A common gut microbe could reduce one's risk of developing multiple sclerosis (MS).
The finding could prove the "hygiene hypothesis," which suggests childhood infections could help fight off autoimmune and allergic diseases later in life, the British Medical Journal (BMJ) reported.
The microbe is usually acquired before the age of 2, and lives in the stomach for the duration of the host's life unless treated. About half of the world's population is believed to be infected with the the microbe.
To make their findings, the researchers tested 550 people with confirmed MS and a comparison group of 299 healthy people and tested for the presence of the of antibodies to Helicobacter pylori.
The study's results showed the prevalence of H. pylori was significantly lower in those with MS compared with the healthy participants, but only among females and women with MS who tested positive for the microbe were generally less disabled by the condition. In men, the opposite was found to be true.
The researchers noted there is no obvious reason behind this gender disparity in MS risk, but they hope to conduct further studies on the subject in the future.
"Collectively, such an inverse correlation of H. pylori infection with MS in developing countries where MS and allergic disorders have increased, may support the 'hygiene hypothesis,' Professor Jun-ichi Kira, of the Neurological Institute at Kyushu University, wrote in a linked editorial."Although why the protective effects of H. pylori against MS were observed only in women remains to be elucidated, but might explain the recent increase in female to male ratio of MS in developed countries."
The findings were published in a recent edition of the Journal of Neurology Neurosurgery & Psychiatry.
