Micronutrients impact the gut microbiota and blood glucose.

Micronutrients influence hormone action and host metabolism. Dietary minerals, trace elements, and vitamins can alter blood glucose and cellular glucose metabolism, and several micronutrients are associated with the risk and progression of type 2 diabetes. Dietary components, microbes, and host immune, endocrine, and metabolic responses all interact in the intestine. There has been a focus on macronutrients modifying the host-microbe relationship in metabolic disease. Micronutrients are positioned to alter host-microbe symbiosis that participates in host endocrine control of glucose metabolism. Minerals and trace elements can alter the composition of the intestinal microbiota, gut barrier function, compartmentalized metabolic inflammation, cellular glucose transport, and endocrine control of glucose metabolism, including insulin and thyroid hormones. Dietary vitamins also influence the composition of the intestinal microbiota and vitamins can be biotransformed by gut microbes. Host-microbe regulation of vitamins can alter immunity, lipid and glucose metabolism, and cell fate and function of pancreatic beta cells. Causal effects of micronutrients in host-microbe metabolism are still emerging, and the mechanisms linking dietary excess or deficiency of specific micronutrients to changes in gut microbes directly linked to metabolic disease risk are not yet clear. Dietary fiber, fat, protein, and carbohydrates are key dietary factors that impact how microbes participate in host glucose metabolism. It is possible that micronutrient and microbiota-derived factors also participate in host-microbe responses that tip the balance in the endocrine control of host glucose metabolism. Dietary micronutrients should be considered, tested, and controlled in pre-clinical and clinical studies investigating host-microbe factors in metabolic diseases.