Bacteria in the Colon
For Dr. Janssen Duijghuijsen, the conclusion that milk consumption can influence the composition of the microbiome and thus the metabolic profile, especially in individuals without lactase persistence, is plausible.
“Individuals with lactase persistence efficiently digest lactose and absorb the resulting galactose and glucose molecules in the small intestine. In contrast, in non-lactase-persistent individuals, lactase is not expressed in the brush border of the small intestine. As a result, lactose remains undigested in the colon and can serve as an energy source for gut bacteria. This can influence the composition of the microbiome, which in turn can alter the concentration of circulating metabolites,” she said.
Dr. Janssen Duijghuijsen has investigated the effect of lactose intake on the microbiome. In a recently published study, she also showed that increasing lactose intake by non-lactase-persistent individuals leads to changes in the microbiome, including an increase in Bifidobacteria.
“In line with the current study, we also found a significant increase in fecal beta-galactosidase activity. Given the close relationship between the composition of the gut microbiome and the metabolite profile, it is likely that changes in one can affect the other,” said Dr. Janssen Duijghuijsen.
Nutritional Recommendations
The nutrition scientist warned against concluding that milk consumption can protect against type 2 diabetes in non-lactase-persistent individuals, however. “The study suggests a statistical association between milk consumption, certain metabolites, and the frequency of type 2 diabetes. These associations do not provide definitive evidence of a causal relationship,” she said. Any dietary recommendations cannot be derived from the study; much more research is needed for that.
This story was translated from the Medscape German edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.