The Prebiotic Effects of Oats on Blood Lipids, Gut Microbiota, and Short-Chain Fatty Acids in Mildly Hypercholesterolemic Subjects Compared With Rice: A Randomized, Controlled Trial

Xu D, Feng M, Chu YF, Wang S, Shete V, Tuohy KM, Liu F, Zhou X, Kamil A, Pan D, Liu H, Yang X, Yang C, Zhu B, Lv N, Xiong Q, Wang X, Sun J, Sun G, Yang Y · Frontiers in Immunology · 2021 December 09

DOI 10.3389/fimmu.2021.787797

Objective

To investigate the cholesterol-lowering effects of oats and the associated mechanisms, including the impact on gut microbiota, short-chain fatty acids (SCFAs), and plasma lipid profiles.

Conclusions

Oats consumption for 45 days significantly reduced total cholesterol (TC) and LDL cholesterol, with a greater reduction compared to rice intake. Oats also influenced the gut microbiota by increasing the abundance of Akkermansia muciniphila and Roseburia, and altering the relative abundance of Dialister, Butyrivibrio, and Paraprevotella. The prebiotic effect of oats was associated with correlations between specific gut bacteria (Bifidobacterium, Faecalibacterium prausnitzii) and plasma lipids. Plasma SCFAs were correlated with changes in gut microbiota, suggesting that the prebiotic activity of oats contributes to its cholesterol-lowering effects.

Critical Appraisal

Published research can offer valuable insights, but a paper’s conclusions may go beyond what its results support. Critical appraisal examines the methods, findings and limitations to clarify what can reasonably be concluded—and what remains uncertain.

This article has not yet been critically appraised by the Research Hub.

Learn more about Critical Appraisal

Insights

Consuming oats significantly lessens total and LDL cholesterol levels and mediates a prebiotic effect on the gut microbiome, contributing to its cholesterol-lowering ability.

In a randomized controlled study, 210 mildly hypercholesterolemic subjects from three various study centers across China were assigned to consume either 80 g of oats or rice daily for 45 days. To ascertain the effects of these diets, measurements were taken of the participants' plasma lipid profiles, short chain fatty acids (SCFAs), and fecal microbiota. Following 30 and 45 days of adherence to these diets, there was a pronounced reduction in total cholesterol (TC) and non-high-density lipoprotein cholesterol (non-HDL-C) in both the oat-consuming and rice-consuming participants. This decrease was more articulated amongst the oat consumers by the 45th day. The consumption of oats led to a significant increase in the abundance of certain beneficial gut microbiota and a corresponding decrease in unclassified harmful types. These microbiota demonstrated associations with changes in plasma lipid levels and SCFAs. The comprehensive findings strongly suggest that the cholesterol-reducing effect of oats may be largely down to its prebiotic activity, which modulates the gut microbiome.