Excessive intake of carbohydrates and lipids is known to result in nonalcoholic fatty liver disease (NAFLD). However, the role of nutritional protein intake is not very clear. The link between the amount or composition of protein intake with the risk for disease severity is also not clearly understood.

Therefore, a study was designed to determine the associations of dietary components with histological disease activity. Detailed 14-day food records in a cohort of 61 patients with biopsy-proven NAFLD were analyzed for the purpose of this study. 16S ribosomal RNA gene sequencing was used to detect associations with different abundances of the gut microbiota with dietary patterns.

Patients with definite nonalcoholic steatohepatitis (NAFLD activity score of 5-8 on liver biopsy) appeared to have a significantly higher daily relative intake of protein compared to patients with NAFLD activity score of 0-4 (18.0% vs. 15.8% of daily protein-based calories). Adjusting for several potentially confounding factors, a higher intake of protein, with ≥17.3% of daily protein-based calories, was shown to be associated with definite nonalcoholic steatohepatitis [odds ratio of 5.09 (95% confidence interval 1.22-21.25)]. The association was guided by serine, glycine, arginine, proline, phenylalanine, and methionine. A higher protein intake was also correlated with a reduced Bacteroides abundance besides altered abundance of several other bacterial taxa.

High protein intake was thus shown to have an independent association with more active and severe histological disease activity in patients with NAFLD.

 Source: Lang S, Martin A, Farowski F, et al. High Protein Intake Is Associated With Histological Disease Activity in Patients With NAFLD. Hepatol Commun. 2020 Mar 26;4(5):681-695.