Abnormal breath testing in IBS: a meta-analysis.
BACKGROUND
Recent evidence suggests a role for enteric bacteria in the development of symptoms in subjects with irritable bowel syndrome (IBS). The concept was initially based on the common finding of an abnormal lactulose breath test to suggest the presence of small intestinal bacterial overgrowth (SIBO). Despite successful antibiotic studies based on these findings, the premise of bacterial overgrowth was met with skepticism due to the perceived inaccuracies of breath testing in humans. In this study, we conduct a systematic review and meta-analysis of the studies using breath testing in IBS subjects with comparison to healthy controls.


METHODS
A literature search was conducted to identify studies in which breath testing was conducted in subjects with IBS. Once abstract titles were identified, studies that examined breath testing in a case-control fashion were identified for paper review. After exclusion criteria were applied, the remaining papers were examined using meta-analysis, among which the prevalence of an abnormal breath test in IBS subjects was compared. Further analysis was conducted among studies with appropriate age- and sex-matched controls.


RESULTS
Eleven studies met criteria for inclusion in the meta-analysis. Although heterogeneity was identified among studies on the basis of substrate used, lactulose was the most common substrate. In pooling the 11 studies, breath testing was more often abnormal among IBS subjects than health controls (OR=4.46, 95% CI=1.69-11.80). This was further evident in more appropriately designed age- and sex-matched studies (OR=9.64, 95% CI=4.26-21.82). The overall sensitivity and specificity for breath testing in separating IBS from healthy controls was 43.6 and 83.6%.


CONCLUSIONS
This study demonstrates that the breath test findings in IBS appear to be valid. While this meta-analysis does not suggest that the breath test findings imply SIBO, the abnormal fermentation timing and dynamics of the breath test findings support a role for abnormal intestinal bacterial distribution in IBS.
Shah
Eric D
ED
School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
Basseri
Robert J
RJ
Chong
Kelly
K
Pimentel
Mark
M
D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001944:Breath Tests; D002241:Carbohydrates; D005260:Female; D005285:Fermentation; D006801:Humans; D007421:Intestine, Small / Q000382:microbiology*; D043183:Irritable Bowel Syndrome / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D007792:Lactulose; D008297:Male; D016017:Odds Ratio; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000900:Anti-Bacterial Agents; D002241:Carbohydrates; D007792:Lactulose
Control Clin Trials. 1986 Sep;7(3):177-88
3802833
Aliment Pharmacol Ther. 2005 Dec;22(11-12):1157-60
16305730
Am J Gastroenterol. 2008 Dec;103(12):2972-6
19086951
J Clin Gastroenterol. 2009 Nov-Dec;43(10):962-6
19525858
Neurogastroenterol Motil. 2008 May;20(5):505-11
18221251
Clin Gastroenterol Hepatol. 2009 Dec;7(12):1279-86
19602448
Ann Intern Med. 2006 Oct 17;145(8):557-63
17043337
Am J Gastroenterol. 2003 Feb;98(2):412-9
12591062
Stat Med. 2004 May 15;23(9):1351-75
15116347
Stat Med. 2004 Jun 15;23(11):1663-82
15160401
Dig Dis Sci. 2006 Aug;51(8):1297-301
16832617
Clin Chem. 2003 Jan;49(1):7-18
12507954
Am J Gastroenterol. 2000 Dec;95(12):3503-6
11151884
Gut. 2008 Sep;57(9):1315-21
18250127
Dig Dis Sci. 2003 Jan;48(1):86-92
12645795
Am J Gastroenterol. 2005 Jul;100(7):1566-70
15984983
Dig Dis Sci. 2010 Jan;55(1):124-30
19888655
J Exp Med. 1971 Mar 1;133(3):572-88
5111441
Gut. 2006 Mar;55(3):297-303
16474100
Stat Med. 2006 Oct 30;25(20):3443-57
16345038
J Pediatr. 2009 Sep;155(3):416-20
19535093
Ann Rheum Dis. 2004 Apr;63(4):450-2
15020342
Dig Dis Sci. 2010 Aug;55(8):2302-8
19834807
Neurogastroenterol Motil. 2008 Sep;20(9):998-1008
18482250
Aliment Pharmacol Ther. 2009 Mar 30;29 Suppl 1:1-49
19344474
Gut. 2007 Jun;56(6):802-8
17148502
Gastroenterology. 2000 Sep;119(3):654-60
10982758
Dig Dis Sci. 2010 Feb;55(2):398-403
19294509
Aliment Pharmacol Ther. 2003 Mar 1;17(5):643-50
12641512
Pharmacoeconomics. 2006;24(1):21-37
16445300
Br J Gen Pract. 2004 Jul;54(504):495-502
15239910
Am J Gastroenterol. 2006 Feb;101(2):326-33
16454838
Trop Gastroenterol. 2008 Jan-Mar;29(1):23-5
18564663
Dig Dis Sci. 1996 Nov;41(11):2248-53
8943980
Dig Dis Sci. 2008 Jun;53(6):1443-54
17990113
Minerva Gastroenterol Dietol. 1991 Jul-Sep;37(3):169-75
1790205
Am J Gastroenterol. 2008 Apr;103(4):958-63
18371134