The role of serotonin and diet in the prevalence of irritable bowel syndrome: a systematic review

Abstract

Serotonin or 5-hydroxytryptamine (5-HT)- a neurotransmitter of both the Enteric Nervous System and the Central Nervous System is synthesized by the hydroxylation of L- tryptophan to 5-hydroxytryptophan.Serotonin has been associated with gut functions like assimilation and absorption, alongside the regulation of particle transport and fluid discharge in the gastrointestinal tract and its deficiency is found to be a prominent factor in the prevalence of gut disorders like Irritable Bowel Syndrome.For this review, we assessed the conventional treatment methods of common drugs, with the recently accredited treatment options like dietary regulation, exercise, meditation, and acupuncture. Having found that the most commonly used drugs exhibited various side effects like nausea, fatigue, rash, and dizziness, an in-depth evaluation of different Indian dietary patterns and their respective effects on tryptophan levels has been highlighted to formulate an ideal diet for patients with Irritable Bowel Syndrome (IBS). This review seeks to explore the numerous studies conducted to link IBS with the lack of serotonin production in the body, alongside exploring the evidence associating certain foods with raised tryptophan levels to hypothesize a suitable Indian diet.This review, in its essence, stresses the crucial need for further research on the dietary implications of common Indian foods and their FODMAP (Fermented Oligosaccharides, Disaccharides, Monosaccharides, And Polyols) contents, while underscoring the benefits of using unconventional and natural methods for the treatment of tryptophan-related gut disorders.

Enteric Microbiota-Mediated Serotonergic Signaling in Pathogenesis of Irritable Bowel Syndrome

“…Enteric microbiota play a critical role in regulating a variety of neurotransmitters, including histamine, serotonin (5-hydroxytryptamine, 5-HT), glutamate, γ-aminobutyric acid (GABA), dopamine, acetylcholine, and catecholamines [ 18 , 22 , 24 ], and each biological substance influences the activity of the enteric nervous system (ENS) independently or corporately as part of the pathology of IBS [ 22 , 25 ]. Among those, 5-HT is one of the most well-studied neurotransmitters in IBS research investigations [ 26 , 27 , 28 ]. Enteric 5-HT boosts visceral hypersensitivity, increases mucosal permeability, alters gut motility, activates the immune system, and induces inflammation, which synergistically contribute to forming IBS symptoms [ 28 ].…”

Polycystic Ovary Syndrome and Irritable Bowel Syndrome: Is There a Common Pathway?

“…The evidence revealed that the decrease in intestinal serotonin leads to weakness in the intestinal lining, which inevitably results in constipation and an increase in serotonin levels within the gut [ 37 ]. Another hypothesis in this context implies the deficiency of the serotonin transporter‐serotonin reuptake transporter (SERT) enterocytes in IBS patients [ 38 ]. Indeed, serotonin, which is regulated by SERT, could influence gut distension, motility and visceral sensitivity [ 39 ].…”

Gut Microbiota Regulates the Sympathetic Nerve Activity and Peripheral Serotonin Through Hypothalamic MicroRNA-204 in Order to Increase the Browning of White Adipose Tissue in Obesity

“…Peripheral serotonin (5-HT) (80%-90% of the total body content of serotonin) is synthesized in the gut predominately by the enterochromaffin cells (ECs) from tryptophan-by-tryptophan hydroxylase 1 (Tph1) [32][33][34][35]. Interestingly, the release of 5-HT from the ECs, the most abundant enteroendocrine cell subtype of the colon [36], is under the control of the autonomous nervous system [37].…”