House Guests Bring Germs And Stronger Immune Systems

Here are some alarming numbers: every person who enters our homes emits 38 million bacterial cells an hour. In fact, even if a guest walked into the kitchen and held their breath, they still would slough off 10 million bacterial cells in just 60 minutes through skin shed. Those numbers come from researchers at the University of Chicago, who consider the bacteria as welcome visitors, because they stimulate our immune systems and thus enable us to better stave off the kind of disease that could do serious damage in a more germ-free environment. A U of Chicago news release quotes Jack A. Gilbert, UChicago associate professor in ecology & evolution and group leader for microbial ecology in the Biosciences Division at the U.S. Department of Energy’s Argonne National Laboratory, advising that our over-sanitized environment may ultimately leave us weaker than our ancestors, who were agrarian and were constantly surrounded by a wide variety of plants and animals. “Our ancestors experienced many different types of bacteria on a regular basis,” he said. “When you live with such rich biodiversity, the body expects to see it and when it doesn’t, it freaks out, which is why we are seeing an explosion in allergies, asthma and hay fever. Our bodies are overreacting to the absence of these organisms.”