8 2 / 2021 // LEOPOLDINA / NEWS
“ I still need to get to know the Academy ”
Leopoldina member Ruth Ley presents microbiome research at Class II Life Sciences symposium
The second virtual Life Science Symposium on 21 June is an opportunity for Class II to exchange views and to get to know the new members elected in 2020 . Among them is Ruth Ley ML , who conducts research on the human microbiome .
You often hear that 90 percent of the cells in our bodies are bacteria . Is that true ? Ruth Ley : It ‘ s used as a catchy phrase . I think someone redid the math recently and revised the number . But even if it ‘ s just the same amount as our body cells , they have 150 times the number of genes that we have , even though they weigh only half a kilo to a kilo .
Now there is a lot of talk about how the microbiome influences our health . What is your research interest ? Ley : We are more interested in where it comes from . How microbiota have been carried by people as they spread around the globe and adapted to novel conditions .
How much of the microbiome is inherited and how much is acquired ? Ley : Definitely your mother and your father are important players , your close environment . Genetics have an influence on a specific suite of microbes . What we ‘ ve seen is that host genetics influence the relative abundance of some of these microbes , and we think they have particular role to play in the gut .
One of your interests is to look at how the microbiome influences obesity . Ley : I was the first to point out that obese people have a different relative abundance of microbes . Now we are interested in a specific microbe that we see more of in lean people . We ‘ re doing studies in mice , and when we add these microbes to the mix , the mice move around more . I certainly wouldn ‘ t say that these microbes prevent obesity , but they might play a role in it .
Ruth Ley ML
The British developmental biologist and microbiologist first turned her attention to researching the microbiome at the Washington School of Medicine in Seattle / USA in 2004 . She has been a director at the Max Planck Institute for Developmental Biology in Tübingen / Germany since 2016 .
Image : Jörg Abendroth | MPI for Developmental Biology
Could that lead to an anti-obesity pill ? Ley : I think that would be something that you take over and over again . It would never work alone , but maybe as part of a package together with nutrition and lifestyle . In the States now 42 percent of the population is obese . That ’ s a public health crisis . It would be great if the microbiome could be part of the solution .
How do antibiotics influence the microbiome ? Ley : If you take antibiotics once , it doesn ’ t really have a big longterm effect . But if you ‘ re doing it over and over again , I ‘ d be concerned . Another danger is that the microbiome might act as a reservoir for antibiotic resistance genes , and they might pass those genes to pathogens that come in .
When you received the Otter Bayer Prize last year , you said that you hope it helps to get microbiome research more into the mainstream of science . Is it still on the sidelines ? Ley : I think there is this pervasive attitude out there that the jury is still out . Is it really going to be useful in the medical sciences ? Is it going to be incorporated into therapeutic approaches to disease ? And I think we ‘ re at the very beginning of that .
What made you decide to go to Germany to do your research ? Ley : The stability of the research budget that you get at Max Planck . It gives you the possibility of freeing your mind from grant restraints . Just be able to start working on anything you want without asking permission , to figure out something hard that takes a long time . That ‘ s a bit of a tough sell to the NIH , for instance . So in that sense we ‘ re really privileged and I couldn ’ t turn it down .
What does the election into the Leopoldina mean for you ? Ley : Oh , that was a complete surprise , and I feel very honored . I still have to get to know the Academy .
That wasn ’ t made easier during the pandemic when you didn ’ t receive your acceptance documents in person and the symposium had to be postponed ? Ley : Yes , that ‘ s one thing Germans do really nicely , these events where everyone has a glass of wine and and you chat with people informally . So I am looking forward to meeting the people in the Leopoldina in person . Meeting people , cross-pollinating and chance encounters – that ‘ s what it ‘ s all about , even though scientists will probably still travel less than before when the pandemic is over .
■ THE INTERVIEW WAS CONDUCTED BY CHRISTOPH DROESSER
Life Science Symposium