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.

Keywords: gut microbiome; hepatic steatosis; interaction; red meat; trimethylamine N‐oxide.