Toxin produced by a bacteria may cause Type 2 diabetes, according to a new study that may pave the way for vaccines to prevent and treat one of the most prevalent diseases of our time.
Researchers found that prolonged exposure to a toxin produced by Staphylococcus aureus (staph) bacteria causes rabbits to develop the hallmark symptoms of Type 2 diabetes, including insulin resistance, glucose intolerance and systemic inflammation.
"We basically reproduced Type 2 diabetes in rabbits simply through chronic exposure to the staph superantigen," Patrick Schlievert, professor at the University of Iowa, said.
The findings suggest that therapies aimed at eliminating staph bacteria or neutralising the superantigens might have potential for preventing or treating Type 2 diabetes.
Obesity is a known risk factor for developing Type 2 diabetes, but obesity also alters a person's microbiome - the ecosystem of bacteria that colonise our bodies and affect our 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," Schlievert said.
"People who are colonised by staph bacteria are being chronically exposed to the superantigens the bacteria are producing," Schlievert said.
The study shows that superantigens - toxins produced by all strains of staph bacteria - interact with fat cells and the immune system to cause chronic systemic inflammation, and this inflammation leads to insulin resistance and other symptoms characteristic of Type 2 diabetes.
In examining the levels of staph colonisation on the skin of four patients with diabetes, the team estimates that exposure to the bacterial superantigens for people who are heavily colonised by staph is proportional to the doses of superantigen that caused the rabbits to develop diabetes symptoms in the experiments.
"I think we have a way to intercede here and alter the course of diabetes," Schlievert said.
"We are working on a vaccine against the superantigens, and we believe that this type of vaccine could prevent the development of Type 2 diabetes," said Schlievert.
The team also is investigating the use of a topical gel containing glycerol monolaurate, which kills staph bacteria on contact, as an approach to eliminate staph bacteria from human skin.
They plan to test whether this approach will improve blood sugar levels in patients with prediabetes.
The study was published in the journal mBio.
