Q: I was recently prescribed antibiotics and I’m worried that it might kill the “good” bacteria in my gut. What can I do to minimize the damage?
Since penicillin was discovered in 1928, antibiotics have transformed once life-threatening infections into treatable conditions. But in the process of wiping out the “bad” bacteria, they can decimate the “good” ones, too.
Fortunately, for most people, these effects on the gut microbiome are temporary, said Dr. Tien Dong, a gastroenterologist at UCLA Health. If you’re generally in good health, “you’ll likely recover on your own,” Dr. Dong said.
Still, you can take actions to encourage that recovery. And while much of this research is limited and in early phases, it does suggest what is perhaps the most important action: Paying attention to your diet.
What do antibiotics do to your gut?
Antibiotics affect the microbes in your gut in a similar way that wildfires affect the plants and animals in a forest, Dr. Dong said. The landscape regrows, but with less diversity than before. The first plants to repopulate after a fire are weedy and opportunistic, and they grow all over the place. The same thing happens in the gut after antibiotics, Dr. Dong said. The initial bacteria to return are fast-growing generalists that quickly take over the gut. This forms a less diverse and therefore less healthy microbiome, Dr. Dong said.
Fortunately, broad-spectrum oral antibiotics won’t kill your entire native flora, said Amy Langdon, a microbial genomicist who recently left a postdoctoral position at Simon Fraser University in Canada. Similar to how random patches of greenery might survive in a burned landscape, small communities of good bacteria can hide in parts of the digestive tract that antibiotics can’t reach. “We’re counting on those to reseed the intestine,” Dr. Langdon said.