Research on mice shows that those carrying the most lice had calmer immune systems than uninfested rodents, and they [the researchers, not the mice!] said their finding may have implications for studying the causes of asthma and allergies in people.
This study is more evidence that a high level of foreign substances in our body to which the immune system responds is beneficial. The researchers say nothing about fermented foods, which are an easy and easy-to-control way to ingest such substances. It’s hard to vary your dose of lice but easy to vary how much yogurt you eat.
Thanks to Oskar Pearson.