There are more than a hundred million bacteria in the human gut. They are distributed among 2000 different species and help in digestion and absorption of food in the gut. While these bacteria are considered friendly and necessary for gastrointestinal functions, new research has now revealed a different side. The friendly bacteria in the gut can be a trigger for multiple sclerosis. The study was carried on at Max Planck Institute of Neurobiology, situated in Munich, Germany. The team of researchers has found that naturally occurring bacteria in the gut trigger T-Cells, followed by B-Cells and end up damaging the myelin layer on the brain. The research was carried out on mice, where it was found that the brains of genetically engineered mice, which had common gut bacteria, developed inflammation that was akin to the condition of human brains affected by multiple sclerosis.
Multiple Sclerosis is a disorder of the immune system. When affected by this disease, the immune system of the body begins to attack the brain cells and cause damage to nerves and myelin layer on the brain. As of now, not much is known about why the disease is caused although the process of deterioration of the brain cells has been explored. Several explanations ranging from genetic factors to environmental factors have been given for the condition. The latest study offers a completely new perspective for the cause of disease. T Cells and B Cells are passive components of the human immune system. Multiple sclerosis might be caused when these passive components are made aggressive. So far, external pathogens that enter the human body through various environmental factors are known to cause the problem. The role of friendly bacteria was never expected in the process. The present study focuses on this aspect.
The genetically engineered mice in the laboratory were tested for relapsing-remitting disease of the immune system caused due to CD4+ T cells for which gut bacteria are essential. The mice were divided into two groups. One group was left to have normal gut function while for the second group, intestinal flora was removed. It was seen that the first group of mice developed symptoms akin to multiple sclerosis but the second group remained safe from such symptoms. The number of T Cells were lesser in the second group of mice and it was also found that the antibodies produced against the myelin layer was lesser for the second group. In the next stage of experiments, gut bacteria was introduced in the second set of mice. They developed MS symptoms similar to the first group. Further studies are necessary to validate this find in humans.