Volatile organic compound profiling as a potential biomarker in irritable bowel syndrome: A feasibility study.

Background: Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder for which no diagnostic tools are currently available. Patients are diagnosed using the Rome IV criteria and subtyped into a diarrhea, constipation, or mixed phenotype based on their dominant stool pattern. A recent development in the biomarker area is the analysis of volatile organic compounds (VOCs). The aim of this study was to evaluate the potential of VOCs as diagnostic and phenotypic biomarkers for IBS in breath and fecal samples. Materials and methods: Breath and fecal samples from IBS patients and healthy asymptomatic controls (HC) were analyzed with multicapillary column/ion mobility spectrometry (MCC/IMS) and classification models were created based upon VOCs and clinical characteristics. Discussion: Irritable bowel syndrome patients were differentiated from HC by means of volatile profiling in both breath and fecal samples with area under the curve (AUCs) of respectively 0.62 and 0.80. Patient subtypes could also be differentiated from each other with AUCs ranging between 0.65 and 0.78. Furthermore, VOC models could differentiate IBS patients based on clinical characteristics like psychological comorbidities and microbiota-influencing therapies. Conclusion: This study is the first to demonstrate the use of VOC profiling with the help of MCC/IMS to differentiate IBS patients. Furthermore, the importance of clinical characteristics beside the dominant stool pattern in the differentiation of IBS patients was emphasized.

Volatomics in inflammatory bowel disease and irritable bowel syndrome.

Volatile organic compounds (VOCs) are produced by the human metabolism, inflammation and gut microbiota and form the basis of innovative volatomics research. VOCs detected through breath and faecal analysis hence serve as attractive, non-invasive biomarkers for diagnosing and monitoring irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). This review describes the clinical applicability of volatomics in discriminating between IBS, IBD and healthy volunteers with acceptable accuracy in breath (70%-100%) and faecal (58%-85%) samples. Promising compounds are propan-1-ol for diagnosing and monitoring of IBD patients, and 1-methyl-4-propan-2-ylcyclohexa-1,4-diene as biomarker for IBS diagnosis. However, these VOCs often seem to be related to inflammation and probably will need to be used in conjunction with other clinical evidence. Furthermore, three interventional studies underlined the potential of VOCs in predicting treatment outcome and patient follow-up. This shows great promise for future use of VOCs as non-invasive breath and faecal biomarkers in personalised medicine. However, properly designed studies that correlate VOCs to IBD/IBS pathogenesis, while taking microbial influences into account, are still key before clinical implementation can be expected.

Malignancy and Meckel's diverticulum: A systematic literature review and 14-year experience at a tertiary referral center.

BACKGROUND: Meckel's diverticulum is present in about 2% of the population. The literature reports 3.2% incidence of tumors within Meckel's diverticulum; the tumors are predominantly benign. OBJECTIVE AND METHODS: The purpose of this study was to evaluate malignant tumors in Meckel's diverticulum through systematic review of the literature and review of electronic medical records including pathology reports over 14 years at the Mayo Clinic, Rochester, USA. RESULTS: A literature review over the last 10 years identified 37 citations with 402 patients (median age: 58 years; 68.9% males). The predominant malignancy reported was neuroendocrine tumor 84.6%, followed by gastrointestinal stromal tumor 8.2%, and adenocarcinoma 6%. At the time of diagnosis, 29.5% of patients had metastases. In the Mayo Clinic electronic medical records review, there were 19 patients (5.1% of them surgically removed Meckel's diverticulum) who had a malignancy associated with Meckel's diverticulum: 63.2% neuroendocrine tumor, 10.5% gastrointestinal stromal tumor, 5.3% adenocarcinoma, 5.3% pancreatic epithelial neoplasia, and 15.8% metastases from secondary location. Median size of the malignancy was 7 mm, and 17/19 malignancies were coincidental findings. Most neuroendocrine tumors infiltrated the submucosa, while gastrointestinal stromal tumor and adenocarcinoma invaded the serosa. At the time of diagnosis, 33.3% of patients had metastases. CONCLUSION: About 5% of Meckel's diverticulums resected were associated with malignant tumors, most commonly neuroendocrine tumor, and a significant portion of Meckel's diverticulum malignancy was metastatic at the time of discovery.