Animal Models for Functional Gastrointestinal Disorders

Abstract

Functional gastrointestinal disorders (FGID), such as functional dyspepsia (FD) and irritable bowel syndrome (IBS) are characterized by chronic abdominal symptoms in the absence of an organic, metabolic or systemic cause that readily explains these complaints. Their pathophysiology is still not fully elucidated and animal models have been of great value to improve the understanding of the complex biological mechanisms. Over the last decades, many animal models have been developed to further unravel FGID pathophysiology and test drug efficacy. In the first part of this review, we focus on stress-related models, starting with the different perinatal stress models, including the stress of the dam, followed by a discussion on neonatal stress such as the maternal separation model. We also describe the most commonly used stress models in adult animals which brought valuable insights on the brain-gut axis in stress-related disorders. In the second part, we focus more on models studying peripheral, i.e., gastrointestinal, mechanisms, either induced by an infection or another inflammatory trigger. In this section, we also introduce more recent models developed around food-related metabolic disorders or food hypersensitivity and allergy. Finally, we introduce models mimicking FGID as a secondary effect of medical interventions and spontaneous models sharing characteristics of GI and anxiety-related disorders. The latter are powerful models for brain-gut axis dysfunction and bring new insights about FGID and their comorbidities such as anxiety and depression.

The Role of Leaky Gut in Functional Dyspepsia

“…To the best of our knowledge, the BB-rat is the only available animal model which demonstrates gastric dysmotility, small intestinal hyperpermeability and eosinophilia ( Vanuytsel et al, 2014a ). Therefore, mechanistic evidence from preclinical studies with similar alterations to FD patients is lacking as recently reviewed ( Accarie and Vanuytsel, 2020 ).…”

Clinical Trials of Probiotics in Patients With Irritable Bowel Syndrome: Some Points to Consider

“…Nevertheless, there are ample templates to guide the investigator towards a clear demonstration of the actual biological effects of a given bacterium; effects that should guide the choice of a particular strain for a given clinical problem. 20,21 Several examples of the successful application of this bench-to-bedside approach are extant; in inflammatory disorders, 22 infectious diseases, 23 metabolic processes, 24 and stress management, 25 to name but a few. In choosing your probiotic for IBS one may need to make this decision based on likely relevance of demonstrated effects to your IBS population--not an easy task!…”

Probiotics, Prebiotics, and Synbiotics in the Irritable Bowel Syndrome Treatment: A Review

“…A few studies were conducted on animal models which can be applied if the etiology of the induced disease is as similar as possible as it is in humans. These models play an important role in pre-clinical research on the treatment or mechanisms of functional gastrointestinal disorders, including IBS [ 74 ]. Since psychological pressure might cause the development of IBS or provoke its symptoms in humans, stress is an inducing factor for most animal models.…”