A Novel Microbial Dysbiosis Index and Intestinal Microbiota-Associated Markers as Tools of Precision Medicine in Inflammatory Bowel Disease Paediatric Patients.

Recent evidence indicates that the gut microbiota (GM) has a significant impact on the inflammatory bowel disease (IBD) progression. Our aim was to investigate the GM profiles, the Microbial Dysbiosis Index (MDI) and the intestinal microbiota-associated markers in relation to IBD clinical characteristics and disease state. We performed 16S rRNA metataxonomy on both stools and ileal biopsies, metabolic dysbiosis tests on urine and intestinal permeability and mucosal immunity activation tests on the stools of 35 IBD paediatric patients. On the GM profile, we assigned the MDI to each patient. In the statistical analyses, the MDI was correlated with clinical parameters and intestinal microbial-associated markers. In IBD patients with high MDI, Gemellaceae and Enterobacteriaceae were increased in stools, and Fusobacterium, Haemophilus and Veillonella were increased in ileal biopsies. Ruminococcaceae and WAL_1855D were enriched in active disease condition; the last one was also positively correlated to MDI. Furthermore, the MDI results correlated with PUCAI and Matts scores in ulcerative colitis patients (UC). Finally, in our patients, we detected metabolic dysbiosis, intestinal permeability and mucosal immunity activation. In conclusion, the MDI showed a strong association with both severity and activity of IBD and a positive correlation with clinical scores, especially in UC. Thus, this evidence could be a useful tool for the diagnosis and prognosis of IBD.

Perception of fecal microbiota transplantation in patients with ulcerative colitis in Korea: a KASID multicenter study.

BACKGROUND/AIMS: Fecal microbiota transplantation (FMT) is a promising therapy for inducing and maintaining remission in patients with ulcerative colitis (UC). However, FMT has not been approved for UC treatment in Korea. Our study aimed to investigate patient perceptions of FMT under the national medical policy. METHODS: This was a prospective, multicenter study. Patients with UC ≥ 19 years of age were included. Patients were surveyed using 22 questions on FMT. Changes in perceptions of FMT before and after education were also compared. RESULTS: A total of 210 patients with UC were enrolled. We found that 51.4% of the patients were unaware that FMT was an alternative treatment option for UC. After reading the educational materials on FMT, more patients were willing to undergo this procedure (27.1% vs. 46.7%; p < 0.001). The preferred fecal donor was the one recommended by a physician (41.0%), and the preferred transplantation method was the oral capsule (30.4%). A large proportion of patients (50.0%) reported that the national medical policy influenced their choice of FMT treatment. When patients felt severe disease activity, their willingness to undergo FMT increased (92.3% vs. 43.1%; p = 0.001). CONCLUSION: Education can increase preference for FMT in patients with UC. When patients have severe disease symptoms or their quality of life decreases their willingness to undergo FMT increases. Moreover, national medical policies may influence patient choices regarding FMT.

A disturbed metabolite-GPCR axis is associated with microbial dysbiosis in IBD patients: Potential role of GPR109A in macrophages.

Inflammatory Bowel Disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract characterized by disrupted immune function. Indeed, gut microbiota dysbiosis and metabolomic profile alterations, are hallmarks of IBD. In this scenario, metabolite-sensing G-protein coupled receptors (GPCRs), involved in several biological processes, have emerged as pivotal players in the pathophysiology of IBD. The aim of this study was to characterize the axis microbiota-metabolite-GPCR in intestinal surgical resections from IBD patients. Results showed that UC patients had a lower microbiota richness and bacterial load, with a higher proportion of the genus Cellulosimicrobium and a reduced proportion of Escherichia, whereas CD patients showed a decreased abundance of Enterococcus. Furthermore, metabolomic analysis revealed alterations in carboxylic acids, fatty acids, and amino acids in UC and CD samples. These patients also exhibited upregulated expression of most metabolite-sensing GPCRs analysed, which positively correlated with pro-inflammatory and pro-fibrotic markers. The role of GPR109A was studied in depth and increased expression of this receptor was detected in epithelial cells and cells from lamina propria, including CD68+ macrophages, in IBD patients. The treatment with ß-hydroxybutyrate increased gene expression of GPR109A, CD86, IL1B and NOS2 in U937-derived macrophages. Besides, when GPR109A was transiently silenced, the mRNA expression and secretion of IL-1ß, IL-6 and TNF-α were impaired in M1 macrophages. Finally, the secretome from siGPR109A M1 macrophages reduced the gene and protein expression of COL1A1 and COL3A1 in intestinal fibroblasts. A better understanding of metabolite-sensing GPCRs, such as GPR109A, could establish their potential as therapeutic targets for managing IBD.

Dehydroevodiamine Alleviates Ulcerative Colitis by Inhibiting the PI3K/AKT/NF-κB Signaling Pathway via Targeting AKT1 and Regulating Gut Microbes and Serum Metabolism.

Ulcerative colitis (UC) is a typical inflammatory bowel disease (IBD), impairing the quality of life of patients. Dehydroevodiamine (DHE) is an active alkaloid isolated from Tetradium ruticarpum that exerts significant anti-inflammatory effects in gastrointestinal diseases. However, the effect and mechanisms of DHE on UC remain unclear. We performed a DSS-induced experimental UC rat model to reveal the efficacy and potential mechanisms of DHE on UC. HE and AB-PAS staining were used for the evaluation of pathologies, and 16S rRNA sequencing was used to detect changes in gut microbes. Metabolomics was used to detect changes in serum metabolites. Network pharmacology and transcriptomics were conducted to reveal the underlying mechanisms of DHE for UC. HuProt proteome microarrays, molecular docking, and SPR were used to reveal the targets of action of DHE. WB, RT-qPCR, and IHC were used to assess the action effects of DHE. DHE demonstrated significant alleviation of DSS-induced colitis symptoms in rats by suppressing inflammatory and oxidative stress responses, amending colonic barrier injury, and inhibiting apoptosis. In terms of gut microbial modulation, DHE decreased the abundance of Allobaculum, Clostridium, Escherichia, Enterococcus, and Barnesiella and increased the abundance of Lactobacillus, Bifidobacterium, and SMB5. Moreover, metabolomics suggested that the regulation of DHE in DSS-induced UC rats mainly involved aminoacyl-tRNA biosynthesis, vitamin B6 metabolism, phenylalanine, tyrosine, and so on. Mechanically, DHE alleviated UC in rats by targeting AKT1, thereby inhibiting the PI3K/AKT/NF-κB signaling pathway.

Protection against DSS-induced colitis in mice through FcεRIα deficiency: the role of altered Lactobacillus.

The role of mast cells (MCs) in ulcerative colitis (UC) development is controversial. FcεRI, the IgE high-affinity receptor, is known to activate MCs. However, its role in UC remains unclear. In our study, Anti-FcεRI showed highly diagnostic value for UC. FcεRIα knockout in mice ameliorated DSS-induced colitis in a gut microbiota-dependent manner. Increased Lactobacillus abundance in FcεRIα deficient mice showed strongly correlation with the remission of colitis. RNA sequencing indicated activation of the NLRP6 inflammasome pathway in FcεRIα knockout mice. Additionally, Lactobacillus plantarum supplementation protected against inflammatory injury and goblet cell loss, with activation of the NLRP6 inflammasome during colitis. Notably, this effect was absent when the strain is unable to produce lactic acid. In summary, colitis was mitigated in FcεRIα deficient mice, which may be attributed to the increased abundance of Lactobacillus. These findings contribute to a better understanding of the relationship between allergic reactions, microbiota, and colitis.

Oral inoculation of Fusobacterium nucleatum exacerbates ulcerative colitis via the secretion of virulence adhesin FadA.

Fusobacterium nucleatum (F. nucleatum), an anaerobic resident of the oral cavity, is increasingly recognized as a contributing factor to ulcerative colitis (UC). The adhesive properties of F. nucleatum are mediated by its key virulence protein, FadA adhesin. However, further investigations are needed to understand the pathogenic mechanisms of this oral pathogen in UC. The present study aimed to explore the role of the FadA adhesin in the colonization and invasion of oral F. nucleatum in dextran sulphate sodium (DSS)-induced colitis mice via molecular techniques. In this study, we found that oral inoculation of F. nucleatum strain carrying the FadA adhesin further exacerbated DSS-induced colitis, leading to elevated alveolar bone loss, disease severity, and mortality. Additionally, CDH1 gene knockout mice treated with DSS presented increases in body weight and alveolar bone density, as well as a reduction in disease severity. Furthermore, FadA adhesin adhered to its mucosal receptor E-cadherin, leading to the phosphorylation of ß-catenin and the degradation of IκBα, the activation of the NF-κB signalling pathway and the upregulation of downstream cytokines. In conclusion, this research revealed that oral inoculation with F. nucleatum facilitates experimental colitis via the secretion of the virulence adhesin FadA. Targeting the oral pathogen F. nucleatum and its virulence factor FadA may represent a promising therapeutic approach for a portion of UC patients.

Water-soluble garlic polysaccharide (WSGP) improves ulcerative volitis by modulating the intestinal barrier and intestinal flora metabolites.

WSGP has demonstrated significant potential for various bioactive effects. However, limited research has explored their anti-ulcerative colitis (UC) effects and mechanism on the colonic system and gut microbial metabolites. We evaluated the ameliorative effects of WSGP on the UC mice model. Using H&E to assess histological injury of colon morphology, AB-PAS staining to detect mucin secretion from goblet cells and the mucous layer, IF to evaluate the expression of intercellular tight junction proteins, ELISA to measure inflammatory factors, WB analysis to measure protein expression of inflammatory signaling pathways, RT-qPCR to quantify gene transcription of inflammatory factors, and LC-MS to analyze metabolites in mouse cecum contents. WSGP supplementation increased food intake, body weight, and colon length while reducing disease activity and histological scores in colitis-afflicted mice. WSGP mitigated colonic tissue damage and restored intestinal barrier integrity by suppressing NF-κB/STAT3 signaling, thereby decreasing gene transcription, protein expression of proinflammatory factors, and nitric oxide production. Additionally, WSGP improved UC by altering the variety of intestinal microbial metabolites. This study demonstrates that WSGP supplementation attenuates UC mice by suppressing the NF-κB/STAT3 signaling pathway, enhancing mucosal barrier function, reducing pro-inflammatory cytokines, and modulating gut microbial metabolites.

Bacteroides salyersiae Is a Candidate Probiotic Species with Potential Anti-Colitis Properties in the Human Colon: First Evidence from an In Vivo Mouse Model.

Previous studies have indicated a critical role of intestinal bacteria in the pathogenesis of ulcerative colitis (UC). B. salyersiae is a commensal species from the human gut microbiota. However, what effect it has on UC development has not been investigated. In the present study, we explored this issue and demonstrated for the first time that oral administration of B. salyersiae CSP6, a bacterium previously isolated from the fecal sample of a healthy individual, protected against dextran sulfate sodium (DSS)-induced colitis in C57BL/6J mice. In particular, B. salyersiae CSP6 improved mucosal damage and attenuated gut dysbiosis in the colon of DSS-fed mice. Specifically, B. salyersiae CSP6 decreased the population of pathogenic Escherichia-Shigella spp. and increased the abundance of probiotic Dubosiella spp. and Bifidobacterium pseudolongum. Additionally, by reshaping the colonic microbiota, B. salyersiae CSP6 remarkably increased the fecal concentrations of equol, 8-deoxylactucin, and tiglic acid, three beneficial metabolites that have been well documented to exert strong anti-inflammatory effects. Altogether, our study provides novel evidence that B. salyersiae is a candidate probiotic species with potential anti-colitis properties in the human colon, which has applications for the development of next-generation probiotics.

Neohesperidin Attenuates DSS-Induced Ulcerative Colitis by Inhibiting Inflammation, Reducing Intestinal Barrier Damage, and Modulating Intestinal Flora Composition.

Flavonoid natural products are emerging as a promising approach for treating Ulcerative Colitis (UC) due to their natural origin and minimal toxicity. This study investigates the effects of Neohesperidin (NEO), a natural flavonoid, on Dextran Sodium Sulfate (DSS)-induced UC in mice, focusing on the underlying molecular mechanisms. Early intervention with NEO (25 and 50 mg/kg) mitigated colon shortening, restored damaged barrier proteins, and significantly reduced the inflammatory cytokine levels. Moreover, NEO inhibited the MAPK/NF-κB signaling pathway and enhanced the levels of intestinal barrier proteins (Claudin-3 and ZO-1). Additionally, NEO increased beneficial intestinal probiotics (S24-7 and Lactobacillaceae) while reducing harmful bacteria (Erysipelotrichi, Enterobacteriaceae). Fecal microbial transplantation (FMT) results demonstrated that NEO (50 mg/kg) markedly improved UC symptoms. In conclusion, early NEO intervention may alleviate DSS-induced UC by inhibiting inflammatory responses, preserving intestinal barrier integrity and modulating gut microbiota.

Sustained mucosal colonization and fecal metabolic dysfunction by Bacteroides associates with fecal microbial transplant failure in ulcerative colitis patients.

Fecal microbial transplantation (FMT) offers promise for treating ulcerative colitis (UC), though the mechanisms underlying treatment failure are unknown. This study harnessed longitudinally collected colonic biopsies (n = 38) and fecal samples (n = 179) from 19 adults with mild-to-moderate UC undergoing serial FMT in which antimicrobial pre-treatment and delivery mode (capsules versus enema) were assessed for clinical response (≥ 3 points decrease from the pre-treatment Mayo score). Colonic biopsies underwent dual RNA-Seq; fecal samples underwent parallel 16S rRNA and shotgun metagenomic sequencing as well as untargeted metabolomic analyses. Pre-FMT, the colonic mucosa of non-responsive (NR) patients harbored an increased burden of bacteria, including Bacteroides, that expressed more antimicrobial resistance genes compared to responsive (R) patients. NR patients also exhibited muted mucosal expression of innate immune antimicrobial response genes. Post-FMT, NR and R fecal microbiomes and metabolomes exhibited significant divergence. NR metabolomes had elevated concentrations of immunostimulatory compounds including sphingomyelins, lysophospholipids and taurine. NR fecal microbiomes were enriched for Bacteroides fragilis and Bacteroides salyersiae strains that encoded genes capable of taurine production. These findings suggest that both effective mucosal microbial clearance and reintroduction of bacteria that reshape luminal metabolism associate with FMT success and that persistent mucosal and fecal colonization by antimicrobial-resistant Bacteroides species may contribute to FMT failure.

Engineered probiotic ameliorates ulcerative colitis by restoring gut microbiota and redox homeostasis.

Probiotics are potential treatments for ulcerative colitis (UC), but their efficacy is frequently compromised by gastrointestinal conditions that limit adhesion and activity. Here, we use machine learning and bioinformatics to confirm that patients with UC have decreased prevalence of Lactobacillus genus and increased oxidative stress, which correlate with inflammation severity. Accordingly, we developed a probiotic-based therapeutic that synergistically restores intestinal redox and microbiota homeostasis. Lactobacillus casei (Lac) were induced to form a pericellular film, providing a polysaccharide network for spatially confined crystallization of ultrasmall but highly active selenium dots (Se-Lac). Upon oral administration, the selenium dot-embedded pericellular film efficiently enhanced gastric acid resistance and intestinal mucoadhesion of Lac cells. At the lesion site, the selenium dots scavenged reactive oxygen species, while Lac modulated the gut microbiota. In multiple mouse models and non-human primates, this therapeutic effectively relieved inflammation and reduced colonic damage, thus showing promise as a UC treatment.

Morin alleviates DSS-induced ulcerative colitis in mice via inhibition of inflammation and modulation of intestinal microbiota.

Ulcerative colitis (UC) is a chronic inflammatory condition with recurrent and challenging symptoms. Effective treatments are lacking, making UC management a critical research area. Morin (MO), a flavonoid from the Moraceae family, shows potential as an anti-UC agent, but its mechanisms are not fully understood. Using a dextran sulfate sodium (DSS)-induced UC mouse model, we employed network pharmacology to predict MO's therapeutic effects. Assessments included changes in body weight, disease activity index (DAI), and colon length. Immunofluorescence, hematoxylin and eosin (H&E), and PAS staining evaluated colon damage. ELISA and western blot analyzed inflammatory factors, tight junction (TJ)-associated proteins (Claudin-3, Occludin, ZO-1), and Mitogen-Activated Protein Kinase (MAPK)/ Nuclear Factor kappa B (NF-κB) pathways. 16S rRNA sequencing assessed gut microbiota diversity, confirmed by MO's modulation via Fecal Microbial Transplantation (FMT). Early MO intervention reduced UC severity by improving weight, DAI scores, and colon length, increasing goblet cells, enhancing barrier function, and inhibiting MAPK/NF-κB pathways. MO enriched gut microbiota, favoring beneficial bacteria like Muribaculaceae and Erysipelotrichaceae while reducing harmful Erysipelotrichaceae and Muribaculaceae. This study highlights MO's potential in UC management through inflammation control, mucosal integrity maintenance, and gut flora modulation.

[Research advance on the interaction between gut microbes and cytokines in inflammatory bowel disease].

Dysregulation of interaction between the gut microbiota and the host immune system leads to the development of chronic inflammation, such as inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Numerous studies have shown that the host-microbiota of IBD can directly or indirectly affect the homeostasis of the immune system. Furthermore, the balance between pro-inflammatory and anti-inflammatory cytokines involves in maintaining a healthy microbiota community and enhances epithelial barrier functions. Understanding the interactions between gut microbiota and cytokines (IL-10, IL-17, IL-18, TNF-α) provides crucial insights into the pathogenesis of inflammatory bowel disease.

Oral aged garlic (Allium sativum) alleviates ulcerative colitis in mice by improving gut homeostasis.

Aged garlic, obtained by heating raw garlic (Allium sativum) under high temperature and controlled humidity for a period, possesses a wide range of bioactivities, but its role in ulcerative colitis and its mechanism are not fully elucidated. We investigated the bioactive constituents in aged garlic (AG) and explored the effect of oral AG delivery on DSS-induced murine colitis. The results revealed that the aging process up-regulated anti-oxidative, anti-inflammatory and anti-microbial compounds such as dihydrocaffeic acid, 5-acetylsalicylic acid, verticine, S-allyl-L-cysteine and D-fucose. Oral AG obviously alleviated colitis, reducing colon damage and enhancing anti-oxidative and anti-inflammatory effects. Escherichia coli and Streptococcus equinus dramatically were enriched in the colon of mice with colitis that were strongly associated with Parkinson's disease, bacterial invasion of epithelial cells, aerobactin biosynthesis, and heme biosynthesis, but a distinct AG-mediated alteration in the colon due to increasing abundance of Akkermansia muciniphila, Lactobacillus sp. L-YJ, Bifidobacterium breve, Blautia wexlerae, Desulfomicrobium sp. P100A, and Lentilactobacillus hilgardii was observed. Next, we demonstrated that colonic microbiome reconstruction by oral AG significantly increased the production of short-chain fatty acids such as acetic acid, propionic acid, isobutyric acid, and isovaleric acid. This study provides the first data indicating that oral AG ameliorates colonic inflammation in a gut microbiota-dependent manner. Our findings provide novel insights into the AG-mediated remission of colitis and AG as a functional food for modulating the gut microbiota to prevent and treat colitis.

Modified Gegen Qinlian Decoction modulated the gut microbiome and bile acid metabolism and restored the function of goblet cells in a mouse model of ulcerative colitis.

Objective: Modified Gegen Qinlian Decoction (MGQD) has been shown to effectively relieve ulcerative colitis (UC) without a known pharmacological mechanism. In this study, the anti-colitis efficaciousness of MGQD and its underlying mechanisms in UC were evaluated. Methods: Mice with colitis were administered MGQD for 7 days. Following the evaluation of clinical symptoms, gut microbiota in the feces of UC mice was examined using 16S rRNA sequencing and bile acids (BAs) were examined using LC/MS. Gut microbiota consumption and fecal microbiota transplantation (FMT) were used to explore the involvement of gut microbiota in the anti-UC action of MGQD. Results: MGQD relieved colitis as shown by weight loss protection, a lower disease activity index (DAI), restoration of intestinal length reduction, and lower histopathologic scores. MGQD also restored crypt stem cell proliferation and function of colonic goblet cells, and promoted MUC2 protein secretion. Interestingly, investigations using gut bacterial depletion and FMT showed that MGQD attenuated colonic damage in a gut-dependent way. The modulation of the gut microbiota by MGQD might be attributed to a decrease in Odoribacter and an increase in norank_f_Muribaculaceae. In addition, MGQD modulated the metabolism of BAs while restoring the structure of the gut microbiota. Conclusion: MGQD significantly alleviated colitis in mice, which may be associated with the modulation of gut microbiota and BA metabolism and restoration of function of goblet cells. However, factors other than the gut microbiota may also be involved in the amelioration of UC by MGQD.

More on the interplay between gut microbiota, autophagy, and inflammatory bowel disease is needed.

The concept of inflammatory bowel disease (IBD), which encompasses Crohn's disease and ulcerative colitis, represents a complex and growing global health concern resulting from a multifactorial etiology. Both dysfunctional autophagy and dysbiosis contribute to IBD, with their combined effects exacerbating the related inflammatory condition. As a result, the existing interconnection between gut microbiota, autophagy, and the host's immune system is a decisive factor in the occurrence of IBD. The factors that influence the gut microbiota and their impact are another important point in this regard. Based on this initial perspective, this manuscript briefly highlighted the intricate interplay between the gut microbiota, autophagy, and IBD pathogenesis. In addition, it also addressed the potential targeting of the microbiota and modulating autophagic pathways for IBD therapy and proposed suggestions for future research within a more specific and expanded context. Further studies are warranted to explore restoring microbial balance and regulating autophagy mechanisms, which may offer new therapeutic avenues for IBD management and to delve into personalized treatment to alleviate the related burden.

Higher alpha diversity and Lactobacillus blooms are associated with better engraftment after fecal microbiota transplant in inflammatory bowel disease.

Fecal Microbiota Transplant (FMT) has shown some success in treating inflammatory bowel diseases (IBD). There is emerging evidence that host engraftment of donor taxa is a tenet of successful FMT. We undertook a double-blind, randomized, placebo-controlled pilot study to characterize the response to FMT in children and young adults with mild to moderate active Crohn's disease (CD) and ulcerative colitis (UC). Subjects with CD or UC were randomized to receive antibiotics and weekly FMT or placebo in addition to baseline medications. We enrolled 15 subjects aged 14-29 years. Four subjects had CD, and 11 had UC. Subjects exhibited a wide range of microbial diversity and donor engraftment. Specifically, engraftment ranged from 26 to 90% at week 2 and 3-92% at 2 months. Consistent with the current literature, increases over time of both alpha diversity (p < 0.05) and donor engraftment (p < 0.05) correlated with improved clinical response. We discovered that the post-antibiotic but pre-FMT time point was rich in microbial correlates of eventual engraftment. Greater residual alpha diversity after antibiotic treatment was positively correlated with engraftment and subsequent clinical response. Interestingly, a transient rise in the relative abundance of Lactobacillus was also positively correlated with engraftment, a finding that we recapitulated with our analysis of another FMT trial.

Dietary Fiber's Physicochemical Properties and Gut Bacterial Dysbiosis Determine Fiber Metabolism in the Gut.

A fiber-rich diet is considered beneficial for gut health. An inflamed gut with a dysbiotic bacterial community can result in altered fiber metabolism depending on the fiber's physicochemical properties. This study examined the effect of fiber's physicochemical properties on fiber fermentation in the presence of healthy and colitis-associated bacteria. Sixteen fibers with different levels of solubility, complexity, and fermentation rate were used in in vitro fermentation with healthy human gut bacteria. Resistant maltodextrins (RMD), pectin (HMP), inulin (ChIn), and wheat bran (WB) were selected for fermentation using ulcerative colitis (UC)-associated bacteria to assess bacterial dysbiosis effect. UC-associated gut microbiota showed a significant reduction in α-and ß-diversity indices compared to healthy-associated microbiota. The differences in the gut microbiota composition and diversity between the donors resulted in decreased fermentation rates with UC-associated bacteria. Fiber fermentation metabolites, short-chain fatty acids (SCFA) and gas production were significantly lower in the presence of UC-associated bacteria for all four fibers tested. Overall, we conclude that dietary fiber properties and microbial dysbiosis are influential in fiber fermentation and metabolite production in the gut.

ZG16 impacts gut microbiota-associated intestinal inflammation and pulmonary mucosal function through bacterial metabolites.

Zymogen granule 16 (ZG16) is a secretory glycoprotein found in zymogen granules, which also plays an important role in colorectal inflammation and cancer. Herein, a ZG16 gene knock-out (ZG16-/-) mouse line was established and we found that ZG16 deletion damaged the intestinal mucosal barrier and gut microbiota, which resulted in low-level inflammation and further promoted the development of ulcerative colitis and inflammation-related colorectal cancer. Meanwhile, a metabolomics analysis on mouse feces showed that the metabolites significantly differed between ZG16-/- and WT mice, which were important mediators of host-microbiota communication and may impact the pulmonary inflammation of mice. Indeed, ZG16-/- mice showed more severe inflammation in a bronchial asthma model. Taken together, the results demonstrate that ZG16 plays a pivotal role in inhibiting inflammation and regulating immune responses in colorectum and lung of experimental animals, which may provide a better understanding of the underlying mechanism of human inflammatory diseases associated with ZG16.