Small intestinal bacterial overgrowth (SIBO) in irritable bowel syndrome: frequency and predictors

J Gastroenterol Hepatol. 2011 Apr;26 Suppl 3:135-8. doi: 10.1111/j.1440-1746.2011.06654.x.

Small intestinal bacterial overgrowth (SIBO) in irritable bowel syndrome: frequency and predictors.

Sachdeva S, Rawat AK, Reddy RS, Puri AS.

Department of Gastroenterology, GB Pant Hospital, New Delhi, India. This email address is being protected from spambots. You need JavaScript enabled to view it.

OBJECTIVE AND BACKGROUND: Small intestinal bacterial overgrowth (SIBO) has been implicated in pathogenesis of IBS. We aimed to study frequency and predictors of SIBO in patients with IBS.

METHODOLOGY: We included 59 consecutive patients of IBS & 37 healthy controls (HC). Evaluation for SIBO was done by glucose breath test (GBT) using 100 gm of glucose after an overnight fast. Breath hydrogen & methane concentration were noted at baseline & every 15 min after administration of glucose for a total of 3 h. Persistent rise in breath hydrogen or methane > 12 ppm above basal was considered diagnostic of SIBO

RESULTS: Of 59 patients, 27 were diarrhoea predominant (D-IBS), 11 were constipation predominant (C-IBS) and 21 were mixed type (M-IBS). Median age of patients (34 [18-47] years) were comparable to controls (35 [20-48] years) (P = 0.21). Patient group was similar to HC in gender distribution (male 41/59 [69.5%]vs 25/37 [67.6%], P = 0.36). SIBO was more frequent in patients with IBS than HC (14/59 [23.7%]vs 1/37 [2.7%], P = 0.008). Patients with D-IBS more often had SIBO as compared to non-D-IBS (10/27 [37%]vs 4/32 [12.5%], P = 0.02). C-IBS had lowest frequency of SIBO (1/11 [9%]) among all IBS subgroups. Patients with history of bloating more often had SIBO as compared to those without this symptom (11/23 [47.8%]vs 3/36 [8.3%], P = 0.002). Among IBS patients, females more often had SIBO as compared to males (8/18 [44.4%]vs 6/41 [14.6%], P = 0.01).

CONCLUSIONS: SIBO was more frequent in patients with IBS as compared to healthy controls. D-IBS subtype, female gender & bloating were predictors of SIBO in patients with IBS.

PMID: 21443727 [PubMed - in process]