Bacteria in the Lungs Can Regulate Autoimmunity in Rat Brains

Amazing stuff! More on the symbiosis between human and internal living bacteria (microbiome)!

"The community of microbes living on the folds of the lung’s alveoli doesn’t attract the same scientific fascination as its neighbor, the gut microbiome. But new research in rats suggests it exerts significant influence over the immune system, just like gut microbes can. ...
Scientists f... demonstrated that perturbing the rat lung microbiome—a bacterial community that was long thought to not exist—can regulate autoimmunity in the central nervous system. ... Specifically, the scientists found that certain microbial treatments could alter the behavior of microglial cells in the animals’ brains—cells that typically maintain the central nervous system by clearing dead or damaged cells—influencing the development of symptoms in a rat model of multiple sclerosis (MS). ..."

From the abstract:

"... Here we detected a tight interconnection between the lung microbiota and the immune reactivity of the brain. A dysregulation in the lung microbiome significantly influenced the susceptibility of rats to developing autoimmune disease of the central nervous system. Shifting the microbiota towards lipopolysaccharide-enriched phyla by local treatment with neomycin induced a type-I-interferon-primed state in brain-resident microglial cells. Their responsiveness towards autoimmune-dominated stimulation by type II interferons was impaired, which led to decreased proinflammatory response, immune cell recruitment and clinical signs. ... Our data demonstrate the existence of a lung–brain axis in which the pulmonary microbiome regulates the immune reactivity of the central nervous tissue and thereby influences its susceptibility to autoimmune disease development."

Bacteria in the Lungs Can Regulate Autoimmunity in Rat Brains | The Scientist Magazine® Making specific alterations to the bacterial population in a rat’s lungs either better protects the animals against multiple sclerosis–like symptoms or makes them more vulnerable, a study finds—the first demonstration of a lung-brain axis.

The lung microbiome regulates brain autoimmunity (no public access, but the above article contains a link to the PDF file)