Using antibiotics for too long may disrupt brain functions and affect the formation of new brain cells, says a study in the journal Cell Reports . A special kind of cell, which deals with immunity, serves as an intermediary between gut bacteria and the brain and talk to one another via hormones, metabolic products or direct neural connections. In their study on mice, researchers from the Max Delbruck Centre for Molecular Medicine in Germany found that antibiotics can halt the growth of new brain cells in the hippocampus, a region of the brain associated with memory. The researchers switched off the gut microbiome in mice, that is their intestinal bacteria, with a strong concoction of antibiotics. Compared to the mice that had not undergone treatment, they subsequently observed significantly fewer newly formed nerve cells (called neurogenesis) in the hippocampus region of the brain.
As well as impaired neurogenesis, researchers also found that the population of a specific immune cell in the brain — the Ly6C(hi) monocytes — decreased significantly when the microbiota was switched off.