(P02-023-23) Red Meat Intake, Fecal Microbiome, Serum Trimethylamine-N-Oxide, and Hepatic Steatosis Among Chinese Adults

Objectives: Red meat intake was shown to be associated with the higher risk of hepatic steatosis. Trimethylamine N-oxide (TMAO) is a metabolite derived via gut microbial metabolism of choline-rich foods such as red meat. We investigated whether gut microbiome could modify associations of red meat with serum concentrations of TMAO and its precursors, and the likelihood of hepatic steatosis among Chinese adults.

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 days dietary recall (i.e., 12 24-h recalls). We profiled fecal microbiome using 16S rRNA sequencing. Serum concentrations of TMAO and its precursors were measured by LC-tandem MS. Hepatic steatosis was defined by controlled attenuation parameter (CAP) using transient elastography (TE). The associations between TMAO and the fecal microbiome were assessed by hurdle regression, while the association between TMAO and red meat was assessed by linear regression. The adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) for the associations of red meat, TMAO and its precursors with hepatic steatosis were evaluated using Logistic regression.

Results: Among 333 participants with TE examination, 91 were diagnosed with hepatic steatosis (CAP ≥ 268). TMAO level was positively associated with the likelihood of hepatic steatosis (aOR comparing extreme tertiles = 3.12, 95% CI: 1.37-7.12). We identified 8 bacterial genera whose abundance was associated with TMAO concentration (PFDR < 0.05), and constructed a TMAO-predicting microbial score (TMS). Per 10 gram/day increase in red meat intake was positively associated with TMAO level among participants with higher TMS (β = 0.07, P = 0.04), but not among participants with lower TMS (β = -0.01, P = 0.38, P<sub>interaction = 0.08). Red meat intake was associated with higher odds of hepatic steatosis (aOR = 1.12, 95% CI: 1.01-1.24). Such positive association was more pronounced in participants with higher TMS (aOR = 1.21, 95% CI: 1.07-1.37, P<sub>interaction = 0.03).

Conclusions: We identified multiple bacterial genera that were associated with serum TMAO concentration. These genera jointly modified the associations of red meat intake with TMAO level and the likelihood of hepatic steatosis.

Funding Sources: National Natural Science Foundation of China