Taking a course of antibiotics can actually stop the growth of new brain cells in the hippocampus; a region of the brain associated with memory. One negative side effect of taking antibiotics is the loss of good bacteria in your gut. Now there’s another problem to worry about; antibiotics can impair your memory. How do antibiotics affect your brain? Researchers discovered that a type of white blood cell actually facilitates communication between your brain, your immune system and your gut. This particular study was carried out on mice, but the same mechanism is believed to occur in humans. The immune cells are called Ly6Chi cells. Susanne Asu Wolf of the Max-Delbrueck-Center for Molecular Medicine in Berlin, Germany is a senior author of the study. She said "We found prolonged antibiotic treatment might impact brain function. But probiotics and exercise can balance brain plasticity and should be considered as a real treatment option." Dr Wolf first noticed signs that the immune system can influence the health and growth of brain cells through research into a type of white blood cell called T cells almost 10 years ago. At that stage there wasn’t enough research to establish a link from the brain to the immune system and back to the gut again. Taking a probiotic after a course of antibiotics can mitigate these harmful effects. Dr Wolf went on to say "The magnitude of the action of probiotics on Ly6Chi cells, neurogenesis, and cognition impressed me”. Antibiotics can be life saving drugs, and when used responsibly have enormous benefits. Unfortunately they are often over prescribed. If you are regularly developing infections, perhaps it is important to work on improving the health of your immune system so that you’ll be less susceptible in the future. If you must take antibiotics, please remember to always take a probiotic afterwards. Reference: Möhle, Mattei, and Heimesaat et al. Ly6Chi Monocytes Provide a Link between Antibiotic-Induced Changes in Gut Microbiota and Adult Hippocampal Neurogenesis. Cell Reports, 2016 DOI: 10.1016/j.celrep.2016.04.074