What Are Probiotics, and Why Should I Try Them?

In a world in which our bottomless passion for health and wellness has culminated in the widespread availability of things like goat yoga, the rise of probiotics—bacteria carefully selected and voluntarily ingested in order to promote better “gut health,” and thus better bowel movements—doesn’t even crack the top decile of unsettling-sounding fitness fads. Yet many of the 60 million U.S. adults who suffer from some form of digestive disease are using these products to treat everything from indigestion to Crohn’s, and today the probiotics industry is valued at over $40 billion. Bacteria, it turns out, is lucrative stuff.

For those who may be pondering the merits of probiotic-infused products, we asked a few experts for advice on how to make the most of one’s microbiome. We also asked them to define “microbiome.”