The human body: stranger than you can imagine

In my last blog I wrote about some recent discoveries that shed new light on the role of bacteria in human beings. When I was a medical student we called bacteria that lived on or inside the body "commensals"- harmless and therefore insignificant. Now we know they are anything but insignificant. Bacteria, far from being the villains for which the immune system is there to destroy, actually work in harmony with the immune system to fight truly dangerous microbes.

It's a lot stranger than that. You may not have heard of a single celled organism  called toxoplasma gondii (the practice nurse at my surgery hadn't), but it's one of those organisms that infects many people, but only causes disease in a few; the old, the very young and those with defective immune systems. Not long ago a microbiology professor in Prague decided to work on it and to begin with, looked for it in his own body. Like anything up to 25% of the population, it was present. Now our professor was one of those people addicted to high-risk sports, hang-gliding, rock climbing and so on. His next task was to test all his students. Acting on an instinct he also inquired into their lifestyle, looking for evidence of high risk activity, not only sports but driving at excessive speed, getting into bar-fights etc. To his astonishment he found students with toxoplasma in their bloodstreams were 2.6 times more likely than the controls to engage in high risk activity. So far, no explanation has been offered for this extraordinary correlation, but the findings are out there.

Once when I was working as a psychiatrist we had a patient with really florid schizophrenia. She believed herself to be Marie-Antoinette and was in constant fear that someone was going to come into the ward and chop off her head. She also reported other vague, non-specific symptoms of unwellness, though these were dismissed as part of her psychosis. Then one day someone went into the loo after her and noted the hideous stench and also that her motions were difficult to flush away. It was a lightbulb moment. We decided to test her for coeliac disease, and it turned out she had a quite severe case. We instituted a gluten free diet and pretty soon her bowels regularised themselves and she reported feeling a little better in herself. At the same time, her symptoms of schizophrenia disappeared. Within a month she was discharged completely rational and a little embarrassed about  troubling us with her bizarre delusions. Again, no explanation was ever offered for what had happened; it was just "one of those inexplicable things". Just one of those things indeed...