TY - JOUR T1 - Microbiome-based companion diagnostics: no longer science fiction? JF - Gut JO - Gut SP - 896 LP - 897 DO - 10.1136/gutjnl-2015-311015 VL - 65 IS - 6 AU - J Raes Y1 - 2016/06/01 UR - http://gut.bmj.com/content/65/6/896.abstract N2 - In the last decade, our knowledge on the role of the gut microbiome in health and disease has greatly increased, accompanied by an unseen hype around both its diagnostic and therapeutic potential. Yet, one application area of the microbiome has thus far remained understudied: its role as guidance for therapeutic decisions, treatment monitoring and prediction of response.In this issue of Gut, Mondot et al1 investigate to what extent the microbiome can both inform us on as well as contribute to treatment outcome in resection surgery for Crohn's disease (CD). Although often the only resort next to dilatation,2 this intervention is not curative, with first-year endoscopic recurrence rates at 28–93% and frequent necessity of reoperation.3 As such, there is an important need for effective postoperative maintenance strategies and predictions for postoperative outcome.In a longitudinal study of both the faecal and mucosa-adherent microbiota in 20 patients undergoing resection surgery, Mondot et al describe the microbial groups recolonising the intestinal lining around the anastomosis and show different trajectories in recurring patients versus those in remission; the latter were found to exhibit … ER -