Microbiome and Immunity

Right now, most of your immune system is sitting in the dark, lining your gut, quietly taking notes on every bite you eat. A tiny shift in which microbes show up to that daily roll call can decide whether you shrug off a virus—or spend a week flat in bed.

About 70% of your immune cells are stationed right along your intestinal wall, shoulder‑to‑shoulder with an estimated 38 trillion microbial neighbors. That’s not an accident—it’s a long‑term co‑working agreement. These immune cells constantly “read” microbial signals to decide what counts as a threat, what’s safe, and how aggressively to respond.

When that daily conversation is rich and varied, the system tends to stay calm but prepared. When it gets one‑sided—after a course of broad antibiotics, months of ultra‑processed food, or a nasty infection—the script can flip. The same defenses meant to stop an invader can start overreacting to pollen, food proteins, or even your own tissues.