After Covid, Your Health May Depend on Living With Germs

Other healthy habits like exercise and getting adequate sleep are all supportive of microbiome health. Gardening, hiking and other interactions with nature may be especially beneficial.

“The more we learn about our relationships with the microbial world, the clearer it is that we are connected to them and to the rest of the natural world,” says Brendan Bohannan, a professor of environmental studies and biology at the University of Oregon. “Getting outside and exposing ourselves to microbes beyond our indoor spaces may have many positive impacts.” Such exposure, he notes, might even counterbalance any negative effect that extended indoor stays might be having on our microbiomes.

For politicians and health officials, the great challenge of the pandemic has been weighing the immediate threat of the virus against the many detriments (social, economic, psychological, developmental) that accompany business and school closures, distancing imperatives and other measures intended to slow its spread. The longer the pandemic lasts, the more these collateral concerns start to feel like primary ones.

While there is much we can do, and much we can stop doing, to strengthen our microbial communities without exposing ourselves to undue risk, experts say that convincing a rightfully skittish public is a tall order. As this pandemic has made clear, all people are walking and coughing vectors for infectious disease. In the United States and elsewhere, there are also long-held and deeply embedded sociocultural norms that prioritize hygiene and denigrate dirt and bacteria. Meanwhile, technology has made it easier than ever for us to live and work in isolation.

When he educates people about the importance of intermingling with microbes, Dr. Finlay likes to point out that our bodies contain at least as many bacterial cells as human cells. He also emphasizes that, before the pandemic, only one of the top 10 causes of death in America — influenza — was attributable to an infectious disease that someone could “catch.” Nearly all the rest, such as heart disease and stroke, cancer, brain disease and diabetes, are associated with poor microbiome health or dysfunction.

“You can’t change your genes, but you can change your microbes,” he says. “They’re our friends.”

He and other experts will continue to work to raise awareness about the importance of bacteria and the microbiome. But for many people, only the passage of time and the suppression of the coronavirus will assuage fears of hidden pathogens.

“What I’m most worried about after this pandemic has passed is that people will be nervous about being exposed to microbes, and so they won’t interact with other people and with the world,” says Dr. Bohannan. “That’s totally understandable — we’re all going to be traumatized by this. But like a storm, this will pass. And after the storm we’re going to need to go outside and be with each other again.”

Markham Heid is a health and science journalist who writes regularly about the microbiome and human health. His work has appeared in Time, Popular Mechanics, Everyday Health, Sports Illustrated and elsewhere.

Photographs by Maisie Cousins for The New York Times.

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