Abstract Aims Obesity is linked to various adverse health effects, with body fat percentage being a key indicator of these risks. While the gut microbiota (GM) plays important roles in obesity, the specific species involved remain poorly understood. We aimed to identify gut species that may influence obesity in a cohort of US men. Methods and Results We conducted a comprehensive integrative analysis using metagenomics and whole-genome sequencing data in the US cohort. MaAsLin2 was used to identify associations between GM and whole body fat percentage (PFAT). Mendelian randomization (MR) was applied to investigate potential directional relationships between GM species and PFAT, as well as possible interactions between microbial species. Porphyromonas asaccharolytica (P.asaccharolytica) was negatively associated (β=-0.181, P=0.005) with PFAT, while Bacteroides fragilis (B.fragilis) was positively associated (β=0.239, P=0.001); these associations were validated in an independent Chinese cohort. MR analysis suggested that P.asaccharolytica may influence PFAT in part through its potential effect on B. fragilis abundance. Conclusion Gut species P.asaccharolytica and B.fragilis are associated with host body fat percentage and may influence obesity individually or collaboratively. The observed associations provide evidence consistent with a potential directional relationship between these species and human adiposity.
Tian et al. (Wed,) studied this question.