Benefits
Bowel habits and abdominal discomfort in adults
In 66 adults with irritable bowel syndrome on their usual medicines, adding coated sodium butyrate for 12 weeks made pain during bowel movements less frequent and improved urgency and bowel habit, but did not change overall symptom severity. In 52 adults with type 2 diabetes and IBS, more people on butyrate than on placebo stopped reporting pain, diarrhea and bloating. Both trials were small.
Abdominal comfort in children and teens
In 51 children aged 4 to 17 with irritable bowel syndrome, slow-release calcium butyrate tablets (500 mg a day for 8 weeks) cut pain scores by at least half in 73% of children versus under 4% on placebo, with no reported side effects. The tablets also contained zinc and vitamin D, the maker supplied them, and the result has not yet been repeated.
Gut microbiota composition
Coated butyrate has been linked to more bacteria that make short-chain fatty acids, such as Lachnospiraceae, in a placebo-controlled pilot in adults with inflammatory bowel disease and in the children's trial. These are shifts in stool bacteria, and it is not yet clear whether they translate into lasting health benefits.
Studied as an add-on to medical care in bowel inflammation trials
Crohn's disease and ulcerative colitis need a doctor's care. In 98 adults with mild to moderate ulcerative colitis, coated sodium butyrate added to usual treatment for 8 weeks improved clinical scores more than placebo. A trial in 140 adults gave mixed results, and a trial in children with newly diagnosed disease found no benefit.
Fuel and signals for gut-lining cells
Butyrate is a key energy source for colon cells, can switch genes on and off by blocking enzymes called histone deacetylases, and acts on several cell receptors. Its effects on the gut barrier and inflammation come mainly from lab and animal work. Plain capsules did not raise stool butyrate in two human trials, while a coated product did in one.
Body weight and blood sugar markers
In 46 adults with overweight on a reduced-calorie diet, sodium butyrate for 12 weeks gave more weight loss than placebo in those without diabetes but not in those with it. An earlier 4-week pilot found better insulin sensitivity in lean men only. These are small early studies, and the sodium load is a concern for people with high blood pressure.
Mechanism of action
Fuel for colon-lining cells
Colon cells burn butyrate for energy. Butyrate is normally made in the colon by bacteria fermenting fiber, which is why supplements aim to deliver it to the lower gut.
Gene and receptor signaling
Butyrate blocks histone deacetylase enzymes, which changes how some genes are read, and binds G-protein-coupled receptors on gut and immune cells. These signals underlie the barrier and anti-inflammatory effects seen mainly in animal studies.
Where it is absorbed depends on the coating
Uncoated butyrate salts are absorbed quickly in the upper gut, so little reaches the colon. In a breath-test study a coated tablet delayed release by 2 to 3 hours and released butyrate at the end of the small intestine and in the colon. Plain capsules raised blood butyrate but not stool butyrate in another trial.
Clinical trials
Randomized, placebo-controlled trial of microencapsulated sodium butyrate added to each patient's usual IBS medicine, assessed at 4 and 12 weeks with symptom questionnaires (Banasiewicz et al. 2013, Colorectal Dis).
66 adults with irritable bowel syndrome who had been on standard drug treatment for at least 3 months and continued it during the study.
In the butyrate group, pain during bowel movements fell at 4 weeks, and urgency and bowel habit improved at 12 weeks. Changes in abdominal pain, wind and disordered bowel movements were not statistically significant, and the authors found no significant effect on how severe symptoms were, only on how often some occurred.
Double-blind, placebo-controlled trial of slow-release tablets containing 500 mg calcium butyrate with 5 mg zinc and 500 IU vitamin D, once daily for 8 weeks plus 4 weeks of follow-up (Cristofori et al. 2025, J Pediatr Gastroenterol Nutr).
51 children aged 4 to 17 with IBS by Rome IV criteria, in Bari, Italy.
Treatment success (pain score down by at least half) was 73% on the butyrate tablets versus 3.8% on placebo, and symptom scores stayed lower after the washout. Bacteria that make short-chain fatty acids increased. No adverse events were reported; one child stopped because the tablets were hard to swallow. The active tablet also contained zinc and vitamin D, so the effect cannot be pinned on butyrate alone, and the maker supplied the product.
Double-blind, placebo-controlled pilot trial of microencapsulated sodium butyrate 1.5 g/day for 12 weeks; product and placebo provided by the company Bioton (Panufnik et al. 2026, Sci Rep).
52 adults with type 2 diabetes who also met Rome IV criteria for IBS, in Warsaw, Poland (29 butyrate, 23 placebo).
Compared with placebo, more people on butyrate went from having to not having abdominal pain, diarrhea, constipation and bloating, and weight (about 2 kg) and HbA1c (0.3 points) fell more; insulin resistance (HOMA-IR) did not differ between groups. Symptoms were rated on a questionnaire written for this study that had not been validated, and all butyrate patients had bloating at the start compared with 82.6% on placebo. A later correction fixed only the authors' names.
Randomized, placebo-controlled multicenter trial of sodium butyrate 150 mg twice daily for 12 weeks on top of standard therapy (Pietrzak et al. 2022, Nutrients).
Children and adolescents aged 6 to 18 with newly diagnosed Crohn's disease of the colon or ulcerative colitis; 72 completed (29 butyrate, 43 placebo).
Most patients in both groups reached remission on their standard treatment. Remission rate and disease activity did not differ between butyrate and placebo, so the add-on showed no benefit. No adverse events were reported.
Multicenter, double-blind, placebo-controlled trial of microencapsulated sodium butyrate 300 mg twice daily or rice-starch placebo for 8 weeks, added to usual treatment (Karłowicz et al. 2025, Med Sci Monit).
98 adults with active mild to moderate ulcerative colitis in Poland who completed the study.
Clinical improvement was 51% with butyrate versus 21.3% with placebo, and clinical remission 31.4% versus 6.4%. Endoscopic improvement and calprotectin-based remission also favored butyrate, but full endoscopic remission did not differ significantly (11.8% versus 2.1%). This was an add-on to medical care for a diagnosed disease, run over 8 weeks.
Randomized, double-blind, placebo-controlled trial of a microencapsulated butyrate product added to conventional therapy, with stool bacteria and calprotectin measured (Facchin et al. 2026, Dig Liver Dis).
140 adults with inflammatory bowel disease in Italy (60 Crohn's disease, 80 ulcerative colitis).
In the Crohn's group, disease activity and fecal calprotectin improved after supplementation; in ulcerative colitis calprotectin fell only marginally. Benefits were larger in people with one type of gut-bacteria profile. The lead and senior authors report fees from several supplement and drug companies.
Double-blind, placebo-controlled trial of 3.9 g/day sodium butyrate (26 capsules a day) for 4 weeks, with a sodium chloride placebo matched for sodium, after stopping blood pressure medicines (Verhaar et al. 2024, Hypertension).
23 adults with high blood pressure, average age 59, in the Netherlands.
Daytime systolic blood pressure rose by about 9.6 mmHg and diastolic by about 5.1 mmHg more on butyrate than on placebo, the opposite of what animal studies predicted. Plasma butyrate rose but stool butyrate did not, and the authors note the capsules released butyrate in the small intestine rather than the colon.
Double-blind, placebo-controlled proof-of-concept trial of sodium butyrate 1875 mg/day for 12 weeks, both groups on the same moderately reduced-calorie diet (Testa et al. 2026, Clin Nutr).
46 adults aged 30 to 70 with overweight or obesity, 23 of them with type 2 diabetes.
In people without diabetes, weight fell 7.0 kg on butyrate versus 3.2 kg on placebo. In people with diabetes, weight change did not differ, though triglycerides fell and time spent in a tight glucose range rose by 9%. A small first study that needs repeating.