Peter van Baarlen studies interactions between microbes and their plant, human and animal hosts. He has a Ph.D. in Evolutionary Genetics and Cytogenetics.

His work experience relates to the molecular and physiological basis of host susceptibility, tolerance and resistance to pathogens and commensal microbes, and the molecules that mediate interactions. His expertise includes in vivo fluorescence microscopy and classic histology, population biology and co-evolution and interactions of pathogens and their hosts, -omics and in silico pathway analysis, and network biology. At HMI, an important part of his research involves the integration of laboratory and in silico data, using -omics to study the interplay between pathogenic and commensal microbes including the intestinal microbiota, their human and mouse, pig and zebrafish hosts, and the impact of nutrition on these interactions. His common research aims are to identify human (or animal) pathways that are modulated in response to a dietary or microbial stimulus using pathway analysis and network biology approaches. Of special relevance is the correlation between microbiota, host transcriptomics and host metabolomics. Main research interests are: interaction biology, microbial pathology, virulence of Campylobacter and streptococci, human disease, human genetic variation and impact of variation on the response to bacteria, and patient stratification. For this, he has collaborations with groups in (medical) microbiology, human nutrition and mucosal immunity. His colleagues work at universities, veterinary institutes and hospitals, and university medical centres.