After a BSc in Chemical Engineering and MSc in Bioinformatics at Chalmers University of Technology in Gothenburg, Marcus completed his PhD at University College Cork (UCC) sequencing and comparing commensal Lactobacillus species. This was followed by postdoctoral fellowships mining probiotic bacteria and analysing the microbiomes of older people as part of the ELDERMET project. Marcus is now an Associate Professor in Bioinformatics at the School of Microbiology and APC Microbiome Ireland, UCC, where his main research interests in the role of microbiota in inflammatory bowel disease, and methods development for various 'omics' technologies. He is also coordinating the MSc programme in Bioinformatics and Computational Biology, and lectures on the subject to MSc, Microbiology and Genetics students. Marcus currently chairs the EU COST Action ML4Microbiome with the aim to optimise, standardise and disseminate best practice of machine learning in microbiome science. He has authored 80 peer-reviewed publications, which in Oct 2022 had been cited over 15,300 times. This has placed him among the top 0.3% most cited scientists up to 2021 according to Elsevier, and one of the 35 Irish scientists on the Clarivate Highly Cited 2022 list. In 2020, Marcus co-founded SeqBiome Ltd, a spin-out company providing high-quality microbiome analysis for industry and academia.

My main research interests are the development of bioinformatics methods of “omics” technologies for application on particularly, but not exclusively, human microbiological systems. These technologies include compositional microbiota analysis, metagenomics and metatranscriptomics. I also have a particular interest in exploring the gut microbiomes involved in inflammatory bowel disease patients using the aforementioned methods. This work has been funded by both a Postdoctoral Fellowship award from the Health Research Board, and a Starting Investigator Research Granf from the Science Foundation Ireland. My research focus up to recently has been on microbiota analysis as part of the ELDERMET project, which aims to use metagenomic and metabolomic approaches to determine the composition and function of the gut microbiome in elderly Irish subjects. I have analysed microbiota composition of over 300 subjects, as well as developed analysis methods to be applied on these systems. In our latest study we reveal novel relationships between microbiota, diet and health status within the elderly population. Previous research included comparative analysis of sequenced genomes of beneficial commensal Lactobacillus and Bifidobacterium species. After sequencing the first genome in Ireland, that of Lactobacillus salivarius UCC118, I discovered a so-called mega-plasmid, which was the first one of its kind in Lactic Acid Bacteria. Although not essential for survival, it showed probiotic properties and appeared to increase the metabolic flexibility and competitiveness of the strain.

I currently teach the following modules MB4019 - Computational Biology MB6300 - Computational systems biology MB6301 - Genomic data analysis I am also coordinating the MSc in Bioinformatics and Computational Biology.