Cell‐free supernatants of Escherichia coli Nissle 1917 modulate human colonic motility: evidence from an in vitro organ bath study

Abstract

Clinical studies have shown that probiotics influence gastrointestinal motility, e.g. Escherichia coli Nissle 1917 (EcN) (Mutaflor) proved to be at least as efficacious as lactulose and more potent than placebo in constipated patients. As the underlying mechanisms are not clarified, the effects of EcN culture supernatants on human colonic motility were assessed in vitro. Human colonic circular smooth muscle strips (n = 94, 17 patients) were isometrically examined in an organ bath and exposed to different concentrations of EcN supernatants. Contractility responses were recorded under (i) native conditions, (ii) electrical field stimulation (EFS), (iii) non-adrenergic non-cholinergic conditions, and (iv) enteric nerve blockade by tetrodotoxin (TTX). As concentrations of acetic acid were increased in EcN supernatants, contractility responses to acetic acid were additionally tested. EcN supernatants significantly increased the maximal tension forces both at low and high concentrations. Neither blockade of both adrenergic and cholinergic nerves nor application of TTX abolished these effects. EFS-induced contractility responses were not altered after exposure to EcN supernatants. Acetic acid elicited effects comparable to EcN supernatants only under TTX conditions. EcN supernatants modulate in vitro contractility of the human colon. As neither partial nor TTX blockade of enteric nerves abolished these effects, EcN supernatants appear to enhance colonic contractility by direct stimulation of smooth muscle cells. Active metabolites may include other substances than acetic acid, as acetic acid only partially resembled the effects elicited by EcN supernatants. The data provide a rationale for therapeutical application of probiotics in gastrointestinal motility disorders.

Gastrointestinal neuromuscular apparatus: An underestimated target of gut microbiota

“…These in vitro studies support the recent evidence that indicates the neuromuscular apparatus as possible target for probiotics[13-15]. Escherichia coli strain Nissle 1917 specifically modulates contractility of human colonic muscle strips[84], Lactobacillus species regulate jejunal motility[14], colonic neuron excitability[15] and attenuate post-infective muscle hypercontractility[85]. Bifidobacterium and Lactobacillus also alleviate visceral hypersensitivity and recover intestinal barrier function as well as inflammation[86].…”

Antibiotic-induced dysbiosis alters host-bacterial interactions and leads to colonic sensory and motor changes in mice

“…53,54 In the present conditions, basal colonic contractility was increased in dysbiotic mice. This, together with the observed increased responses to carbachol and NO-synthase (neural and endothelial) inhibition suggests that during dysbiosis enhanced colonic contractility represents an imbalance between excitatory (mainly cholinergic) and inhibitory (mainly NO-dependent) systems.…”

Role of F1C Fimbriae, Flagella, and Secreted Bacterial Components in the Inhibitory Effect of Probiotic Escherichia coli Nissle 1917 on Atypical Enteropathogenic E. coli Infection

“…Proposed probiotic actions of EcN include effects on pathogens, host epithelial cells, host smooth muscle cell activity, and the host immune system (20)(21)(22)(23)(24)(25)(26)(27)(28). In vitro, EcN has been shown to inhibit invasion of host cells by several enteric pathogens, including Salmonella, Yersinia, Shigella, Legionella, Listeria, and adherent-invasive E. coli (29,30).…”