Disruptions to our microbiome have been linked to everything from obesity to anxiety. But while probiotics are sometimes touted for those and other ailments, Consumer Reports On Health notes that there's little evidence that they can help treat them. The strongest studies of probiotics have instead focused on their role in immunity.
Studies have shown there are 10 times more bacterial cells than there are human cells living in our bodies, concentrated mostly in the intestines. Those bacteria help digest food and synthesize vitamins. They also help fortify our defenses against germs that can cause infections.
Scientists speculate that our increasingly sterile environment may be weakening this microbial shield. Our homes are more hygienic and we have less contact with bacteria-laden soil and animals than our ancestors did. Our food and water are also treated in ways that reduce microscopic freeloaders. These developments have no doubt reduced our exposure to potentially dangerous microorganisms, but they may also be limiting the microbial diversity that helps keep our immune defenses humming.
Perhaps the biggest threat to our microbiome, though, is our reliance on antibiotics. Those drugs are prized for their ability to treat infections caused by bacteria. Unfortunately, they often kill helpful bacteria along with harmful ones.
Consumer Reports says: There are important gaps in the evidence, but studies suggest that probiotics could be an effective precaution against the development of antibiotic-associated diarrhea, including cases that are caused by C-diff. Consider taking a probiotic whenever you are prescribed antibiotics for more than just a few days.
Though the evidence is weak, some experts say probiotics are worth a try in other risky situations, such as when taking a cruise or visiting a developing country. Finally, consider asking your doctor about taking probiotics before being admitted to a hospital, where potentially harmful bacteria may lurk. And never use probiotics as a substitute for medical care.