Short-chain fatty acids (SCFAs) are one of the most important groups of postbiotic metabolites produced by probiotic bacteria. SCFAs have a number of important health-regulating functions in the intestinal tract including reducing inflammationi, establishing and maintaining optimal acid/base balanceii and they are also the main source of nutrition for the renewal of healthy new cells that line the gastrointestinal tract.iii
Short-chain fatty acids also get absorbed into systemic circulation. When they reach the liver, they inhibit the activity of the key enzyme that is responsible for cholesterol synthesis. Studies in both animals and humans have shown that SCFAs act to reduce levels of both cholesterol and triglycerides.iv
Short chain fatty acids function to decrease cholesterol by several mechanisms including inhibiting cholesterol synthesis in the liver, redistributing cholesterol from plasma to the liver and also interfering with cholesterol absorption.v
To date, only a few clinical trials have been conducted in humans. However, this is a new area of research that shows how one particular class of postbiotic metabolites, namely short chain fatty acids, impact human health by playing a role in the regulation of cholesterol levels.