Butyrate
Also called: butyric acid, short-chain fatty acid butyrate
Butyrate is one of three short-chain fatty acids produced when gut bacteria ferment fibre in the colon. It is the primary fuel of the cells lining the colon. Higher butyrate production is associated with lower inflammation, better gut barrier function, and steadier blood sugar. The cheapest way to get more is more diverse fibre, not supplements.
Where butyrate comes from
Butyrate is made when bacteria in the colon ferment fermentable fibres. The species that produce most of it include Faecalibacterium prausnitzii, Roseburia, and Eubacterium rectale. The fibres they prefer are resistant starches (in cooled potatoes, slightly green bananas, cooked-and-cooled rice and pasta), inulin and FOS (in onion, garlic, leeks, asparagus), and beta-glucan (in oats and barley).
What butyrate does
- Fuels colonocytes. Up to 70 percent of the energy used by cells lining the colon comes from butyrate.
- Strengthens the gut barrier. Butyrate signals to tight junction proteins that hold colon cells together, reducing the kind of permeability sometimes called leaky gut.
- Reduces inflammation. Butyrate inhibits histone deacetylases and reduces NF-kB activity, both of which lower local inflammation in the colon.
- Supports immune regulation. It encourages production of regulatory T cells, which keep inflammation in balance.
- Influences metabolism. Butyrate signalling helps regulate appetite hormones and insulin sensitivity in studies.
Why supplements rarely work
Oral butyrate supplements are absorbed in the small intestine and rarely reach the colon, which is where the action is. Some products use enteric-coated or microencapsulated butyrate to delay release, but evidence for benefit in healthy users is weak. The reliable route is to feed the bacteria that already live in your colon, so they make the butyrate themselves at the right place.
Foods that produce the most
- Resistant starch: cooled cooked potato, cooled cooked rice, slightly underripe bananas, cold pasta.
- Oats and barley, especially porridge oats and pearl barley.
- Onion, garlic, leek, asparagus, Jerusalem artichoke (high in inulin).
- Beans and pulses: chickpeas, lentils, butter beans, kidney beans.
- Apples, pears, plums (high in pectin).
When butyrate production drops
Low fibre intake is the most common reason. UK average daily fibre is around 19 grams against a recommended 30 grams. Antibiotic courses also wipe out butyrate-producers and recovery can take months. People with IBD, especially ulcerative colitis, often have measurably lower butyrate levels in their colons, which is one reason high-fibre therapeutic diets are studied for these conditions.
Common questions
- What's the difference between butyrate and butter?
- The names share a root but they are different. Butter contains a small amount of butyric acid (the same molecule as butyrate), but most of the butyrate that affects gut health is made internally by your own gut bacteria. Eating butter does not meaningfully raise colonic butyrate.
- Should I take a butyrate supplement?
- Probably not as a first step. Most oral butyrate is absorbed in the small intestine before reaching the colon. Eating more diverse fibre is cheaper and more effective. Supplements are sometimes considered in inflammatory bowel conditions under specialist guidance.
- Are there other short-chain fatty acids?
- Yes. The three most studied are acetate, propionate and butyrate, made in roughly that order of abundance. Acetate enters the bloodstream and reaches the brain. Propionate affects appetite and liver glucose handling. Butyrate stays mostly local to the colon.
- Can you measure butyrate at home?
- Some stool tests report short-chain fatty acid levels. Day-to-day variation in those readings is high. They are useful for comparing people in research but less useful for tracking your own status over time.