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Hammer, Johann

https://orcid.org/0000-0002-2452-1201

Mayo Clinic

Medical University of Vienna

Citations 2

Prevalence of small intestinal bacterial overgrowth in intestinal failure syndrome: A systematic review and meta‐analysis
Shah, Ayesha, Fairlie, Thomas, Morrison, Mark , Martin, Neal, Hammer, Johann , Rezaie, Ali , Pimentel, Mark , Kashyap, Purna , Jones, Michael P, Holtmann, Gerald , Jones, Michael , Holtmann, Gerald J , Jones, Michael P , Shah, Ayesha , Hammer, Karin, Koloski, Natasha , Jones, Michael P

Journal of Gastroenterology and Hepatology | June 27, 2024 | Volume: 39 | Issue: 11 | Pages: 2308-2318

10.1111/jgh.16668 Get It

AbstractBackground and AimPatients with intestinal failure (IF) have abnormal intestinal anatomy, secretion, and dysmotility, which impairs intestinal homeostatic mechanisms and may lead to small intestinal bacterial overgrowth (SIBO). We conducted a systematic review and meta‐analysis to determine the prevalence of SIBO in patients with IF and to identify risk factors for SIBO.MethodsMEDLINE (PubMed) and Embase electronic databases were searched from inception to December 2023 for studies that reported the prevalence of SIBO in IF. The prevalence rates, odds ratio (OR), and 95% confidence intervals of SIBO in IF and the risk factors for SIBO in IF were calculated using random effects model.ResultsFinal dataset included nine studies reporting on 407 patients with IF. The prevalence of SIBO in IF was 57.5% (95% CI 44.6–69.4), with substantial heterogeneity in this analysis (I2 = 80.9, P = 0.0001). SIBO prevalence was sixfold higher in patients with IF who received parenteral nutrition (PN) compared with IF patients not on PN (OR = 6.0, 95% CI 3.0–11.9, P = 0.0001). Overall, the prevalence of SIBO in patients with IF using PPI/acid‐suppressing agents (72.0%, 95% CI 57.5–83.8) was numerically higher compared with IF patients not using these agents (47.6%, 95% CI 25.7–70.2).ConclusionsThis systematic review and meta‐analysis suggests that there is an increased risk of SIBO in patients with IF and that PN, and potentially, the use of PPI/acid‐suppressing agents is risk factors for SIBO development in patients with IF. However, the quality of evidence is low and can be attributed to lack of case–control studies and clinical heterogeneity seen in the studies.
Phenotyping of subjects for large scale studies on patients with IBS
Dumitraşcu, Dan L. , Farmer, A D, Hammer, Johann , Hausken, Trygve , Niesler, Beate , Pohl, Daniel , Pojskić, Lejla , Polster, Annikka , Goebel‐Stengel, Miriam , Oudenhove, Lukas Van , Vassallo, Mario, Wensaas, Knut‐Arne , Aziz, Qasim , Houghton, Lesley A. , members, COST Action BM1106 GENIEUR, Boeckxstaens, Guy E. , Drug, Vasile Liviu , Simrén, Magnus , members, COST Action BM1106 GENIEUR, Houghton, L A , Kapur-Pojskič, Lejla , Farmer, Adam D

Neurogastroenterology & Motility | June 20, 2016 | Volume: 28 | Issue: 8 | Pages: 1134-1147

10.1111/nmo.12886 Get It

Abstract Background Irritable bowel syndrome (IBS) is a complex condition with multiple factors contributing to its aetiology and pathophysiology. Aetiologically these include genetics, life‐time events and environment, and physiologically, changes in motility, central processing, visceral sensitivity, immunity, epithelial permeability and gastrointestinal microflora. Such complexity means there is currently no specific reliable biomarker for IBS, and thus IBS continues to be diagnosed and classified according to symptom based criteria, the Rome Criteria. Carefully phenotyping and characterisation of a ‘large’ pool of IBS patients across Europe and even the world however, might help identify sub‐populations with accuracy and consistency. This will not only aid future research but improve tailoring of treatment and health care of IBS patients. Purpose The aim of this position paper is to discuss the requirements necessary to standardize the process of selecting and phenotyping IBS patients and how to organise the collection and storage of patient information/samples in such a large multi‐centre pan European/global study. We include information on general demographics, gastrointestinal symptom assessment, psychological factors, quality of life, physiological evaluation, genetic/epigenetic and microbiota analysis, biopsy/blood sampling, together with discussion on the organisational, ethical and language issues associated with implementing such a study. The proposed approach and documents selected to be used in such a study was the result of a thoughtful and thorough four‐year dialogue amongst experts associated with the European COST action BM1106 GENIEUR ( www.GENIEUR.eu ).