Short-chain fatty acids and their importance to gut health
Short-chain fatty acids are saturated fatty acids that play an important role in gut health. They have several functions in human metabolism. Increasing the level of short-chain fatty acids in the gut might be a beneficial strategy to support overall health. Consumption of prebiotics and/or postbiotics can lead to higher levels of short-chain fatty acids.
What are short-chain fatty acids?
The gut microbiome is the community of microorganisms that can be found living in the gut. Evidence that bacteria in the gut are important to your health is growing each day. That’s why it is important to have a good balance of different bacteria in the gut. Not having a well-balanced microbiome is an indicator for several health issues, such as obesity (1).
The bacteria in the gut partially fulfill their role in health by making short-chain fatty acids (SCFAs). SCFAs are saturated fatty acids that contain six or fewer carbon molecules.
SCFAs are produced by the microbiota when they break down dietary fibers and resistant starches that are not metabolized by the body. To break these substrates down, the microbiota do not need oxygen, which is why this process is called anaerobic fermentation.
The most important SCFAs that are produced in the gut are acetate, propionate, and butyrate, and all of them have different effects on gut health (2).
Following the production of SCFAs by microbiota, they are taken up by the first layer of gut cells. They are used directly as fuel by these gut cells and if the colonocytes don’t metabolize them, they are used elsewhere, for example as an energy source for liver cells (3).
The benefits of short-chain fatty acids
Other than being fuel for different types of cells, SCFAs have a beneficial effect on your gut health.
Short-chain fatty acids maintain the intestinal barrier
One of the benefits of SCFAs is that they help maintain the intestinal barrier. The intestinal barrier is important because it forms a layer of cells that separates the inside of your body from everything that passes through your gastrointestinal tract.
The structural integrity of the gut wall is key, as pathogens (e.g., viruses, bacteria, and toxins) can enter the body if there are gaps between cells of the gut wall.
SCFAs help preserve the intestinal barrier by feeding the cells of the gut wall and by stimulating the dilation of blood vessels, resulting in more blood flow to these cells. This is positive as the cells will get more oxygen.
Short-chain fatty acids increase mucus production in the gut
SCFAs have also been shown to increase mucus production in the gut. Mucus is a slimy substance that forms a protective layer on your gut wall.
An increase in mucus production is beneficial since the protective layer between the intestinal cells and the contents of your gut will be thicker. The thicker the better, meaning that this improves the function of the mucus and decreases the risks of pathogenic infiltration (3).
Short-chain fatty acids reduce gut inflammation
Gut inflammation is often seen in older people or people with irritable bowel syndrome. SCFAs help bring this inflammation down by altering the DNA expression of gut cells.
The result of this alteration is a decrease in the release of chemokines, which are signaling proteins that are usually involved in white blood cell attraction. Reducing the recruitment of white blood cells is an anti-inflammatory action (4).
Short-chain fatty acids can induce satiety
Researchers have demonstrated that SCFAs are able to modify food intake by promoting satiety and the SCFA responsible for that is propionate, which is also produced by the gut bacteria.
Propionate is transferred to the liver where it can bind to specific receptors and this leads the liver to start making gut hormones that induce satiety and thus lower hunger (5).
In short, SCFAs are relevant not only for gut health, but for overall health as well, which means it is valuable to raise the level of SCFAs in the gut. One way to achieve a higher level of SCFAs is by consuming prebiotics and, less familiar to most people, postbiotics.
What are prebiotics?
Prebiotics are non-digestible food ingredients that have a health benefit to the host. There are different types of prebiotics, and they have several health benefits. These health benefits range from supporting your immune system to providing energy to microbiota that help maintain gut health.
Prebiotics are food compounds, such as fibers and starches, that are not digested by the human digestive system. This means that the prebiotics reach the gut and the microbiota while still intact. The microbiota can digest them, leading to the creation of substrates that can be useful for human health.
How can prebiotics lead to higher levels of short-chain fatty acids?
Prebiotics go through anaerobic fermentation, which results in SCFA production. This means that taking prebiotics can help increase SCFA levels in the gut. As we have mentioned above, there are several reasons why you would want this!
There are several food products that contain high levels of prebiotic fibers, but it is also possible to increase prebiotic intake by taking supplements.
One example of a prebiotic fiber food is chicory root. It contains high amounts of prebiotic fiber inulin. Other good foods are arabinoxylan rich foods, such as wheat, corn, rice and oat. Arabinoxylans have a lot of health benefits and they have strong prebiotic properties.
The downside of prebiotics is that everyone has a different microbiome composition, which means that everyone also experiences different outcomes of prebiotic consumption.
For this reason, research has been done on alternatives. This led to an increase in interest in something that is more unknown than prebiotics, namely postbiotics.
Postbiotics are bacterial products, meaning that they aren’t fermented by the gut microbiota after consumption. An example of postbiotics are different short-chain fatty acids, as these are products of the microbiota.
Do you want to know more about postbiotics? Read this article.
How can MicrobiomeX® support SCFA levels?
MicrobiomeX® is an ingredient based on citrus flavonoids that can boost the immune system and improve gut defense. It has several ways to boost gut health and your immune system.
One way MicrobiomeX® helps is by promoting the growth of butyrate-producing strains of bacteria in the gut. Among these are the Faecalibacterium prausnitzii, Clostridium leptum and Roseburia. As mentioned before, butyrate is a SCFA that has several health benefits on the host.
Want to read more about MicrobiomeX®? Click here!
