Bacteria, which have long been known to cause a range of conditions, could also be responsible for Type 2 diabetes, according to a new study.
Researchers at the University of Iowa in the US found that prolonged exposure to a toxin produced by Staphylococcus aureus (staph) bacteria caused rabbits to develop the hallmark symptoms of Type 2 diabetes.
As well as increasing the risk of diabetes, obesity alters a person's microbiome - the ecosystem of bacteria that colonise the body and affect an individual's health.
"What we are finding is that as people gain weight, they are increasingly likely to be colonised by staph bacteria - to have large numbers of these bacteria living on the surface of their skin," said Professor Patrick Schlievert, who led the research team
"People who are colonised by staph bacteria are being chronically exposed to the superantigens the bacteria are producing."
Superantigens - toxins produced by all strains of staph bacteria - disrupt the immune system and are responsible for the deadly effects of various staph infections, such as toxic shock syndrome, sepsis, and endocarditis.
The team's latest research shows that superantigens interact with fat cells and the immune system to cause chronic systemic inflammation, which leads to insulin resistance and other symptoms characteristic of Type 2 diabetes.
According to the researchers' estimates, the exposure to the bacterial superantigens for people who are heavily colonised by staph is proportional to the amount that caused the rabbits to develop diabetes symptoms in the team's experiments.
The findings suggest new preventive measures or treatments for the condition could be developed, either by eliminating staph bacteria or neutralising its superantigens.
Currently, the team is investigating the use of a topical gel containing glycerol monolaurate to eliminate staph bacteria from human skin. They plan to conduct further research to determine whether doing so will improve blood sugar levels in patients with prediabetes.