According to some surveys, approximately four million Americans take probiotics, which are available as pills, powders, foods and drinks. Probiotics are a huge industry — at least a $40 billion dollar one, according to Zion Market Research — and popular brands sell for 35 cents to $1 a dose, with a shelf life of several months.
Proponents argue that they improve the composition of the gut microbiome, which is involved in many aspects of health including immunity, metabolism and mood.
Framed this way, probiotics may seem like a no-brainer. But before you reach for your wallet, keep in mind that while many scientists and doctors believe that probiotics have promise, they also say that a lot of products on the market don’t live up to the hype.