Your gut bacteria are in constant conversation with your immune system — here's what that means for your score.
Your gut is home to trillions of bacteria that do far more than digest food — they're in constant conversation with your immune system, which makes gut health one of the more interesting threads connecting diet to inflammation.
A large share of your immune system lives in and around your gut lining. A healthy, diverse population of gut bacteria helps maintain that lining and produces compounds — like short-chain fatty acids from fermented fibre — that appear to help regulate inflammatory signalling.
Diets low in fibre and plant diversity, high in ultra-processed food, and — separately — heavy or frequent alcohol intake are all associated with reduced gut bacterial diversity and a less resilient gut lining.
A wide variety of plants (aim for variety, not just volume), fermented foods like yogurt, kefir, kimchi and sauerkraut, and adequate fibre intake are the most consistently supported levers. This is part of why THE FAD's Food signal rewards plant diversity specifically, not just "eating vegetables" as a single checkbox.
Simple starting point: if your meals repeat the same 5–6 plants every week, adding variety — not necessarily more quantity — is usually the highest-leverage change.
THE FAD