A good gut feeling

A balanced intestinal microbiota is indispensable for human well-being—anyone with irritable bowels can testify to that. This is why Alexander Westermann and his team are investigating the complex interactions between microbes that colonize the human gut and invading pathogens. “Normally, our intestinal microbiota keeps pathogens in check—but if the natural balance is disturbed, for example after antibiotic treatment, harmful germs can multiply more easily and cause disease,” explains Westermann. A prominent example is the bacterium Bacteroides thetaiotaomicron. As one of the most abundant bacteria in the human body, it is part of the natural human intestinal microbiota. It plays an important role in food uptake, but it can also determine the outcome of Salmonella and Clostridioides infections. These multi-partite interactions fascinate Westermann.

Under the spell of RNA since his student days, his doctoral thesis led him to infection biology. It was then that he discovered that short nucleic acid molecules, known as ‘small RNAs’, play a crucial role in the successful infection of human somatic cells with Salmonella.

Now, heading his own lab, he continues this line of research with his team. “To counteract infection, one can target the pathogen directly or foster the protective host-microbiota axis. The latter is what we strive for,” he describes. Asked what captivates him about his work, he says, “My driving force is to discover the unexpected.”

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