We have all probably experienced that Stomach pain and discomfort when we are nervous, excited or sad. People refer to it as the nervous stomach. This is a sign that there is some connection between our mood and our gastrointestinal system, and the new study suggests there is a really strong connection between the two.

Good bacteria essential for digestive tract

We are well aware of the fact there is a complex community of microorganisms living in our digestive tract. 300 to 500 bacterial species live in the human gut and the so-called "good bacteria" do not only help digestion but can ease and lessen depression symptoms.

Those good bacteria or probiotics can improve our mood.

According to Premysl Bercik, a researcher at Ontario Canada's McMaster University, a huge amount of people (40-90 percent) suffering from irritable bowel syndrome, or Ibs, also show signs of anxiety or depression. The real cause of IBS is still not known but it can cause a lot of discomfort and pain to the person suffering from it. The body’s waste removal process is jeopardized and this is one of the reasons for possible depression. However, Bercik came to the conclusion that a person's mood is also affected by the presence or lack of gut bacteria.

He concluded that the gut symptoms in patients treated with probiotic bacterium improved and, at the same time, depression scores decreased significantly.

Early study findings

What Bercik conducted was just an early study. He focused on IBS patients also showing signs of depression and anxiety. He included 44 of them in the study. One group was given a daily probiotic while the other one was given a placebo. That is an inactive substance that doesn't have a real physical effect on the patient.The progress in patients was followed for 10 weeks.

The first part of the study focused on researchers evaluating levels of anxiety and depression in patients. The patients were shown a combination of happy and sad images while their brain reactions to those images were recorded with imaging devices. This gave the researchers an insight into what parts of the brain were active when patients got exposed to those images.

The researchers made their first conclusion in the sixth week of the study. The group that was being given the probiotic showed fewer symptoms connected to depression, around 64 percent of patients. The group taking placebo also showed lower depression scores, around 32 percent drop. An imaging study now showed changes in parts of the brain connected with mood control.

What's next?

While Bercik says this is just an early study and larger studies are needed to confirm this connection, he admits it is a great promise. If confirmed, the findings would help both patients suffering from IBS and offer some new ways to treat patients with anxiety, depression and other primary Psychiatric Disorders.