P837 Changes in the intestinal microbiota of patients with inflammatory bowel disease during an 8-week infliximab infusion cycle

G. Seong, J.H. Song, J. Shin, S.M. Kong, E.R. Kim, D.K. Chang, S.N. Hong, Y.H. Kim

Samsung Medical Center, Gastroenterology, Seoul, Republic of Korea

Background

This study investigated changes in the intestinal microbiota during 8-week infliximab maintenance therapy in inflammatory bowel disease (IBD) patients with clinical remission. Microbial compositional differences were analysed according to the trough level of infliximab (TLI) and mucosal healing (MH) status.

Methods

16S rRNA gene-based microbiome profiling was performed on 10 and 74 faecal samples from 10 healthy volunteers and 40 adult IBD patients, respectively. All enrolled IBD patients were in clinical remission during infliximab maintenance therapy. To identify changes in the intestinal microbiota, faecal sampling occurred at 1–2 weeks (1W) and 7–8 weeks (7W) after infliximab infusion. TLI was measured by ELISA at 8 weeks immediately before the subsequent infusion; MH was evaluated by endoscopy within 3 months.

Results

No significant differences were found in microbial composition, species richness, and diversity indices between 1W and 7W samples or in microbial composition and diversity between healthy volunteer and 1W or 7W samples. However, 7W faecal samples from the patients with TLI≥5 μg/ml showed increased species richness compared with TLI<5 μg/ml, and patients with MH showed increased species diversity compared with non-MH. Beta-diversity analysis showed clustering between samples in the MH and non-MH groups. LefSe analysis identified differential expression of Faecalibacterium prausnitzii group between TLI < 5 μg/ml and TLI ≥ 5 μg/ml and MH and non-MH groups.

Conclusion

There were no significant changes in the intestinal microbiota during an 8-week infliximab infusion cycle in IBD patients with clinical remission; however, microbial composition, species richness, and diversity were associated with TLI and MH status.