Urinary enterolignans and enterolignan-predicting microbial species are favourably associated with liver fat and other obesity markers.

Aims: Plant-derived lignans may protect against obesity, while their bioactivity needs gut microbial conversion to enterolignans. We used repeated measures to identify enterolignan-predicting microbial species and investigate whether enterolignans and enterolignan-predicting microbial species are associated with obesity. Methods: Urinary enterolignans, fecal microbiota, body weight, height, and circumferences of the waist (WC) and hips (HC) were repeatedly measured at the baseline and after 1 year in 305 community-dwelling adults in Huoshan, China. Body composition and liver fat [indicated by the controlled attenuation parameter (CAP)] were measured after 1 year. Multivariate-adjusted linear models and linear mixed-effects models were used to analyze single and repeated measurements, respectively. Results: Enterolactone and enterodiol levels were both inversely associated with the waist-to-hip ratio, body fat mass (BFM), visceral fat level (VFL), and liver fat accumulation (all P < 0.05). Enterolactone levels were also associated with lower WC (β = -0.0035 and P = 0.013) and HC (β = -0.0028 and P = 0.044). We identified multiple bacterial genera whose relative abundance was positively associated with the levels of enterolactone (26 genera) and enterodiol (22 genera, all P false discovery rate < 0.05), and constructed the enterolactone-predicting microbial score and enterodiol-predicting microbial score to reflect the overall enterolignan-producing potential of the host gut microbiota. Both these scores were associated with lower body weight and CAP (all P < 0.05). The enterolactone-predicting microbial score was also inversely associated with the BFM (β = -0.1128 and P = 0.027) and VFL (β = -0.1265 and P = 0.044). Conclusion: Our findings support that modulating the host gut microbiome could be a potential strategy to prevent obesity by enhancing the production of enterolignans.