The gut microbiota in our body produces various substances called metabolites. One of those metabolites is short-chain fatty acids (SCFAs). These are the compounds our digestive system produces when dietary fiber that we can’t digest ferments in the gut. Acetate, butyrate and propionate are some of the major SCFAs. SCFAs are important biofuels that provide energy for colon cells and regulate epithelial barrier function. They also act as messenger molecules that regulate various body systems.

How we produce SCFAs

Eating a variety of high-fiber foods, such as vegetables, fruits, legumes, and whole grains, helps our body make SCFAs. The overuse or unsupervised use of antibiotics can lower the diversity of microbiota, which then changes the amount of SCFAs we make. Consuming prebiotics and probiotics can also change the gut microenvironment, gut microbiota composition, prevent growth of harmful microbiota and enhance the availability of SCFAs.

Benefits of SCFAs

Ninety-five percent of the SCFAs we produce are absorbed by the cells lining our colon. They have been reported to inhibit the growth of cancer cells and may help reduce the risk of many chronic health conditions, including:

• Type 2 diabetes
• Obesity
• Metabolic dysfunction-associated fatty liver disease (MAFLD)
• Chronic kidney disease
• High blood pressure
• Ulcerative colitis  and irritable bowel syndrome

Acetate helps regulate appetite and metabolism, particularly how we process fats and sugars. Propionate plays an important role in modulating hepatic cholesterol metabolism and has been found to protect against neurological disorders, such as Parkinson’s disease. Butyrate, another of the major SCFAs, has been reported to maintain intestinal epithelial barrier function and prevent intestinal inflammation. Butyrate may also prevent the occurrence and development of colon cancer cells.

Friend or foe?

When it comes to SFCAs, sometimes too much of a good thing isn’t always great for your body. A buildup of propionate may harm nerve cells and has been linked to autism spectrum disorder and mitochondrial dysfunction. Butyrate supplements may increase blood pressure in people with hypertension. If you’re going to take SFCA supplements, discuss with your doctor whether it’s right for you.

What comes next?

Because SCFAs are produced by gut microbiota, anything that alters the gut microbiome can also change how much SCFA is available in your body. This interplay highlights the need to understand how diet, lifestyle, and the antibiotics you take affect your gut. More clinical trials focused on SCFAs to treat diseases could be beneficial to learn how they can affect human health.