Red meat intake, faecal microbiome, serum trimethylamine N‐oxide and hepatic steatosis among Chinese adults

Abstract Background and Aims Emerging evidence suggests a detrimental impact of high red meat intake on hepatic steatosis. We investigated the potential interplay between red meat intake and gut microbiome on circulating levels of trimethylamine N‐oxide (TMAO) and hepatic steatosis risk. Methods This cross‐sectional study was conducted in a representative sample of 754 community‐dwelling adults in Huoshan, China. Diet was collected using 4 quarterly 3 consecutive 24‐h dietary (12‐day) recalls. We profiled faecal microbiome using 16S ribosomal RNA sequencing and quantified serum TMAO and its precursors using LC‐tandem MS ( n = 333). We detected hepatic steatosis by FibroScan. The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated using logistic regression. Results TMAO levels but not its precursors were positively associated with the likelihood of hepatic steatosis (aOR per 1‐SD increment 1.86, 95% CI 1.04–3.32). We identified 14 bacterial genera whose abundance was associated with TMAO concentration ( p FDR < .05) belonging to the phyla Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria families. Per 10 g/day increase in red meat intake was positively associated with TMAO levels among participants who had higher red meat intake (>70 g/day) and higher TMAO‐predicting microbial scores (TMS, β = .045, p = .034), but not among others ( p interaction = .030). TMS significantly modified the positive association between red meat and steatosis ( p interaction = .032), with a stronger association being observed among participants with higher TMS (aOR 1.30, 95% CI 1.07–1.57). Conclusions The bacterial genera that predicted TMAO levels may jointly modify the association between red meat intake and TMAO levels and the subsequent risk of hepatic steatosis.