Being Clean Doesn't Have to Be Bad for Our Immune System, Scientists Say Alerts A handwashing station at the Exmoor Zoo in Barnstaple, England, in a photo taken June 11, 2020 Photo: Harry Trump (Getty Images) Staying clean might not be as bad for your immune system as is sometimes believed, researchers in the UK say. In a new paper this week, the authors argue that claims about the so-called hygiene hypothesis are overblown and people do benefit overall from keeping their home environment relatively clear of germs. But we do need regular contact with our microbial neighbors, they say—just in specific contexts, like being outside in nature.