Targeting the gut–microbiota–brain axis in irritable bowel disease to improve cognitive function – recent knowledge and emerging therapeutic opportunities

Abstract

The brain–gut axis forms a bidirectional communication system between the gastrointestinal (GI) tract and cognitive brain areas. Disturbances to this system in disease states such as inflammatory bowel disease have consequences for neuronal activity and subsequent cognitive function. The gut–microbiota–brain axis refers to the communication between gut-resident bacteria and the brain. This circuits exists to detect gut microorganisms and relay information to specific areas of the central nervous system (CNS) that in turn, regulate gut physiology. Changes in both the stability and diversity of the gut microbiota have been implicated in several neuronal disorders, including depression, autism spectrum disorder Parkinson’s disease, Alzheimer’s disease and multiple sclerosis. Correcting this imbalance with medicinal herbs, the metabolic products of dysregulated bacteria and probiotics have shown hope for the treatment of these neuronal disorders. In this review, we focus on recent advances in our understanding of the intricate connections between the gut–microbiota and the brain. We discuss the contribution of gut microbiota to neuronal disorders and the tangible links between diseases of the GI tract with cognitive function and behaviour. In this regard, we focus on irritable bowel syndrome (IBS) given its strong links to brain function and anxiety disorders. This adds to the growing body of evidence supporting targeted therapeutic strategies to modulate the gut microbiota for the treatment of brain/mental-health-related disease.

Role of Gut Microbiota in Neurological Disorders and Its Therapeutic Significance

“…Currently, the role of GM in the development of neurological disorders, neuro-inflammation, and neurobehavioral activities is well documented [ 9 , 16 ]. The GM play an important role in the pathogenesis and therapy of multiple neurological disorders such as Alzheimer’s disease (AD), multiple sclerosis (MS), Parkinson’s disease (PD), autism spectrum disorder (ASD), epilepsy, stroke, brain injury, amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD) [ 17 , 18 ]. Among the therapies, probiotics, postbiotics, prebiotics, symbiotic, antibiotics, and fecal transplantation have been investigated for GM-derived neurological disorders [ 19 , 20 , 21 ].…”

Patient-Physician Relationship in Irritable Bowel Syndrome: Review on Empathy and Stigma

“…A comprehensive model of brain-gut-microbiome interactions has emerged in the past decade aiming to explain the nature of IBS as well as offer a basis for novel treatment options targeting microbiota, brain function, and other possible pathogenetic mechanisms [10][11][12]. Still there is not yet a breakthrough in this process, and gastroenterologists still encounter a large workload of gut-brain axis diseases.…”

Enteric Nervous System Alterations in Inflammatory Bowel Disease: Perspectives and Implications

“…The GBA involves two-way communication between the central nervous system (CNS) and the enteric nervous system (ENS), connecting the emotional and cognitive areas of the brain to the functions of the GI tract [ 8 ]. A functional GBA is required for regulation of digestion, nutrient absorption, and normal functioning of the gut; the dysregulation of this axis in IBD adds another layer of complexity in the pathophysiology of this disease that needs to be addressed to reduce the incidence of mental disorders in these patients [ 9 , 10 ]. Moreover, IBD-mediated changes in the ENS could alter bi-directional communication through the GBA [ 11 ], potentially exacerbating gut symptoms in individuals with IBD.…”