Irritable bowel syndrome (IBS) is a functional disorder of brain-gut interactions. Differential brain responses to rectal distention between IBS and healthy controls (HCs) have been demonstrated, particularly in the pain matrix and the default mode network. This study aims to compare resting-state functional properties of these networks between IBS patients and HCs using graph analysis in two independent cohorts. We used a weighted graph analysis of the adjacency matrix based on partial correlations between time series in the different regions in each subject to determine subject specific graph measures. These graph measures were normalized by values obtained in equivalent random networks. We did not find any significant differences between IBS patients and controls in global normalized graph measures, hubs, or modularity structure of the pain matrix and the DMN in any of our two independent cohorts. Furthermore, we did not find consistent associations between these global network measures and IBS symptom severity or GI-specific anxiety but we found a significant difference in the relationship between measures of psychological distress (anxiety and/or depressive symptoms) and normalized characteristic path length. The responses of these networks to visceral stimulation rather than their organisation at rest may be primarily disturbed in IBS.

肠易激综合症（IBS）是一种脑-肠相互作用的功能障碍。已经证明 IBS 和健康对照 (HC) 之间的大脑对直肠扩张的反应存在差异，特别是在疼痛矩阵和默认模式网络中。本研究旨在通过两个独立队列的图形分析来比较 IBS 患者和 HC 之间这些网络的静息态功能特性。我们使用基于每个受试者不同区域的时间序列之间的部分相关性的邻接矩阵的加权图分析来确定受试者特定的图测量。这些图形测量值通过等效随机网络中获得的值进行标准化。在我们的两个独立队列中，我们没有发现 IBS 患者和对照组之间在疼痛矩阵和 DMN 的全局标准化图表测量、中心或模块化结构方面存在任何显着差异。此外，我们没有发现这些全球网络测量值与 IBS 症状严重程度或胃肠道特异性焦虑之间存在一致的关联，但我们发现心理困扰（焦虑和/或抑郁症状）测量值与标准化特征路径长度之间的关系存在显着差异。在肠易激综合征中，这些网络对内脏刺激的反应而不是其静止组织的反应可能主要受到干扰。