Here’s how your gut microbiome changes as you age—and what you can do to keep it healthy

Keeping the good bacteria in your gut happy—and helping it multiply—is advice health experts preach no matter your age. But it’s especially important to pay attention to your gut microbiome later in life, according to gastroenterologist Will Bulsiewicz, MD.

“While it would seem that your gut microbiome is completely capable of regenerating itself and would simply never age, it’s unfortunately not the case,” says Dr. Bulsiewicz. He points to a study that shows how the microbiomes of older participants are less capable of processing fiber and producing short-chain fatty acids than participants in their 30s. (Fiber is the crown jewel of gut health, of course.) He highlights another study that shows how the diversity of good bacteria has a tendency to decrease as a person ages.

A decrease in the diversity of good bacteria likely has to do with lifestyle changes that occur as people get older. “These were cross sectional studies, so we haven’t tracked the human microbiome ‘through the years,’ and frankly that would be a difficult study to do,” says Dr. Bulsiewicz. “But I think we can all agree that as we age, it’s quite common for our diet to change. Some have dental issues or inadequate saliva and struggle to chew on fibrous foods. Others have an altered sense of smell or taste and as a result narrow their dietary preferences, reducing the diversity of their diets.”

Fortunately, there’s plenty that you can do in order to keep your gut bacteria flourishing. “We know from the American Gut Project that the single greatest predictor of a healthy gut microbiome is the diversity of plants in your diet,” he says. Besides making sure you’re eating a variety of plant-based foods, he says considering a probiotic supplement, limiting antibiotic use (when possible), and staying active are all linked to boosting gut health.

Most importantly, Dr. Bulsiewicz says this intel shouldn’t make you fearful. “Embrace aging,” he says. “It turns out that with the right outlook—and a healthy gut—getting older doesn’t have to be a downward slide and, in fact, can be quite the ride.”

A dietitian’s guide to gut health:

These are the six golden rules of gut health, according to doctors. Plus, how sugar affects the gut.