A new study suggests that H. pylori confers a protective effect on women and may prevent the development of multiple sclerosis (MS). Researchers are seeking alternative treatments as the prevalence of MS has been increasing steadily with no defined cause.
The research participants consists of 550 people with confirmed MS and a comparison group of 299 healthy people, matched for age and sex, for the presence of antibodies to Helicobacter pylori. The tests were done between 2007 and 2011.
The study findings revealed that the prevalence of the infection was significantly lower in those with MS than in the comparison group, but only among women, who demonstrated a 30% decreased infection rate. Researchers found that among women with MS, 14 percent had evidence of past infection with H. pylori.
Women with MS who tested positive for H. pylori seemed to be less disabled by their condition than those who tested negative for the infection. The reverse was true in men, among whom a positive test result was linked to higher rates of disability.
The researchers recommend further research to explain the sex differences and suggest that the H. pylori bacterium may move the immune system into a less inflammatory state, which may reduce its sensitivity and lower the risk of autoimmune disorders like MS. The hypothesis is referred to as the hygiene hypothesis based on the theory that certain infections early in life might curb the risk of MS later on.
Helicobacter pylori infection as a protective factor against multiple sclerosis risk in females, Allan Kermode, Marzena Fabis Pedrini, et al., Journal of Neurology, Neurosurgery & Psychiatry, doi:10.1136/jnnp-2014-309495, published online 19 January 2015, abstract.