Prominence of ileal mucosa-associated microbiota to predict postoperative endoscopic recurrence in Crohn's disease.

Objective: Following ileal resection for Crohn's disease (CD), recurrence is very frequent. Although several clinical risk factors of recurrence have been identified, predicting relapse remains challenging. Performing an ileocolonoscopy within the first year after surgery is currently recommended to assess endoscopic recurrence and to adjust the treatment. We took advantage of a large prospective multicentric cohort to investigate the role of the ileal mucosa-associated microbiota in postoperative endoscopic recurrence.
Patients and Methods: Ileal mucosa-associated microbiota was analysed by 16S sequencing at the time of surgery and/or of endoscopic evaluation in 201 patients (288 samples in total) prospectively recruited in France.
Results: Ileal mucosa-associated microbiota exhibits profound changes following surgery in CD. Compared with non-recurrence setting, endoscopic recurrence is associated with strong changes in ileal mucosa-associated microbiota that are highly reminiscent of those observed generally in ileal CD compared with healthy subjects with a reduction in alpha diversity, an increase in several members of the Proteobacteria phylum and a decrease in several members of the Lachnospiraceae and the Ruminococcaceae families within the Firmicutes phylum. At the time of surgery, we identified several bacterial taxa associated with endoscopic recurrence and that can better predict relapse than usual clinical risk factors.
Conclusion: Surgery has an important impact on ileal mucosa-associated microbiota. Postoperative endoscopic recurrence is associated with changes in microbiota composition and alpha diversity. The gut microbiota has the potential to predict postoperative evolution and recurrence.
Competing Interests: Competing interests: MA received honoraria from Abbvie, MSD, Janssen, Takeda, Pfizer, Novartis, Ferring, Tillots, Celgene and Genentech/Roche. CA, NB, LLB and CS declares no competing interest. SN received honoraria from MSD, Abbvie, Takeda, Janssen, HAC Pharma, Tillots, Ferring and Novartis. AB received honoraria from MSD, Abbvie, Ferring, Takeda, Vifor Pharma, Sanofi‐Aventis, Hospira and Janssen. BP received honoraria from AbbVie, MSD, Takeda, Janssen, Bioagaran and Ferring. MF received honoraria from AbbVie, MSD, Takeda, Janssen, Pfizer, Ferring and Boehringer. HS received unrestricted study grants from Danone, Biocodex and Enterome; was a board member and a consultant, or received lecture fees from Carenity, Abbvie, Astellas, Danone, Ferring, Mayoly Spindler, MSD, Novartis, Roche, Tillots, Enterome, Maat, BiomX, Biose, Novartis and Takeda; and was cofunder of Nextbiotix. XT received honoraria from Abbvie, MSD, Takeda, Ferring, Norgine and Janssen. PS received honoraria from Takeda, MSD, Biocodex, Ferring and Abbvie, and non-financial support from Takeda.
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