Associations between IL‐1RA polymorphisms and small intestinal bacterial overgrowth among patients with irritable bowel syndrome from India. Issue 10 (30th July 2014)

• Record Type: Journal Article
• Authors: Srivastava, D.; Ghoshal, U.; Mittal, R. D.; Ghoshal, U. C.
• Is Part Of: Neurogastroenterology & motility. Volume 26:Issue 10(2014:Oct.)
• Page Start: 1408
• Page End: 1416
• Publication Date: 2014-07-30
• Subjects: Gastrointestinal system -- Motility -- Periodicals; Gastrointestinal system -- Innervation -- Periodicals; 616.33
• DOI: 10.1111/nmo.12399
• Languages: English
• ISSNs: 1350-1925

Abstract

<abstract abstract-type="main" id="nmo12399-abs-0001"> <title>Abstract</title> <sec id="nmo12399-sec-0001" sec-type="section"> <title>Background</title> <p>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‐1<italic>α</italic> and <italic>β</italic> levels (pro‐inflammatory) in relation to the presence of SIBO were evaluated in a subset of patients.</p> </sec> <sec id="nmo12399-sec-0002" sec-type="section"> <title>Methods</title> <p>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‐1<italic>α</italic> and <italic>β</italic> levels (pg/mg of biopsy) were estimated (ELISA) in 82/221 patients with and without SIBO (≥10<sup>5</sup> CFU/mL upper gut aspirate bacteria).</p> </sec> <sec id="nmo12399-sec-0003" sec-type="section"> <title>Key Results</title> <p>Genotype 1/1 (IL‐1RA over‐producer) was less frequent among patients than controls (<italic>p</italic> = 0.007); genotypes 1/3 (<italic>p</italic> = 0.012, OR = 3.301, 95% CI = 1.31–8.35) and 2/3 (both under‐producers; <italic>p</italic> = 0.009, OR = 7.703, 95% CI = 1.66–35.82) were commoner among IBS. Fifteen of 82 (18.3%) patients had SIBO. Levels of IL‐1<italic>α</italic> and <italic>β</italic> were higher among patients with SIBO than without (IL‐1<italic>α</italic>: 35.4 [20.1–66.8] <italic>vs</italic> 25.5 [4.2–65.3], <italic>p</italic> < 0.001; IL‐1<italic>β</italic>: 206.8 [133.5–365.9] <italic>vs</italic> 93.1 [25.5–197.7], <italic>p</italic> < 0.001) and those with bloating than without (<italic>p</italic> = 0.012; <italic>p</italic> = 0.015). IL‐1<italic>β</italic> was higher among patients with Bristol stool type 6 than those with type 1–2 (<italic>p</italic> = 0.002) and type 3–5 (<italic>p</italic> = 0.007).</p> </sec> <sec id="nmo12399-sec-0004" sec-type="section"> <title>Conclusions & Inferences</title> <p>Polymorphisms 1/1 (IL‐1RA over‐producer) was infrequent and 1/3 and 2/3 (under‐producers) frequent among IBS. Increased IL‐1<italic>α</italic> and <italic>β</italic> levels were associated with SIBO. Increased IL‐1<italic>β</italic> level was predominantly associated with bloating and loose stools (Bristol type 6).</p> </sec> </abstract>