Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society

Associations between IL-1RA polymorphisms and small intestinal bacterial overgrowth among patients with irritable bowel syndrome from India.

PMID 25073651


Low-grade inflammation (controlled by pro and anti-inflammatory molecules), induced by gut microbes in patients with small intestinal bacterial overgrowth (SIBO), may be associated with irritable bowel syndrome (IBS). Polymorphisms of IL-RA gene (anti-inflammatory) was evaluated in IBS and healthy subjects (HS); small intestinal mucosal IL-1α and β levels (pro-inflammatory) in relation to the presence of SIBO were evaluated in a subset of patients. Two hundred and twenty-one IBS patients and 273 age- and gender-matched HS were included. Exactly 209 of 221 patients (Rome III) and 273 HS were genotyped (PCR) for IL-1RA polymorphism. Mucosal IL-1α and β levels (pg/mg of biopsy) were estimated (ELISA) in 82/221 patients with and without SIBO (≥10(5) xa0CFU/mL upper gut aspirate bacteria). Genotype 1/1 (IL-1RA over-producer) was less frequent among patients than controls (pxa0=xa00.007); genotypes 1/3 (pxa0=xa00.012, ORxa0=xa03.301, 95% CIxa0=xa01.31-8.35) and 2/3 (both under-producers; pxa0=xa00.009, ORxa0=xa07.703, 95% CIxa0=xa01.66-35.82) were commoner among IBS. Fifteen of 82 (18.3%) patients had SIBO. Levels of IL-1α and β were higher among patients with SIBO than without (IL-1α: 35.4 [20.1-66.8] vs 25.5 [4.2-65.3], pxa0