Adults with self-reported lactose intolerance were shown to have significant improvement in their clinical outcomes, including abdominal pain, after consuming an oral, liquid supplement intended to increase lactose-fermenting gut bacteria, M. Andrea Azcarate-Peril, PhD , assistant professor of medicine at the University of North Carolina, Chapel Hill, and her colleagues have shown in a small phase IIa study (Proc Nat Acad Sci. doi: 10.1073/pnas.1606722113 ).

In a placebo-controlled, double-blind trial, randomly assigned in a 2:1 ratio and conducted at two U.S. sites, highly purified (more than 95%) short-chain galactooligosaccharide (GOS) was given to 42 adults with a self-reported history of lactose intolerance, confirmed by a hydrogen breath test administered after a 25-g lactose challenge. The 20 controls were given a corn syrup mixture formulated according to the same sweetness and consistency as the test drug. Each study arm was started on its regimen at 1.5 g daily, with incremental increases in dose every 5 days until reaching 15 g. Beginning with their first dose at day 1, through day 35, all participants avoided consumption of dairy foods. Stool samples were collected from both groups at days 0 and 36. After day 36, all participants were asked to resume eating dairy foods. At day 66, stool samples were once again collected. Changes in the microbiome at all endpoints were measured by testing the stools via polymerase chain reaction.

Of the 30 study arm participants for whom complete stool samples were available, 27 were found to have had a bifidobacterial response at day 36, including a significant increase in the lactose-fermenting Bifidobacterium, Faecalibacterium, and Lactobacillus species. The remaining three participants in the study arm were considered nonresponders.

In an interview, Andrew Ritter, whose company, Ritter Pharmaceuticals, sponsored the trial, reported that of the 36 study arm participants who had reported abdominal pain pretreatment, 18 said they no longer had the pain at either endpoint, day 36 or day 66 (P = .019); three of 19 in the placebo group reported they no longer had abdominal pain at either endpoint. The study group was also six times more likely to report lactose tolerance at day 66 compared with their pretreatment levels (P = .0389); 28% of the placebo arm reported lactose tolerance at the endpoints. These results were previously published in Nutrition Journal in 2013. [doi: 10.1186/1475-2891-12-160]

“We’re super excited about these results,” said Mr. Ritter. “This is really one of the first clinical studies in a lactose-intolerant population that shows changes in the microbiome.” As to how long before the treatment will be ready for the Food and Drug Administration approval process, Mr. Ritter said, “We’re probably just a couple of years away.”

Two coauthors are advisers to Ritter Pharmaceuticals, which provided the highly purified GOS used in the study. The North Carolina Agriculture Foundation also provided funding for the study.

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