The role of iron ions in the vital activity of the intestinal microbiota

Objective: to systematize modern data on the role of iron in the vital activity of opportunistic and resident bacteria of the intestinal microbiome. The review describes current data on the importance of iron in the functioning of the intestinal microbiome, due to the presence of iron ions in the prosthetic groups of respiratory chain enzymes, antioxidant systems, and carbohydrate catabolism enzymes. Both lack and excess of iron intake causes a change in the qualitative and quantitative composition of the intestinal microbiome. The issue of changing the virulence of opportunistic bacteria in the presence/absence of iron ions is discussed. Thus, in order to obtain the necessary amount of iron, hemolysin synthesis begins in Staphylococcus epidermidis, Escherichia coli, which leads to increased biofilm formation and an increase in antibiotic resistance of bacteria. Iron-dependent protein Irfp was found in Klebsiella pneumoniae, which regulates capsule formation, fimbria and siderophores genes depending on the state of the environment, which establishes grounds for the appearance of hypervirulent clinically significant strains. The study describes the role of bifidobacteria and lactobacilli in regulating the amount of iron in the intestine associated with the sequestration of Fe2+ ions in the cytosol of cells, which is one of the mechanisms for regulating the virulence of opportunistic bacteria.