Lactose intolerance (LI) is a common medical problem with limited treatment options. The primary symptoms are abdominal pain, diarrhea, bloating, flatulence, and cramping. Limiting dairy foods to reduce symptoms contributes to low calcium intake and the risk for chronic disease. Adaptation of the colon bacteria to effectively metabolize lactose is a novel and potentially useful approach to improve lactose digestion and tolerance. RP-G28 is novel galacto-oligosaccharide (GOS) being investigated to improve lactose digestion and the symptoms of lactose intolerance in affected patients.


A randomized, double-blind, parallel group, placebo-controlled study was conducted at 2 sites in the United States. RP-G28 or placebo was administered to 85 patients with LI for 35 days. Post-treatment, subjects reintroduced dairy into their daily diets and were followed for 30 additional days to evaluate lactose digestion as measured by hydrogen production and symptom improvements via a patient-reported symptom assessment instrument.


Lactose digestion and symptoms of LI trended toward improvement on RP-G28 at the end of treatment and 30 days post-treatment. A reduction in abdominal pain was also demonstrated in the study results. Fifty percent of RP-G28 subjects with abdominal pain at baseline reported no abdominal pain at the end of treatment and 30 days post treatment (p = 0.0190). RP-G28 subjects were also six times more likely to claim lactose tolerance post-treatment once dairy foods had been re-introduced into their diets (p = 0.0389).


Efficacy trends and favorable safety/tolerability findings suggest that RP-G28 appears to be a potentially useful approach for improving lactose digestion and LI symptoms. The concurrent reduction in abdominal pain and improved overall tolerance could be a meaningful benefit to lactose intolerant individuals.

Study registration

ClinicalTrials.gov NCT01113619.


This is the publisher pdf of Dennis A Savaiano, Andrew J Ritter, Todd R Klaenhammer, Gareth M James, Amy T Longcore, Justin R Chandler, W Walker, Howard L Foyt. Improving Lactose Digestion and Symptoms of Lactose inTolerance with a Novel Galacto-Oligosaccharide (RP-G28): a Randomized, Double-Blind Clinical Trial. Nutrition Journal 2013, 12:160 (13 December 2013) and is available at: 10.1186/1475-2891-12-160.


Lactose intolerance; Colonic adaptation; Galacto-oligosaccharides; GOS; Hydrogen breath test; RP-G28; Microbiome; Microflora

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