All About Short Chain Fatty Acids: Why SCFAs Are Crucial to Your Diet

( - The human microbiome is the collection of microbes that live on and in our body. Our stomachs and intestines contains most of these, with millions of different microorganisms and species which can have a massive affect on human health and disease (1).

Few people are aware of the integrative role that the bacteria in our gut plays. For example, our gut bacteria has the potential to produce harmful metabolites associated with development of disease or beneficial metabolites that protect against disease and improve health (1).

Interestingly, there is a large connection between the bacteria in our gut and our diet (2). The composition (e.g. “bad food” vs “good food”) of our diet can influence the development and survival of both beneficial or harmful bacteria (2). This is just one reason to show that eating whole foods and not just doing IIFYM all the time is important.

Because humans lack the enzymes to digest the bulk of dietary fibers, there is a large amount of non-digestible material flowing through the body. The bacteria in our GI tract feed off this material and produce byproducts such as Short Chain Fatty Acids (SCFA) (3).

Few people are aware of the numerous benefits that SCFA provide, this article will teach you everything you need to know.

What Are Short Chain Fatty Acids

SCFA are fatty acids that consist of one to six carbons of which acetate, propionate, and butyrate are the most abundant. While these may just sound like complex words, they are actually responsible for many of the health benefits discussed below  (3).

The amount of total fiber per day and even the specific type of fiber consumed has dramatic effects on the number and variety of bacteria in your gut. Consequently, the type and amount of SCFAs produced is also affected by your diet and fiber intake (4).

Screen Shot 2016-07-12 at 8.36.53 PMAs shown above, SCFA can play a key role for any physique athlete or individual trying to lose body fat or improve health.

In addition, SCFAs might play a key role in the prevention and treatment of the metabolic syndrome, diabetes, bowel disorders, and certain types of cancer (5, 6, 7, 8, 9).

Short Chain Fatty Acids and Gut Health

The incidence of both inflammatory and autoimmune diseases has increased dramatically in Westernized countries over the past several decades. Experts now believe “inflammation” is a key factor is in most serious diseases and illnesses.
For an athlete, inflammation can lead to joint issues, injury risk, insulin resistance, fat gain, immune system issues and of course, ill health.

While both genetic and environmental factors influence your chances of developing these lifestyle-based diseases, the contribution of diet and the relevance of SCFAs are only just starting to be appreciated (13).

For example, low levels or intake of SCFAs have been linked to ulcerative colitis, a condition of chronic bowel inflammation. Adding SCFAs through diet or supplementation has also been shown to reduce symptoms (or even potentially eliminate) ulcerative colitis and a similar condition called Chrohn’s Disease (14, 15, 16, 17, 1819, 20).

New research has also suggested that SCFAs could play a role in the prevention and treatment of certain cancers, particularly colon cancer. The mechanisms are still being investigated, but SCFAs may play a role in preventing growth of tumor cells, destroying cancer cells, and keeping the cells of the colon healthy and functional (7,8,9, 21, 22, 23).

It is also possible that a high-fiber diet – resulting in production of a lot of SCFA – may protect you from certain cancers; however the evidence is still mixed (24, 25, 26).

Short Chain Fatty Acids and Diabetes

High fiber diets have been shown to decrease the risk of being diagnosed with Type 2 diabetes and may also play a beneficial role in reducing symptoms and other related metabolic diseases (27, 28)

Specifically, SCFAs may help to treat and prevent diabetes in several ways:

  • Decreasing blood sugar levels (29)
  • Reducing insulin resistance and improving sensitivity (30, 31)
  • Fighting inflammation (32, 33)

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Source: Puddu, A., Sanguineti, R., Montecucco, F., & Viviani, G. L. (2014). Evidence for the gut microbiota short-chain fatty acids as key pathophysiological molecules improving diabetes. Mediators of inflammation, 2014.

As a result, SCFAs may dictate the status of someone’s metabolic control and ultimate risk of developing diabetes or unhealthy body composition.

Short Chain Fatty Acids and Cardiovascular Health

There is mounting evidence that SCFAs may play a role in lowering cholesterol levels, primarily through reducing the body’s cholesterol production. (34, 35, 36, 37)

This could partially explain the link between high-fiber diets and reduction of heart disease risk. (38, 39)

While the formation of CV is certainly multifactorial, SCFA may help with many of the issues that increase the risk of developing CV disease. As discussed in this article, SCFA may aid with inflammation, elevated blood sugar levels, weight gain, diabetes and insulin, all of which are closely linked to cardiovascular disease.

Short Chain Fatty Acids and Weight Management

Daily SCFAs may be a secret weapon in losing weight, keeping it off, and improving body composition.

There is compelling evidence that suggests that SCFAs can help to control appetite, increase energy expenditure, and decrease food intake.

In addition to these direct effects, SCFA have long-term benefits on blood sugar levels, insulin sensitivity and inflammation, all of which are linked to weight gain and your physique (40).

The Body Fat Burning Connection

Despite what the internet may say, not all carbohydrates are bad. In fact, there is some interesting evidence suggesting that certain carbohydrates such as SCFA can actually help you burn body fat!

The main example is “Resistant Starch”, a special type of starch that isn’t fully broken down and absorbed like normal carbohydrates. Because it is not fully digested it gets broken down into SCFAs by the bacteria in our gut, which can provide all the benefits mentioned in this article.

Several Studies have shown that resistant starch has many positive effects on your physique, fat loss and overall body composition. These include:

  • Reducing blood sugar levels (41)
  • Increased release of satiating hormones, helping you eat less (42)
  • Increased fat burning (43)
  • Lower fat storage in fat cells (44)
  • Increasing the energy required to digest food, helping you burn more food. (46)

To get the most resistant starch in your diet, you can:

  • Prepare starch-based food in advance and allow it to cool overnight (batches of oats, potatoes, rice, beans, etc).
  • Daily supplementation with something similar to Bob’s Red Mill Potato Starch (or any brand). Try taking 5 to 8 grams two times per day.

Food Sources of Short Chain Fatty Acids

Since SCFAs are produced from the digestion of fiber in the intestines, the best sources are generally fiber-rich fruits, vegetables, legumes and grains.

Specifically, the fibers inulin, fructooligosaccharide (FOS), pectin, guar gum, arabinoxylan, and resistant starches are the main compounds that the bacteria feed off of (10,11).

Many of these can be taken in supplement form, which is highly recommended if you don’t eat a large amount of fiber. For most supplements, start with 5 grams per day.

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However, you can also get some SCFAs from dairy products such as milk, cheese, and butter, although the amount will be much lower and may not provide a significant amount to elicit the desired effect (12).


We’ve known for a long time that a high-fiber diet can be beneficial for our overall health and body composition.

However, SCFA and even Resistance Starch are less well known. Interestingly, these two forms of fiber may actually be the main reason for all the health benefits witnessed from a high fiber diet.

Focus on eating more vegetables, which are a low calorie, nutritious source of fiber. In addition, some legumes, beans, seeds, nuts and even healthy grains such as ezekiel bread or quinoa are all good sources.

On top of these foods, you will probably want to supplement with a fiber supplement, just to ensure you are getting plenty of SCFA, which can be very hard to achieve during a diet.

While several supplements can work well, I often recommend Inulin at 5 grams per day along with Bob Mills Potato Starch at 5 grams twice per day.

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