Ever wake up feeling nauseous on the day of a big meeting? The gut and the brain stand in constant communication with one another. The gut is home to the Enteric Nervous System (ENS), which many call the second brain, and is a network of neurons embedded in the lining of the gastro-intestinal system. The ENS directly communicates with the brain by sending messenger signals and hormones back and forth. This communication is often referred to as the gut-brain-axis. Probiotics play an active role in this communication and the composition of the gut microbiome can influence mood, ability to concentrate, memory, and emotional disorders.