As the nose is closely connected to the brain in anatomical terms via the olfactory nerve, the nasal microbiome, i.e. all the bacteria inside the nose, can exert an influence on brain function—in a similar way to the gut microbiome, which is linked to the brain via the gut-brain axis.

As the nose is closely connected to the brain in anatomical terms via the olfactory nerve, the nasal microbiome, i.e. all the bacteria inside the nose, can exert an influence on brain function—in a similar way to the gut microbiome, which is linked to the brain via the gut-brain axis.