Effects of short-chain fatty acids on the cholinergic regulation of colonic motility in a mice model of irritable bowel syndrome

Irritable bowel syndrome (IBS) refers to a multifactorial disease, one of the symptoms of which is an impaired colon motility. The aim of our work was to analyze the effect of SCFAs on the contraction of the proximal mouse colon specimens, caused by the activation of acetylcholine receptors, in the model of IBS. Mice with a model of IBS showed visceral hypersensitivity, while histological analysis of their colon tissues did not reveal significant differences from the control group. The SCFAs level analysis showed a significant increase in the concentrations of acetic, propionic, and butyric acids in the feces of mice from the IBS group. In study of cholinergic regulation of the contractile activity of the colon segment, it was found that in control sodium butyrate, sodium propionate and sodium acetate decreased contractile responses caused by carbachol, a nonspecific agonist of M- and N-cholinergic receptors and epibatidine, a specific agonist of N-cholinergic receptors. However, SCFAs did not affect the response evoked by bethanechol, an agonist of Mcholinergic receptors. At the same time, we did not observe the inhibitory effects of SCFAs on the contractions induced by carbachol and epibatidine. The obtained data indicate that in the postinflammatory IBS model of a mouse, along with an increase in the level of SCFAs, their effects on the colon contractility were significantly impaired, which may be one of the factors of increased motility in IBS.