As the old saying goes, “an apple a day keeps the doctor away”. We all know fiber is good for health but why is this? It turns out it is more complicated than just a way to help you feel full and stay regulated.
The type and amount of fiber you intake turns out to have amazing influence throughout your body. This is all because of what your body does with the fiber. One thing it does is produce short-chain fatty acids. Research shows that these produce a variety of health benefits – and that by altering your diet you can capitalize on these benefits.
Does Your Body Produce Short-Chain Fatty Acids?
You see, your gut is composed of a complex ecosystem of different bacteria, yeasts, and other microbial beings. The relationship we have with the microbes that live in our gut is known as symbiotic – meaning both parties involved are benefitting from the relationship.
And when we consume fiber, it’s not just “in one end and out the other”. Instead, this fiber benefits the microbes in our gut by giving them their favorite food source and sends them into a feeding frenzy. And in return, our gut flora repays the favor by producing incredible health-promoting molecules known as short-chain fatty acids.
What Are Short-Chain Fatty Acids?
When you consume dietary fiber, the microbes that reside in your gut begin breaking down and feeding on the undigested fiber as it travels through your digestive tract. This process, known as fermentation, yields a number of different health-promoting compounds such as amino acids, vitamins, and fatty acids.
One of the most notable by-products of fermentation are short-chain fatty acids (SCFAs). The term “short-chain” simply refers to fatty acids that have less than six carbon atoms.1
About 95 percent of SCFAs in your body are one of these three main types:2
- Acetate
- Propionate
- Butyrate
Why Are Short Chain Fatty Acids So Important?
SCFAs might start in the gut, but their impact on our bodies is far and wide. SCFA’s have been found to influence everything from gene expression to cancer risk. Let’s take a look at some of the most significant findings of the roles SCFAs play in our bodies.
Short Chain Fatty Acids and Your Gut Health
SCFAs, particularly butyrate, serve as a primary food source for the cells that line your gut, known as colonocytes.3 Meaning without adequate SCFAs these cells can actually start to degrade.
SCFAs are essential for our guts to function properly. They play a critical role in:
- Maintaining the integrity of the lining of your intestinal tract through regulation of tight junction proteins – this relates to the guts ability to breakdown and absorb nutrients.4
- Regulating blood flow, motility, and healing in the gut – this is essential to gut health, overall nutrition, and gut health over our lifespan. This is because if our guts don’t get the nutrition they need (via our blood) they can’t function properly. 5
- Enhancing the production of mucin, the gel-like substance that lines the walls of your intestines, which is crucial for lubrication and cell wall health.
SCFAs are so important to gut health that reduced levels have been directly linked with digestive disorders such as irritable bowel syndrome (IBS), Crohn’s disease, and even colon cancer.6,7 Unsurprisingly, multiple studies have found that restoring healthy levels of SCFAs can significantly improve symptoms and even reverse the damage associated with certain digestive disorders.8,9,10
In short (pun intended), more SCFAs equals happier, healthier gut flora.
Short Chain Fatty Acids and Your Immune System
Chronic inflammation plays a key role in many chronic health conditions. SCFAs are powerful anti-inflammatory agents – and not just in the gut, but throughout the rest of your body. And lower inflammation leads to a more regulated immune system.
SCFAs regulate the immune system and lower inflammation by:11,12
- Influencing immune cell migration and adhesion
- Inducing cell proliferation or apoptosis (depending on SCFAs levels)
- Functioning as an HDAC inhibitor – suppressing the activity of certain immune cells
- Inhibiting nuclear factor kappa B (NF-Kb) – which controls the expression of a number of other inflammatory signaling/pathways
- Minimizing oxidative stress
Short Chain Fatty Acids and Weight Loss
SCFAs make up about 70 percent of the fuel used by colonocytes and about 10 percent of our daily calories.13 But they also influence how other nutrients are absorbed in the body. Meaning SCFAs can help bring your metabolism into balance – and maybe even help you shed a few pounds.
SCFAs act as energy substrates for the metabolism of glucose, cholesterol, and lipids – meaning they serve as starting materials for the biochemical reactions that break down these molecules. Because they play a role in how glucose is metabolized, reduced SCFAs levels have been associated with the development of chronic metabolic disorders such as:14
- Obesity
- Insulin resistance
- Diabetes
Regulating SCFAs levels can improve glucose homeostasis, increase insulin sensitivity, and aid in weight loss – all positive metabolic changes.15 And these metabolic changes are what leads to weight loss.
But wait, there’s more. They may also impact weight loss in another way. SCFA’s enhance the secretion of gut hormones glucagon-like-peptide 1 (GLP-1) and Peptide YY (PYY). When secreted, these hormones can help reduce your appetite, inhibit gastric emptying, and help your body burn fat.14 Meaning more SCFAs results in you feeling less hungry and giving your metabolism a boost.
Short Chain Fatty Acids and Your Brain
More and more studies are finding evidence that directly links the health of your gut and the composition of your microbiome to the health of your brain. Microbiome composition and SCFAs have been found to directly impact various diseases of the central nervous system including:16
- Neurodegenerative diseases
- Neuroinflammatory diseases
- Psychiatric diseases
SCFAs play an important role in overall brain health because they help maintain the blood-brain barrier. This barrier acts as a gatekeeper and controls the exchange of molecules between your brain and your circulatory system. They also play a critical role in the maturation and function of microglia – a type of immune cell designed to protect your brain and spinal cord.
Researchers have been studying the potential effects of SCFAs in the treatment of multiple sclerosis (MS) – a chronic inflammatory disease of the central nervous system characterized by demyelination (degradation) of the myelin sheath that protects nerve axons. This is a debilitating genetic disorder that results in the decline of function in every body system.
An imbalanced microbiome resulting in a lack of SCFAs was found to increase demyelination, resulting in increased symptoms and disease progression. But the introduction of an SCFA supplement in the form of Butyrate was found to decrease demyelination and actually induce remyelination, or repair of myelin sheath.16 This would result in fewer MS symptoms, slower disease progression, and higher quality of life for longer in MS patients.
SCFA’s role in psychiatric disorders is gaining interest because they have been found to mediate communications along the gut-brain axis through their impact on various communication channels your gut and brain use to “talk” to each other, such as:
- The vagus nerve
- Gut hormones
- Neurotransmitters
- Endocrine system
This has the potential to completely change the way we treat psychiatric conditions such as anxiety and depression.
Short Chain Fatty Acids Food List
One of the biggest reasons people don’t get enough SCFAs is because they are lacking fermentable fiber in their diets.17 While a diet high in fiber that comes from a variety of fruits and vegetables is a good foundation – one of the best sources of fermentable fiber are resistant starches.
Resistant starches are a type of fiber that is “resistant” to digestion, meaning they make it to your intestines intact. This is important because the bacteria in your colon (the end of your intestinal tract) have more material to work with – meaning more SCFAs are produced. Some of the best sources of resistant starches include:
- Green bananas (adding green banana flour to your daily routine works well!)
- Raw plantains
- Raw potato starch
- Cooked and cooled rice
- Legumes
How Can I Get More Short Chain Fatty Acids?
A healthy diet high in fermentable fiber is the best way to increase your natural production of SCFAs. But because there is so much diversity and potential for imbalance in the microbiome, the amount of SCFAs you produce will vary greatly depending on the unique make-up of your gut flora “ecosystem”.
Since the overall health of your gut and microbiome is pivotal when it comes to your ability to produce SCFAs, here’s what I recommend:
Focus On Balancing Your Microbiome:
Without the right balance of bacteria, your body won’t be able to properly break down fiber or produce SCFAs. Give your gut the boost it needs with a daily probiotic like my Probiotic Essentials.
Add Gut Detox Binders:
Detox binders literally “bind” to toxins so you can eliminate them more easily. This speeds up the process of eliminating harmful substances and helps your gut repair itself. Both of these are crucial to creating and maintaining an environment that supports healthy gut flora. I recommend GI Detox and Upgraded Coconut Charcoal.
Minimize Your Toxic Burden:
We are constantly bombarded with countless and potentially harmful toxins that can wreak havoc on your gut health. Taking steps to reduce your overall toxic burden can go a long way in promoting a healthy gut. You can grab my free guide that will help you reduce your daily toxin exposure by clicking here.
What About Butyrate Supplements?
While butyrate or butyric acid supplementation has shown some promising results, particularly in those struggling with IBS, more research is needed to determine its efficacy.18 The issue with most supplements is that they are absorbed before they reach the colon, meaning all the benefits for the cells in your colon are lost.
Set Yourself up for Success
So, it’s much more complicated than just “an apple a day”. But there are tangible steps you can take to promote gut health, and maximize the health benefits from SCFA’s.
The best way to increase your butyrate and SCFAs is to focus on your internal production. Feed your gut bacteria a healthy high fiber diet and give your gut the support it needs by following the steps outlined above.
And if you’re ready to mix it up in the kitchen and need some new recipes to up your fiber intake, you’ve got to check out my recipe library! I’ve got tons of delicious fiber-packed recipes like my Eggplant Bolognese With Zucchini Noodles or my Green Bean Buddha Bowl With Tahini Drizzle.
References:
- https://www.ncbi.nlm.nih.gov/pubmed/9678808
- https://www.ncbi.nlm.nih.gov/pubmed/24136789
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4939913/
- https://academic.oup.com/jn/article/139/9/1619/4670520?ijkey=f7ff8ca9fef23588e7bdd3486988b5c659c62967&keytype2=tf_ipsecsha
- https://mbio.asm.org/content/10/1/e02566-18#ref-2
- https://www.ncbi.nlm.nih.gov/pubmed/21658926
- https://www.ncbi.nlm.nih.gov/pubmed/24160296
- https://www.ncbi.nlm.nih.gov/pubmed/9176076
- https://www.ncbi.nlm.nih.gov/pubmed/16225487
- https://www.ncbi.nlm.nih.gov/pubmed/12769445
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6104520/
- https://academic.oup.com/advances/article/9/1/21/4849000
- https://microbialcellfactories.biomedcentral.com/articles/10.1186/s12934-017-0691-z
- https://academic.oup.com/advances/article/9/1/21/4849000
- https://www.ncbi.nlm.nih.gov/pubmed/26260141
- https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-019-1552-y
- https://academic.oup.com/advances/article/9/1/21/4849000
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4027835/
This is a great post on SCFA’s, thank you. However, I have a concern over the Genexa products that you recommend. I looked at the ingredients, and it appears that all, or almost all, of their products in pill form contain maltodextrin. As a Crohn’s sufferer, this is something that I make sure to avoid. However, maltodextrin is not good for anybody, and it is a rampant ingredient in processed food. Studies are pointing to maltodextrin increasing bad bacteria and lowering good bacteria. It has been shown to promote the growth of E.Coli as well as Salmonella. Another reference stated that it may compromise the ability of the gut to respond to bacteria, and suppresses the intestinal defense mechanisms, which can lead to Crohn’s, UC, etc. I cannot begin to understand why a company based on clean alternatives to OTC medications would include such an ingredient, particularly when their market share will include gut-compromised people and children, who will be most harmed by it.
Hi Dale,
Thank you for your comments. I do agree that maltodextrin best avoided in patients who have inflammatory bowel disease. And I also agree that it will take consumer pressure to continue to help companies create the cleanest options available for sensitive patients. I don’t think that maltodextrin is a problem for everyone but should certainly be avoided by the most sensitive patients.
warmly
Dr Jill
I’ve heard that eating an apple also causes your gut to produce hydrogen, which leaves the body fairly quickly but is an anti-inflammatory and has health benefits.