Bacteria have thousands of genes and functions that we, the human host, do not have. For instance, bacteria can help us digest fiber, provide support to our immune systems, and absorb important nutrients. But reaping the benefits of "good bacteria" is easier said than done. Andrea Azcarate-Peril, Ph.D., is trying to understand how to better prescribe probiotics based on our individual microbiomes—or the collection of genomes from all microbes that naturally live inside of us. Azcarate-Peril says that if you want to start boosting your microbiome more effectively and reliably, rotate your probiotics and consume a variety of fermented foods...