Bart Keijser is Principal Scientist working within the Microbiology and Systems Biology team of the Netherlands Organization for Applied Scientific Research (TNO). His main field of expertise is applied systems microbiology, focusing on understanding and steering microbial communities for applications in health, and biotechnology. In 2026 he was appointed Professor of Applied Systems Microbiology and Health at Leiden University. Bart has led multiple industrial consortia in innovation projects on novel strategies for disease prevention and health promotion based on microbiome modulation.

Bart is trained as a molecular microbiologist at Wageningen University (NL). He obtained his PhD at Leiden University (NL) and held two post-doctoral positions in the field of applied microbiology at Leiden University and the University of Amsterdam. In 2005, he joined the TNO Microbiology and Systems Biology group of the Netherlands Organization for Applied Scientific Research (TNO).