The gut and immunity: a constant conversation

I often tell my patients that health begins in the gut. This is not a metaphor: most of our immune system lives there, in permanent dialogue with the microorganisms that inhabit us.

The gut microbiome (the trillions of bacteria, fungi and viruses that populate our digestive tract) is today one of the most fascinating fields in medicine. Far from being mere passengers, these microbes help digest food, produce vitamins and short-chain fatty acids, and continuously educate the immune system to distinguish friend from threat.

When this balance is disrupted (a state we call dysbiosis), the consequences can extend far beyond the gut. Research has associated microbiome alterations with autoimmune diseases, allergies, metabolic disorders and even mood, through the so-called gut-brain axis. The intestinal barrier, when compromised, allows molecules to pass through that keep the immune system in a state of chronic alert.

That is why, in my approach, caring for the gut means caring for immunity. A diverse diet rich in plant fibre, fermented foods, less sugar and ultra-processed foods, and the judicious use of antibiotics are simple but powerful pillars. Nourishing our microbes is, at its core, nourishing ourselves.