Let the microbes live

Professor Maria Jenmalm want to find ways to prevent allergies. An important issue when a third of all Swedish children are suffering from allergies.

MariaWhen I interview Maria Jenmalm about her research career, there’s one name that keeps coming up: Bengt Björkstén, paediatrician and allergist, currently professor emeritus at Karolinska Institutet.

“He was a pioneer, with a new approach to children’s allergies, and a fantastic supervisor. As a doctoral student I was given lots of responsibility and freedom. I even got to replace him as keynote speaker at a conference in Lisbon.”

Today Maria is herself a professor – of experimental allergology. Her aim was to reach that level before she turned 40, which she missed by a hair. She works more in basic research than clinical research, and never became a paediatrician.

”In senior secondary school I wanted to be a paediatrician. But then I started to think, what if I made a mistake that caused a child to die. I would never be able to handle that.”

By way of a master’s degree in chemistry she ended up on the allergy track. Bengt Björkstén had started to gather a cohort of 100 newborn children in Linköping and just as many in the Estonian university town of Tartu, who were monitored for five years. It turned out that the occurrence of atopic eczema was far less common in Tartu, although the towns are comparable.

Other studies showed the same trend. Polish children had only a third as many allergies as children in northern Sweden, despite being constantly subject to coal smoke. East German children suffered less than West German.

”When it became clear that the immune system matured later and less in the Swedish children than the Estonian, it got really interesting. Was the explanation the western lifestyle, rather than air pollution? We started to think about the importance of gut flora,” says Professor Jenmalm.

The dust that gathered in a home in Tartu contained much higher proportions of endotoxins, potentially poisonous immunostimulants that exist on the surface of some bacteria. Still, the children there had fewer allergies. Everything indicated that they must have better protection from a very young age, possibly even from the womb.

”An exciting new hypothesis is that the mother’s gut and oral flora, and components in the immune system are transferred to the foetus via the placenta. Then it can continue with breast milk, well-chewed food and a dummy the mother has had in her mouth. If we give our children broad-spectrum antibiotics for innocuous diseases, wash their hands with alcohol gel and have Caesarean sections, we lose this important communication,” says Prof Jenmalm.

The idea that bacteria have two sides is increasingly accepted. All multicellular life has arisen in the presence of microbes, and during the course of evolution we have adapted to each other. Today we higher organisms could not live without them. Researchers who have studied "bacteria-free" mice in sterile environments have seen that they have poor immune systems, less mucus in their mucous membranes and acquire an ADHD-like behaviour.

So there are good reasons for Maria Jenmalm to proceed on the allergy track. She is now in charge of a group of two doctoral students, a biomedical analyst, a principal research engineer and two research nurses. Outside the group she collaborates closely with paediatricians, obstetricians and clinical immunologists. Her contact with the clinical reality, where she takes part in studies relating to allergy prevention, is an example of the somewhat hyped concept of translational research. And she is no stranger to another of this century’s concepts, epigenetics.

”Epigenetic phenomena, that environmental factors around the pregnant woman can affect the offspring, could be a link in the communication between the mother and the foetus’s immune system."

Professor Jenmalm is a productive researcher with a long list of publications. But she doesn’t let her research take up all her time:
”I also really enjoy teaching. It gives me ideas. And teaching is the best way to stay in touch with the latest research.”