SCFA: Bacterial Boosters
When probiotic bacteria are discussed, the “magic word” SCFA always comes up. These are short-chain fatty acids, a product of helpful and beneficial bacteria. But what exactly are SCFAs, how do they work, and why are they so unique?
Probiotic bacteria are gaining ground. The increasing knowledge about the microbiome and the positive effects of beneficial bacteria is leading more and more interested people to focus on their diet and the
What are the SCFA of bacteria?
First, some basic but very simple chemistry: SCFA stands for “short chain fatty acids” and refers to substances that are mainly formed in the large intestine when bacteria living there ferment fiber from our food, i.e. process it. Chemically, they are a short hydrocarbon chain with a methyl group and a carboxyl group at their ends. They usually consist of two to six carbon atoms. Short-chain fatty acids are acetic acid (acetate, two carbon atoms), propionic acid (propionate, three carbon atoms), butyric acid (butyrate, four carbon atoms), valeric acid (valerate, five carbon atoms) and caproic acid (capronate, six carbon atoms).
In acetate, with its two carbon atoms, the entire chain consists only of the methyl group and the carboxyl group. The longer the chain, the more carbon atoms are in between. That’s all. They are simply quite short carbon chains.
Brevity is the spice of life
And that is precisely the advantage of these short chains. Because they are so small and compact, they can relatively easily penetrate human cells and bind to receptors. As a result, they have an important function in metabolism and the immune system. For example, in the large intestine, they can be quickly absorbed by the cells of the intestinal mucosa and serve as the main energy source there.
Their short length makes them water-soluble and thus allows them to distribute well. In the intestine, SCFAs that have been formed by the microbiome and are not absorbed by the intestinal epithelial cells pass directly into the blood through the intestinal wall or with the help of transporters. However, the larger part of the remaining SCFAs is first transported via the portal vein to the liver and only then enters the systemic circulation.
The systemic cycle
The systemic circulation is the “large” circulation that distributes the oxygen-rich blood from the left side of the heart via the aorta to all regions of the body and then brings the used, i.e. oxygen-poor, blood back to the right side of the heart via the veins, from where it is pumped into the lungs (small circulation), where it is enriched with oxygen and returns to the left side of the heart via the small circulation.
The systemic circulation is the “large” circulation that distributes the oxygen-rich blood from the left side of the heart via the aorta to all regions of the body and then brings the used, i.e. oxygen-poor, blood back to the right side of the heart via the veins, from where it is pumped into the lungs (small circulation), where it is enriched with oxygen and returns to the left side of the heart via the small circulation.
Effect of the SCFA of the bacteria
SCFAs have a variety of effects in the body.
Energy source
Butyrate is the main energy source for the epithelial cells of the large intestine, the so-called colonocytes. This supports the integrity of the intestinal mucosa and prevents microorganisms from entering the bloodstream.
Anti-inflammatory
SCFAs have anti-inflammatory effects by influencing various signaling pathways. For example, they inhibit an excessive release of cytokines, the immune system’s messenger molecules. While these are necessary when the body reacts to infections and injuries, SCFAs ensure that the immune response is balanced and does not overreact or lead to chronic inflammation.
Immune-boosting
By regulating a balanced release of cytokines, SCFA have an immune-boosting effect and ensure that the body can react better to threats.
Better blood sugar levels
Reduced inflammation promotes better insulin sensitivity because body cells become more responsive to insulin again and can efficiently absorb glucose.
Weight Management
SCFAs act on certain cells, which then increasingly release hormones that, in turn, reduce hunger by signaling to the brain that enough energy has been taken in. Additionally, insulin is increasingly released, which stabilizes blood sugar levels and further reduces hunger. SCFAs are therefore perfectly suited to naturally prevent cravings.
Gut Microbiota
SCFAs generally support a healthy balance of the gut microbiota and ensure high diversity.
Reduction of Colon Cancer Risk
Butyrate can reduce the risk of colon cancer by stimulating aberrant intestinal cells to undergo programmed cell death. This prevents them from developing into a tumor.
Cholesterol Levels
Propionate, in particular, can reduce the activity of certain enzymes in the liver that are responsible for cholesterol formation. Furthermore, LDL cholesterol levels are positively affected.
Brain Health
The gut continuously communicates with the brain, for example, via nerve connections such as the vagus nerve. SCFAs can serve as signaling molecules that support this communication.
Support of Bone Metabolism
Butyrate reduces inflammation and thus prevents excessive activation of osteoclasts, which are responsible for bone tissue breakdown. This positively influences the balance between bone formation and breakdown.
SCFAs thus offer a multitude of benefits. It is worthwhile to activate and promote the beneficial bacteria that produce these fatty acids.
7 Tips for Promoting SCFA Formation by the Microbiome
The microbiome’s production of SCFAs can be specifically encouraged. In principle, it does not matter whether SCFAs are produced by bacteria or introduced into the body in other ways. But as always, it’s not just about the end products. Bacterial populations fulfill many other important functions besides just the formation of SCFAs. The body must always be viewed holistically. Therefore, the goal should always be to specifically boost the natural production of SCFAs by the microbiome.
Tip 1: Fiber
Maintain a fiber-rich diet. Whole grains, vegetables, and legumes are full of food for your beneficial, SCFA-producing bacteria.
Tip 2: Probiotics
Eat more probiotic foods such as yogurt, kefir, sauerkraut, and other fermented products. Commercial probiotics can also help.
Tip 3: Exercise
Apologies if we keep repeating this: But you must exercise. There’s no way around it. Physical activity supports gut health.
Tip 4: Sugar
Skip it. Avoid sweets and simple sugars. If that’s not possible, then reduce your consumption. Every piece of cake you skip helps. Instead, reward yourself with a piece of dark chocolate.
Tip 5: Processed Foods
Processed foods are not good for you. You know it, and yet you eat them because they can be prepared quickly. Just stop.
Tip 6: Stress
Engage in meditation or autogenic training to reduce your stress. Try it. It offers so many benefits!
Tip 7: Hydration
Drink. Drink. Drink. Ideally, an electrolyte-rich fluid such as mineral water. Or at least add a pinch of salt to your glass of water.
You will already know many of these tips. But the secret is not knowing the solution, but implementing it. SCFAs, formed by the microbiome, are powerful health boosters. It’s worth supporting these bacteria to boost your health and better protect yourself from diseases.
The choice is yours. As always. (JS)
Sources and further Reading
Zhang et al. (2023). Short-chain fatty acids in diseases. Cell Communication and Signaling, 21:212. DOI: 10.1186/s12964-023-01219-9
Silva, Y.P., Bernardi, A., & Frozza, R.L. (2020). The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication. Frontiers in Endocrinology, 11:25. DOI: 10.3389/fendo.2020.00025
Kopczyńska, J. & Kowalczyk, M. (2024). The potential of short-chain fatty acid epigenetic regulation in chronic low-grade inflammation and obesity. Frontiers in Immunology, 15:1380476. DOI: 10.3389/fimmu.2024.1380476
Portincasa et al. (2022). Gut Microbiota and Short Chain Fatty Acids: Implications in Glucose Homeostasis. International Journal of Molecular Sciences, 23:1105. DOI: 10.3390/ijms23031105
Motăţianu, A., Şerban, G., & Andone, S. (2023). The Role of Short-Chain Fatty Acids in Microbiota–Gut–Brain Cross-Talk with a Focus on Amyotrophic Lateral Sclerosis: A Systematic Review. International Journal of Molecular Sciences, 24:15094. DOI: 10.3390/ijms242015094
Fusco et al. (2023). Short-Chain Fatty-Acid-Producing Bacteria: Key Components of the Human Gut Microbiota. Nutrients, 15:2211. DOI: 10.3390/nu15092211
Tan et al. (2014). The Role of Short-Chain Fatty Acids in Health and Disease. Advances in Immunology, 121:91-119. DOI: 10.1016/B978-0-12-800100-4.00003-9
