Type 2 diabetes, obesity, and metabolic syndrome reshape the gut ecosystem, while the microbiota feeds back on insulin sensitivity and inflammation.
Hay fever and allergic rhinitis often trace back to low microbial diversity in the gut, which weakens immune tolerance.
At the hormonal turning points of pregnancy and menopause the gut microbiota shifts too, and through the estrobolome it feeds back on circulating estrogen.
Microbial diversity and butyrate production decline with age, yet diet, exercise, and careful medication use can still bend that trajectory.