Could changes in your gut be causing changes in your brain? It looks like it, according to new research that found that mice behaviour changed when their intestinal flora was changed. And some mice treated with antibiotics became less cautious or anxious.
Doctors have already linked anxiety with irritable bowel syndrome, of course, but the new research from McMaster University takes this steps further on. It suggests that probiotics may have a psychological effect. And raises questions about how couples and families may affect each other through swapping gut flora.
The researchers started by distrupting the usual bacteria in mice guts with antibiotics. They found that produced changes in behaviour – the mice became less anxious or cautious, and the substance ‘brain derived neurorophic factor’ increased. BDNF has been linked to depression and anxiety. When the antibiotics stopped, and the bacteira reverted to its usual state, so did the mice’s behaviours.
McMaster University Professor Stephen Collins says the results ‘provide stimulus for further investigating a microbial component to the causation of behavioural illnesses"
To test the idea further the researchers started with germ free mice that had been bred to be passive. They took bacteria from the intestines of mice that were more exploratory, and passed them on. And the formerly quiet mice became more active and daring. When they gave normally active mice bacteria from the quieter mice, they became more passive too.
The researchers say that behaviour has many causes, but the nature and stability of bacteria in the gut appear to influence behaviours. Change your bugs and you may change your behaviours.
The research appears in the journal Gastoenterology.
Source: McMaster University