Short chain fatty acids are a group of fatty acids that confer many health benefits. Butyrate is, perhaps, the most notorious type of short chain fatty acid for its many health benefits specific to gut health and function. This article will discuss why measuring and optimizing butyrate levels is instrumental in achieving optimal wellness.
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What is Butyrate?
Butyrate is one of the predominant types of short chain fatty acids (SCFAs) produced in the colon. SCFAs are fatty acids produced when friendly colonic bacteria ferment undigested dietary fiber, resistant starch, and protein. Butyrate, propionate, and acetate constitute 95% of the SCFAs produced in the gut. Two of the main actions of butyrate and other SCFAs are to fuel colonocytes (the cells that make up the internal lining of the colon) and to maintain the integrity of the intestinal barrier. (1, 2)
Gut Health Benefits of Butyrate
Butyrate plays many vital roles in the maintenance of a healthy large intestine. It is the preferred fuel source for colonocytes; it stimulates the growth and proliferation of healthy intestinal cells; it inhibits inflammation and oxidative stress; it improves the integrity of the intestinal barrier; it stimulates mucus secretion; it stimulates fluid and electrolyte absorption; and it inhibits cancer formation in the colon. (4)
Given these properties, research suggests sufficient butyrate levels can improve symptoms of inflammatory bowel disease (IBD) by modulating intestinal inflammation underlying IBD (5). Additionally, butyrate supplementation has decreased pain and urgency related to defecation for people with irritable bowel syndrome (IBS) (6). (3)
Furthermore, butyrate can reduce colon cancer risk. As a histone deacetylase (HDAC) inhibitor, butyrate can stop the growth and induce cell death (called apoptosis) in colorectal cancer cells. (3, 7)
Immune Health Benefits of Butyrate
The gut houses approximately 70-80% of the body's immune system. By maintaining the intestinal gut barrier through supporting intestinal mucus secretions and regulating intestinal permeability, butyrate can improve the body's defenses against infection. (8)
Studies have shown that butyrate supplements can reduce the severity of bacterial infections by reducing systemic inflammation (9).
Metabolic Health Benefits of Butyrate
Butyrate supports the intestinal production of hormones related to blood sugar regulation. Research suggests adequate intestinal butyrate production promotes insulin response, reducing insulin resistance and type 2 diabetes risk. (3, 10)
Cardiovascular Health Benefits of Butyrate
The anti-inflammatory and antioxidant effects of butyrate can protect the body against cardiovascular disease and associated risk factors, including high cholesterol (3, 11)
Neurological Health Benefits of Butyrate
Butyrate has been shown to promote brain health, and preliminary studies suggest that it may play a role in preventing neurological diseases like Parkinson's disease and Alzheimer's disease. (3, 12)
Which Bacteria Produce Butyrate?
Bacteria can produce SCFAs from fiber because they have enzymes that humans do not. Based on the literature, the three major butyrate-producers in the gut are Faecalibacterium prausnitzii, Eubacterium rectale, and Roseburia species of bacteria (1). Blautia, Lachnospiraceae, Ruminococcus, Clostridium, Anaeostipes, Coprococcus, and Butyricicoccus are other minor butyrate-producing bacteria (13).
How to Test Butyrate Levels
Comprehensive stool analysis allows for the measurement of total SCFAs and breakdown into percentages of butyrate, acetate, and propionate. Additionally, the microbiome evaluation portion of these tests will quantify the abundance of butyrate-producing bacteria. Stool testing options include Genova Diagnostic's GI Effects, Doctor's Data's GI360, and Microbiome Labs' BiomeFx. Every company measures and reports short chain fatty acids in different units, and optimal levels have yet to be established. Interpreting all test results with the listed reference ranges on the lab reports is important.
What Do High Butyrate Levels Mean?
SCFA levels depend highly on commensal bacterial abundance and diversity and dietary fiber intake. High dietary intake of fiber and resistant starches will increase butyrate levels. Higher butyrate levels are generally considered beneficial but can indicate large and/or small intestinal bacterial overgrowth (14). Additional signs of small/large intestinal bacterial overgrowth on comprehensive stool testing include an elevated total abundance of commensal bacteria and elevations in fecal fats and products of protein breakdown.
What Do Low Butyrate Levels Mean?
People with IBD and IBS-C have been shown to have lower stool levels of butyrate and other SCFAs compared to controls (15, 16).
Decreased carbohydrate/fiber consumption due to dietary patterns and restricted diets, like the low FODMAP diet, is correlated with low SCFAs. Intestinal dysbiosis characterized by a lack of beneficial butyrate-producing bacteria can also contribute to low butyrate levels. Poor diet, intestinal inflammation, and frequent antibiotic use can contribute to dysbiosis. (17, 18)
What Foods Have Butyrate?
Diets high in prebiotic dietary fibers and resistant starches feed the healthy bacteria that naturally produce butyrate, promoting a healthy microbiome and butyrate levels. Prebiotic foods to focus on incorporating into the diet include seeds, nuts, whole grains, legumes, green bananas, and potatoes. (19, 20)
Fermented foods, like yogurt, kefir, sauerkraut, and kombucha, contain probiotics that can help improve the microbiome's diversity and balance.
Full-fat dairy products, like butter and ghee, are naturally rich in butyrate. It is recommended to moderate the consumption of these foods due to their high levels of saturated fats, which can increase the risk of cardiovascular disease. (3)
Butyrate Supplements
Probiotics can introduce target species of bacteria into the microbiome for balancing effects to treat and prevent dysbiosis.
Supplemental fibers, like inulin and arabinogalactan, can help meet fiber intake goals if dietary intake is insufficient.
Butyric acid is available in supplemental form, most commonly in a sodium butyrate form, and can be purchased online or in most health food stores. Butyrate is typically dosed orally but can be administered through colonic enemas for a more direct and local effect.
Summary
Butyrate is a short chain fatty acid that is the primary fuel source for colonocytes. Along with its many benefits for gut health, emerging research suggests that it is also beneficial in optimizing systemic health through its immunoregulatory and antioxidant properties. Working with a functional medicine doctor, you can measure butyrate status and identify factors contributing to imbalances. When needed, dietary modifications and dietary supplements are exceptionally effective in creating a healthy butyrate balance and supporting optimal wellness.