Could a cup of yogurt be the trick to turning your frown upside down? It certainly seems like a possibility as mounting evidence suggests that probiotics may influence mental health and produce anti-anxiety effects.
A recent animal study found that mice whose gut flora had been disrupted with antibiotics displayed changes in their behavior and brain chemistry. The mice became less anxious, more adventurous and developed an increase in the brain protein BDNF which affects depression and anxiety. A group of control mice were given water instead of antibiotics; they displayed no behavioral changes at all.
Further studies have found early evidence suggesting the link between gut flora and mental health exists in humans as well. Neurobiologists at Oxford University administered prebiotic supplements – a carbohydrate that boosts healthy gut bacteria – or a placebo to a group of healthy individuals every day for three weeks. At the end of the study, researchers evaluated participants’ emotional processing. They found that participants who had taken the prebiotic supplement paid more attention to positive information and less attention to negative information than those who had taken the placebo. Researchers also found that participants who took the prebiotic had lower levels of cortisol, the "stress hormone" linked with anxiety and depression.
Given the results of these studies, scientists are now delving deeper into the possibility that probiotics and prebiotics may be used to treat depression and anxiety or improve patients’ response to psychiatric medications. However, experts stress that this remains an unproven hypothesis and further research is needed.
Dr. Roger McIntyre, a professor of psychiatry and pharmacology at the University of Toronto, said future studies will be necessary to understand whether gut microbes contribute to psychiatric disorders such as depression and anxiety. It will also be important to identify which bacterial species are important (Source: LiveScience).