Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.
Department of Pharmacology and Toxicology, Maastricht University, Maastricht, The Netherlands.
PLoS One. 2023 Sep 21;18(9):e0291636. doi: 10.1371/journal.pone.0291636. eCollection 2023.
Analysis of volatile organic compounds (VOCs) in exhaled breath has the potential to serve as an accurate diagnostic tool for gastro-intestinal diseases. Animal studies could be instrumental as a preclinical base and subsequent clinical translation to humans, as they are easier to standardize and better equipped to relate specific VOCs to metabolic and pathological processes. This review provides an overview of the study design, characteristics and methodological quality of previously published animal studies on analysis of exhaled breath in gastrointestinal and hepatic diseases. Guidelines are provided for standardization in study design and breath collection methods to improve comparability, avoid duplication of research and reduce discomfort of animals in future studies.
PubMed and Embase database were searched for animal studies using exhaled breath analysis to detect gastro-intestinal diseases. Risk of bias was assessed using the SYRCLE's risk of bias tool for animal studies. Information on study design, standardization methods, animal models, breath collection methods and identified VOCs were extracted from the included studies.
10 studies were included (acute liver failure n = 1, non-alcoholic steatohepatitis n = 1, hepatic ischemia n = 2, mesenteric ischemia n = 2, sepsis and peritonitis n = 3, colitis n = 1). Rats were used in most of the studies. Exhaled breath was mostly collected using invasive procedures as tracheal cannulation or tracheostomy. Poor reporting on standardization, breath collection methods, analytical techniques, as well as heterogeneity of the studies, complicate comparison of the different studies.
Poor reporting of essential methodological details impaired comprehensive summarizing the various studies on exhaled breath in gastrointestinal and hepatic diseases. Potential pitfalls in study design, and suggestions for improvement of study design are discussed which, when applied, lead to consistent and generalizable results and a reduction in the use of laboratory animals. Refining the methodological quality of animal studies has the potential to improve subsequent clinical trial design.
分析呼出气中的挥发性有机化合物（VOCs）有可能成为胃肠疾病的准确诊断工具。动物研究可以作为临床前基础和随后向人类的临床转化提供帮助，因为它们更容易标准化，并且能够更好地将特定的 VOC 与代谢和病理过程联系起来。本综述概述了先前发表的关于胃肠和肝脏疾病中分析呼出气的动物研究的研究设计、特征和方法学质量。为了提高可比性、避免研究重复和减少动物的不适，提供了研究设计和呼气收集方法标准化的指南。
在 PubMed 和 Embase 数据库中搜索使用呼出气分析来检测胃肠疾病的动物研究。使用 SYRCLE 动物研究偏倚风险工具评估偏倚风险。从纳入的研究中提取研究设计、标准化方法、动物模型、呼气收集方法和鉴定的 VOC 信息。
纳入了 10 项研究（急性肝衰竭 n = 1、非酒精性脂肪性肝炎 n = 1、肝缺血 n = 2、肠系膜缺血 n = 2、脓毒症和腹膜炎 n = 3、结肠炎 n = 1）。大多数研究使用大鼠。呼出气主要通过气管插管或气管切开等有创程序收集。对标准化、呼气收集方法、分析技术的报告不充分，以及研究的异质性，使得难以比较不同的研究。
对基本方法细节的报告不足，妨碍了对胃肠和肝脏疾病中呼出气的各种研究进行全面总结。讨论了研究设计中的潜在陷阱和改进建议，当应用这些建议时，可以得到一致且可推广的结果，并减少实验动物的使用。改进动物研究的方法学质量有可能改善随后的临床试验设计。
