Wednesday, August 24, 2016
Gut bacteria, antibiotics, and the rise of type 1 diabetes
When the mice were tested at the end of the trial, 53 percent of those exposed to PAT had developed type 1 diabetes, compared with 26 percent of the control mice that received no antibiotics.
As Dr. Blaser says: "Our study begins to clarify the mechanisms by which antibiotic-driven changes in gut microbiomes may increase risk for type 1 diabetes."
Each mouse's gut bacteria was sampled before, during, and after the study to measure any changes in number and species.
The changes were profound. In the 3-month-old PAT mice, one specific species of gut bacteria - which has previously been shown to help train the immune system - had almost totally disappeared. In each of the three bacteria-sampling tests, the PAT mice's bacterial diversity was reduced when compared with the control mice.
To assess the ability of the changed gut flora to affect health, the team carried out a further experiment. They transferred the gut bacteria of a PAT mouse into the gut of a mouse bred to have none of its own gut flora (germ-free mice).
After the transfer was complete, the researchers observed similar changes in their immune system; this proves that the changes in gut bacteria alone (independent of antibiotics) can make significant changes to the developing immune system.