Scientists discover link between bacteria in nose and Alzheimer's disease 

Researchers in Australia discovered evidence that bacteria in the nose can enter the brain via nasal cavity nerves, triggering a chain of events that could lead to Alzheimer's disease.

The study adds to the growing body of research that suggests Alzheimer's disease is caused by viral or bacterial infections. 

Chlamydia pneumoniae is a widespread bacteria that causes pneumonia and a variety of other respiratory illnesses, as its name suggests.

However, it has been found in the brain on rare occasions, implying that it could produce more insidious problems. 

Researchers from Griffith University and Queensland University of Technology set out to find out how C. pneumoniae got into the brain and if it might cause damage once there for the new study.

The scientists had a hunch about how this nose-dwelling bug might make the journey. 

The researchers discovered that C. pneumoniae may infect the olfactory and trigeminal nerves, then the olfactory bulb — the small neuronal structure in the forebrain that mediates the sensation of smell – within 72 hours of being introduced to the nose in mice.

It's only a short trip to the rest of the brain from there.

Most intriguingly, the researchers discovered that after the bacteria entered the central nervous system, it caused a number of alterations that are linked to Alzheimer's disease. 

(With inputs from agencies)