RP-G28: Therapeutic Treatment for Lactose Intolerance


RP‐G28 has the potential to become the first FDA‐approved treatment for lactose intolerance, a condition that affects millions worldwide.

RP-G28 effectively stands out as the only therapeutic regimen impacting the natural history of the disease, alleviating the symptoms and reducing the frequency of symptomatic episodes of lactose intolerance. The product stimulates the growth of lactose-metabolizing bacteria in the colon, which reduces lactose-derived gas production, and thereby mitigates the symptoms of lactose intolerance in the process.

RP-G28 Promotes Colonic Adaptation

The following depicts RP-G28’s mechanism of action:

  1. Inadequate lactase activity in the small intestine results in lactose not being broken down properly, thus the undigested lactose proceeds through to the large intestine
  2. RP-G28 stimulates and adapts the bacteria in the large intestine to metabolize the undigested lactose by:
    • Increasing lactose-metabolizing bacteria
    • Decreasing gas producing bacteria
  3. The adapted bacteria in the large intestine breaks down lactose, thus reducing gas production and gastric symptoms associated with lactose intolerance

Clinical Trial Results

Phase 2b/3 Trial

We completed a Phase 2b/3 multi-center, randomized, double-blind, placebo-controlled, parallel-group trial of RP-G28 in patients with lactose intolerance symptoms. The trial aimed to evaluate a patient’s ability to consume dairy foods post-treatment with improved tolerance and reduced digestive symptoms. A total of 377 subjects were enrolled in the trial with 18 clinical sites participating throughout the United States.

Clinical results are currently under consideration for scientific publication.

Phase 2a Trial

We completed a double-blinded, randomized, multi-center, placebo-controlled Phase 2a clinical trial of RP-G28. The purpose of the trial was to assess the effectiveness, safety and tolerability of RP-G28 compared to a placebo when administered to subjects with symptoms associated with lactose intolerance. An additional goal of the Phase 2a clinical trial was to establish proof-of-concept that treatment with RP-G28 facilitates improved lactose metabolism via the adaptation of intestinal bacteria metabolism (i.e. colonic adaptation). The trial evaluated RP-G28 in 85 patients with lactose intolerance. The clinical results from the Phase 2a trial was published in Nutrition Journal in a manuscript entitled, “Improving lactose digestion and symptoms of lactose intolerance with a novel galacto-oligosaccharide (RP-G28): a randomized, double-blind clinical trial.”


  • Subjects in the RP-G28 group reported a reduction in total symptoms after treatment. Reported symptom improvement continued 30 days post-treatment.
  • A majority of subjects who began the study with abdominal pain associated with dairy consumption reported no abdominal pain after taking RP-G28.
  • The reduction in total symptoms was consistent with the improvement in hydrogen breath test results following post-treatment lactose challenge as compared to baseline (pre-treatment) results.
  • RP-G28 was well tolerated with no significant study-drug related adverse events.

A link to the publication can be found here.

Microbiome Results

This research is particularly noteworthy because it marked one of the first instances where researchers identified a beneficial change in the specific bacteria species in the human microbiome as a result of a course of treatment for a disease, specifically, lactose intolerance. Significant changes in the diversity of the microbiota occurred in RP-G28 treated subjects upon reintroduction of dairy into the diet. Notably, 90% of the RP-G28 treatment group showed a bifidogenic response compared to other studies, which reported a bifidogenic response in 50% of the treated subjects. As a result, the Phase 2a trial further validates RP-G28’s mechanism of action and supports the product as a potential treatment for lactose intolerance.

The clinical microbiome data from the Phase 2a clinical trial was published in the Proceedings of the National Academy of Science.  A link to the publication can be found here.

Featuring Recent Posts WordPress Widget development by YD