The Role of the Gastrointestinal Microbiota in Visceral Pain

Abstract

A growing body of preclinical and clinical evidence supports a relationship between the complexity and diversity of the microorganisms that inhabit our gut (human gastrointestinal microbiota) and health status. Under normal homeostatic conditions this microbial population helps maintain intestinal peristalsis, mucosal integrity, pH balance, immune priming and protection against invading pathogens. Furthermore, these microbes can influence centrally regulated emotional behaviour through mechanisms including microbially derived bioactive molecules (amino acid metabolites, short-chain fatty acids, neuropeptides and neurotransmitters), mucosal immune and enteroendocrine cell activation, as well as vagal nerve stimulation.The microbiota-gut-brain axis comprises a dynamic matrix of tissues and organs including the brain, autonomic nervous system, glands, gut, immune cells and gastrointestinal microbiota that communicate in a complex multidirectional manner to maintain homeostasis and resist perturbation to the system. Changes to the microbial environment, as a consequence of illness, stress or injury, can lead to a broad spectrum of physiological and behavioural effects locally including a decrease in gut barrier integrity, altered gut motility, inflammatory mediator release as well as nociceptive and distension receptor sensitisation. Centrally mediated events including hypothalamic-pituitary-adrenal (HPA) axis, neuroinflammatory events and neurotransmitter systems are concomitantly altered. Thus, both central and peripheral pathways associated with pain manifestation and perception are altered as a consequence of the microbiota-gut-brain axis imbalance.In this chapter the involvement of the gastrointestinal microbiota in visceral pain is reviewed. We focus on the anatomical and physiological nodes whereby microbiota may be mediating pain response, and address the potential for manipulating gastrointestinal microbiota as a therapeutic target for visceral pain.

The enduring effects of early‐life stress on the microbiota–gut–brain axis are buffered by dietary supplementation with milk fat globule membrane and a prebiotic blend

“…A growing body of evidence supports a role for the gut microbiota in modulating the effects of stress (Foster et al., ; O'Mahony et al., ; Rea, O'Mahony, Dinan, & Cryan, ) and here we show that the addition of MFGM to the diet was sufficient to influence the gut microbiota of both NS and to a greater extent, MS rats. We have previously shown that early‐life stress in rats reduced microbial diversity alongside behavioural changes (O'Mahony et al., ; Pusceddu et al., ).…”

The Evolving Role of Gut Microbiota in the Management of Irritable Bowel Syndrome: An Overview of the Current Knowledge

“…In IBS patients, GI dysbiosis has been associated with a visceral increased perception of pain and enhanced mucosal permeability that is provoked by the defective mucosal epithelial barrier, interfering with gut immune homeostasis and subsequently promoting gut inflammation and enhancing cellular and mucosal immune activation [28,29]. Moreover, it has also been associated with changing gut motility, low-grade chronic inflammation, alterations of the enteric nervous system, and vagal afferents neurons as well as brain functions [30][31][32].…”

Fecal microbiota profile in a group of myasthenia gravis patients

“…Among these, several studies strongly suggest that the intestinal microbiota may interplay with the nervous system and the brain 8 . Animal studies have evidenced the potential of the gut microbiota to modulate pain perception 9 – 11 , behaviour, mood and stress response 5 , 12 , 13 . The gut microbiota is able to produce neuroactive molecules such as histamine, acetylcholine or GABA, among others 14 .…”