Thursday, January 1, 2009
Let Them Eat Dirt
For almost 11 years I have been wondering what MS is good for, or to put it in other terms, how did MS evolve into what we know it as today?
Who or what organism benefits from a body having MS?
I have spoken about the "hygiene hypothesis" on this blog and the use of worms (called helminths) in possibly treating MS and other auto-immune disorders. Studies are currently under way to see if these creatures are truly beneficial to people with MS. If they are, we need to understand why. Do the worms provoke a type of response that protects from MS symptoms? If so, how?
I came across the "old friends" hypothesis recently and it is related to the hygiene hypothesis. Friendly microorganisms exist all over the world and in our guts. We eat them, drink them, and breathe them in without being aware of it. But we are an obsessed society these days, with improved sanitation and potable water systems, anti-bacterial soaps, and germaphobia, so many of these organisms don't stand a chance of surviving. There appears to be evidence that these "old friends" are needed to build and maintain healthy immune systems. And perhaps the presence of these "old friends" affects our own gene's expressions. If we don't have them, our genes are activated and ta-da! MS appears.
Humans have evolved to the point where we need certain microbes to live in and on us in order for us to maintain our health. If we didn't have the myriad of creatures living with us that we do, the world would be a lot less habitable.
We have been investigating the "viral" theory of MS for years; in other words, we are exposed to a virus that years later provokes an immune response we identify as MS. Maybe we should be looking at what we are missing from our bodies that causes MS. A virus may be the ultimate culprit for MS but what if there's another organism that by its mere existence in our system, battles the virus' long term effect on our immune system and stops the development of MS?
Scientists have identified certain genes that may be involved in MS. How they are activated remains to be seen. But it could be the simple presence of micro-organisms that keep them in line. So now I have to rethink my original question and perhaps look at who doesn't get MS and why not.
The other part of this post comes from an article I came across about a microorganism that when ingested seems to boost serotonin levels.
Researchers first spotted the special effects of the bacterium, Mycobacterium vaccae, when they used it to help treat patients with lung cancer. They discovered that the bacterium reduced the patient's pain and increased their feelings of well-being.
Lead researcher Dr Chris Lowry explains: 'We thought this might be due to some affect on serotonin in the brain - a chemical that affects happiness. It's a really important chemical and low levels of serotonin can lead to depression in some people.'
We injected the bacteria into mice and found that it had a very similar effect on them as antidepressant drugs such as Prozac', says Chris Lowry. 'The bacteria were triggering an immune response in the body which somehow led to an increase of serotonin in the brain.
'This response was really specific. The bacteria were activating groups of nerve cells that produce serotonin in the areas of the brain that regulate mood and brain function, but no where else. This was what was really striking to us - we didn't expect that,' he explains.
The scientists think their results could help unravel why immune system upsets can lead to depression in some people. But before they can put the bacteria to work treating depression, they need to do some more investigations.
'But before conducting clinical trials on people we need to understand exactly how this works. We believe that the bacteria may trigger sensory nerves in our body that send information back to the brain, causing the increase in serotonin. But at the moment we're really not sure.'
Other experts agree this could be an important step. 'If you take a drug like Prozac, you are setting off all the serotonin neurons, some of which can cause nasty side effects like insomnia,' says Graham Rook, an expert in Immunology at University College London.
'But this response is very specific and activates just the neurons that affect depression. If you could work out the exact molecular mechanisms by which this bacterium works you could find a whole new way of treating depression.'
To sum everything up: eat dirt, it's good for you.