Project description:Gut microbiota participates in diverse metabolic and homeostatic functions related to health and well-being. Individual variation in its composition depends on many factors including dietary factors. We profiled enzymatic activity of fecal microbiota in 63 healthy adult individuals using metaproteomics, and identified Bacteroides and Prevotella –derived microbial CAZy (carbohydrate-active) enzymes involved in glycan foraging. One particular profile with many Bacteroides-derived CAZy was identified in one-third of subjects (n=20), and it associated with high abundancy of Bacteroides in most subjects. In other subjects (n=8) with dietary parameters similar to former, microbiota showed intense expression of Prevotella-derived CAZy including exo−beta−(1,4)−xylanase, xylan-1,4−beta−xylosidase, alpha−L−arabinofuranosidase and several other CAZy belonging to glycosyl hydrolase families involved in digestion of complex plant-derived polysaccharides. This associated invariably with robust representation of Prevotella in gut microbiota, while subjects with intermediate representation of Prevotella showed no CAZy profile. Identification of Bacteroides- and Prevotella-derived CAZy in microbiota proteome and their association with robust differences in microbiota composition, the latter with exceptionally high Prevotella abundancy in the gut, are in evidence of individual variation in metabolic adaptation of gut microbiota with an impact on colonizing competence.
Project description:Chronic inflammation and gut microbiota dysbiosis are risk factors for colorectal cancer. In clinical practice, inflammatory bowel disease (IBD) patients have a greatly increased risk of developing colitis associated colorectal cancer (CAC). However, the basis underlying the initiation of CAC remains to be explored. Systematic filtration through existing genome-wide association study (GWAS) and conditional deletion of Zfp90 in CAC mice model indicated that Zfp90 was a putative oncogene in CAC development. Strikingly, depletion of gut microbiota eliminated the tumorigenic effect of Zfp90 in CAC mice model. Moreover, fecal microbiota transplantation demonstrated Zfp90 promoted CAC depending on gut microbiota. Combining 16s rDNA sequencing in feces specimens from CAC mice model, we speculated that Prevotella copri-defined microbiota might mediate the oncogenic role of Zfp90 in the development of CAC. Mechanistic studies revealed Zfp90 accelerated CAC development through Tlr4-Pi3k-Akt-Nf-κb pathway. Our findings elucidated the crucial role of Zfp90-microbiota-Nf-κb axis in creating a tumor-promoting environment and suggested therapeutic targets for CAC prevention and treatment.
