Bacteria in the head? The mystery of the brain microbiome

Are there bacteria in the brain or not? In My Bacteria – Weekly Update, Dr. Jiri Snaidr gets to the bottom of the possible brain microbiome. The brain is considered sterile but new studies point to bacteria and fungi in brain tissue. Are they real inhabitants or just contaminants? A controversial search for clues between neurobiology and microbiome research.

For decades, the human brain has been considered one of the most sterile places in the body. But time and again, researchers report finding traces of DNA, structures, or even cultures of bacteria and fungi in brain tissue. What is behind this? In this episode, we shed light on the blood-brain barrier, the difference between infection and a possible “brain microbiome,” and explore the question of how Alzheimer's, Parkinson's, and other neurodegenerative diseases are linked to microorganisms. From spectacular studies to sobering contaminations—a scientific thriller about sterile dogmas, new hypotheses, and the question of whether our brain is really as germ-free as we believe.