Gut bacteria influences brain chemistry and behavior

Researchers at McMaster University have conclusive evidence that bacteria residing in the gut influence brain chemistry and behavior.

The findings are important because several common types of gastrointestinal diseases, including irritable bowel syndrome, are frequently associated with anxiety or depression. In addition there has been speculation that some psychiatric disorders, such as late onset autism, may be associated with an abnormal bacterial content in the gut.
Working with healthy adult mice, the researchers showed that disrupting the normal bacterial content of the gut with antibiotics, produced changes in behavior; the mice became less cautious or anxious. This change was accompanied by an increase in brain derived neurotrophic factor (BDNF), which has been linked, to depression and anxiety. When oral antibiotics were discontinued, bacteria in the gut returned to normal. This was accompanied by restoration of normal behavior and brain chemistry.
To confirm that bacteria can influence behavior, the researchers colonized germ-free mice with bacteria taken from mice with a different behavioral pattern. They found that when germ-free mice with a genetic background associated with passive behavior were colonized with bacteria from mice with higher exploratory behavior, they became more active and daring. Similarly, normally active mice became more passive after receiving bacteria from mice whose genetic background is associated with passive behavior.
While previous research has focused on the role bacteria play in brain development early in life. Latest research indicates that while many factors determine behavior, the nature and stability of bacteria in the gut appear to influence behavior and any disruption, from antibiotics or infection might produce changes in behavior.
These results lay the foundation for investigating the therapeutic potential of probiotic bacteria and their products in the treatment of behavioral disorders, particularly those associated with gastrointestinal conditions such as irritable bowel syndrome.


Source: http://www.news-medical.net/news/20110518/Gut-bacteria-influences-brain-chemistry-and-behaviour-Research.aspx


Aporte: Fernando Fuentes Pinochet