Keratin 1 modulates intestinal barrier and immune response via kallikrein kinin system in ulcerative colitis

BACKGROUND External factors in ulcerative colitis(UC)exacerbate colonic epithelial permea-bility and inflammatory responses.Keratin 1(KRT1)is crucial in regulating these alterations,but its specific role in the progression of UC remains to be fully eluci-dated.AIM To explore the role and mechanisms of KRT1 in the regulation of colonic epithelial permeability and inflammation in UC.METHODS A KRT1 antibody concentration gradient test,along with a dextran sulfate sodium(DSS)-induced animal model,was implemented to investigate the role of KRT1 in modulating the activation of the kallikrein kinin system(KKS)and the cleavage of bradykinin(BK)/high molecular weight kininogen(HK)in UC.RESULTS Treatment with KRT1 antibody in Caco-2 cells suppressed cell proliferation,induced apoptosis,reduced HK expression,and increased BK expression.It further downregulated intestinal barrier proteins,including occludin,zonula occludens-1,and claudin,and negatively impacted the coagulation factor XII.These changes led to enhanced activation of BK and HK cleavage,thereby intensifying KKS-mediated inflammation in UC.In the DSS-induced mouse model,administration of KRT1 antibody mitigated colonic injury,increased colon length,alleviated weight loss,and suppressed inflammatory cytokines such as interleukin(IL)-1,IL-6,tumor necrosis factor-α.It also facilitated repair of the intestinal barrier,reducing DSS-induced injury.CONCLUSION KRT1 inhibits BK expression,suppresses inflammatory cytokines,and enhances markers of intestinal barrier function,thus ameliorating colonic damage and maintaining barrier integrity.KRT1 is a viable therapeutic target for UC.

Dietary supplementation of zinc oxide modulates intestinal functionality during the post-weaning period in clinically healthy piglets

Background To improve our understanding of host and intestinal microbiome interaction,this research investigated the effects of a high-level zinc oxide in the diet as model intervention on the intestinal microbiome and small intestinal functionality in clinically healthy post-weaning piglets.In study 1,piglets received either a high concentration of zinc(Zn)as zinc oxide(Zn O,Zn,2,690 mg/kg)or a low Zn concentration(100 mg/kg)in the diet during the post weaning period(d 14–23).The effects on the piglet's small intestinal microbiome and functionality of intestinal tissue were investigated.In study 2,the impact of timing of the dietary zinc intervention was investigated,i.e.,between d 0–14 and/or d 14–23 post weaning,and the consecutive effects on the piglet's intestinal functionality,here referring to microbiota composition and diversity and gene expression profiles.Results Differences in the small intestinal functionality were observed during the post weaning period between piglets receiving a diet with a low or high concentration Zn O content.A shift in the microbiota composition in the small intestine was observed that could be characterized as a non-pathological change,where mainly the commensals inter-changed.In the immediate post weaning period,i.e.,d 0–14,the highest number of differentially expressed genes(DEGs)in intestinal tissue were observed between animals receiving a diet with a low or high concentration Zn O content,i.e.,23 DEGs in jejunal tissue and 11 DEGs in ileal tissue.These genes are involved in biological processes related to immunity and inflammatory responses.For example,genes CD59 and REG3G were downregulated in the animals receiving a diet with a high concentration Zn O content compared to low Zn O content in both jejunum and ileum tissue.In the second study,a similar result was obtained regarding the expression of genes in intestinal tissue related to immune pathways when comparing piglets receiving a diet with a high concentration Zn O content compared to low Zn O content.Conclusions Supplementing a diet with a pharmaceutical level of Zn as Zn O for clinically healthy post weaning piglets influences various aspects intestinal functionality,in particular in the first two weeks post-weaning.The model intervention increased both the alpha diversity of the intestinal microbiome and the expression of a limited number of genes linked to the local immune system in intestinal tissue.The effects do not seem related to a direct antimicrobial effect of Zn O.

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℃),2)HS(heat stress,33.2±1.5℃ 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(s Ig A)content,apoptosis,gene and protein expression analysis;cecal contents were also collected for microbiota analysis based on 16S r DNA 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 s Ig A 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 m RNA expression of Occludin,ZO-1,γ-GCLc and IL-10 of the jejunum(P<0.05),whereas downregulated the relative m RNA expression of NF-κB p65,TNF-αand IL-1βof 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.

Damage on intestinal barrier function and microbial detoxification of deoxynivalenol:A review

Deoxynivalenol(DON)is a mycotoxin that is produced by various species of Fusarium and is ubiquitous in food and feed.At low concentrations,it can cause metabolic disorders in animals and humans and,at high concentrations,it can lead to pathological changes in the body.The impact of DON on human/animal health and animal productivity has thus attracted a great deal of attention around the world.DON causes severe damage to the intestine,including compromised intestinal barrier,mucosal damage,weakened immune function,and alterations in gut microbiota composition.These effects exacerbate intestinal infections and inflammation in livestock and poultry,posing adverse effects on overall health.Furthermore,research into biological methods for DON detoxification is a crucial avenue for future studies.This includes the utilization of adsorption,enzymatic degradation,and other biological approaches to mitigate DON's impact,offering new strategies for prevention and treatment of DON-induced diseases.Future research will focus on identifying highly efficient detoxifying microorganisms or enzymes to reduce DON levels in food and feed,thereby mitigating its risks to both animals and human health.

Umbilical cord mesenchymal stem cell exosomes alleviate necrotizing enterocolitis in neonatal mice by regulating intestinal epithelial cells autophagy

BACKGROUND Necrotizing enterocolitis(NEC)is a severe gastrointestinal disease that affects premature infants.Although mounting evidence supports the therapeutic effect of exosomes on NEC,the underlying mechanisms remain unclear.AIM To investigate the mechanisms underlying the regulation of inflammatory response and intestinal barrier function by umbilical cord mesenchymal stem cell(UCMSCs)exosomes,as well as their potential in alleviating NEC in neonatal mice.METHODS NEC was induced in 5-d-old C57BL/6 pups through hypoxia and gavage feeding of formula containing lipopolysaccharide(LPS),after which the mice received human UCMSC exosomes(hUCMSC-exos).The control mice were allowed to breastfeed with their dams.Ileal tissues were collected from the mice and analyzed by histopathology and immunoblotting.Colon tissues were collected from NEC neonates and analyzed by immunofluorescence.Molecular biology and cell culture approaches were employed to study the related mechanisms in intestinal epithelial cells.RESULTS We found that autophagy is overactivated in intestinal epithelial cells during NEC,resulting in reduced expression of tight junction proteins and an increased inflammatory response.The ability of hUCMSC-exos to ameliorate NEC in a mouse model was dependent on decreased intestinal autophagy.We also showed that hUCMSC-exos alleviate the inflammatory response and increase migration ability in intestinal epithelial cells induced by LPS.CONCLUSION These results contribute to a better understanding of the protective mechanisms of hUCMSC-exos against NEC and provide a new theoretical and experimental foundation for NEC treatment.These findings also enhance our understanding of the role of the autophagy mechanism in NEC,offering potential avenues for identifying new therapeutic targets.

Effects of oral probiotics on inflammation and intestinal function in adult patients after appendectomy:Randomized controlled trial

BACKGROUND Appendectomy is an acute abdominal surgery that is often accompanied by severe abdominal inflammation.Oral probiotics are one of the postoperative treatments for rapid rehabilitation.However,there is a lack of prospective studies on this topic after appendectomy.AIM To investigate whether the postoperative probiotics can modulate the inflammatory response and restore intestinal function in patients following appendectomy.METHODS This was a prospective,randomized trial.A total of 60 emergency patients were randomly divided into a control group(n=30)and a probiotic group(n=30).Patients in the control group started to drink some water the first day after surgery,and those in the probiotic group were given water supplemented with Bacillus licheniformis capsules for 5 consecutive days postsurgery.The indices of inflammation and postoperative conditions were recorded,and the data were analyzed with RStudio 4.3.2 software.RESULTS A total of 60 participants were included.Compared with those in the control group,the C-reactive protein(CRP),interleukin 6 and procalcitonin(PCT)levels were significantly lower in the probiotic group at 2 d after surgery(P=2.224e-05,P=0.037,and P=0.002,respectively,all P<0.05).This trend persisted at day 5 post-surgery,with CRP and PCT levels remaining significantly lower in the probiotic group(P=0.001 and P=0.043,both P<0.05).Furthermore,probiotics0.028,both P<0.05).CONCLUSION Postoperative oral administration of probiotics may modulate the gut microbiota,benefit the recovery of the early inflammatory response,and subsequently enhance recovery after appendectomy.

Jianpi-Huatan-Huoxue-Anshen formula ameliorates gastrointestinal inflammation and microecological imbalance in chemotherapytreated mice transplanted with H22 hepatocellular carcinoma

BACKGROUND Jianpi-Huatan-Huoxue-Anshen formula[Tzu-Chi cancer-antagonizing&lifeprotecting II decoction(TCCL)]is a Chinese medical formula that has been clinically shown to reduce the gastrointestinal side effects of chemotherapy in cancer patients and improve their quality of life.However,its effect and mechanism on the intestinal microecology after chemotherapy are not yet clear.AIM To discover the potential mechanisms of TCCL on gastrointestinal inflammation and microecological imbalance in chemotherapy-treated mice transplanted with hepatocellular carcinoma(HCC).METHODS Ninety-six mice were inoculated subcutaneously with HCC cells.One week later,the mice received a large dose of 5-fluorouracil by intraperitoneal injection to establish a HCC chemotherapy model.Thirty-six mice were randomly selected before administration,and feces,ileal tissue,and ileal contents were collected from each mouse.The remaining mice were randomized into normal saline,continuous chemotherapy,Yangzheng Xiaoji capsulestreated,and three TCCL-treated groups.After treatment,feces,tumors,liver,spleen,thymus,stomach,jejunum,ileum,and colon tissues,and ileal contents were collected.Morphological changes,serum levels of IL-1β,IL-6,IL-8,IL-10,IL-22,TNF-α,and TGF-β,intestinal SIgA,and protein and mRNA expression of ZO-1,NF-κB,Occludin,MUC-2,Claudin-1,and IκB-αin colon tissues were documented.The effect of TCCL on the abundance and diversity of intestinal flora was analyzed using 16S rDNA sequencing.RESULTS TCCL treatment improved thymus and spleen weight,thymus and spleen indexes,and body weight,decreased tumor volumes and tumor tissue cell density,and alleviated injury to gastric,ileal,and colonic mucosal tissues.Among proteins and genes associated with inflammation,IL-10,TGF-β,SIgA,ZO-1,MUC-2,and Occludin were upregulated,whereas NF-κB,IL-1β,IL-6,TNF-α,IL-22,IL-8,and IκB-αwere downregulated.Additionally,TCCL increased the proportions of fecal Actinobacteria,AF12,Adlercreutzia,Clostridium,Coriobacteriaceae,and Paraprevotella in the intermediate stage of treatment,decreased the proportions of Mucipirillum,Odoribacter,RF32,YS2,and Rikenellaceae but increased the proportions of p_Deferribacteres and Lactobacillus at the end of treatment.Studies on ileal mucosal microbiota showed similar findings.Moreover,TCCL improved community richness,evenness,and the diversity of fecal and ileal mucosal flora.CONCLUSION TCCL relieves pathological changes in tumor tissue and chemotherapy-induced gastrointestinal injury,potentially by reducing the release of pro-inflammatory factors to repair the gastrointestinal mucosa,enhancing intestinal barrier function,and maintaining gastrointestinal microecological balance.Hence,TCCL is a very effective adjuvant to chemotherapy.

Application of Saccharomyces boulardii in combination with sulfasalazine in ulcerative colitis patients demonstrates significant effectiveness

BACKGROUND Ulcerative colitis(UC)is a complex inflammatory bowel disease,and its etiology and pathogenesis remain incompletely elucidated.AIM To analyze the effects of Saccharomyces boulardii in combination with sulfasalazine on intestinal microbiota and intestinal barrier function in patients with UC.METHODS A retrospective analysis of clinical data from 127 UC patients admitted to our hospital between January 2021 and January 2023 was conducted.All patients met complete inclusion and exclusion criteria.Based on the treatment interventions received,they were divided into a control group(n=63)and an observation group(n=64).Both groups of patients received routine treatment upon admission.The control group received sulfasalazine in addition to routine interventions,while the observation group received a combination of Saccharomyces boulardii on the basis of the control group’s treatment.The clinical efficacy,improvement in symptoms,modified Baron endoscopic scores,quality of life“inflammatory bowel disease questionnaire(IBDQ)”,levels of intestinal microbial indicators(such as Lactobacillus,Bifidobacterium,Enterococcus,and Escherichia coli),intestinal mucosal barrier function indicators[diamine oxidase(DAO),lipopolysaccharide(LPS),D-lactic acid(D-LA)],and adverse reaction occurrences were compared between the two groups.RESULTS(1)Clinical efficacy:The total effective rate in the control group was 79.37%,while in the observation group,it was 93.75%,significantly higher than that of the control group(P<0.05);(2)Improvement in symptoms:The observation group showed significantly lower relief time for abdominal pain,diarrhea,rectal bleeding,fever symptoms,and mucosal healing time compared to the control group(P<0.05);(3)Baron endoscopic scores and IBDQ scores:Before treatment,there was no significant difference in Baron endoscopic scores and IBDQ scores between the two groups(P>0.05).However,after treatment,the observation group showed significantly lower Baron endoscopic scores and higher IBDQ scores compared to the control group(P<0.05);(4)Levels of intestinal microbial indicators:Before treatment,there was no significant difference in the levels of Lactobacillus,Bifidobacterium,Enterococcus,and Escherichia coli between the two groups(P>0.05).After treatment,the levels of Lactobacillus and Bifidobacterium in the observation group were significantly higher than those in the control group,while the levels of Enterococcus and Escherichia coli were significantly lower than those in the control group(P<0.05);(5)Levels of intestinal mucosal barrier function indicators:Before treatment,there was no significant difference in the levels of DAO,LPS,and D-LA between the two groups(P>0.05).However,after treatment,the levels of DAO,LPS,and D-LA in the observation group were significantly lower than those in the control group(P<0.05);and(6)Occurrence of adverse reactions:The incidence of adverse reactions in the control group was 9.52%,while in the observation group,it was 10.94%.There was no significant difference in the occurrence of adverse reactions between the two groups(P>0.05).CONCLUSION The application of Saccharomyces boulardii in combination with sulfasalazine in UC patients demonstrates significant effectiveness.Compared to sole sulfasalazine intervention,the combined application of Saccharomyces boulardii further promotes the relief of relevant symptoms in patients,alleviates intestinal mucosal inflammation,and improves the quality of life.Its action may be related to rectifying the imbalance in intestinal microbiota and improving intestinal mucosal barrier function.Moreover,the combined use of Saccharomyces boulardii does not increase the risk of adverse reactions in patients,indicating a higher level of medication safety and advocating for its clinical promotion and application.

Gegen Qinlian decoction enhances immunity and protects intestinal barrier function in colorectal cancer patients via gut microbiota

BACKGROUND We previously showed,using the Traditional Chinese Medicine System Pharmacology Database,that Gegen Qinlian decoction(GQD)had a direct antitumor effect,and was combined with programmed cell death protein(PD)-1 inhibitors to treat microsatellite stable(MSS)tumor-bearing mice.However,the effect of GQD on patients with colorectal cancer(CRC)is not clear.AIM To determine the therapeutic mechanism of GQD in improving immune function,reducing inflammation and protecting intestinal barrier function.METHODS Seventy patients with CRC were included in this study:37 in the control group and 33 in the treatment group.The proportions of CD4+T,CD8+T,natural killer(NK),NKT and T regulatory cells were measured by flow cytometry.Levels of the cytokines tumor necrosis factor(TNF)-α,interferon(IFN)-γ,interleukin(IL)-2,IL-6,IL-10 and serotonin(5-hydroxytryptamine;5-HT)in serum were assessed by enzyme-linked immunosorbent assay(ELISA).The expression of zonula occludens(ZO)-1,occludin,nuclear factor(NF)-κB and TNF-αin tumor and normal tissues was measured by immunohistochemistry.The composition of gut microbiota from patients in the treatment group was assessed using 16S rDNA analysis.RESULTS There were no adverse events in the treatment group.The proportion of CD4+T cells and NKT cells in the post-treatment group was significantly higher than that in the pre-treatment and control groups(P<0.05).The level of TNF-αin the posttreatment group was significantly lower than that in the pre-treatment and control groups(P<0.05).The concentration of 5-HT in the post-treatment group was significantly lower than that in the pre-treatment group(P<0.05).The expression of ZO-1 and occludin in tumor tissues in the treatment group was significantly higher than that in the control group(P<0.05).The expression of ZO-1 in normal tissues of the treatment group was significantly higher than that in the control group(P=0.010).Compared with the control group,expression of NF-κB and TNF-αin tumor tissues of the treatment group was significantly decreased(P<0.05).Compared with the pre-treatment group,GQD decreased the relative abundance of Megamonas and Veillonella.In addition,GQD increased the relative abundance of Bacteroides,Akkermansia and Prevotella.CONCLUSION GQD enhances immunity and protects intestinal barrier function in patients with CRC by regulating the composition of gut microbiota.

Glutamine and recombinant human growth hormone protect intestinal barrier function following portal hypertension surgery

AIM： To evaluate the effects of combined treatment of glutamine （Gln） and recombinant human growth hormone（rhGH） on intestinal barrier function following portal hypertension surgery. METHODS： This study was designed as a prospective, randomized and controlled clinical trial. Forty two patients after portal hypertension surgery were randomly assigned into 2 groups： control group （n = 20） and supplemental group （adding Gin and rhGH, n = 22）. Every patient received isocaloric and isonitrogenous standard total parenteral nutrition （TPN） starting 3 d after surgery for 7 d. Blood samples were obtained before surgery and at the 3rd and 10th day postoperatively. Host immunity was evaluated by measuring levels of CD4, CD8, CD4/CD8, IgG, IgM and IgA, and the inflammatory responses were determined by assessing IL-2, TNF-α and C-reactive protein （CRP） levels. Intestinal permeability and integrity was evaluated by L/M test and histological examination, respectively. RESULTS： On postoperative d 10, CD4, CD4/CD8, IgG and IL-2 levels in supplemental group were significantly higher than those in control group （33.7±5.5 vs 31.0 ± 5.4, P 〈 0.05, （1.17±0.32 vs 1.05 ± 0.15, P 〈 0.05, 13.94±1.09 vs 12.33±1.33, P 〈 0.05, and 368.12 ± 59.25 vs 318.12 ± 45.65, P 〈 0.05, respectively）, whereas the increase in serum TNF-α concentration was significantly reduced （41.02 ± 27.56 vs 160.09 ± 35.17, P 〈 0.05）. The increase in L/M ratio was significantly lower in the supplemental group than in the control group （0.0166 ± 0.0017 vs 0.0339 ± 0.0028, P 〈 0.05）. Moreover, mucosal integrity in the supplemental group was better than in the control group.CONCLUSION： Postoperative administration of TPN supplemented with Gin and rhGH in patients after portal hypertension surgery improves immune function, modulates inflammatory response, prevents the intestinal mucous membrane from atrophy and preserves intestinal integrity.

Enteric glial cells and their role in the intestinal epithelial barrier

The intestinal epithelium constitutes a physical and functional barrier between the external environment and the host organism. It is formed by a continuous monolayer of intestinal epithelial cells maintained together by intercellular junctional complex, limiting access of pathogens, toxins and xenobiotics to host tissues. Once this barrier integrity is disrupted, inflammatory disorders and tissue injury are initiated and perpetuated. Beneath the intestinal epithelial cells lies a population of astrocyte-like cells that are known as enteric glia. The morphological characteristics and expression markers of these enteric glia cells were identical to the astrocytes of the central nervous system. In the past few years, enteric glia have been demonstrated to have a trophic and supporting relationship with intestinal epithelial cells. Enteric glia lesions and/or functional defects can be involved in the barrier dysfunction. Besides, factors secreted by enteric glia are important for the regulation of gut barrier function. Moreover, enteric glia have an important impact on epithelial cell transcriptome and induce a shift in epithelial cell phenotype towards increased cell adhesion and cell differentiation.Enteric glia can also preserve epithelial barrier against intestinal bacteria insult. In this review, we will describe the current body of evidence supporting functional roles of enteric glia on intestinal barrier.

Protective effect of probiotics on intestinal barrier function in malnourished rats after liver transplantation

BACKGROUND: Most patients waiting for liver transplantation have end-stage liver diseases with malnutrition, which is prone to induce intestinal barrier dysfunction after liver transplantation. We aimed to study the effect of probiotics on intestinal barrier function in malnourished rats following liver transplantation with long-term antibiotics. METHODS: Twelve Lewis rats were selected as donors. Twelve BN rats, which served as recipients, were subjected to malnutrition by semi-starvation for 4-5 weeks. They were randomly divided into two groups: a control group which received phosphate-buffered saline and a probiotics group which received Bifidobacterium and Lactobacillus. All recipients were injected with intramuscular imipenem and subcutaneous cyclosporine A. Furthermore, six normal BN rats without any drugs or operations served as a normal group. Eight days after operation, all rats were sacrificed for examination of the following parameters: serum levels of endotoxin and TNF-α, bacterial translocation, intestinal microflora, ileocecal sIgA, lymphocyte numbers, and phenotypes (CD4, CD8, αβTCR, γδTCR)ofPeyer’spatches. RESULTS: In recipients subjected to malnutrition, weight decreased by 20% and they survived until 8 days after operation. Compared with the normal group, all recipients on postoperative day 8 showed increased levels of serum endotoxin and TNF-α as well as increased counts oftranslocated bacteria. Meanwhile, there were decreases in counts of Bifidobacterium and Lactobacillus in the ileocecum, sIgA concentration, and lymphocytes of Peyer’s patches. Moreover, partial alteration in lymphocyte phenotypes was evidenced by elevated ratios of CD8 + and γδTCR + lymphocytes. In contrast, compared to the control group, supplementation with probiotics reduced the levels of serum endotoxin, TNF-α and bacterial translocation, increased the counts of Bifidobacterium and Lactobacillus, the concentration of sIgA and lymphocytes of Peyer’s patches, and also slightly restored the alteration of lymphocyte phenotypes. CONCLUSION: Supplementation with probiotics including Bifidobac-terium and Lactobacillus promoted partial restoration of intestinal microflora and improved intestinal barrier function in malnourished rats after liver transplantation with long-term use of antibiotics.

Enteral supplementation with glycyl-glutamine improves intestinal barrier function after liver transplantation in rats

BACKGROUND:Most patients after liver transplantation (LT) suffer from intestinal barrier dysfunction.Glycyl-glutamine (Gly-Gln) by parenteral supplementation is hydrolyzed to release glutamine,which improves intestinal barrier function in intestinal injury.This study aimed to investigate the effect of GlyGln by enteral supplementation on intestinal barrier function in rats after allogenetic LT under immunosuppressive therapy.METHODS:Twelve inbred Lewis rats were selected randomly as donors,and 24 inbred Brown Norway (BN) rats as recipients of allogenetic LT.The recipients were divided into a control group (Ala,n=12) and an experimental group (Gly-Gln,n=12).In each group,6 normal BN rats were sampled for normal parameters on preoperative day 3.The 6 recipients in the control group received alanine (Ala) daily by gastric perfusion for 3 preoperative days and 7 postoperative days,and the 6 recipients in the experimental group were given Gly-Gln in the same manner.The 12 BN recipients underwent orthotopic LT under sterile conditions after a 3-day fast and were given immunosuppressive therapy for 7 days.They were harvested for sampling on postoperative day 8.The following parameters were assessed:intestinal mucosal protein content,mucosal ultrastructure,ileocecal sIgA content,portal plasma levels of endotoxin and TNF-α,and bacterial translocation.RESULTS:All recipients were alive after LT.On preoperative day 3,all parameters were similar in the two groups.On postoperative day 8,all parameters in the two groups were remarkably changed from those on preoperative day 3.However,compared to the Ala group,supplementation withGly-Gln increased the levels of intestinal mucosal protein and ileocecal sIgA,improved mucosal microvilli,and decreased portal plasma levels of endotoxin and TNF-α as well as bacterial translocation.CONCLUSION:Enteral supplementation with Gly-Gln improved intestinal barrier function after allogenetic LT in rats.

Combined probiotic bacteria promotes intestinal epithelial barrier function in interleukin-10-gene-deficient mice

AIM: To investigate the protective effects of combinations of probiotic (Bifico) on interleukin (IL)-10-gene-deficient (IL-10 KO) mice and Caco-2 cell monolayers.

Growth efficiency,intestinal biology,and nutrient utilization and requirements of black soldier fly(Hermetia illucens)larvae compared to monogastric livestock species:a review

In recent years,interest in the larvae of black soldier fly(BSF)(Hermetia illucens)as a sustainable protein resource for livestock feed has increased considerably.However,knowledge on the nutritional and physiological aspects of this insect,especially compared to other conventional farmed animals is scarce.This review presents a critical comparison of data on the growth potential and efficiency of the BSF larvae(BSFL)compared to conventional monogastric livestock species.Advantages of BSFL over other monogastric livestock species includes their high growth rate and their ability to convert low-grade organic waste into high-quality protein and fat-rich biomass suitable for use in animal feed.Calculations using literature data suggest that BSFL are more efficient than broilers,pigs and fish in terms of conversion of substrate protein into body mass,but less efficient than broilers and fish in utilization of substrate gross energy to gain body mass.BSFL growth efficiency varies greatly depending on the nutrient quality of their dietary substrates.This might be associated with the function of their gastrointestinal tract,including the activity of digestive enzymes,the substrate particle characteristics,and their intestinal microbial community.The conceived advantage of BSFL having an environmental footprint better than conventional livestock is only true if BSFL is produced on low-grade organic waste and its protein would directly be used for human consumption.Therefore,their potential role as a new species to better close nutrient cycles in agro-ecological systems needs to be reconsidered,and we conclude that BSFL is a complementary livestock species efficiently utilizing organic waste that cannot be utilized by other livestock.In addition,we provide comparative insight into morpho-functional aspects of the gut,characterization of digestive enzymes,gut microbiota and fiber digestion.Finally,current knowledge on the nutritional utilization and requirements of BSFL in terms of macro-and micronutrients is reviewed and found to be rather limited.In addition,the research methods to determine nutritional requirements of conventional livestock are not applicable for BSFL.Thus,there is a great need for research on the nutrient requirements of BSFL.

Tauroursodeoxycholic acid(TUDCA)improves intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets

Background:Tauroursodeoxycholic acid(TUDCA),a hydrophilic bile acid,is the main medicinal component of bear bile and is commonly used to treat a variety of hepatobiliary diseases.Meanwhile,TUDCA has been shown to modulate the intestinal barrier function and alleviate DSS-induced colitis in mice.However,the effect of TUDCA on the intestinal barrier of weaned piglets remains largely unclear.Methods:The weaned piglets and porcine IPEC-J2 intestinal epithelial cells were used to investigate the effects of TUDCA on intestinal barrier function in weaned piglets and explore the possible underlying mechanisms.In vivo,72 healthy weaned piglets were randomly allocated into 2 groups according to their gender and body weight,and piglets were fed the basal diet with 0(control,CON)and 200 mg/kg TUDCA for 30 d,respectively.Three female and three male piglets reflecting the average bodyweight were slaughtered in each group and samples were collected.In vitro,IPEC-J2 cells were subjected to 100μmol/L TUDCA to explore the possible underlying mechanisms.Results:Our results demonstrated that dietary TUDCA supplementation significantly reduced the diarrhea incidence of weaned piglets,possibly attributing to the TUDCA-enhanced intestinal barrier function and immunity.In addition,TUDCA supplementation altered serum metabolites and the relative abundance of certain gut bacteria,which might contribute to the improved intestinal barrier function.Furthermore,the in-vitro results showed that TUDCA improved the E.coli-induced epithelial barrier impairment of IPEC-J2 cells and increased Takeda G-coupled protein receptor 5(TGR5)protein expression.However,knockdown of TGR5 and inhibition of myosin light chain kinase(MLCK)pathway abolished the TUDCA-improved epithelial barrier impairment in E.coli-treated IPEC-J2 cells,indicating the involvement of TGR5-MLCK in this process.Conclusions:These findings showed that TUDCA improved intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets,suggesting the potential application of TUDCA in improving gut health in piglet production.

Effect of EPEC endotoxin and bifidobacteria on intestinal barrier function through modulation of toll-like receptor 2 and toll-like receptor 4 expression in intestinal epithelial cell-18

AIM To investigate toll-like receptor 2(TLR2) and TLR4 expression, following bifidobacteria and low-dose EPEC endotoxin treatment, and intestinal barrier function in rat intestinal epithelial cell-18(IEC-18).METHODS Six experimental groups were established-normal control, EPEC, Bifidobacteria infantis(B. infantis), B. longum, B. bifidum, and B. youth groups. Optimal EPEC endotoxin concentration, bifidobacteria fold dilution, and treatment duration were determined. Quantitative real-time polymerase chain reaction and western blot, respectively, were conducted to detect TLR2 and TLR4 m RNA and protein expression in IEC-18 cells. Transepithelial electrical resistance(TEER) was measured by the EVOM chopstick voltohmmeter in each group. All experiments were conducted in triplicate and data were analyzed on SPSS 16.RESULTS TLR2 and TLR4 m RNA and protein expression in the EPEC group were significantly higher than in the control group(P < 0.05). TLR2 m RNA and protein expression in the B. infantis, B. longum and B. youth groups were significantly lower than in the normal control group(P < 0.05). TLR4 m RNA and protein expression in the B. bifidum and B. youth groups were significantly lower than in normal controls(P < 0.05). In addition, the TEER in B. infantis, B. longum, B. bifidum, and B. youth groups were decreased by 19%, 18%, 23% and 23%, respectively, after 120 min of intervention, as compared to the control group. However, the TEER in the EPEC group was significantly decreased by 67% in comparison to the normal control group(P < 0.05).CONCLUSION Bifidobacteria protect IEC-18 cells against injury by down-regulating TLR2 and TLR4 expression and enhance intestinal barrier function to protect the intestinal epithelial cells from pathogenic invasion.

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 lactu-lose 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 coagu-lans 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.

Supplementation of oligosaccharide-based polymer enhanced growth and disease resistance of weaned pigs by modulating intestinal integrity and systemic immunity

Background:There is a great demand for antibiotic alternatives to maintain animal health and productivity.The objective of this experiment was to determine the efficacy of dietary supplementation of a blood group A6 type 1antigen oligosaccharides-based polymer(Coligo)on growth performance,diarrhea severity,intestinal health,and systemic immunity of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli(ETEC),when compared with antibiotics.Results:Pigs in antibiotic carbadox or Coligo treatment groups had greater(P<0.05)body weight on d 5 or d 11post-inoculation(PI)than pigs in the control group,respectively.Supplementation of antibiotics or Coligo enhanced(P<0.05)feed efficiency from d 0 to 5 PI and reduced(P<0.05)frequency of diarrhea throughout the experiment,compared with pigs in the control group.Supplementation of antibiotics reduced(P<0.05)fecalβ-hemolytic coliforms on d 2,5,and 8 PI.Pigs in antibiotics or Coligo groups had reduced(P<0.05)neutrophil counts and serum haptoglobin concentration compared to pigs in the control group on d 2 and 5 PI.Pigs in Coligo had reduced(P<0.05)total coliforms in mesenteric lymph nodes on d 5 and 11 PI,whereas pigs in antibiotics or Coligo groups had reduced(P<0.05)total coliforms in spleen on d 11 PI compared with pigs in the control group.On d 5 PI,pigs in the Coligo group had greater(P<0.05)gene expression of ZO1 in jejunal mucosa,but less(P<0.05)m RNA expression of IL1B,IL6,and TNF in ileal mucosa,in comparison with pigs in the control group.Supplementation of antibiotics enhanced(P<0.05)the gene expression of OCLN in jejunal mucosa but decreased(P<0.05)IL1B and IL6 gene expression in ileal mucosa,compared with the control.On d 11 PI,supplementation of antibiotics or Coligo up-regulated(P<0.05)gene expression of CLDN1 in jejunal mucosa,but Coligo reduced(P<0.05)IL6 gene expression in ileal mucosa compared to pigs in the control group.Conclusions:Supplementation of Coligo improved growth performance,alleviated diarrhea severity,and enhanced gut health in weaned pigs infected with ETEC F18 in a manner similar to in-feed antibiotics.

Measurement of the intestinal permeability in chronic kidney disease

AIM： To evaluate methods measuring the intestinal permeability in chronic kidney disease （CKD） and clarify whether there is an increased intestinal permeability in CKD.METHODS： We reviewed the literature in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis （PRISMA） protocol and performed a systematic literature search through MEDline and EMBASE. All controlled trials and cohort studies using non-invasive methods to assess intestinal permeability in CKD patients were included. Excluded were： Conference abstracts and studies including patients younger than 18 years or animals. From the included studies we summarized the used methods and their advantages and disadvantages. For the comparison of their results we divided the included studies in two categories based on their included patient population, either assessing the intestinal permeability in mild to moderate CKD patients or in end stage renal disease （ESRD） patients. Results were graphically displayed in two plots, one comparing the intestinal permeability in mild to moderate CKD patients to healthy controls and one comparing the intestinal permeability in ESRD patients to healthy controls. RESULTS： From the 480 identifed reports, 15 met our inclusion criteria. Methods that were used to assess the intestinal permeability varied from markers measured in plasma to methods based on calculating the urinary excretion of an orally administered test substance. None of the applied methods has been validated in CKD patients and the infuence of decreased renal function on the different methods remains unclear to a certain extent. Methods that seem the least likely to be influenced by decreased renal function are the quantitative PCR （qPCR） for bacterial DNA in blood and D-lactate. Considering the results published by the included studies; the studiesincluding patients with mild to moderate CKD conductedconflicting results. Some studies did report an increasein intestinal permeability whilst other did not find asignificant increased permeability. However, despite thevariety in used methods among the different studies, allstudies measuring the intestinal permeability in ESRDpoint out a significant increased intestinal permeability.Results should nevertheless be interpreted with cautiondue to the possible infuence of a decreased glomerularfltration rate on test results.CONCLUSION： The intestinal permeability in CKD： （1） could be measured by qPCR for bacterial DNA in blood and D-lactate; and （2） seems to be increased in ESRD.