More on Mind Controlling Bacteria

Canadian researchers have

demonstrated that mice fed with Lactobacillus rhamnosus JB-1 showed significantly fewer stress, anxiety and depression-related behaviours than those fed with just broth. Moreover, ingestion of the bacteria resulted in significantly lower levels of the stress-induced hormone, corticosterone.

One of the researchers said,

This study identifies potential brain targets and a pathway through which certain gut organisms can alter mouse brain chemistry and behaviour. These findings highlight the important role that gut bacteria play in the bidirectional communication between the gut and the brain, the gut-brain axis, and opens up the intriguing opportunity of developing unique microbial-based strategies for treatment for stress-related psychiatric disorders such as anxiety and depression. . . .

The researchers also showed that regular feeding with the Lactobacillus strain caused changes in the expression of receptors for the neurotransmitter GABA in the mouse brain. The authors also established that the vagus nerve is the main relay between the microbiome (bacteria in the gut) and the brain. This three way communication system is known as the microbiome-gut-brain axis and these findings highlight the important role of bacteria in the communication between the gut and the brain, and suggest that certain probiotic organisms may prove to be useful adjunct therapies in stress-related psychiatric disorders.

I find the cultural implications of this fascinating -- what if different diets and climates give us different gut bacteria, and change our personalities?

And you just have to love the "microbiome-gut-brain axis."