Curcumin cuts hepatic fat content in NASFL

Supplementation with curcumin helps lower hepatic fat content in patients with nonalcoholic simple fatty liver (NASFL), driven by improvements in gut microbiota-dependent bile acid metabolism and Takeda G protein-coupled receptor 5 (TGR5) activation, a study has found.

Consumption of curcumin resulted in a significant decrease in controlled attenuation parameter (CAP) value relative to placebo (‒17.5 dB/m, 95 percent confidence interval [CI], ‒27.1 to ‒7.8; p<0.001). In particular, weight decreased by 2.6 kg (95 percent CI, ‒4.4 to ‒0.8; p<0.001) and BMI by 1.0 kg/m² (95 percent CI, ‒2.0 to ‒0.1; p=0.032).

Curcumin intake also reduced free fatty acid (‒0.12 mmol/L, 95 percent CI, ‒0.20 to ‒0.04; p=0.004), triglycerides (‒0.29 mmol/L, 95 percent CI, ‒0.41 to ‒0.14; p<0.001), fasting blood glucose (‒0.06 mmol/L, 95 percent CI, ‒0.12 to ‒0.01; p=0.038), haemoglobin A1c (‒0.06 percent, 95 percent CI, ‒0.33 to ‒0.01; p=0.019), and insulin (‒4.94 μU/L, 95 percent CI, ‒9.73 to ‒0.15; p=0.043) versus placebo.

In gut microbiota analysis, curcumin significantly reduced the Firmicutes-to-Bacteroidetes ratio and increased Bacteroides abundance.

The curcumin group also showed elevated serum levels of deoxycholic acid (37.5 ng/mL, 95 percent CI, 6.7‒68.4; p=0.018), the most potent activator of TGR5. In addition, curcumin consumption raised TGR5 expression in peripheral blood mononuclear cells and serum glucagon-like peptide-1 levels (0.73 ng/mL, 95 percent CI, 0.16‒1.30; p=0.012).

This double-blind randomized trial was conducted for 24 weeks and included 80 patients with NASFL who received curcumin 500 mg/d or placebo. The investigators measured hepatic fat content using FibroTouch-based CAPs and analysed microbial composition and bile acid metabolites using 16S rRNA sequencing and metabolomics.