Two colostrum capsules a day for everyday indigestion: 83 Australian adults, eight weeks. The higher dose beat placebo, the lower one didn't

Colostrum is the thick first milk a cow makes after giving birth, and it is packed with antibodies and other proteins that protect a newborn calf's gut. Dried bovine colostrum has been sold as a supplement for years. A trial published in Nutrients on 28 October tested a more refined version: a filtered fraction that removes most of the fat, casein and lactose and keeps a concentrate of proteins such as immunoglobulins. The product, sold as MaolactinGI, was tested in adults who were generally healthy but had regular stomach trouble.

The study ran at a research clinic in Brisbane, with some people taking part remotely from Sydney, between February 2024 and May 2025. To join, adults had to have at least one of reflux, heartburn, regurgitation, nausea, bloating or abdominal pain at least once a week for more than three months, and no serious chronic illness. After a four-week run-in with nothing to take, they were randomly assigned to one of three groups for eight weeks: 500 mg of the colostrum fraction a day, 250 mg a day, or 500 mg of maltodextrin as a placebo. Everyone took two identical capsules before breakfast, and neither the participants nor the researchers knew who had what.

Ninety people were randomised, but seven never collected their capsules, five of them from the placebo group, so 83 were analysed: 29 on each dose and 25 on placebo. The main measure was the Gastrointestinal Symptom Rating Scale, a 15-question survey of pain, reflux, indigestion, diarrhoea and constipation. By week 8 the total score had dropped by 2.66 points on the higher dose against 1.17 points on placebo (p = 0.044). The higher dose also did better than placebo on abdominal pain, indigestion and constipation, on how full and uncomfortable the stomach felt, and on a digestive quality-of-life questionnaire, where the gap showed from week 2. The 250 mg dose improved on most measures too, but never clearly more than placebo.

Several things did not change. Reflux scores on a separate reflux questionnaire stayed flat in all groups, and so did stool shape and the number of bowel movements. Blood markers of inflammation, faecal calprotectin (a marker of gut inflammation) and a sugar test of gut permeability showed no differences; the authors point out that participants were normal on these at the start. Diets, checked with 24-hour recalls, didn't change either.

The stool samples gave a mixed picture. One measure of the number of bacterial types, Chao1 richness, held steady on the higher dose while it fell in the placebo group, a difference that just crossed the line for statistical significance after correction (adjusted p = 0.0496). Overall community make-up didn't differ between groups. The shifts towards bacteria linked to short-chain fatty acid production came from before-and-after comparisons within each group, not against placebo, and the authors call them hypothesis-generating.

There are reasons to hold the result loosely. The trial was funded by Maolac, the company that makes the product, and run by a clinical research company; the authors declare no conflicts of interest. Groups were small, the placebo group was a little heavier at the start (average BMI 27.1 against 24.6 on the higher dose), and each time point was compared with simple t-tests rather than one model across the whole study, with missing values filled in from the last visit. Everyone's symptoms eased over the eight weeks, placebo included, which is common in gut trials. As the authors say, these were healthy adults with moderate symptoms, not people diagnosed with a gut disorder, and the right dose of colostrum is still unknown.