Christensenella strain resources, genomic/metabolomic profiling, and association with host at species level.

The gut commensal bacteria species are negatively associated with many metabolic diseases, and have been seen as promising next-generation probiotics. However, the cultured strain resources were limited, and their beneficial mechanisms for improving metabolic diseases have yet to be explored. In this study, we developed a method that enabled the enrichment and cultivation of strains from fecal samples. Using this method, a collection of Gut Microbial Biobank (ChrisGMB) was established, composed of 87 strains and genomes that represent 14 species of 8 genera. Seven species were first described and the cultured resources have been significantly expanded at species and strain levels. strains exerted different abilities in utilization of various complex polysaccharides and other carbon sources, exhibited host-adaptation capabilities such as acid tolerance and bile tolerance, produced a wide range of volatile probiotic metabolites and secondary bile acids. Cohort analyses demonstrated that and were prevalent in various cohorts and the abundances were significantly reduced in T2D and OB cohorts. At species level, showed different changes among healthy and disease cohorts. , , , and significantly reduced in all the metabolic disease cohorts. The relative abundances of and showed no significant change in NAFLD and ACVD. and and showed no significant change in ACVD, and and showed no significant change in NAFLD, when compared with the HC cohort. So far as we know, this is the largest collection of cultured resource and first exploration of prevalences and abundances at species level.