Review: Effect of probiotics on gastrointestinal function: evidence from animal models

Abstract

Abstract:The digestive tract works through a complex net of integrative functions. At the level of the gut, this integration occurs between the immune, neuromotor and endocrine systems, the intestinal barrier and gut luminal contents. Gastrointestinal function is controlled and coordinated by the central nervous system to ensure effective motility, secretion, absorption and mucosal immunity. Thus, it is clear that the gut keeps a tightly regulated equilibrium between luminal stimuli, epithelium, immunity and neurotransmission in order to maintain homeostasis. It follows that perturbations of any of these systems may lead to gut dysfunction. While we acknowledge that the gutbrain axis is crucial in determining coordinated gut function, in this review we will focus on peripheral mechanisms that influence gastrointestinal physiology and pathophysiology. We will discuss the general hypothesis that the intestinal content is crucial in determining what we consider normal gastrointestinal physiology, and consequently that alteration in luminal content by dietary, antibiotic or probiotic manipulation can result in changes in gut function. This article focuses on lessons learned from animal models of gut dysfunction.

Probiotics, Prebiotics, and Synbiotics for the Prevention of Necrotizing Enterocolitis

“…Animal models that described the beneficial effects of probiotics on the enteric nervous system (62) and intestinal motility (63) corroborate findings in humans.…”

Bacteroides fragilis polysaccharide A is necessary and sufficient for acute activation of intestinal sensory neurons

“…This allowed us to deduce how a certain symbiont and probiotic bacteria act on the ENS and thereby gut function. As this parallels the timing of effects on motility in ex vivo peristalsis preparations 10 , the actions of beneficial bacteria on intestinal motility are likely due to actions on neurons rather than second-order effects, which depend on initial involvement of the host's immune or endocrine systems 34 . This is underscored by our observation that killed JB-1 or LS that do not alter ex vivo motility, also failed to alter IPAN excitability, suggesting strain specificity for probiotic neuroactivity.…”

Change of Fecal Flora and Effectiveness of the Short-term VSL#3 Probiotic Treatment in Patients With Functional Constipation

“…The other possibility is that physiologically active substances produced by the gut flora may have affected colon transit, regardless of the fold differences in the concentration of bacterial species. 12,[24][25][26] Several studies have demonstrated that administering probiotics or prebiotics such as Lactobacillus-enriched artichoke reduced visceral hypersensitivity and inflammation, or relieved symptoms of constipation, without altering bacterial populations. [26][27][28] Probiotics are capable of lowering intracolonic pH due to bacterial SCFA production.…”

“…30 Orally administered probiotics have been considered to target the motor and neural apparatus in post-infective gut dysfunctions. 25 Probiotics including lactic acid bacteria were shown to be effective for the relief of abdominal bloating in patients with diarrhea-predominant irritable bowel syndrome (D-IBS), but did not show a significant alteration in gut transit. 31,32 Studies involving the administration of a probiotic, B. lactis DN-173 010, showed improved colonic transit times in both a healthy population and constipated patients.…”