Micronutrients and the gut microbiome: a bidirectional interaction

A review of the literature in recent years was carried out using the RSCI, Google Scholar, Pubmed, and ResearchGate databases. The purpose of the review was characterization of the influence of dietary micronutrients on the intestinal microbiome and assessment of the role of the microbiome in providing the host with micronutrients. Results . Approximately half (40–65 %) of all types of prototrophic bacteria inhabiting the intestine are capable of synthesizing all B vitamins and are donors for auxotrophic bacteria. Only four vitamins (B6, folate, B12, niacin) can be produced in quantities that represent about 25 % of a person’s physiological requirement, but the lack of transporters for the absorption of vitamin B12 in the colon makes it unavailable to the host. Vitamin K (menaquinones) synthesized by intestinal bacteria does not enter the systemic circulation, which does not exclude their local effect on the intestinal epithelium. A lack of micronutrients (vitamin A, iron, zinc, folate) in the host’s diet disrupts the composition and function of the intestinal microbiota; taking vitamins (groups B, C, D, E) improves the composition of the microbiome. Excessive consumption of some vitamins causes them to enter the large intestine, where they have a beneficial effect on the number and diversity of bacteria. Micro- and macroelements are necessary to ensure the viability of representatives of the intestinal microbiota, which is also necessary to maintain optimal elemental homeostasis. Taking prebiotics (soluble dietary fiber) improves the bioavailability of iron, calcium and other minerals. Conclusion . Microorganisms inhabiting the human gastrointestinal tract bidirectionally interact with micronutrients included in the diet, which affects, on the one hand, the species diversity and functions of microorganisms, and on the other hand, the microbiome affects the absorption and bioavailability of micronutrients.