Slimy partners: the mucus barrier and gut microbiome in ulcerative colitis.
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ABSTRACT:
SUBMITTER: Fang J
PROVIDER: S-EPMC8178360 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Background and aimsThe trigger hypothesis opens the possibility of anti-flare initiation therapies by stating that ulcerative colitis (UC) flares originate from inadequate responses to acute mucosal injuries. However, experimental evidence is restricted by a limited use of suitable human models. We thus aimed to investigate the acute mucosal barrier injury responses in humans with and without UC using an experimental injury model.MethodsA standardized mucosal break was inflicted in the sigmoid colon of 19 patients with UC in endoscopic and histological remission and 20 control subjects. Postinjury responses were assessed repeatedly by high-resolution imaging and sampling to perform Geboes scoring, RNA sequencing, and injury niche microbiota 16S ribosomal RNA gene sequencing.ResultsUC patients had more severe endoscopic postinjury inflammation than did control subjects (P < .01), an elevated modified Geboes score (P < .05), a rapid induction of innate response gene sets (P < .05) and antimicrobial peptides (P < .01), and engagement of neutrophils (P < .01). Innate lymphoid cell type 3 (ILC3) markers were increased preinjury (P < .01), and ILC3 activating cytokines were highly induced postinjury, resulting in an increase in ILC3-type cytokine interleukin-17A. Across groups, the postinjury mucosal microbiome had higher bacterial load (P < .0001) and lower α-diversity (P < .05).ConclusionsUC patients in remission respond to mucosal breaks by an innate hyperresponse engaging resident regulatory ILC3s and a subsequent adaptive activation. The postinjury inflammatory bowel disease-like microbiota diversity decrease is irrespective of diagnosis, suggesting that the dysbiosis is secondary to host injury responses. We provide a model for the study of flare initiation in the search for antitrigger-directed therapies.
| S-EPMC8455368 | biostudies-literature
Project description:The active stages of intestinal inflammation and the pathogenesis of ulcerative colitis are associated with superficial mucosal damage and intermittent wounding that leads to epithelial barrier defects and increased permeability. The standard therapeutic interventions for colitis have focused mainly on maintaining the remission levels of the disease. Nonetheless, such treatment strategies (using anti-inflammatory, immunomodulatory agents) do not address colitis' root cause, especially the mucosal damage and dysregulated intestinal barrier functions. Restoration of barrier functionality by mucosal healing or physical barrier protecting strategies shall be considered as an initial event in the disease suppression and progression. Herein, a biphasic hyaluronan (HA) enema suspension, naïve-HA systems that protect the dysregulated gut epithelium by decreasing the inflammation, permeability, and helping in maintaining the epithelial barrier integrity in the dextran sodium sulfate-induced colitis mice model is reported. Furthermore, HA-based system modulates intestinal epithelial junctional proteins and regulatory signaling pathways, resulting in attenuation of inflammation and mucosal protection. The results suggest that HA-based system can be delivered as an enema to act as a barrier protecting system for managing distal colonic inflammatory diseases, including colitis.
| S-EPMC8811821 | biostudies-literature
Project description:The present study aimed to determine if metformin exerts anti-inflammatory and mucus-protective effects via the gut microbiota. Metformin has extensive benefits including anti-inflammatory effects. Previous studies showed that metformin changed the gut microbiota composition and increases the number of goblet cells. Intestinal dysbiosis and goblet cell depletion are important features of ulcerative colitis (UC). The underlying mechanism and whether metformin can improve the mucus barrier in UC remain unclear. Metformin (400 mg/kg/day) was administered to mice with dextran sulfate sodium (DSS)-induced UC for 2 wk to investigate the effects of metformin on the intestinal mucus barrier. The gut microbiota was depleted, using antibiotics, to explore its role in the mucus-protecting effects of metformin. Akkermansia muciniphila (A. muciniphila), which was enriched in metformin-treated mice, was administered to mice to investigate the effects of the bacteria on UC and the mucus barrier. Metformin attenuated DSS-induced UC in mice, as evidenced by the alleviation of diarrhea, hematochezia, and the decrease in body weight. The expression of mucin2, a prominent mucus barrier protein, was increased in the metformin-treated group compared to the DSS-treated group. Furthermore, fecal 16S rRNA analysis showed that metformin treatment changed the gut microbiota composition by increasing the relative abundance of Lactobacillus and Akkermansia species while decreasing Erysipelatoclostridium at the genus level. Antibiotic treatment partly abolished the anti-inflammatory and mucus-protecting effects of metformin. Administration of A. muciniphila alleviated the colonic inflammation and mucus barrier disruption. Metformin alleviated DSS-induced UC in mice and protected against cell damage via affecting the gut microbiota, thereby providing a new mechanism for the therapeutic effect of metformin in patients with UC. This study also provides evidence that A. muciniphila as a probiotic has potential benefits for UC.
| S-EPMC8514724 | biostudies-literature
Project description:The colonic inner mucus layer protects us from pathogen invasion and commensal-induced inflammation. Mucus abnormalities are common in ulcerative colitis (UC), but their cause and importance are unknown. The aim of this study was to determine the role of compositional mucus barrier alterations in UC. In this single-center case-control study, sigmoid colon biopsies were obtained from UC patients with ongoing inflammation (n=36) and in remission (n=28), and from 47 patients without inflammatory bowel disease. Mucus samples were collected from biopsies ex vivo, and their protein composition analyzed by mass spectrometry. Mucus barrier integrity and goblet cell response to microbial challenge were also assessed for a subset of patients. The core colonic mucus proteome was shown to consist of a small set of 29 secreted proteins. Patients with active UC had reduced levels of major structural components, including the mucin MUC2 (p<0.0001), also in mucus from non-inflamed segments, and their goblet cell secretory response to microbial stimulus was abrogated. Functional mucus barrier failure was observed in a subset of UC patients with and without active inflammation, and accompanied by alterations in proteins associated with mucus secretion and luminal organization. This study represents the first characterization and comparison of the mucus proteomes of the inflamed and non-inflamed colon. Core mucus structural components were reduced in active UC, also in mucus from non-inflamed segments. Thus, weakening of the mucus barrier is likely to occur early in UC pathogenesis, and represents a novel target for intervention.
2021-03-26 | PXD012632 | Pride
Project description:BackgroundUlcerative colitis is a heterogeneous disease in terms of disease course, location, and therapeutic response. The current study was done to assess the alteration of the gut microbiome in UC patients and its relationship to severity, response to therapy, and outcome.Patients and methodsThe study included 96 participants who were divided into a case group (n = 48, recent onset, treatment naive ulcerative colitis patients who were subdivided into mild, moderate, and severe subgroups based on Truelove-Witts and endoscopic severity) and a healthy control group (n = 48). All were subjected to a thorough history, clinical examination, colonoscopy, routine laboratory tests, and quantitative real-time PCR to quantify Bacteroides, Lactobacilli, Faecalibacterium prausnitzii, Veillonella, and Hemophilus in fecal samples at baseline and 6 months after treatment.ResultsBacterial 16S rRNA gene sequencing revealed a significant reduction in the phylum Firmicutes in UC patients, with a significant predominance of the phylum Bacteriodetes. F. prausnitzii and lactobacilli were inversely proportional to disease severity, whereas Bacteroides, Hemophilus, and Veillonella were directly proportional to it. Six months after therapy, a statistically significant increase in F. prausnitzii and lactobacilli was observed, with a decrease in the levels of other bacteria. Lower baseline F. praustinizii (< 8.5) increased the risk of relapse; however, lower ESR (< 10), lower post-treatment CRP (< 6), lower Bacteroides (< 10.6) indefinitely protect against relapse.ConclusionThe gut microbiome of recently diagnosed UC showed lower levels of Lactobacilli, Faecalibacterium, and higher levels of Bacteroides and Veillonella, and the change in their levels can be used to predict response to therapy.
| S-EPMC10460709 | biostudies-literature
Project description:The Role of the Gut Microbiota in Ulcerative Colitis - Demonstration project for Human Microbiome Project (HMP)
| PRJNA51445 | ENA
Project description:Taxifolin is a bioflavonoid which has been used to treat Inflammatory Bowel Disease. However, taxifolin on DSS-induced colitis and gut health is still unclear. Here, we studied the effect of taxifolin on DSS-induced intestinal mucositis in mice. We measured the degree of intestinal mucosal injury and inflammatory response in DSS treated mice with or without taxifolin administration and studied the changes of fecal metabolites and intestinal microflora using 16S rRNA. The mechanism was further explored by fecal microbiota transplantation. The results showed that the weight loss and diarrhea score of the mice treated with taxifolin decreased in DSS-induced mice and longer colon length was displayed after taxifolin supplementation. Meanwhile, the expression of GPR41 and GPR43 in the colon was significantly increased by taxifolin treatment. Moreover, the expression of TNF-α, IL-1β, and IL-6 in colon tissue was inhibited by taxifolin treatment. The fecal metabolism pattern changed significantly after DSS treatment, which was reversed by taxifolin treatment. Importantly, taxifolin significantly increased the levels of butyric acid and isobutyric acid in the feces of DSS-treated mice. In terms of gut flora, taxifolin reversed the changes of Akkermansia, and further decreased uncultured_bacterium_f_Muribaculaceae. Fecal transplantation from taxifolin-treated mice showed a lower diarrhea score, reduced inflammatory response in the colon, and reduced intestinal mucosal damage, which may be related to the increased level of butyric acid in fecal metabolites. In conclusion, this study provides evidence that taxifolin can ameliorate DSS-induced colitis by altering gut microbiota to increase the production of SCFAs.
| S-EPMC8912346 | biostudies-literature
Project description:Few studies reported the relation of intestinal microbiome composition and diversity in pediatric patients with primary sclerosing cholangitis (PSC) and ulcerative colitis (UC). In this cross-sectional study, we selected patients younger than 19 years old from the pediatric gastroenterology and hepatology outpatient clinic of a tertiary hospital to describe the intestinal microbiome of pediatric patients with PSC associated or not to UC. Patients were divided in PSC, PSC+UC, and UC diagnosis. A stool sample was collected from each patient (n=30) and from a healthy relative/neighbor (n=23). The microbiome composition was assessed using MiSeq (Illumina) platform. Differences in microbial composition were found between PSC and PSC+UC groups. The relative abundance of Veillonella and Megasphaera genera were increased depending on patients' age at diagnosis. Veillonella was also increased in patients who were in an active status of the disease. Both genera were positively correlated to total bilirubin and gamma-glutamyl transferase. As a conclusion, the disease, the age and the disease activity status seem to influence the intestinal microbiome, highlighting the difference of intestinal microbiome profile for patients depending on age at diagnosis. We also showed an increase of Veillonella in patients with PSC and PSC+UC, and a positive correlation of dysbiosis and higher gamma-glutamyl transferase and total bilirubin in PSC+UC patients. Our findings are promising in the diagnosis, prognosis, and future therapeutic perspectives for PSC patients.
| S-EPMC7893080 | biostudies-literature
Project description:ObjectiveThe pathogenesis of UC relates to gut microbiota dysbiosis. We postulate that alterations in the viral community populating the intestinal mucosa play an important role in UC pathogenesis. This study aims to characterise the mucosal virome and their functions in health and UC.DesignDeep metagenomics sequencing of virus-like particle preparations and bacterial 16S rRNA sequencing were performed on the rectal mucosa of 167 subjects from three different geographical regions in China (UC=91; healthy controls=76). Virome and bacteriome alterations in UC mucosa were assessed and correlated with patient metadata. We applied partition around medoids clustering algorithm and classified mucosa viral communities into two clusters, referred to as mucosal virome metacommunities 1 and 2.ResultsIn UC, there was an expansion of mucosa viruses, particularly Caudovirales bacteriophages, and a decrease in mucosa Caudovirales diversity, richness and evenness compared with healthy controls. Altered mucosal virome correlated with intestinal inflammation. Interindividual dissimilarity between mucosal viromes was higher in UC than controls. Escherichia phage and Enterobacteria phage were more abundant in the mucosa of UC than controls. Compared with metacommunity 1, metacommunity 2 was predominated by UC subjects and displayed a significant loss of various viral species. Patients with UC showed substantial abrogation of diverse viral functions, whereas multiple viral functions, particularly functions of bacteriophages associated with host bacteria fitness and pathogenicity, were markedly enriched in UC mucosa. Intensive transkingdom correlations between mucosa viruses and bacteria were significantly depleted in UC.ConclusionWe demonstrated for the first time that UC is characterised by substantial alterations of the mucosa virobiota with functional distortion. Enrichment of Caudovirales bacteriophages, increased phage/bacteria virulence functions and loss of viral-bacterial correlations in the UC mucosa highlight that mucosal virome may play an important role in UC pathogenesis.
| S-EPMC6582748 | biostudies-literature
Project description:Ulcerative colitis (UC) is driven by disruptions in host-microbiota homoeostasis, but current treatments exclusively target host inflammatory pathways. To understand how host-microbiota interactions become disrupted in UC, we collected and analysed six faecal- or serum-based omic datasets (metaproteomic, metabolomic, metagenomic, metapeptidomic and amplicon sequencing profiles of faecal samples and proteomic profiles of serum samples) from 40 UC patients at a single inflammatory bowel disease centre, as well as various clinical, endoscopic and histologic measures of disease activity. A validation cohort of 210 samples (73 UC, 117 Crohn's disease, 20 healthy controls) was collected and analysed separately and independently. Data integration across both cohorts showed that a subset of the clinically active UC patients had an overabundance of proteases that originated from the bacterium Bacteroides vulgatus. To test whether B. vulgatus proteases contribute to UC disease activity, we first profiled B. vulgatus proteases found in patients and bacterial cultures. Use of a broad-spectrum protease inhibitor improved B. vulgatus-induced barrier dysfunction in vitro, and prevented colitis in B. vulgatus monocolonized, IL10-deficient mice. Furthermore, transplantation of faeces from UC patients with a high abundance of B. vulgatus proteases into germfree mice induced colitis dependent on protease activity. These results, stemming from a multi-omics approach, improve understanding of functional microbiota alterations that drive UC and provide a resource for identifying other pathways that could be inhibited as a strategy to treat this disease.
| S-EPMC8852248 | biostudies-literature