Cross-Talk: Microbiome & Immune System Balance

The human intestinal microbiome acts as a signalling hub that integrates environmental inputs, such as diet and lifestyle, with our genetic and metabolic pathways. Its impacts are widespread across host systems, including the immune system,¹ which is capable of adapting and responding to a wide range of challenges. How does the microbiome interact with the immune system, and how do these interactions help determine a state of health or disease in the body?
Reciprocal cross-talk between the microbiome and cells in the intestinal mucosal immune system is well-documented. We now understand that this cross-talk is important for immune system maturation and modulation across all developmental stages; studies of germ-free mice demonstrate that a lack of gut microbiota leads to significant immune deficiency. Maintaining a homeostatic balance between microbial activity and host immune response toward the microbiota is what allows the immune system to function appropriately to defend against infection yet also demonstrate appropriate tolerance.
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