Gut Microbiota and Metabolome Alterations Associated with Chinese Monks’ Practice

BackgroundThe practices of monks mainly include long-term vegetarianism and meditation, which are likely to fundamentally influence the gut microbiota and fecal metabolites. We aim to study the relationship between the practices of Chinese monks and gut microbiotas and metabolites.MethodsTwenty-four monks and forty-eight omnivorous controls (never meditated) were included. The microbiotas of all samples were profiled by 16S rRNA gene sequencing, and the metabolomes were examined by nontargeted LC–MS metabolomics. Twenty-four monks were divided into the H group and the L group according to the median time of practice, and microbiota and metabolite analyses were carried out in the two groups.ResultsMicrobial communities and metabolites were decreased in monks. Bacteroidetes was increased in monks, while the Firmicutes, Actinobacteria, and Firmicutes/Bacteroidetes ratios were decreased. At the genus level, Faecalibacterium, Lachnospira, Roseburia, norank_f__Lachnospiraceae, etc. were higher in monks, while Blautia, Eubacterium__hallii_group, Bifidobacteria, etc. were lower (all p < 0.05). Most identical KEGG categories in both Tax4Fun and PICRUSt2 were related to metabolism (6/8, 75.0%). Most higher abundance genera were positively correlated with higher abundance metabolites in monks, indicating that intestinal flora significantly affects intestinal metabolic function. Lipids and lipid-like molecules were the major differential metabolites (VIP >2, p < 0.05) in the two groups. L-dopa plays an important role in many metabolic pathways in monks. Prevotella_9 was enriched in the L group, while norank_f__Lachnospiraceae was enriched in the H group. DG (16:0/18:0/0:0) was highly expressed in the H group and participated in sixteen KEGG functional pathways as well as many immune-related KEGG enrichment pathways.ConclusionThe monks' lifestyle practices of vegetarianism and meditation have the potential to modulate human metabolism and function by affecting the gut microbial composition and metabolites. The appropriate practice of monks makes the intestine younger and increases immunity, but long-term practice may cause adverse physical and mental events.