Promising breakthrough for fatty liver patients: Resistant starch cuts liver fat

An estimated 30% of the world's population currently has non-alcoholic fatty liver disease (NAFLD), which has reached epidemic proportions globally. It is a multisystem disease that may not only develop into severe chronic hepatic diseases but also contribute to extrahepatic diseases such as type 2 diabetes, cardiovascular disease, and chronic kidney disease, causing a tremendous clinical and economic burden.

To investigate the effects of resistant starch (RS) as a microbiota-directed dietary supplement for NAFLD treatment, the researchers coupled a 4-month randomized placebo-controlled clinical trial in individuals with NAFLD with metagenomics and metabolomics analysis.

A total of 200 participants with NAFLD were recruited and randomized with a 1:1 allocation to the 4-month administration of RS type 2 from high-amylose maize or control starch with equal energy supply.

Relative to the control, the RS intervention resulted in a 9.08% absolute reduction of intrahepatic triglyceride content (IHTC), which was 5.89% after adjusting for weight loss. Serum branched-chain amino acids (BCAAs) and gut microbial species, in particular Bacteroides stercoris, significantly correlated with IHTC and liver enzymes and were reduced by RS.

Multi-omics integrative analyses revealed the interplay among gut microbiota changes, BCAA availability, and hepatic steatosis, with causality supported by fecal microbiota transplantation and monocolonization in mice. Thus, RS dietary supplementation might be a strategy for managing NAFLD by altering gut microbiota composition and functionality.

Reference: Yueqiong Ni et al, Cell Metabolism 35, 1530–1547, September 5, 2023, DOI: https://doi.org/10.1016/j.cmet.2023.08.002