You are more than who you think you are! Yes, that is correct. If you are still thinking of yourself as a single intelligent organism, then think again! I am referring to the 1013 (10 trillion) bacteria in your body, most of them living in your gut, feeding on you, and shown to protect your brain from different inflammatory diseases such as Multiple Sclerosis (MS).
MS is a progressive autoimmune disease, meaning that your immune cells have a difficult time distinguishing your own cells from those aliens finding their way into your body. As a consequence, your immune cells mistakenly attack your own cells. In the case of MS, for instance, they attack the cells that are responsible for the production of a lipid sheet, called myelin, around your neural cells.
Myelin helps neural cells to communicate with each other in a faster, more efficient way. Upon disruption, neural cells might not be able to talk to each other properly, and you can imagine what devastating effects this miscommunication may have on your body. Gradual loss of myelin, for instance, has already been shown to be related to different dysfunctions in learning and memory.
Bacteria can help you against this autoimmune pathological condition. A new study published in the journal Cell Reports by Mangalam and colleagues showed that one specific strain of bacteria can be beneficial in reducing the overreactivity of immune cells in autoimmune diseases. In this way, bacteria have been proven to mitigate the effects of misunderstanding between your immune cells and cells producing myelin. By neutralizing your overreacting immune cells, indeed, these bacteria take the weapons away from your overreacting immune cells to kill other cells in your body.
It is amazing how these microbial strains could be utilized to fight with overreacting immune cells in your brain when they are not functioning for your well being. So, what do you think of these generally commensal, but potentially opportunistic pathogens living with you? Allies or enemies? This is the question!
Mangalam, A., Shahi, S.K., Luckey, D., Karau, M., Marietta, E., Luo, N., Choung, R.S., Ju, J., Sompallae, R., Gibson-Corley, K., et al. (2017). Human Gut-Derived Commensal Bacteria Suppress CNS Inflammatory and Demyelinating Disease. Cell Rep 20, 1269-1277.