What Are Short-Chain Fatty Acids?

The good bacteria in your gut help support your health in a variety of ways, including creating short-chain fatty acids. It’s believed short-chain fatty acids (SCFAs) play important roles in helping keep you healthy and preventing diseases. 

This article explores the potential health benefits of short-chain fatty acids.    

Understanding Short-Chain Fatty Acids

Short-chain fatty acids (SCFAs) are a type of fatty acid with less than six carbon atoms. They are produced when the bacteria that live in your intestines ferment fiber. These bacteria and other microorganisms make up your gut microbiome, also called gut flora. 

In recent years, researchers have been exploring the effects of the gut microbiome on health. And they’ve found SCFAs play an important role in health and disease prevention. SCFAs are used by the cells in your intestines as energy, reduce inflammation, absorb minerals, aid metabolism, and other health benefits. 

The three main types of SCFAs produced are:

• Acetate  
• Propionate
• Butyrate

Dietary Fiber and SCFAs

Dietary fiber is the part of food that bacteria ferment to create SCFAs. Fiber comes from plant-based foods, like fruits, vegetables, beans, and legumes. It gives plants its structure and binds the food together. 

Despite its many health benefits, fiber isn’t considered a nutrient because humans lack the enzymes to digest and absorb fiber. Instead, it promotes regularity in bowel movements by binding to nutrients and waste products created during digestion to pull them out of the body in the stool.

But the bacteria in the gut can break down and ferment some types of fiber. This helps promote the health of the “good” bacteria in the gut and produces SCFAs that the body can use.  

Soluble and Insoluble Fiber

Two main types make up the fiber in the human diet, called soluble and insoluble fiber. 

Soluble fiber dissolves in water and forms a gel-like consistency. It helps stool move through the digestive system easier and may improve blood sugar and cholesterol levels. 

Insoluble fiber doesn’t dissolve in water. It still attracts water and adds bulk to stool. Insoluble fiber promotes bowel regularity, may increase insulin sensitivity (response to insulin to take blood sugar into cells), and reduces the risk for colon diseases. 

Many plant foods contain a mix of soluble and insoluble fibers. A healthy diet should include both types of fiber.

Here are some of the foods high in soluble and insoluble fiber:

Soluble fiber:

• Oats
• Peas
• Beans
• Apples
• Citrus fruits
• Carrots
• Barley

Insoluble fiber:

• Whole wheat flour and products
• Wheat bran
• Beans
• Nuts
• Cauliflower
• Green beans
• Potatoes

Digestive Health Benefits of SCFAs

SCFAs provide numerous benefits for digestive health and other areas of the body. Here are some of the known health benefits of SCFAs: 

Improve Inflammatory Bowel Disease Symptoms

Inflammatory bowel disease (IBD) is a chronic condition that involves an overactive immune response in the gut and gut microbiome. The two forms of IBD are Crohn’s disease and ulcerative colitis. 

Research suggests that the SCFA butyrate may help reduce inflammation in the intestine, support healthy cells, and promote a healthy balance of gut bacteria.

It’s believed an imbalance of “good” and “bad” bacteria in the gut increases the risk of developing IBD. So, SCFAs may be important for preventing IBD and balancing the gut flora for people with IBD. 

Reduce Diarrhea

SCFAs may help prevent and ease digestive symptoms like diarrhea. A 2014 study found that a mixture of sodium butyrate and short-chain fatty acids reduced the risk of developing travelers’ diarrhea (diarrhea illness contracted from food or water during travel).

Lower Colon Cancer Risk

Changes in the gut microbiome are associated with an increased risk of developing colorectal cancer. Research suggests SCFAs may reduce the risk of colon cancer and improve survival rates by preventing the growth of cancer cells and promoting the death of cancer cells.

Help Control Blood Sugar and Diabetes

SCFAs may help regulate the hormones that impact blood sugar levels and diabetes risk. A study found that propionate helps support the health of beta cells in the pancreas, which are responsible for releasing the hormone insulin. 

Another 2019 study showed that SCFAs influence a hormone called glucagon-like peptide 1 (GLP-1), which helps regulate the secretion of the hormones insulin and glucagon. 

These effects may lower blood sugar levels, promote better blood sugar control, and lower the risk of developing type 2 diabetes. 

Support Healthy Weight Maintenance

The impacts of obesity-related health complications have led researchers to explore how to support people in maintaining a healthy weight. 

It’s believed the SCFA acetate may help people lose weight and support healthy weight maintenance. Acetate may be able to regulate hormones (like GLP-1), increase metabolism, and lower appetite. 

However, research is needed to understand these effects because many studies are animal models and the human research studies have mixed results. 

Protect Heart Health

Many research studies have linked a high fiber diet with a lower risk of cardiovascular diseases by lowering cholesterol, blood pressure, and inflammation. These effects are partially explained by the cholesterol-lowering effects of soluble fiber. It’s also believed the conversion of fiber into SCFAs helps support heart health. 

A research review discussed the potential cardiovascular benefits of SCFAs by reducing inflammation, cholesterol levels, and supporting weight loss. 

Ongoing Research About SCFAs

Researchers continue to explore the relationship between the SCFAs produced by gut bacteria and health. They’re still working to fully understand how it influences human health because most of the research studies show the influence of SCFAs on animal health. 

Early studies show similar health benefits in human studies. Still, more research and blind studies are needed to prove the effects. Researchers are continuing to explore the influence of SCFAs on gut, heart, metabolic, brain, and mental health. 

Recommended Fiber Intake

The current recommendations for daily fiber intake are around 30 to 35 grams for males and 25 to 32 grams for females. But most Americans only eat about 50% of the daily recommended amount of fiber. 

Fiber supplements are available. These help bulk up your stool, but it’s unclear if they provide the other health benefits of fiber. Aim for meeting your daily fiber needs from whole foods. 

Here is how many grams (g) are in one serving of some high fiber foods:

• ½ cup of black beans: 6 grams
• 1 medium apple: 2 grams
• 1 packet of instant oatmeal: 4 grams
• 1/2 avocado: 5 grams
• 1 medium orange: 3 grams
• 1 medium russet potato: 3 grams
• 1 cup carrots: 4 grams
• 1 cup green beans: 3 grams
• 1 cup cauliflower: 3 grams

Summary

Short-chain fatty acids (SCFAs) are produced when gut bacteria ferment dietary fiber. The gut bacteria primarily produce three types of SCFAs, including acetate, butyrate, and propionate.

SCFAs may support health by reducing the risk of inflammatory bowel disease, colon cancer, reducing digestive symptoms, promoting healthy weight, improving blood sugar control, and other health benefits. A few high-fiber foods include beans, legumes, green beans, avocados, apples, oats, and citrus fruits. 

A Word From Verywell

Keeping your gut microbiome balanced appears to help support your overall health by lowering disease risk and producing helpful nutrients, like SCFAs. Eating plenty of high fiber foods provides fuel for the “good” gut bacteria to produce SCFAs and may support your overall health.