OP02 - SMALL INTESTINAL BACTERIAL OVERGROWTH IN VARIOUS FUNCTIONAL GASTROINTESTINAL DISORDERS: A CASE-CONTROL STUDY #20

Kee Huat Chuah1, Mung Seong Wong,2,3, Phei Oon Tan2,3, Sze Zee Lim5, Keng Hau Beh5, Sufian Chong Chern Siong2,3, Khairil Khuzaini Zulkifli2,4, Abdul Malik Thalha1, Sanjiv Mahadeva1, Yeong Yeh Lee2,3

1. Gastroenterology and Hepatology Unit, Department of Medicine, University of Malaya
2. School of Medical Sciences, Universiti Sains Malaysia, Kota Bharu, Malaysia
3. Department of Medicine, Hospital Universiti Sains Malaysia, Kota Bharu, Malaysia
4. Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh, Malaysia
5. Department of Medicine, University of Malaya

Objective(s):
Small intestinal bacterial overgrowth (SIBO) is prevalent in irritable bowel syndrome (IBS), but its’ association with other functional gastrointestinal disorders (FGIDs) is less certain. This study aimed to explore SIBO in a multi-racial Asian population with various FGIDs compared to healthy controls.

Methodology:
Consecutive Asian adults (from two tertiary centres: UMMC and HUSM) with Rome III diagnosed common FGIDs (functional dyspepsia/FD, IBS and functional constipation/FC) and healthy controls were subjected to glucose breath testing, with hydrogen (H2) and methane (CH4) levels determined.

Results:
A total of 244 participants (FGIDs n=186, controls n=58, median age 45 years, males 36%, Malay ethnicity 76%) were recruited. FGIDs had a higher prevalence trend of SIBO compared to controls (16% FGIDs vs 10% controls) with 14% in FD, 18% in IBS and 14% in FC. Compared to controls, SIBO was associated with IBS with predominant diarrhea (IBS-D) (24% vs 10%, P=0.050) but not with other types of FGIDs at univariate analysis. IBS-D remained an independent predictor of SIBO (OR=2.864, 95% CI 1.160-7.071, P=0.023) but not PPI usage or history of diabetes (both P>0.05) at multi-variate analysis. Compared to controls, SIBO in IBS-D was associated with greater H2 levels (18% vs 3%, P=0.025), but not CH4 levels (9% vs 7%, P>0.05). In addition, no difference was found in the prevalence of methane positive SIBO between chronic constipation (IBS with predominant constipation and FC) compared to controls (9% vs 7%, P=0.466).

Discussion and Conclusions:
The strengths of this study, which include a multi-centre, multi-ethnic and rural-urban representation of Asian adult subjects, indicate that a true difference in SIBO prevalence in FGIDs may exist between Asia and the West.
In conclusion, SIBO is prevalent among multi-racial Asian adults with and without FGIDs. Amongst various FGIDs, only IBS-D is significantly associated with SIBO.