Exposure to certain microbes as young children may help prevent autoimmune disorders later in life, according to a new study by researchers at the Broad Institute. The findings suggest that people whose immune systems receive this early “education” are less likely to develop the extreme immune system reactions that characterize disorders such as type 1 diabetes and celiac disease. This may explain why the prevalence of autoimmune disorders in the developed world has risen sharply over the past 50 years in tandem with improvements in societal hygiene and child health.
Alberto Ascherio, professor of epidemiology and nutrition at Harvard T.H. Chan School of Public Health, said that this is also true with exposure to the Epstein-Barr virus, which causes multiple sclerosis (MS). Commenting on the new research in a June 3, 2016 New York Times article, he said that childhood Epstein-Barr infection, common in the developing world, lowers MS risk, while acquiring it as an adolescent or adult, when it causes mononucleosis, can more than double it.