Have you ever noticed how in a stressful moment, your stomach can hurt? That's because the gut is more than just an organ for digestion. It acts as our "second brain" and affects moods and well-being too.
The digestive tract houses 100 million neurons that are at least partially responsible for coordinating this system of hormones which not only govern hunger but also regulate sleep, motivation levels, pain threshold (such as what causes us to feel stressed), immune function or even whether we experience happiness on any given day! This means if someone suffers from irritable bowel syndrome (ibs) they may be experiencing anxiety without realizing it; when their intestines become overactive due to stress these sensitive nerves literally cause them so much discomfort.
The neural network that lines the digestive tract is called the enteric nervous system (ENS) and it is involved with neuromodulators that can affect your emotions. The gut microbiome and the bacteria within it directly interact with the ENS. We've recognized this for a while, but new research shows how different types of bacteria can have an impact on our mental health as well.
Researchers found out more about these relations by studying mice who had been separated from their mothers at birth. Some mice were placed into cages containing healthy bifidobacterium which improved anxious behaviors when compared to those without the probiotic microbes present. There has been mounting evidence suggesting that bacteria play a critical role in behavior in mammals.
There's this old adage out there: "you are what you eat."