Figure 4.

A model of interactions between lipocalins and microbiota. Lipocalins protect host’s epithelial cells and also commensal microbiota by scavenging toxic molecules such as reactive oxygen species which originate during oxidative stress (A). Keeping microbiome homeostasis requires blocking the origin of bacterial monoculture. Lipocalins contribute to diversified microbiome by scavenging bacteria-produced quorum sensing signalling molecules (B). Similarly, certain bacterial species use siderophores to gain iron and subseuently outcompete siderophore-lacking bacteria. By binding to siderophore-iron complex, lipocalins further contribute to stable microbiome (C). Finally, lipocalins closely interact with other members of the immune system network (i.e., neutrophils, macrophages and epithelial cells) and together create a complex microbiota-surveillace system (D). The figure was created in Biorender.