Fig. 4

Gut microbial functional components associated with both US exposure and dietary fiber intake, and their associations with obesity and gut bacterial genera. A Correlation heatmap for 12 microbial functional enzymes associated with both US exposure and dietary fiber. B Association of 12 microbial functional enzymes with US exposure, dietary fiber intake and BMI. These associations were estimated in linear regression models after adjustment for demographic, socioeconomic, behavioral, and clinical factors. Red/blue colors depict significant positive/inverse associations (FDR P < 0.05) and the gradient colors reflect the ranks of effect sizes estimated in linear regression models, while white color indicates non-significant associations. C Levels of gut microbial enzyme K15531 xylanase according to US exposure, dietary fiber intake, and host obesity. Data are adjusted mean (SE) of enzyme K15531 xylanase (centered log-ratio transformed) across US exposure groups, levels of dietary fiber intake, and host obesity status estimated in linear regression models after adjustment for demographic, socioeconomic, behavioral, and clinical factors. D Associations of 15 gut bacterial genera with gut microbial enzyme K15531 xylanase. Data are effect sizes and P values estimated in linear regression models after adjustment for demographic, socioeconomic, behavioral, and clinical factors (multivariable adjustment) and further adjustment for other bacterial genera (conditional analysis, mutual adjustment)