From Mark Pallen and Aimee Parker at the Quadram Institute in Norwich, Nick Loman at the University of Birmingham, and Alan Walker at the University of Aberdeen, all in the UK
There is no “brain microbiome” in the sense of a resident microbial community present in the brains of healthy individuals. Instead, microbes enter such sterile tissues through the process of infection. While the role of infections such as Lyme disease in eliciting neurological symptoms may be under-recognised, this is distinct from the idea of a resident microbial community in the brain. Claims of up to 100,000 microbial species per sample in the brain are implausible. Contamination remains the most likely explanation for such findings (28 September, p 32).
