Microbial exposure during pregnancy may offer potential protection from type 1 diabetes
The microbiome – our intestinal bacterial community – is composed of trillions of bacteria, parasites, viruses and fungi that live in and around us, and interact directly with our immune systems. It shields the body from pathogens, cancer, cardiovascular disease and chronic inflammatory diseases including allergies, brain disorders and autoimmune disease. In recent years, clinical studies have demonstrated that changes in the composition or function of the microbiome can either promote the development of type 1 diabetes (T1D), or protect from T1D.
The microbiome is significant in shaping and ensuring that the immune system in early life matures properly. As babies develop in the womb, they are in a sterile environment. Then, when babies are exposed to the outside world at birth, they are also exposed to bacteria. The type of delivery (vaginal or caesarean) alters the intestinal microbiome of the newborn and leads to different bacterial products interacting with the baby’s emerging immune system, which is a normal part of development. There is also a critical window after birth in which a relatively diverse microbiome must be established in order for the neonatal immune system to be stimulated and offer protection from disease. Research has shown that this process begins even prior to delivery through exposure to microbial products derived from the mother’s intestinal bacterial community.
Dr. Kathy McCoy, a JDRF-funded investigator and director of the International Microbiome Centre at the University of Calgary, believes the microbiome may be the single most important factor that can be altered not just to prevent disease, but to promote individual health and wellness. Her current research focuses on better understanding the exact molecular and cellular mechanisms by which the microbiome shapes our immune system, as well as identifying time windows during pregnancy and early childhood when signals from the microbiome can facilitate protection from T1D. She and her team are conducting studies in animal models of T1D that will confirm whether variations in the microbiome can prevent or improve the susceptibility of T1D in newborns.
JDRF-funded researcher, Dr. Jayne Danska, is also investigating the role of the gut microbiome in the development of T1D in humans. One theory – the hygiene hypothesis – suggests the increased frequency of autoimmune diseases is associated with improved public health measures, which have enhanced health, but simultaneously decreased early childhood exposure to microbes that help establish immune function.
Assessing the impact of maternal and early life microbiomes on T1D progression will help define the complex interactions between the two and ultimately lead to new strategies for the treatment and prevention of T1D.