We have previously shown that ingestion of Lactobacillus reuteri may modulate colonic enteric neuron activity but with unknown effects on colon motility. The aim of the present report was to elucidate the neuronal mechanisms of action of the probiotic by comparing the effects on motility of L. reuteri ingestion with blockade of a specific ionic current in enteric neurons.
We have used intraluminal pressure recordings from ex vivo rat colon segments and whole cell patch clamp recordings from neurons of rat longitudinal muscle myenteric plexus preparations to investigate the effects of L. reuteri and TRAM-34 on colon motility and neurophysiology. The effects of daily feeding of 10(9) L. reuteri bacteria or acute application of TRAM-34 on threshold fluid filling pressure or pulse pressure was measured.
Lactobacillus reuteri increased intraluminal fluid filling pressure thresholds for evoking pressure pulses by 51% from 0.47 +/- 0.17 hPa; the probiotic also decreased the pulse pressure amplitudes, but not frequency, by 18% from 3.91 +/- 0.52 hPa. The intermediate conductance calcium-dependent potassium (IK(Ca)) channel blocker TRAM-34 (3 micromol L(-1)) increased filling threshold pressure by 43% from 0.52 +/- 0.22 hPa and reduced pulse pressure amplitude by 40% from 2.63 +/- 1.11 hPa; contraction frequency was unaltered. TRAM-34 (3 micromol L(-1)) reduced membrane polarization, leak conductance and the slow afterhyperpolarization current in 16/16 myenteric rat colon AH cells but 19/19 S cells were unaffected.
The present results are consistent with L. reuteri enhancing tonic inhibition of colon contractile activity by acting via the IK(Ca) channel current in AH cells.
"Maternal separation in rats, a model for early life stress, reduces the similarity of the GM significantly . Administration of Lactobacillus spp. to rats may reduce visceral pain sensitivity  . "
[Show abstract][Hide abstract] ABSTRACT: The gut microbiota (GM) composition and its impact on animal experiments has become currently dramatically relevant in our days: (1) recent progress in metagenomic technologies, (2) the availability of large scale quantitative analyses to characterize even subtle phenotypes, (3) the limited diversity of laboratory rodent GM due to strict barriers at laboratory animal vendors, and (4) the availability of up to 300.000 different transgenic mouse strains from different sources displaying a huge variety in their GM composition. In this review the GM is described as a variable in animal experiments which need to be reduced for scientific as well as ethical reasons, and strategies how to implement this in routine diagnostic procedures are proposed. We conclude that we have both enough information available to state that the GM has an essential impact on animal models, as well as the methods available to start dealing with these impacts.
"It has been shown that Lactobacillus reuteri ingestion consistently alters the motility of colon segments in an ex vivo organ bath recording setup. The effect is a decrease in the amplitudes of contractions at constant luminal filling preasure, and an increase in the threshold luminal pressure required to evoke rhythmic contractions (Wang et al., 2010). On the other hand, an in vivo study showed that administration of probiotics induces increased colonic propulsive contractions and defecation rate in pigs (Ohashi et al., 2001). "
[Show abstract][Hide abstract] ABSTRACT: Twenty one male Wistar albino rats each weighing approximately 280 g were used in this study. Animals were divided into three groups. The first group (n = 7) consisted of sham controls, in the second (n = 7), rats were administrated 0.1 g/1 ml/galactooligosaccharide by by oral gavage for 4 weeks. In the third group (n = 7), rats were administrated 10 9 CFU/1ml/day Bifidobacterium lactis by oral gavage for 4 weeks. After 4 weeks, rats were sacrified; ileum and proximal colon segments were removed. The spontaneous contractions of ileum and proximal colon were evaluated by using organ bath. It has been detected that both prebiotics and probiotics increased intestinal motility. While probiotics have effects on both ileum and proximal colon, prebiotics seem to be effective in colon. All data are expressed as mean ± SEM (standard error of mean). Statistical comparisons between groups were performed using general linear models of analysis of variance (ANOVA) followed by the Turkey test.
African journal of microbiology research 12/2011; 5(32). DOI:10.5897/AJMR11.801 · 0.54 Impact Factor
"Supernatant of Escherichia coli Nissle 1917 enhanced human colonic motility in vitro and acute exposure of colonic mucosa to Lactobacillus rhamnosus GG significantly reduced the acetylcholine-stimulated human colonic contractions in a dose- and time-dependent manners . Administration of L. reuteri altered the motility of ex vivo colonic segment of rat; it decreased the amplitudes of contractions and increased intraluminal fluid filling pressure thresholds for evoking pressure pulses . Overall, probiotics will likely have an emerging therapeutic role in preventing and treating obesity and obesity-related inflammation. "
[Show abstract][Hide abstract] ABSTRACT: Obesity is a chronic disease characterized by persistent low-grade inflammation with alterations in gut motility. Motor abnormalities suggest that obesity has effects on the enteric nervous system (ENS), which controls virtually all gut functions. Recent studies have revealed that the gut microbiota can affect obesity and increase inflammatory tone by modulating mucosal barrier function. Furthermore, the observation that inflammatory conditions influence the excitability of enteric neurons may add to the gut dysfunction in obesity. In this article, we discuss recent advances in understanding the role of gut microbiota and inflammation in the pathogenesis of obesity and obesity-related gastrointestinal dysfunction. The potential contribution of sirtuins in protecting or regulating the circuitry of the ENS under inflamed states is also considered.
Journal of Translational Medicine 11/2011; 9(1):202. DOI:10.1186/1479-5876-9-202 · 3.93 Impact Factor
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