World J Gastroenterol. 2022 Jan 28;28(4):412-431. doi: 10.3748/wjg.v28.i4.412.

Eline Margrete Randulff Hillestad ¹, Aina van der Meeren ², Bharat Halandur Nagaraja ³, Ben René Bjørsvik ², Noman Haleem ², Alfonso Benitez-Paez ⁴, Yolanda Sanz ⁵, Trygve Hausken ¹, Gülen Arslan Lied ², Arvid Lundervold ³, Birgitte Berentsen ¹

Author information

¹Department of Clinical Medicine, University of Bergen, Bergen 5021, Norway.

²National Center for Functional Gastrointestinal Disorders, Department of Medicine, Haukeland University Hospital, Bergen 5021, Norway.

³Mohn Medical Imaging and Visualization Center, Department of Radiology, Haukeland University Hospital, Bergen 5021, Norway.

⁴Host-Microbe Interactions in Metabolic Health Laboratory, Principe Felipe Research Center, Valencia 46012, Spain.

⁵Microbial Ecology, Nutrition and Health Research Unit, Institute of Agrochemistry and Food Technology, National Research Council, Paterna-Valencia 46980, Spain.

Abstract

Irritable bowel syndrome (IBS) is a common clinical label for medically unexplained gastrointestinal symptoms, recently described as a disturbance of the microbiota-gut-brain axis. Despite decades of research, the pathophysiology of this highly heterogeneous disorder remains elusive. However, a dramatic change in the understanding of the underlying pathophysiological mechanisms surfaced when the importance of gut microbiota protruded the scientific picture. Are we getting any closer to understanding IBS' etiology, or are we drowning in unspecific, conflicting data because we possess limited tools to unravel the cluster of secrets our gut microbiota is concealing? In this comprehensive review we are discussing some of the major important features of IBS and their interaction with gut microbiota, clinical microbiota-altering treatment such as the low FODMAP diet and fecal microbiota transplantation, neuroimaging and methods in microbiota analyses, and current and future challenges with big data analysis in IBS.