Jeroen Raes is a Belgian bioinformatician and microbiome researcher, professor at KU Leuven and group leader at VIB.
He is the face of the Flemish Gut Flora Project, in which thousands of Flemish people provided a stool sample and information on their diet, health and medication.
The first major results appeared in Science (2016). They showed which factors shape gut-microbiome composition, the strongest being stool consistency, followed by medication, age and diet.
His team later showed that a particular inflammation-associated microbiome type is more common in people with obesity, and less common in those taking statins.
He also studies links between gut flora and conditions such as depression and inflammatory bowel disease, and is a well-known voice in the Flemish media.
For longevity, his work matters because the gut microbiome is linked to inflammation and metabolism, both important in ageing.
Takeaway: eat a varied, fibre-rich diet; commercial microbiome tests still offer little useful personal advice.