Ms. Ganal-Vonarburg, what is your research about?
All mammals, including humans, are colonized by billions of microbes, which mainly live in our intestines. They can also be found in the respiratory tract, on the skin and in the urogenital tract. In the Gastroenterology research group in the DBMR (Department for BioMedical Research at the University of Bern) we investigate the interaction of these benign intestinal microbes with the host organism. Among other things, we are interested in the positive influence that the intestinal flora has on our immune system. In my work, I concentrate mainly on the role of the maternal intestinal flora in the development of the child's immune system in the womb and immediately after birth.
What fascinates you about the development of the child's immune system?
Today we know that it is mainly the influences early in life, such as the birth method, our diet, infectious diseases and domestic hygiene, that shape our immune system and change our risk of developing autoimmune diseases or allergies later in life. These findings are often summarized in the so-called hygiene hypothesis: While we have seen a decrease in infectious diseases in the Western world in recent decades, allergies and autoimmune diseases are on the rise. This is associated with increased hygiene in industrialized countries, for example through industrially processed food, antibiotics and urbanization. This cannot be observed in developing countries. I find this hypothesis very interesting and I consider it to be very important to understand this phenomenon and to counteract it.
You were able to show for the first time that our immune system is "prepared" before birth. How does it work?
We were able to prove that molecules of the maternal intestinal bacteria already strengthen the immune system in the child's intestine during pregnancy, so it can cope better with the colonizing intestinal flora after birth. We now know that these bacterial products are transmitted to the offspring both via the placenta and after birth via breast milk. It is also impressive that more than 1,000 different genes in the offspring’s small intestine are "switched on" by signals from the maternal microbiota.