Day 1 New Frontiers Symposium on Microbiome
Summary of the 1st day of the New Frontiers Symposium on Microbiome 2017 in Nijmegen, the Netherlands
Last week (October 12th to 13th) I attended the New Frontiers Symposium in the Netherlands. The symposium is organized yearly by the Institute for Molecular Life Sciences at Radboud University. The topic changes every year and this time the symposium focused on microbiome research. The symposium had an excellent, diverse program with speakers form both Europe and North America. There was also plenty of time for networking and poster watching during the breaks.
The first day started off with a session entitled ‘Microbiome & Genetics’. Mike Jetten gave an overview of metagenomics and different techniques to discover new anaerobic microbes from the environment. Cisca Wijmenga talked about using population-based cohort studies for microbiome research, and argued that even larger cohorts are needed to understand the factors that shape the gut microbiome. Interestingly, she pointed out that many widely used prescription drugs, including proton pump inhibitors, can severely affect the gut microbiome. Finally, Jeroen Raes specified numerous factors that should be considered when planning and analysing metagenomics studies for gut microbiome: low-count samples are oversampled, observed sequences are relative abundances and therefore the data is compositional, and stool consistency is a major confounding factor, which is often not taken into account. His group has recently published a paper discussing these considerations (Vandeputte et al., 2017). He also stated that absolute quantification of the microbiome is needed, exemplified by the finding that Crohn’s disease patients have lowered bacterial load.
The second session focused on microbiome and cancer. Julian Marchesi talked about his newly published research (Kinross et al., 2017), which examines the bacterial communities on and off tumour in colon cancer. This presentation sparked some interesting discussion about the ‘passenger-driver hypothesis’ relating to microbial involvement in colon cancer development. Cynthia Sears continued on the topic and also discussed the role of microbial biofilms in colon cancer. Depending on the location of the tumor, invasive polymicrobial biofilms extend to normal colon tissue or are absent in healthy tissue.
In the afternoon, Lars Engstrand and Willem de Vos talked about different therapautic approaches to shape the gut microbiome in clinical practice. These include fecal transplantations or more defined mixtures of bacteria, as well as specific isolated compounds (e.g. proteins) from beneficial bacteria, such as Akkermansia muciniphila. David Underhill reminded us on the importance of intestinal fungi in gut health health and disease, particularly in regards to inflammatory bowel diseases.
The final part of the day was dedicated to the recipient of the Hans Bloemendal Medal, Richard Flavell, who went on to describe NOD-like receptors as guardians of intestinal mucosal barriers in his award lecture.
Kinross J, Mirnezami R, Alexander J, Brown R, Scott A, Galea D, Veselkov K, Goldin R, Darzi A, Nicholson J, Marchesi JR. A prospective analysis of mucosal microbiome-metabonome interactions in colorectal cancer using a combined MAS 1HNMR and metataxonomic strategy. Sci Rep. 2017 Aug 21;7(1):8979. doi: 10.1038/s41598-017-08150-3.
Vandeputte D, Tito RY, Vanleeuwen R, Falony G, Raes J. Practical considerations for large-scale gut microbiome studies. FEMS Microbiol Rev. 2017 Aug 1;41(Supp_1):S154-S167. doi: 10.1093/femsre/fux027.