Article 6 controlled study 6 female microbial diversity nonhuman 6 adult 4 male 4 RNA 16S 3 amplicon 3 animal experiment 3 community structure 3 human 3 intestine flora 3 metagenomics 3 microbial community 3 Gut microbiome 2 Metagenomics 2 Ruminococcus 2 amino acid metabolism 2 bacterial metabolism 2 bacterium 2 bile acid 2 carbohydrate metabolism 2 cohort analysis 2 disease association 2 fatty acid synthesis 2 feces microflora 2 fermentation 2 major clinical study 2 metabolite 2