Cholesterol-lowering effects of oats induced by microbially produced phenolic metabolites

Oats have various positive effects on human health, but the underlying mechanisms are not fully understood. To identify oat-microbiome-host interactions that contribute to metabolic improvements, we conducted two randomized controlled dietary interventions in individuals with metabolic syndrome, comparing a short-term, high-dose and a six-week, moderate oat intake with respective controls (DRKS00022169). While the moderate oat-diet leads to slight changes in metabolism, gut microbiota and metabolomic profiles, the high-dose oat-diet decreases total cholesterol on average by 8% and low-density lipoprotein cholesterol by 10%, accompanied by distinct changes in metabolomic profiles and gut microbiota. Particularly, the increase in microbially produced phenolic compounds is associated with improved lipid metabolism, suggesting that these compounds are driving factors for the cholesterol-lowering effect of oats, besides the known mechanisms of β-glucan. This newly identified mechanism might be of great potential since a short-term, high-dose oat diet is a suitable and rapid approach to alleviate obesity-related lipid disorders.