Higher fiber, milk intake may impact host metabolic health in type 2 diabetes
Higher fiber and milk intake correlated with favorable circulation of tryptophan metabolites for type 2 diabetes, according to a study published in Gut.
"Gut microbiota may interact with host dietary intakes (eg, fiber intake, milk intake) to influence host blood metabolite profiles, which may have an impact on host metabolic health and disease, such as type 2 diabetes,” Qibin Qi, MD, from the department of epidemiology and population health, Yeshiva University Albert Einstein College of Medicine in Bronx, New York told Healio Gastroenterology.
Qi and colleagues assessed correlations between circulating levels of 11 tryptophan metabolites and incident type 2 diabetes in 9,180 patients of diverse racial/ethnic backgrounds from five different cohorts. Investigators evaluated host genome-wide variants, dietary intake and gut microbiome correlated with metabolites.
Results showed tryptophan, four kynurenine-pathway metabolites including kynurenine, kynurenate, xanthurenate and quinolinate and indolelactate were positively correlated with risk for type 2 diabetes. However, indolepropionate was inversely correlated with risk for types 2 diabetes.
“We identified multiple host genetic variants, dietary factors, gut bacteria and their potential interplay associated with these [type 2 diabetes]-related metabolites,” Qi and colleagues wrote. “Intakes of fiber-rich foods, but not protein/tryptophan-rich foods, were the dietary factors most strongly associated with tryptophan metabolites. The fiber-indolepropionate association was partially explained by indolepropionate-associated gut bacteria, mostly fiber-using Firmicutes.”
Investigators noted a novel correlation between a host functional lactase gene variant and serum indolepropionate. This may be associated with a host gene-diet interaction on gut Bifidobacterium. This probiotic bacterium significantly correlated with indolepropionate independent of other fiber-related bacteria.
“Higher milk intake was associated with higher levels of gut Bifidobacterium and serum indolepropionate only among genetically lactase non-persistent individuals,” the researchers wrote.