The saying having "a gut feeling" may be based more on biological science than just a hunch according to medical researchers. Recent studies have found a correlation between mood and stomach bacteria with one of the most interesting finding showing that when people have stomach issues, it was also causing problems in the brain at the same time.
Researches said there appears to be a direct connection, via the Vagus nerve, between the brain and the gut, with bacteria in the stomach producing hormones that could stimulate the nerve and change it.
Most of the bacteria in the human stomach is found in the GI tract and is referred to as "good" bacteria as it helps in the digestion of food. This bacteria changes with what is eaten.
The researchers found that 80 percent of patients with irritable bowel syndrome suffered from anxiety and depression and that people with autism also had increased levels of digestive issues.
Last September, the National Institute of Mental Health gave out four grants of up to $1 million each to encourage research into the gut’s bacterial role in mental disorders. This gave credence to the legitimacy of an area of research that has struggled to attract serious scientific credibility.
Institute Director Tom Insel said "We are, at least from the standpoint of DNA, more microbial than human. That’s a phenomenal insight and one that we have to take seriously when we think about human development."