Project description:Hypervirulent epidemic strains of Clostridium difficile (C. difficile), referred to as NAPI/027, express an additional virulence factor, binary toxin (CDT), and are associated with more severe disease. Emerging evidence indicates gut immunity to C. difficile is a delicate balance between protection and pathology. To identify potential therapeutic host immune targets, we conducted a transcriptome analysis of host genes altered by NAPI/027 infection and identified interleukin-33 (IL-33) as a candidate immune target. Using a murine model, we show that both endogenous IL-33 and exogenous IL-33 treatment protect from the enhanced mortality, weight-loss and tissue pathology which is characteristic of hypervirulent C. difficile. IL-33 mediated protection was elicited through type-2 innate lymphoid cells (ILC2s) and adoptive transfer of purified ILC2s was sufficient to mitigate CDI- associated mortality and weight-loss. Furthermore, dysregulated IL-33 signaling via the soluble IL-33 decoy receptor (sST2) predicted disease severity and mortality in human patients. Lastly, colonic IL-33 expression appears to be regulated by the microbiota as antibiotic- depletion of IL-33 was rescued with mouse fecal microbiota transplant (FMT) and a human fecal spore preparation (HSP). Thus, IL-33 signaling is a novel therapeutic pathway for severe CDI which can potentially be targeted with rationally designed microbial therapies.
Project description:This study aimed to analyze changes in gut microbiota composition in mice after transplantation of fecal microbiota (FMT, N = 6) from the feces of NSCLC patients by analyzing fecal content using 16S rRNA sequencing, 10 days after transplantation. Specific-pathogen-free (SPF) mice were used for each experiments (N=4) as controls.
Project description:A major risk factor for Clostridioides difficile infection (CDI) is the perturbation of the gut microbiota by antibiotic administration, and antibiotic therapy, the standard treatment option for CDI, exacerbates the imbalance of the gut microbiota, leading to a very high recurrent CDI (rCDI) incidence rate. Therefore, CDI treatment based on live biotherapeutic products (LBPs) has recently emerged for long-term CDI management and preventive treatment However, there is limited research and understanding of how these LBPs improve CDI symptoms, which raises the need to elucidate the therapeutic mechanisms of LBPs. To fill this knowledge gap, here, we holistically analyzed and investigated the mechanisms involved in the inhibitory effect of probiotics on C. difficile at the molecular level through a multiomics approach on screened strain from probiotics that inhibit C. difficile growth. First, Bifidobacterium species were co-cultured with C. difficile, and B. longum was screened based on its ability to inhibit the growth of C. difficile. Then, the antimicrobial activity of B. longum against C. difficile was confirmed by spot-on-lawn assay and organic acid quantification. Next, we performed proteomic and metabolomic analysis on C. difficile co-cultured with B. longum, and observed physiological changes associated with the inhibition of C. difficile growth and toxin production. It was found that lactate produced by B. longum up-regulated the lactate dehydrogenase complex of C. difficile, leading to a decrease in intracellular ATP synthesis and a subsequent decrease in (deoxy)ribonucleoside triphosphate synthesis. Furthermore, proteinaceous stress induced by B. longum was also identified through the up-regulation of ribosomal proteins, molecular chaperones, and chaperonins, and the down-regulation of translation-related proteins. Finally, we found that B. longum suppressed butyrate metabolism and toxin production by producing and replenishing proline consumed by C. difficile. Therefore, this study will not only expand our understanding of the mechanisms of probiotics' inhibition of C. difficile, but also contribute to the development of LBPs based on molecular mechanisms for treating CDI.
Project description:Analysis of breast cancer survivors' gut microbiota after lifestyle intervention, during the COVID-19 lockdown, by 16S sequencing of fecal samples.
Project description:We found that low protein diet consumption resulted in decrease in the percentage of normal Paneth cell population in wild type mice, indicating that low protein diet could negatively affect Paneth cell function. We performed fecal microbiota composition profiling. Male mice were used at 4-5 weeks of age. Fecal samples were collected for microbiome analysis.
Project description:We found that western diet consumption resulted in decrease in the percentage of normal Paneth cell population in wild type mice, indicating that western diet could negatively affect Paneth cell function. Subsequent generations of western diet consumption further reduced percentages of normal Paneth cell population. We performed fecal microbiota composition profiling. Male mice were used at 4-5 weeks of age. Fecal samples were collected for microbiome analysis.
Project description:Significant gut microbiota heterogeneity exists amongst UC patients though the clinical implications of this variance are unknown. European and South Asian UC patients exhibit distinct disease risk alleles, many of which regulate immune function and relate to variation in gut microbiota β-diversity. We hypothesized ethnically distinct UC patients exhibit discrete gut microbiotas with unique luminal metabolic programming that influence adaptive immune responses and relate to clinical status. Using parallel bacterial 16S rRNA and fungal ITS2 sequencing of fecal samples (UC n=30; healthy n=13), we corroborated previous observations of UC-associated depletion of bacterial diversity and demonstrated significant gastrointestinal expansion of Saccharomycetales as a novel UC characteristic. We identified four distinct microbial community states (MCS 1-4), confirmed their existence using microbiota data from an independent UC cohort, and show they co-associate with patient ethnicity and degree of disease severity. Each MCS was predicted to be uniquely enriched for specific amino acid, carbohydrate, and lipid metabolism pathways and exhibited significant luminal enrichment of metabolic products from these pathways. Using a novel in vitro human DC/T-cell assay we show that DC exposure to patient fecal water led to MCS -specific changes in T-cell populations, particularly the Th1:Th2 ratio, and that patients with the most severe disease exhibited the greatest Th2 skewing. Thus, based on ethnicity, microbiome composition, and associated metabolic dysfunction, UC patients may be stratified in a clinically and immunologically meaningful manner, providing a platform for the development of FMC-focused therapy. Fecal microbiome was assessed with Affymetrix PhyloChip arrays from patients with ulcerative colitis and healthy controls.
Project description:Microbial RNAseq analysis of cecal and fecal samples collected from mice colonized with the microbiota of human twins discordant for obesity. Samples were colleted at the time of sacrifice, or 15 days after colonization from mice gavaged with uncultured or cultured fecal microbiota from the lean twins or their obese co-twins. Samples were sequenced using Illumina HiSeq technology, with 101 paired end chemistry. Comparisson of microbial gene expression between the microbiota of lean and obese twins fed a Low fat, rich in plant polysaccharide diet.