In chapter 7 of my book, and in my post of Dec 2, 2011, I noted how the hygiene hypothesis is used to explain the relatively recent, serious rise in auto-immune disorders. This is illustrated by the correlation between the dramatic drop in infectious diseases and the corresponding increase in many auto-immune disorders during the 20th century. The figure is taken from Bach’s review in NEJM. Question: If a deficiency in exposure to microbes during early childhood development (good hygiene) leads to hyper-responsivenes to these microbes later in life (auto-immune disorders), is it too late to modulate the auto-immune responses by manipulating exposure to microbes in adulthood? As I’ve discussed here previously, manipulating the gut microbiome by fecal transplants has proven successful in treating severe bowel conditions in human patients. Another approach is to actually infect patients on purpose to possibly modulate the immune system in a favorable direction. This was the case with the Nobel prize winning work of Julius Wagner-Jauregg in which he infected schizophrenia patients with malaria, as discussed in chapter 1 (“Fever and madness”) of my book.
Thus, it is of interest that Correale & Farez in Argentina reported that multiple sclerosis (MS) patients who happen to be infected with intestinal parasites (helminth worms) display markedly lower symptoms (behavioral and MRI) than uninfected MS patients. Moreover, when the infected patients were treated with drugs to kill the parasites, their MS symptoms dramatically increased, as did various markers of inflammation. In a more direct test, a small phase 1 clinical trial of administration of a non-pathogenic helminth (Trichuris suis; TSO) to MS patients by a group in Wisconsin found that TSO was well tolerated and favorable trends were observed in MRI and immunological assessments. Importantly for another, much larger patient population, a test of TSO treatment in adult autism subjects will begin soon.