Oral probiotic treatment of Lactobacillus rhamnosus Lcr35® prevents visceral hypersensitivity to a colonic inflammation and an acute psychological stress

Aims: This study evaluated the efficacy of a repeated oral treatment with two active pharmaceutical ingredients (Lcr Lenio (R) and Lcr Restituo (R)) derivated from the probiotic bacterial strain Lactobacillus rhamnosus Lcr35 (R) in two animal models mimicking different features of irritable bowel syndrome (IBS). IBS is characterized by visceral pain associated with alteration of bowel transit. IBS patients present visceral hypersensitivity with peripheral and central origins. Methods and Results: The injection of 2,4,6-trinitrobenzenesulfonic acid (TNBS) into the proximal colon as well as an acute partial restraint stress (PRS) produces colonic hypersensitivity measured in conscious rats by a decrease in pain threshold in response to distal colonic distension. Visceral hypersensitivity was produced by injection of TNBS 7 days before colonic distension or by acute PRS on testing day. Treatments were performed once a day during eight consecutive days. Conclusions: This study indicates that an 8-day probiotic treatment (Lcr Lenio and Lcr Restituo) produces an antihypersensitivity activity in both TNBS and PRS visceral pain models. As this probiotic strain attenuates peripherally and centrally induced visceral hypersensitivity in rats, it may be active in treatment of IBS symptoms. An immunomodulatory effect of the probiotics was highlighted in the TNBS model on the IL-23 secretion, suggesting a mechanism of action involving a regulation of the local IL-23/Th17 immune activation. Significance and Impact of the Study: Two formulas of Lcr35 (R) probiotic strain show very encouraging results for the treatment of IBS patients. Further studies are needed to better understand the role and mechanisms of probiotics on the pathogenesis of IBS.