A Narrative Review of Human Clinical Trials to Improve Lactose Digestion and Tolerance by Feeding Bifidobacteria or Galacto-Oligosacharides.

Supplementation with the probiotic and prebiotic galacto-oligosaccharides (GOS) could improve gut health and benefit lactose intolerant individuals. A narrative review was conducted to identify human clinical trials that evaluated lactose digestion and/or tolerance in response to consumption of , GOS, or both. A total of 152 studies on and GOS or both were published between 1983 and 2022. Out of the 152 studies, 20 were human clinical trials conducted in lactose intolerant subjects; 8 studies were conducted with supplementation and 3 studies involved GOS supplementation. Five studies reported favorable outcomes of supplementation in managing lactose intolerance (LI). Similarly, three studies reported favorable outcomes with GOS supplementation. The other three studies reported neutral outcomes. In conclusion, most studies reported a favorable effect of and GOS on managing the symptoms of LI. No study has examined the effects of combined supplementation with and GOS in lactose intolerant subjects. Future research could examine if co-supplementation with and GOS is a more effective strategy to reduce the dairy discomfort in LI individuals.