Dear Dr. Roach: I read your recent column about a person who was refusing antibiotics due to a fear of a Clostridioides difficile (C. diff) recurrence. I am interested in your thoughts regarding people who take probiotics to restore a healthy gut biome.

Relatively healthy people ingest probiotics to maintain good digestive health. Shouldn’t people take probiotics after taking antibiotics, especially after experiencing such a drastic condition like C. diff? Good gut health, including a proper gut biome, is critical to overall health.

There are numerous published, peer-reviewed studies that support the benefits of a healthy gut biome, as well as studies that linked gut-health deficiencies with illnesses. — G.B.O.

Answer: The theory makes perfect sense. Antibiotics upset the microbiome (the whole “suite” of bacteria in our intestines), so why not help restore healthy bacteria by taking large amounts of one or more? The studies, however, have only shown a small benefit in preventing serious infections like C. diff.

The expert guidelines make a conditional recommendation to consider the use of probiotics in adults who take antibiotics based on low-quality evidence and a review of all available published evidence. They note that given the small risk of C. diff, it would be reasonable not to take antibiotics.

Only people who are at a high risk for a recurrence of C. diff are clearly recommended for probiotic treatment (especially people who’ve already had recurrences but also older people or those with a disease of the immune system). People who are at a lower risk didn’t receive a benefit from probiotics.

The science of studying the microbiome isn’t fully developed yet, and there isn’t much agreement on which bacteria help make up a healthy gastrointestinal microbiome. It also isn’t clear whether changes in the microbiome are the cause of human diseases or if they are a result of it. (In my opinion, it’s probably both.)

I don’t recommend probiotics for my healthy patients just to prevent diseases, but it does make sense for high-risk people to take probiotics to prevent problems when they have to take antibiotics. However, as I tried to emphasize in the previous column, it’s worth thinking twice about whether antibiotics are truly needed when there is a risk in using them.