Phage Immunoprecipitation Sequencing (PhIP-Seq) can screen antibodies binding against hundreds of thousands of antigen fragments in parallel, far beyond the scale of conventional antibody assays. After incubation with serum or blood samples, antibody-bound phages are immunoprecipitated and identified by next-generation sequencing. The result is an antigen-resolved antibody profile: a high-resolution map of immune recognition. Dr. Thomas Vogl and his team at MedUni Vienna have internationally leading expertise in PhIP-Seq, synthetic antigen libraries, microbiome–immune system interactions, infection-associated immune signatures, autoimmune and chronic inflammatory diseases, multi-omics integration and machine-learning-based analysis of complex antibody repertoires. Published studies show that antibody epitope repertoires against human microbiota are highly individual, systematically interpretable and stable over time. In inflammatory bowel disease, antigen-resolved antibody profiles revealed characteristic signatures for Crohn’s disease and ulcerative colitis, with additional studies indicating that disease-associated antibody patterns can already be detected years before clinical diagnosis.