> The hygiene hypothesis link to the microbiome and "training" of the immune system link is plausible and more and more research is backing it up. There is als

> The hygiene hypothesis link to the microbiome and "training" of the immune system link is plausible and more and more research is backing it up. There is also the hypothesis that the plague epidemics caused a shift to autoimmune diseases because it needed humanity to shift to a more trigger-happy immune system. Another factor could be the much better state of nutrition than in the old times. Malnutrition has massive negative effects on the immune response, and nutrition was pretty shaky for much of human history, so better nutrition could also cause some autoimmune issues.