Butyrate is one of the three most common short-chain fatty acids (SCFAs) in your gut. Although it’s the least abundant of those three, butyrate provides a host of benefits for your body. Research studies point to its role in controlling intestinal inflammation, maintaining gut barrier integrity and modulating the gut-brain axis. Elevated butyrate levels may also alleviate obesity induced by a high-fat diet, reduce insulin resistance and lessen hyperglycemia. In this article, we will discuss what makes butyrate unique, how butyrate supports health, and how you can increase butyrate levels in your body with butyrate foods.
What is butyrate?
Butyrate is a SCFA, a subset of fatty acids produced by the microbes living in your gut. Your gut microbes produce SCFAs by eating the foods — specifically, the insoluble fibers — that your bodies cannot digest on their own. A process called fermentation breaks down these foods to generate energy in the absence of oxygen. A wide range of microbes can produce butyrate through fermentation, including Eubacterium rectale/Roseburia spp., and Faecalibacterium prausnitzii. Together with other microbes that produce other SCFAs, your gut microbiome produces three SCFAs in a 3:1:1 ratio: acetate, propionate, and butyrate. Because butyrate is a vital energy source for colonocytes, the cells lining your colon, its role in gut health is important.
Butyrate and the gut
While SCFAs as a whole provide multiple benefits for your gut, butyrate plays an essential role in these processes:
- Gut integrity: Butyrate helps maintain your intestinal barrier, which protects your body from being attacked by harmful microbes and toxins in your digestive tract. Butyrate accomplishes this by regulating the formation of tight junctions that play a critical role in connecting the intestinal barrier together like a wall. In keeping your gut intact, butyrate cascades into a protective role by preventing inflammation. In contrast, an inadequate level of butyrate increases colon permeability and the risk of inflammation through oxidative stress.
- Gut hormone production: Hormones are chemicals that travel through your bloodstream to tell your organs how to behave. For the gut, your body produces a specific set of hormones, such as ghrelin and peptide YY, which control your appetite and the amount of nutrients you take in. Butyrate, along with propionate, could increase the production of gut hormones that regulate your appetite, helping to protect you from obesity.
- Gut inflammation: Butyrate also acts as a signaling molecule for receptors called G protein-coupled receptors (GPCRs). While over 1000 different GPCRs exist, specific classes of GPCRs bind exclusively to different sets of molecules. When bound, GPCRs change the behavior of the cells harboring them. Butyrate can interact with GPCRs found in your gut and immune cells to control inflammation. Butyrate and propionate also provide an anti-inflammatory effect against macrophages, a type of immune cell, which lessens the production of pro-inflammatory mediators.
- Preventing gut disease: Treating patients with gastrointestinal (GI) diseases with sodium butyrate, a butyrate supplement, could alleviate GI-related symptoms. A subset of 79 irritable bowel syndrome (IBS) patients treated with 300 mg of sodium butyrate daily for 12 weeks had less pain during defecation relative to controls, but they did not experience a lessening of other symptoms. Nine of 13 patients with mild-moderate ileocolonic Crohn’s disease (a type of inflammatory bowel disease) who were treated with 4 g of butyrate for 8 weeks also responded to treatment, seven of whom achieved remission. The control of gut inflammation that butyrate can provide could also help prevent colorectal cancer.
Many of the butyrate studies mentioned in this list were performed on cell and animal models in the lab. On the other hand, there have been only a few, small randomized controlled clinical (human) trials. Thus, more human intervention studies are needed before drawing firm conclusions about butyrate’s benefits. Nevertheless, butyrate’s potential for limiting the risk of gut diseases remains promising.
How can butyrate help the rest of your body?
SCFAs such as butyrate do not just dwell in the gut after they’re produced. They also enter your bloodstream. When circulating around your body, butyrate also benefits the rest of your bodily functions and may protect against these cardiometabolic diseases:
- Type 2 diabetes (T2D): A landmark 2009 study determined that butyrate supplementation in mouse models prevented insulin resistance and obesity even when the animals were provided a high-fat diet. Butyrate supplementation can also decrease glucose concentrations to alleviate hyperglycemia. Your cells may accomplish this by using butyrate to activate insulin signaling and reduce the expression of genes for producing glucose. Interestingly, microbiome studies done with two different groups of people showed that T2D patients had lower abundances of butyrate-producing bacteria. Whether these reductions increase the risk of diabetes or are a symptom of disease remains to be seen, but the correlation is interesting. Furthermore, whether improvements in controlling blood glucose levels are sustained over the long term remains to be seen.
- Obesity: In agreement with the 2009 study, a 2019 study showed that sodium butyrate supplementation reduced body weight gain and inflammation in the liver and blood in mice fed a high-fat diet. While these results in animal models are promising, there are no randomized clinical trials that demonstrate butyrate’s role in preventing obesity in humans.
- Hyperlipidemia: Hyperlipidemia is an excess of fat in your blood stream. The data for butyrate’s role in alleviating this disorder is mixed. On one hand, butyrate supplementation increases fat cell production, contributing to enhanced glucose uptake and insulin sensitivity. Nevertheless, a 2022 review points out that the research remains inconsistent on the effects of butyrate on blood triglyceride levels.
In summary, although the data for T2D is compelling, the research remains cursory, being limited to experiments in animal models that require confirmation through randomized clinical trials. It also remains to be seen whether the benefits against disease are reproducible across diverse populations. Finally, whether the benefits stem from all SCFAs, or specifically butyrate, also requires clarification.
Butyrate foods: Ways to get butyrate into your diet
Butyrate is not a compound immediately available from the food we eat. In fact, butter and cheese are the only foods rich in butyrate, and we do not recommend eating these in surplus to get the butyrate you need. Instead, the butyrate you need comes from bacterial fermentation of fiber from plants. Fibers are carbohydrates that the human body cannot digest, and are considered a prebiotic — a source of food for your gut microbes to grow and help your body function. With that in mind, here are the kinds of butyrate foods to eat to get the fiber you need to keep your gut microbes happy:
- Fruits: One cup of raspberries contains 8 grams of fiber, and a single banana has 3 grams of fiber.
- Vegetables: Many of us may have disliked vegetables growing up, but they are an amazing source of fiber. For example, broccoli contains 5.0 g of fiber per cup.
- Legumes, nuts, and seeds: Beans provide the most amount of fiber per cup. Boiled split beans, lentils and black beans contain twice as much fiber per cup as raspberries.
- Grains: Oat-based products, barley and whole-wheat bread contain fiber as well. While not as much as the other sources listed, a cup of quinoa contains 5.0 g of fiber.
SCFAs help your body function properly, and one of them — butyrate — is a vital energy source for the cells that form your gut’s structure. Produced by your gut microbiome, butyrate keeps your gut together, impacts how full you feel (to help protect you from obesity) and keeps inflammation in check. Butyrate may also help reduce the risk of metabolic disorders such as T2D, obesity and hyperlipidemia. While the magnitude of these impacts needs to be studied more, there are many healthy foods you can eat to support your supply of butyrate. Foods that are rich in fiber are essential for helping your gut microbes produce the butyrate you need.