In recent years, scientists have discovered that the microorganisms in our gut can do much more than simply aid in digestion. Indeed, the “gut microbiota,” composed mostly of bacteria, can even influence emotions and cognition, a finding that has sparked a great deal of interest. Also, there is growing evidence that the gut microbiota play a large role in brain development, and hence in learning and education. As Carolina de Weerth argues in her blog, we should therefore strive to help children acquire and maintain a healthy gut microbiota. One approach may be to give children probiotics – live bacteria that are known to have a beneficial effect on health.