P850 Comparison of sampling methods in assessing the microbiome from patients with ulcerative colitis

H.S. Lee1, T.O. Kim2, S.H. Jung3, D.H. Baek4

1Inje University Busan Paik Hospital, Internal Medicine, Busan, Republic of Korea, 2Inje University Haeundae Paik Hospital, Internal Medicine, Busan, Republic of Korea, 3Eunpyeong St. Mary’s Hospital- College of Medicine- The Catholic University of Korea, Internal Medicine, Seoul, Republic of Korea, 4Pusan National University School of Medicine & Pusan National University Hospital, Internal Medicine, Busan, Republic of Korea

Background

Most of studies have reported a dysbiosis of ulcerative colitis (UC) using readily accessible stool samples. However, the faecal samples might not fully represent mucosa-associated microbiome. We hypothesised that luminal contents including loosely adherent luminal bacteria after bowel preparation may be suitable for diagnosing the dysbiosis of UC.

Methods

Sixteen patients with UC (9 men and 7 women, mean age: 52.13 ± 14.09 years) and 15 sex- and age-matched healthy individuals (8 men and 7 women, mean age: 50.93 ± 14.11 years) participated in the study. The subjects donated faecal samples before colonoscopy and received luminal contents aspiration and endoscopic biopsy during the colonoscopy. The composition of each microbiome samples was analysed by 16S rRNA-based nest-generation sequencing.

Results

Microbiome of stool, luminal contents and biopsy was significantly different from each other in alpha diversity and beta diversity. However, another analysis showed a correlation between the stool and luminal contents in Procrustes test (p = 0.001) and Mantel test (p = 0.0001). Stool microbiome in patients with UC was different from stool microbiome in healthy control. Microbiome of luminal contents microbiome and biopsy samples in patients with UC were not different from that of healthy control. Stool and lavage predicted UC in accuracy of AUC 0.85 and 0.81, respectively

Conclusion

Microbiome of stool, luminal contents and biopsy were significantly different from each other. Further studies would be needed to know optimal sampling of intestinal dysbiosis.