1 Min Read Immunity and the Gut
July 23, 2026Immunity and the Gut
July 23, 2026
Care Framework & Diagram
Your gut is home to seventy percent of your immune system
By the Editors Care Framework & Diagram
70% of your immune cells live in gut tissue, facing a 400 m² surface exposed to the outside world — patrolled by 38 trillion bacteria carrying over 150× more genes than you do.
1
Diversity Is the Key Metric
The single most important gut health measure is diversity, not any one ‘good’ bacteria — changes show up within 3–7 days of a diet change.
2
Butyrate, the Core Signal
Fiber-fed bacteria produce butyrate, which fuels gut cells, seals the barrier, and calms inflammation directly.
3
Gut Aging After 50
Diversity, protective antibodies, and gut motility all decline together after 50 — steadily eroding the gut-immune partnership.
WHAT TO DO
- 30+ different plant foods a week is the single best-evidenced way to build diversity.
- Daily fermented foods, 25g+ fiber, and using antibiotics only when truly necessary all help protect it.