory damage and improving the tight junction proteins expression. These beneficial effects may be related to inhibiting NF-κB/MLCK signaling pathway activation and regulation of cecal microbiota.

Acute chlorothalonil exposure had the potential to influence the intestinal barrier function and micro-environment in mice

The intestinal barrier maintains intestinal homeostasis and metabolism and protects against harmful pollutants. Some environmental pollutants seriously affect intestinal barrier function. However, it remains unclear whether or how chlorothalonil (CTL) impacts the intestinal barrier function in animals. Herein, 6-week-old male mice were acutely exposed to different CTL concentrations (100 and 300 mg/kg BW) via intragastric administration once a day for 7 days. Histopathological examination revealed obvious inflammation in the mice' colon and ileum. Most notably, CTL exposure increased the intestinal permeability, particularly in the CTL-300 group. CTL exposure reduced the secretion of colonic epithelial mucus and changed the transcription levels of genes bound up with ion transport and ileal antimicrobial peptide (AMP) secretion, indicating intestinal chemical barrier damage. The results of terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay and Ki67 staining revealed abnormal apoptosis and increased intestinal epithelial cell proliferation, suggesting that CTL exposure led to cytotoxicity and inflammation. The results of 16S rRNA sequencing revealed that CTL exposure altered the intestinal microbiota composition and reduced its diversity and richness in the colon contents. Thus, acute CTL exposure affected the different intestinal barrier- and gut microenvironment-related endpoints in mice.

High glucose exposure drives intestinal barrier dysfunction by altering its morphological, structural and functional properties

High dietary glucose consumption and hyperglycemia can result in chronic complications. Several studies suggest that high glucose (HG) induces dysfunction of the intestinal barrier. However, the precise changes remain unclear. In our study, we used in vitro models composed of Caco-2 and/or HT29-MTX cells in both monoculture and co-culture to assess the effects of long-term HG exposure on the morphological, structural, and functional properties of the intestinal barrier. Cells were grown in medium containing normal physiologic glucose (NG, 5.5 mM) or a clinically relevant HG (25 mM) concentration until 21 days. Results demonstrated that HG induced morphological changes, with the layers appearing denser and less organized than under physiological conditions, which is in accordance with the increased migration capacity of Caco-2 cells and proliferation properties of HT29-MTX cells. Although we mostly observed a small decrease in mRNA and protein expressions of three junction proteins (ZO-1, OCLN and E-cad) in both Caco-2 and HT29-MTX cells cultured in HG medium, confocal microscopy showed that HG induced a remarkable reduction in their immunofluorescence intensity, triggering disruption of their associated structural network. In addition, we highlighted that HG affected different functionalities (permeability, mucus production and alkaline phosphatase activity) of monolayers with Caco-2 and HT29-MTX cells. Interestingly, these alterations were stronger in co-culture than in monoculture, suggesting a cross-relationship between enterocytes and goblet cells. Controlling hyperglycemia remains a major therapeutical method for reducing damage to the intestinal barrier and improving therapies.

Poria cocos polysaccharide improves intestinal barrier function and maintains intestinal homeostasis in mice

The function of the intestinal tract is critical to human health. Poria cocos is a widely used functional edible fungus in Asia and has been reported to modulate gastrointestinal function. However, the effects of polysaccharides, the main active constituents of Poria cocos, on the intestinal tract remains unclear and is the focus of the study. Poria cocos polysaccharides (PCP) were extracted, characterized, and administered to mice by gavage. The results show that PCP used in this study has a typical polysaccharide peak with a molecular weight of 11.583 kDa and is composed primarily of mannose, D-glucosamine hydrochloride, glucose, galactose, and fucose with a molar ratio of 15.308: 0.967: 28.723: 31.631: 23.371. The methylation results suggest that the PCP backbone may be t-Gal(p), 6-Gal(p) and 2,6-Gal(p). The effects of PCP on the mucosal barrier function of the mouse intestine (duodenum, jejunum, and ileum) were examined in terms of intestinal physiological status, physical barrier, biochemical barrier, immune barrier, and microbial barrier. The results showed that PCP significantly improved the physiological state of mouse intestine. Moreover, PCP strengthened the intestinal physical barrier by upregulating the expression of intestinal Occludin and ZO-1 and downregulating the levels of serum endotoxin, DAO, D-lactate, and intestinal MPO. Regarding biochemical barrier, PCP could upregulate the expression of MUC2, β-defensin, and SIgA in intestinal tissues. In addition, PCP modulated the immune barrier by increasing IL-2, IL-4, IL-6, IL-10, TGF-β, and IFN-γ expression. Besides, PCP increased the level of SCFAs in small intestinal contents. PCP modulates intestinal barrier function by altering the microbial composition of the gut. We also found that PCP could maintain intestinal barrier function by increasing the expression of Wnt/β-Catenin and Lrp5 proteins. Generally, our findings suggested that PCP may be used as a functional food to regulate intestinal mucosal function, thereby enhancing the health of the intestinal and host.

A novel small molecule effectively ameliorates estrogen deficiency-induced osteoporosis by targeting the gut-bone signaling axis

Postmenopausal osteoporosis stems mainly from estrogen deficiency leading to a gut microbiome-dependent disruption of host systemic immunity. However, the underlying mechanisms of estrogen deficiency-induced bone loss remain elusive and novel pharmaceutical intervention strategies for osteoporosis are needed. Here we reveal that ovariectomy (ovx)-induced estrogen deficiency in C57BL/6 mice causes significant disruption of gut microbiota composition, consequently leading to marked destruction of intestinal barrier function and gut leakage. As a result, signals transportation between intestinal microbiota and T cells from the gut to bone marrow is identified to contribute to osteoclastogenesis in ovx mice. Notably, we show that icariside I (GH01), a novel small molecule naturally occurring in Herbal Epimedium, has potential to alleviate or prevent ovx-induced bone loss in mice through regulation of gut-bone signaling axis. We find that GH01 treatment can effectively restore the gut microbiota composition, intestinal barrier function and host immune status markedly altered in ovx mice, thus significantly ameliorating bone loss and osteoporosis. These findings not only provide systematic understanding of the gut-immunity-bone axis-associated pathophysiology of osteoporosis, but also demonstrate the high potential of GH01 for osteoporosis treatment by targeting the gut-bone signaling axis.

Omentin-1 ameliorates experimental inflammatory bowel disease via Nrf2 activation and redox regulation

AIMS

Omentin-1 production is decreased in patients with IBD. However, the specific role of Omentin-1 in IBD has not been fully elucidated. This study aimed to investigate the expression and role of Omentin-1 in IBD and the potential mechanisms.

MAIN METHODS

We collected human serum and colon biopsy samples at the Wuhan Union Hospital. Omentin-1 recombinant protein was injected intraperitoneally in a DSS-induced experimental IBD mouse model. Omentin-1 levels were measured in IBD patients, colitis mice, and LPS-induced HT-29 cells. Omentin-1 and/or a Nrf2 specific inhibitor (ML385) were administered to DSS mice and LPS-induced HT-29 cells. The effects of Omentin-1 on inflammation, intestinal barrier function, Nrf2 pathway, oxidative stress, and NF-κB signaling were detected in vivo and in vitro.

KEY FINDINGS

Serum Omentin-1 levels were significantly reduced in UC and CD patients compared with controls (173.7 (IQR, 120.1-221.2) ng/ml, 80.8 (43.8-151.8) ng/ml, and 270.7 (220.7-306.5) ng/ml, respectively). The levels of Omentin-1 were also significantly lower in colitis mice and LPS-induced HT-29 cells. Omentin-1 treatment effectively ameliorated inflammation and impaired intestinal barrier, decreased ROS and MDA levels, and increased GSH and SOD production in the DSS-induced colitis mice and LPS-induced HT-29 cells. Mechanically, Omentin-1 repaired the intestinal barrier by activating Nrf2, then improving oxidative stress and inhibiting NF-κB signaling. Furthermore, the interaction between Omentin-1 and Nrf2 was identified.

SIGNIFICANCE

Omentin-1 activates the Nrf2 pathway to regulate redox balance, ultimately protecting intestinal barrier function and reducing intestinal inflammation. In general, Omentin-1 can be used as a promising therapeutic target for IBD.

1,8-cineole ameliorates colon injury by downregulating macrophage M1 polarization via inhibiting the HSP90-NLRP3-SGT1 complex

Ulcerative colitis (UC) is characterized by chronic relapsing intestinal inflammation. Currently, there is no effective treatment for the disease. According to our preliminary data, 1,8-cineole, which is the main active compound of Amomum compactum Sol. ex Maton volatile oil and an effective drug for the treatment of pneumonia, showed remarkable anti-inflammatory effects on colitis pathogenesis. However, its mechanism of action and direct targets remain unclear. This study investigated the direct targets and mechanism through which 1,8-cineole exerts its anti-inflammatory effects using a dextran sulfate sodium salt-induced colitis mouse model. The effects of 1,8-cineole on macrophage polarization were investigated using activated bone marrow-derived macrophages and RAW264.7 cells. In addition, 1,8-cineole targets were revealed by drug affinity responsive target stability, thermal shift assay, cellular thermal shift assay, and heat shock protein 90 (HSP90) adenosine triphosphatases (ATPase) activity assays. The results showed that 1,8-cineole exhibited powerful anti-inflammatory properties in vitro and in vivo by inhibiting the macrophage M1 polarization and protecting intestinal barrier function. Mechanistically, 1,8-cineole directly interacted with HSP90 and decreased its ATPase activity, also inhibited nucleotide-binding and oligomerization domain-, leucine rich repeat-, and pyrin domain-containing 3 (NLRP3) binding to HSP90 and suppressor of G-two allele of SKP1 (SGT1) and suppressed NLRP3 inflammasome activation in macrophages. These results demonstrated that 1,8-cineole is a potential drug candidate for UC treatment.

Dietary emodin alleviates lipopolysaccharide-induced intestinal mucosal barrier injury by regulating gut microbiota in piglets

This study was to determine the effects of dietary emodin (ED) on the intestinal mucosal barrier, nuclear factor kappa-B (NF-κB) pathways, and gut microbial flora in lipopolysaccharide (LPS)-induced piglets. Twenty-four weaned piglets were chosen and 4 treatments were created by randomly distributing piglets into CON, ED, LPS, and ED_LPS groups. Experiments were done in a 2 × 2 factorial arrangement and maintained for 21 d. Dietary treatment (a basal diet or 300 mg/kg ED) and immunological challenge (LPS or sterile saline) were 2 major factors. Intraperitoneal injections of LPS or sterilized saline were given to piglets on d 21. Six hours after the LPS challenge, all piglets were euthanized for sample collection and analysis. The results showed that piglets of the ED_LPS group had higher (P < 0.05) villus height to crypt depth ratio (VCR), and lower (P < 0.05) plasma D-lactate and diamine oxidase (DAO) than the LPS group. Furthermore, ED inhibited (P < 0.05) the decrease of glutathione peroxidase (GSH-Px) and catalase (CAT) activities and increase of malonaldehyde level (P < 0.05) in jejunal mucosa induced by LPS. The mRNA levels of pro-inflammatory cytokine genes (IL-6, IL-1β, and TNF-α) were significantly reduced (P < 0.05), and the mRNA levels of antioxidant enzyme genes (GPX-1, SOD2 and CAT), as well as protein and mRNA levels of tight junction proteins (occludin, claudin-1, and ZO-1), were also significantly increased (P < 0.05) by ED addition in LPS-induced piglets. Meanwhile, ED supplementation significantly decreased the LPS-induced protein levels of cyclooxygenase-2 and phosphorylation levels of NF-κB p65 and IκBα in jejunal mucosa. Emodin had a significant effect on the composition of gut microbial flora at various taxonomic positions as indicated by 16S RNA sequencing. The acetic acid, isobutyric acid, valeric acid, and isovaleric acid concentrations in the cecum were also increased by ED addition in pigs (P < 0.05). Furthermore, the correlation analysis revealed that some intestinal microbiota had a potential relationship with jejunal VCR, plasma D-lactate and DAO, jejunal mucosa GSH-Px and CAT activity, and cecal short-chain fatty acid concentration. These data suggest that ED is effective in alleviating LPS-induced intestinal mucosal barrier injury by modulating gut microbiota in piglets.

Arula-7 powder improves diarrhea and intestinal epithelial tight junction function associated with its regulation of intestinal flora in calves infected with pathogenic Escherichia coli O1

BACKGROUND

The effects of Arula-7 powder (ASP) on diarrhea and intestinal barrier function associated with its regulation of intestinal microflora in calves infected with pathogenic Escherichia coli O1 (E. coli O1) were studied.

METHOD

Twenty Holstein calves were randomly divided into four treatment groups: normal control (NC), model control (MC), 0.5 mg/kg ciprofloxacin (CIP) and 2.50 g/kg ASP groups.

RESULTS

ASP inhibited the relative abundance of Proteobacteria, Selenomonadales, and Enterobacteriales, and increased the relative abundance of Lactobacillus, Faecalibacterium, and Alloprevotella. Moreover, we demonstrated for the first time that the ASP and CIP promoted weight gain, reduced the diarrhea rate (P < 0.05), and enhanced antioxidant capacity (P < 0.05) due to the increase in average daily gain (ADG), total protein (TP), and albumin (ALB). In addition, ASP and CIP increased the expression of Zunola occludens-1 (ZO-1), Occludin, and Claudin-1 in the ileum (P < 0.05), and improved immunity due to increase levels of interleukin-2 (IL-2), interleukin-4 (IL-4), interferon-γ (IFN-γ), immunoglobulin A (IgA), and immunoglobulin G (IgG) in the serum, strengthened CD4+T levels in the ileal mucosa and reducing CD8+T and CD11c+T (P < 0.05).

CONCLUSION

Hence, The intestinal microbiota environment formed by early intervention of ASP powder has a protective effect on the intestinal mucosal function of calves infected with pathogenic E. coli. Video Abstract.

Selenium nanoparticles alleviate deoxynivalenol-induced intestinal epithelial barrier dysfunction by regulating endoplasmic reticulum stress in IPEC-J2 cells

The intestinal epithelial barrier plays a crucial role in maintaining human and animal health. Deoxynivalenol (DON) is a mycotoxin that contaminates cereal-based foods worldwide, which is a serious threat to human and animal health. This study was aimed to investigate the protective effect of selenium nanoparticles (SeNPs) synthesized by Lactobacillus casei ATCC 393 against DON-induced intestinal epithelial barrier dysfunction and its relationship with PERK-mediated signaling pathway. IPEC-J2 cells were randomly assigned to four groups: Con (vehicle), DON (0.6 μg DON/mL, 48 h), SeNPs+DON (8 μg Se/mL, 24 h; 0.6 μg DON/mL, 48 h) and SeNPs (8 μg Se/mL, 24 h). Compared with Con group, the transepithelial electrical resistance (TEER) and the tight junction proteins expression of IPEC-J2 cells exposed to DON was increased and decreased, respectively. In addition, DON exposure led to increased ROS content, decreased antioxidant capacity, structural damage of endoplasmic reticulum (ER), and activation of endoplasmic reticulum stress (ERS)-related protein kinase R-like endoplasmic reticulum kinase (PERK) pathway in IPEC-J2. Compared with SeNPs+DON group, SeNPs alleviated oxidative stress, ER structure damage and PERK pathway activation and the increase of intestinal epithelial permeability of IPEC-J2 cells exposed to DON. PERK agonist (CCT020312) and inhibitor (GSK2656157) treatments were performed to identify the role of PERK signaling pathway in the regulatory effects of SeNPs on DON-induced intestinal epithelial barrier dysfunction. Compared with SeNPs+DON group, PERK agonist increased the expression levels of p-PERK. PERK inhibitor exerted a similar inhibitory effect to SeNPs on the p-PERK expression. In conclusion, SeNPs effectively alleviate DON-induced intestinal epithelial barrier dysfunction in IPEC-J2 cells, which are closely associated with ERS-related PERK signaling pathway. This will provide a potential solution for prevention and control of DON in the aquaculture industry.

Gastrodia elata and parishin ameliorate aging induced 'leaky gut' in mice: Correlation with gut microbiota

BACKGROUND

The aging-induced decrease in intestinal barrier function contributes to many age-related diseases. Studies on preventive measures for "leaky gut" may help improve the quality of life of geriatric patients. The potent anti-aging effect of Gastrodia elata and parishin, which is one of its active ingredients, has been reported previously. However, their effects on the gut remain elusive, and the effect of parishin on mammals has not been studied.

METHODS

We used quantitative RT-PCR, western blotting, immunohistochemical analysis, and 16S rRNA sequencing to investigate the effect of G. elata and parishin on the intestinal barrier function of D-Gal-induced aging mice.

RESULTS

G. elata and parishin prevented the decrease in tight junction protein (TJP) expression and morphological changes, modulated the composition of fecal microbiota to a healthier state, and reversed the translocation of microbial toxins and systemic inflammation. The correlation analyses showed that TJP expression and systemic inflammation were significantly positively or negatively correlated with the composition of fecal microbiota after G. elata and parishin administration. Additionally, TJP expression was also correlated with systemic inflammation. Moreover, G. elata and parishin administration reversed the decreased or increased expression of aging-related biomarkers, such as FOXO3a, SIRT1, CASPASE3 and P21, in the gut.

CONCLUSIONS

These results suggested that G. elata and parishin could prevent gut aging and ameliorate the "leaky gut" of aged mice and that the underlying mechanism is related to the mutual correlations among barrier function, fecal microbiota composition, and inflammation.

Bifidobacterium lactis TY-S01 protects against alcoholic liver injury in mice by regulating intestinal barrier function and gut microbiota

Alcohol-induced liver injury poses a significant threat to human health. Probiotics have been proven to prevent and treat alcohol-induced liver injury. In this study, the preventive effect of Bifidobacterium lactis TY-S01 on alcohol-induced liver injury in mice was investigated. TY-S01 pretreatment effectively protected mice against alcohol-induced liver injury by preserving the levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, triglyceride and high-density lipoprotein-cholesterol in serum and maintaining the levels of the inflammatory cytokines tumor necrosis factor-α, interleukin-6 and interleukin-1β in liver tissue. Additionally, TY-S01 could maintain the endotoxin levels in serum, maintain the mRNA expression levels of zonula occluden-1, occludin, claudin-1 and claudin-3 in the gut, and prevent gut microbiota dysbiosis in mice with alcoholic liver injury. Spearman's correlation analysis revealed that there was a clear correlation among serum indicators, inflammatory cytokines and gut microbiota. In conclusion, TY-S01 attenuates alcohol-induced liver injury by protecting the integrity of the intestinal barrier and maintaining the balance of the gut microbiota.

Ability of lactulose breath test results to accurately identify colorectal polyps through the measurement of small intestine bacterial overgrowth

BACKGROUND

While colorectal polyps are not cancerous, some types of polyps, known as adenomas, can develop into colorectal cancer over time. Polyps can often be found and removed by colonoscopy; however, this is an invasive and expensive test. Thus, there is a need for new methods of screening patients at high risk of developing polyps.

AIM

To identify a potential association between colorectal polyps and small intestine bacteria overgrowth (SIBO) or other relevant factors in a patient cohort with lactulose breath test (LBT) results.

METHODS

A total of 382 patients who had received an LBT were classified into polyp and non-polyp groups that were confirmed by colonoscopy and pathology. SIBO was diagnosed by measuring LBT-derived hydrogen (H) and methane (M) levels according to 2017 North American Consensus recommendations. Logistic regression was used to assess the ability of LBT to predict colorectal polyps. Intestinal barrier function damage (IBFD) was determined by blood assays.

RESULTS

H and M levels revealed that the prevalence of SIBO was significantly higher in the polyp group than in the non-polyp group (41% vs 23%, P < 0.01; 71% vs 59%, P < 0.05, respectively). Within 90 min of lactulose ingestion, the peak H values in the adenomatous and inflammatory/hyperplastic polyp patients were significantly higher than those in the non-polyp group (P < 0.01, and P = 0.03, respectively). In 227 patients with SIBO defined by combining H and M values, the rate of IBFD determined by blood lipopolysaccharide levels was significantly higher among patients with polyps than those without (15% vs 5%, P < 0.05). In regression analysis with age and gender adjustment, colorectal polyps were most accurately predicted with models using M peak values or combined H and M values limited by North American Consensus recommendations for SIBO. These models had a sensitivity of ≥ 0.67, a specificity of ≥ 0.64, and an accuracy of ≥ 0.66.

CONCLUSION

The current study made key associations among colorectal polyps, SIBO, and IBFD and demonstrated that LBT has moderate potential as an alternative noninvasive screening tool for colorectal polyps.

Triclocarban exposure aggravates dextran sulfate sodium-induced colitis by deteriorating the gut barrier function and microbial community in mice

Triclocarban (TCC) is an antibacterial component widely used in personal care products with potential toxicity possessing public health issues. Unfortunately, enterotoxicity mechanisms of TCC exposure remain largely unknown. Using a combination of 16S rRNA gene sequencing, metabolomics, histopathological and biological examinations, this study systematically explored the deteriorating effects of TCC exposure on a dextran sulfate sodium (DSS)-induced colitis mouse model. We found that TCC exposure at different doses significantly aggravated colitis phenotypes including shortened colon length and altered colonic histopathology. Mechanically, TCC exposure further disrupted intestinal barrier function, manifested by significant downregulation of the number of goblet cells, mucus layer thickness and expression of junction proteins (MUC-2, ZO-1, E-cadherin and Occludin). The gut microbiota composition and its metabolites such as short-chain fatty acids (SCFAs) and tryptophan metabolites were also markedly altered in DSS-induced colitis mice. Consequently, TCC exposure markedly exacerbated colonic inflammatory status of DSS-treated mice by activating NF-κB pathway. These findings provided new evidence that TCC could be an environmental hazards for development of IBD or even colon cancer.

Akkermansia muciniphila Protects Against Antibiotic-Associated Diarrhea in Mice

Probiotics are used to prevent antibiotic-associated diarrhea (AAD) via the restoration of the gut microbiota. However, the precise effects of Akkermansia muciniphila (Akk), which is a promising probiotics, on AAD are unknown. Here, AAD models were established via the administration of lincomycin and ampicillin with or without pasteurized Akk or Amuc_1100 treatment. A diffusion test revealed that Akk was susceptible to the majority of the antibiotics, such as ampicillin. These effects were confirmed by the reduced Akk abundance in AAD model mice. Pasteurized Akk or Amuc_1100 significantly decreased the diarrhea status score and colon injury of AAD model mice. Additionally, these treatments significantly decreased the relative abundance of Citrobacter at genus level and reshaped the metabolic function of gut microbiota. Notably, pasteurized Akk or Amuc_1100 significantly changed the serum metabolome of AAD model mice. In addition, pasteurized Akk or Amuc_1100 suppressed intestinal inflammation by upregulating the expression of GPR109A and SLC5A8 and downregulating the expression of TNFα, IFNγ, IL1β, and IL6. Furthermore, they enhanced water and electrolyte absorption by upregulating AQP4, SLC26A3, and NHE3. Pasteurized Akk or Amuc_1100 also restored intestinal barrier function by ameliorating the downregulation of ZO-1, OCLN, CLDN4, and Muc2 in AAD model mice. In summary, optimizing intestinal health with pasteurized Akk or Amuc_1100 may serve as an approach for preventing AAD.

The synbiotic mixture of lactulose and Bacillus coagulans protects intestinal barrier dysfunction and apoptosis in weaned piglets challenged with lipopolysaccharide

BACKGROUND

Lactulose as an effective prebiotic protects intestinal mucosal injury. Bacillus coagulans is widely used in feed additives because of its ability to promote intestinal health. Our previous study suggests that the combination of lactulose and Bacillus coagulans may be a good candidate as alternative for antibiotic growth promoters. However, the in vivo effects of lactulose and Bacillus coagulans on growth and intestinal health under immune challenge in piglets remains unclear. The objective of this study is to explore the protective effects of synbiotic containing lactulose and Bacillus coagulans on the intestinal mucosal injury and barrier dysfunction under immune challenge in weaned piglets.

METHODS

Twenty four weaned piglets were assigned to 4 groups. Piglets in the CON_-saline and LPS_-LPS group were fed the basal diet, while others were fed either with chlortetracycline (CTC) or synbiotic mixture of lactulose and Bacillus coagulans for 32 d before injection of saline or lipopolysaccharide (LPS). Piglets were sacrificed 4 h after LPS injection to collect samples to determine intestinal morphology, integrity and barrier functions as well as relative genes and proteins.

RESULTS

Our data showed that no differences were observed in the growth performance of the four test groups. LPS injection induced higher serum diamine oxidase activities, D-lactic acid levels, and endotoxin status, lower villus height and ratio of villus height to crypt depth, greater mRNA and lower protein expression related tight junction in both jejunum and ileum. In addition, a higher apoptosis index, and protein expression of Bax and caspase-3 were also observed in the LPS challenge group. Interestingly, dietary synbiotic mixture with lactulose and Bacillus coagulans protected against LPS-induced intestinal damage, barrier dysfunction and higher apoptosis as well as CTC.

CONCLUSIONS

Our data suggest that dietary supplementation of synbiotic mixture with lactulose and Bacillus coagulans showed resilience to LPS-induced intestinal morphological damage, barrier dysfunction and aggressive apoptosis in piglets as well as the protective effects of CTC. These results indicate that synbiotic mixture of lactulose and Bacillus coagulans showed beneficial effects on performance and resilience to acute immune stress in weaned piglets.

Shengjiang Xiexin Decoction ameliorates antibiotic-associated diarrhea by altering the gut microbiota and intestinal metabolic homeostasis

BACKGROUND

Antibiotic-associated diarrhea (AAD) has had a significant increase in the last years, with limited available effective therapies. Shengjiang Xiexin Decoction (SXD), a classic traditional Chinese medicine formula for treating diarrhea, is a promising alternative for reducing the incidence of AAD.

PURPOSE

This study aimed to explore the therapeutic effect of SXD on AAD and to investigate its potential therapeutic mechanism by integrated analysis of the gut microbiome and intestinal metabolic profile.

METHODS

16S rRNA sequencing analysis of the gut microbiota and untargeted-metabolomics analysis of feces were performed. The mechanism was further explored by fecal microbiota transplantation (FMT).

RESULTS

SXD could effectively ameliorate AAD symptoms and restore intestinal barrier function. In addition, SXD could significantly improve the diversity of the gut microbiota and accelerate the recovery of the gut microbiota. At the genus level, SXD significantly increased the relative abundance of Bacteroides spp (p < 0.01) and decreased the relative abundance of Escherichia_Shigela spp (p < 0.001). Untargeted metabolomics showed that SXD significantly improved gut microbiota and host metabolic function, particularly bile acid metabolism and amino acid metabolism.

CONCLUSION

This study demonstrated that SXD could extensively modulate the gut microbiota and intestinal metabolic homeostasis to treat AAD.

Amuc attenuates high-fat diet-induced metabolic disorders linked to the regulation of fatty acid metabolism, bile acid metabolism, and the gut microbiota in mice

Amuc_1100 (hereafter called Amuc) is a highly abundant pili-like protein on the outer membrane of Akkermansia muciniphila and has been found to be effective for in anti-obesity, which is probably through the activation of TLR2. However, the precise mechanisms underlying the contributions of TLR2 to obesity resistance remain unknown. Here, TLR2 knockout mice were used to decipher the anti-obesity mechanism of Amuc. Mice exposed to a high-fat diet (HFD) were treated with Amuc (60 μg) every other day for 8 weeks. The results showed that Amuc supplementation decreased mouse body weight and lipid deposition by regulating fatty acid metabolism and reducing bile acid synthesis by activating TGR5 and FXR and strengthening the intestinal barrier function. The ablation of TLR2 partially reversed the positive effect of Amuc on obesity. Furthermore, we revealed that Amuc altered the gut microbiota composition by increasing the relative abundance of Peptostreptococcaceae, Faecalibaculum, Butyricicoccus, and Mucispirillum_schaedleri_ASF457, and decreasing Desulfovibrionaceae, which may serve as a contributor for Amuc to reinforce the intestinal barrier in HFD-induced mice. Therefore, the anti-obesity effect of Amuc was accompanied by the mitigation of gut microbes. These findings provide support for the use of Amuc as a therapy targeting obesity-associated metabolic syndrome.

Bisphenol P exposure in C57BL/6 mice caused gut microbiota dysbiosis and induced intestinal barrier disruption via LPS/TLR4/NF-κB signaling pathway

Despite being one of the most world's widely used and mass-produced compounds, bisphenol A (BPA) has a wide range of toxic effects. Bisphenol P (BPP), an alternative to BPA, has been detected in many foods. The effects of BPP dietary exposure on gut microbiota and the intestinal barrier were unclear. We designed three batches of animal experiments: The first studied mice were exposed to BPP (30 µg/kg BW/day) for nine weeks and found that they gained weight and developed dysbiosis of the gut microbiota. The second, using typical human exposure levels (L, 0.3 µg/kg BW/day BPP) and higher concentrations (M, 30 µg/kg BW/day BPP; H, 3000 µg/kg BW/day BPP), caused gut microbiota dysbiosis in mice, activated the Lipopolysaccharide (LPS) /TLR4/NF-κB signaling pathway, triggered an inflammatory response, increased intestinal permeability, and promoted bacterial translocation leading to intestinal barrier disruption. The third treatment used a combination of antibiotics and alleviated intestinal inflammation and injury. This study demonstrated the mechanism of injury and concentration effects of intestinal damage caused by BPP exposure, providing reference data for BPP use and control and yielding new insights for human disease prevention.

Exosomes derived from EphB2-overexpressing bone marrow mesenchymal stem cells regulate immune balance and repair barrier function

BACKGROUND

Disruption of intestinal barrier function and an imbalance in intestinal immunity are crucial for the occurrence and development of ulcerative colitis. Because of their important roles in regulating inflammation and immunity, exosomes (Exos) released from bone marrow mesenchymal stem cells (BMSCs) may be useful for treating ulcerative colitis. The EphB/EphrinB signaling pathway plays a crucial role in the inflammatory process and the development and function of immune cells, and can mediate long-distance intercellular communication through extracellular vesicles. This study was conducted to explore the effects of pre-modified BMSC-Exos expressing EphB2 (EphB2-Exos) on immunoregulation in vitro.

METHODS

We transfected a lentivirus vector encoding EphB2 into BMSCs and isolated EphB2-Exos from the culture supernatant. Inflammation and oxidative damage in the human colon adenocarcinoma cell line (Caco-2) were induced by dextran sulfate sodium/hydrogen peroxide. In addition, spleen CD4⁺ T lymphocytes of rats were sorted in vitro. We conducted a series of experiments to explore the biological functions of EphB2-Exos.

RESULTS

EphB2-Exos were successfully isolated and were found to significantly protect the activity, proliferation, and migration of Caco-2 cells that were inhibited by dextran sulfate sodium. EphB2-Exos alleviated inflammation and apoptosis and increased the activity of antioxidant enzymes while inhibiting oxidative stress in Caco-2 cells. EphB2-Exos restored intestinal barrier function by inhibiting the RhoA/ROCK pathway and regulated the polarization of CD4⁺T cells.

CONCLUSION

EphB2-Exos enhanced intestinal barrier function and regulated the immune balance by inhibiting the RhoA/ROCK pathway in vitro. These findings suggest that EphB2-Exos can be applied as a cell-free therapy for ulcerative colitis.

Consumption of a multi-deficient diet causes dynamic changes in the intestinal morphofunctional barrier, body composition and impaired physical development in post-weaning mice

Few studies have focused on nutrient-deficient diets and associated pathobiological dynamics of body composition and intestinal barrier function. This study evaluated the impact of a nutrient-deficient diet on physical development and intestinal morphofunctional barrier in mice. C57BL/6 (21 days of age) mice were fed a Northeastern Brazil regional basic diet (RBD) or a control diet for 21 d. The animals were subjected to bioimpedance analysis, lactulose test, morphometric analysis and quantitative reverse transcription-PCR to evaluate tight junctions and intestinal transporters. RBD feeding significantly reduced weight (P < 0·05) from day 5, weight gain from day 3 and tail length from day 14. The intake of RBD reduced total body water, extracellular fluid, fat mass and fat-free mass from day 7 (P < 0·05). RBD induced changes in the jejunum, with an increase in the villus:crypt ratio on day 7, followed by reduction on days 14 and 21 (P < 0·05). Lactulose:mannitol ratio increased on day 14 (P < 0·05). Changes in intestinal barrier function on day 14 were associated with reductions in claudin-1 and occludin, and on day 21, there was a reduction in the levels of claudin-2 and occludin. SGLT-1 levels decreased on day 21. RBD compromises body composition and physical development with dynamic changes in intestinal barrier morphofunctional. RBD is associated with damage to intestinal permeability, reduced levels of claudin-1 and occludin transcripts and return of bowel function in a chronic period.

The high dose of inulin exacerbated food allergy through the excess accumulation of short-chain fatty acids in a BABL/c mouse model

Inulin dietary supplement is conventionally beneficial to gut health and can potentially prevent food allergy (FA). This study aimed to determine how dietary inulin interventions at different doses affect the OVA-induced FA in a BALB/c mouse model. Although the middle dose of inulin (50 mg per mouse) showed the best therapeutic effect on FA, high-inulin supplementation (80 mg per mouse) provoked severe allergic and intestinal inflammatory responses, which were characterized by elevated serum allergic inflammation-related factor levels, dysfunctional gut barrier, unbalanced luminal pH value, decrease in intestinal antioxidant capacity, and disordered gut microecology. Moreover, profiling of SCFAs indicated that the high-inulin-induced excess accumulation of SCFAs in the colon was responsible for the gut immune disorders. Spearman correlation analysis unraveled that the featured bacterial taxa in the high-inulin-treated mice were Ruminococcaceae and Bifidobacterium, of which the relative abundance was negatively correlated with expression of tight junction proteins and improvement of T cell homeostasis, and positively correlated with levels of allergic inflammation-related indexes. Our work suggested that high-inulin dietary supplementation can be detrimental to allergic individuals and highlighted the importance for personalized use of inulin-type dietary supplements to safely improve human health.