The theory of disappearing microbiota and the epidemics of chronic diseases.

In recent decades, the incidence of many apparently unrelated chronic diseases has markedly increased. Here, I theorize that losses of particular bacterial species of our ancestral microbiota have altered the context in which immunological, metabolic and cognitive development occur in early life, which results in increased disease. This ominous trend suggests that we must refocus efforts to understand and reverse the underlying circumstances that are responsible for our disappearing microbiota.