Quantitative polymerase chain reaction (qPCR) and reverse transcription (RT)-PCR microarrayRNA isolation, purity determination, electrophoresis monitoring, reverse transcription, and quantification were performed according to the standard

1Objective: An excess of fecal bile acids (BAs) is thought to be one of the mechanisms for diarrhea-2 predominant irritable bowel syndrome (IBS-D). However, the factors causing excessive BA excretion 3 remains unclear. Given the importance of gut microbiota in BA metabolism, we hypothesized that gut 4 dysbiosis might contribute to excessive BA excretion in IBS-D. 5Design: Metabolomic and metagenomic analyses were performed of specimens from 290 IBS-D 6 patients and 89 healthy volunteers. By transplanting human microbiota and manipulating specific 7 microbiome species in mice, the effects of microbiota on host BA metabolism were assessed at 8 metabolic, genetic and protein levels. Effects of individual and mixed BAs on enterohepatic feedback 9 pathways were also tested in vitro and in vivo.

Background：Although dietary patterns are recognized to affect health by interfering with gut microbiota homeostasis, whether live or dead bacteria-bearing spring mineral water (MW) would also exert beneficial effects on health upon curing gut dysbiosis remains unknown. Results：Due to harboring live bacteria, the heated but unboiled MW from Bama, where centenarians are ubiquitously inhabited, reshapes the gut microbiota from a traveler-type to a local resident-type except for Prevotella. While chondroitin sulfate, a component occurring in livestock and poultry meats, increases the richness of sulfatase-secreting bacteria and sulfate-reducing bacteria, Bama MW dampens the overgrowth of those colonthinning bacteria and hampers the overexpression of multiple genes responsible for anti-inflammation, anti-oxidation, anti-hypoxia, anti-mutagenesis, and anti-tumorigenesis. Conclusions：Bama spring MW prevents the early-phase onset of breast cancer by curating gut dysbiosis. MW also compromises chromosomal DNA damage and ameliorate mitochondrial dysfunctions, implying it may extend lifespan.