For how we live.
Around 60–70% of infants carry Clostridioides difficile without illness. A Science study finds its toxins remodel the newborn gut in mice — but the direct human evidence is still limited to cells and biopsies.
Additives such as carboxymethylcellulose stabilise processed food. A large cohort links some to slightly higher heart-disease risk, and a small trial shows one disturbs the gut — but proof of harm is not settled.
Animal studies show plastic particles disturbing the gut and triggering inflammation. Human evidence is mostly detection, with cause and effect still unresolved.
The human intestinal-permeability literature lists endurance exercise, NSAIDs, pregnancy and surfactants as stressors. Coffee is not on that list, and alcohol's case is largely inferred.
Using causal-inference methods on 1,269 people, researchers linked two bacterial genera to depression independent of body weight and medication — the first such evidence in humans, not proof of mechanism.