Alterations in gut microbiome linked to weaker immune system and type 1 diabetes
Lead researcher and PhD student, Tommi Vatanen, found that the integrity of the gut microbiome during the first three years of life is critical for building a balanced immune system and protecting against type 1 diabetes.
"In a way, intestinal microbes teach the body's immune system. If something goes wrong this early on, autoimmune diseases may become more common," Vatanen explained to Medscape Medical News.
Vatanen has conducted many studies on infants from Northern European countries, Eastern Europe, and the Netherlands to learn more about the impact of environmental factors on the developing gut microbiome before the onset of type 1 diabetes.
A majority of the immune system resides within the gut, and Vatanen believes that certain environmental factors, such as diet and overreliance on antibiotic treatment, can cause disruptions to the gut microbiome, which then raise risks for type 1 diabetes.
His first finding was that despite sharing a geographical region and a similar genetic background, the incidence rates of type 1 diabetes and other autoimmune diseases between those countries vary greatly.
Finnish children have a much higher (five to six fold) rate of type 1 diabetes, and they develop antoantibodies much earlier than Russian children do, which some scientists have argued could be due to different gut microbiome compositions.
In fact, the DIABIMMUNE study has found that children with very specific populations of gut bacteria went on to develop type 1 diabetes. Imbalances in the gut microbiome causes the intestines to become leaky, allowing the release of bacterial products that trigger inflammation and impair immune function.
For Vatanen, these imbalances in the gut microbiome could be partly explained by increased antibiotic usage. Antibiotic treatments kill pathogens but they also kill off commensal (good) bacteria in the gut, causing antibiotic-treated children to have less stable and less diverse bacterial communities.
Russians are also known to be more conservative when it comes to antiobiotic treatment use. They have a lower level of total consumption of antibiotics than other Eastern Europe countries.
There may be other factors aside from antibiotic use playing a role in the incidence of type 1 diabetes between these populations, and Vatanen is determined to uncover them all.