mycobacterium vaccae и депрессия

Mycobacterium vaccae, a harmless bacteria normally found in dirt, has been found to stimulate the immune system of mice and boost the production of serotonin, a mood-regulating brain chemical.
The bacterium has already been successfully used in people as a vaccine against tuberculosis. It is also being tested as a treatment for cancer patients and in asthma sufferers, as a way to control the allergic reaction and help 'rebalance' the immune system.
Interest in the unusual antidepressant properties of M.vaccae arose by accident following an experimental treatment for human lung cancer led by cancer researcher Mary O'Brien at the Royal Marsden Hospital in London, England. Under that treatment, patients received heat-killed inoculations of the bacteria.
Following the tests, O'Brien's team observed not only fewer symptoms of cancer, but also improvements in their patients' vitality, emotional health and mental abilities.
Lowry and his colleagues speculated that the bacteria in these earlier experiments might have activated brain cells to release mood-lifting chemicals. To investigate the idea further, they injected heat-killed bacteria into a group of mice and found that they initiated an immune response, which activated serotonin-producing neurons in the brain.
Low levels of serotonin cause depression – an illness which afflicts around 1.3 million Australians. The most commonly prescribed antidepressant medications help treat depression by delaying the re-uptake of serotonin, thus raising levels in the brain.
According to Lowry, the strange effect of the bacteria may work by prompting the body's immune cells to release cytokines, chemicals known to activate sensory nerves that stimulate the brain. The findings are published in the journal Neuroscience.
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