“Like the gut microbiota, the oral microbiota also participates in such interactions. People with schizophrenia showed a higher ratio of Streptococcus bacteria to Prevotella, along with shifts in other bacterial groups. If manipulating oral bacteria could make even a small difference to these cognitive challenges, it would matter. Next steps involve longitudinal studies (following people over time to see how changes in oral microbiota relate to changes in cognition). Somewhere in the complex chemical conversations between mouth bacteria and human cells, there might be clues to protecting the mind.