Search

The intestinal epithelium constitutes a selectively permeable barrier between the internal and external environment that allows the absorption of nutrients, electrolytes, and water, as well as an effective defense against intraluminal bacteria, toxins, and potentially antigenic material. Experimental evidence suggest that intestinal inflammation is critically dependent on an imbalance of homeostasis between the gut microbiota and the mucosal immune system. In this context, mast cells play a crucial role. The intake of specific probiotic strains can prevent the development of gut inflammatory markers and activation of the immune system. Here, the effect of a probiotic formulation containing L. rhamnosus LR 32, B. lactis BL04, and B. longum BB 536 on intestinal epithelial cells and mast cells was investigated. To mimic the natural host compartmentalization, Transwell co-culture models were set up. Co-cultures of intestinal epithelial cells interfaced with the human mast cell line HMC-1.2 in the basolateral chamber were challenged with lipopolysaccharide (LPS), and then treated with probiotics. In the HT29/HMC-1.2 co-culture, the probiotic formulation was able to counteract the LPS-induced release of interleukin 6 from HMC-1.2, and was effective in preserving the epithelial barrier integrity in the HT29/Caco-2/ HMC-1.2 co-culture. The results suggest the potential therapeutic effect of the probiotic formulation.

In healthy individuals, tight junction proteins (TJPs) maintain the integrity of the intestinal barrier. Dysbiosis and increased intestinal permeability are observed in several diseases, such as inflammatory bowel disease. Many studies highlight the role of probiotics in preventing intestinal barrier dysfunction. The present study aims to investigate the effects of a commercially available probiotic formulation of L. rhamnosus LR 32, B. lactis BL 04, and B. longum BB 536 (Serobioma, Bromatech s.r.l., Milan, Italy) on TJPs and the integrity of the intestinal epithelial barrier, and the ability of this formulation to prevent lipopolysaccharide-induced, inflammation-associated damage. An in vitro model of the intestinal barrier was developed using a Caco-2 cell monolayer. The mRNA expression levels of the TJ genes were analyzed using real-time PCR. Changes in the amounts of proteins were assessed with Western blotting. The effect of Serobioma on the intestinal epithelial barrier function was assessed using transepithelial electrical resistance (TEER) measurements. The probiotic formulation tested in this study modulates the expression of TJPs and prevents inflammatory damage. Our findings provide new insights into the mechanisms by which probiotics are able to prevent damage to the gut epithelial barrier.

Objective: In recent years, a great number of studies have been directed toward the evaluation of gastrointestinal microbiota modulation through the introduction of beneficial microorganisms, also known as probiotics. Many studies have highlighted how this category of bacteria is very important for the good development, functioning, and maintenance of our immune system. There is a delicate balance between the immune system, located under the gut epithelial barrier, and the microbiota, but many factors can induce a disequilibrium that leads to an inflammatory state and dysbiosis. The aim of this work is to verify the anti-inflammatory effects of a probiotic formulation of Lactobacillus rhamnosus, Bifidobacterium lactis, and Bifidobacterium longum (Serobioma)., Methods: To mimic the natural host compartmentalization between probiotics and immune cells through the intestinal epithelial barrier in vitro, the transwell model was used. We focused on a particular subset of immune cells that play a key role in the mucosal immune system. The immunomodulatory effects of probiotic formulation were investigated in the human macrophage cell line THP1 and macrophages derived from ex vivo human peripheral blood mononuclear cells., Results: Probiotic formulation induced a significant increase in anti-inflammatory cytokine interleukin-10 (IL-10) production and was able to decrease the secretion of the major proinflammatory cytokines IL-1β and IL-6 by 70% and 80%, respectively. Finally, for the first time, the ability of probiotic formulation to favor the macrophage M2 phenotype has been identified., Conclusion: The transwell model is an intriguing toll approach to studying the human epithelial barrier., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Inflammatory bowel diseases (IBD) are characterized by inflammatory conditions of the intestine. Probiotic bacteria (PB) can have beneficial effects in several gastrointestinal disorders. The objectives of this study were: (i) to provide an acute experimental IBD model induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) in CD-1 mice, and (ii) to assess the preventive effects of Citogenex (Lactobacillus casei and Bifidobacterum lactis) supplementation on intestinal tissues and microbiota. Mice were inoculated intrarectally with saline, ethanol or different TNBS solutions. 1%TNBS induced clinical signs of colitis (P less than 0.01) and histological damage (P less than 0.01). Based on these results, mice were pre-treated with Citogenex or saline for 1, 2 or 3 weeks before 1%TNBS treatment. Probiotic pre-treatment determined a reduction of clinical signs (P less than 0.05), histological alterations of colitis (P less than 0.05) and increased beneficial bacteria (P less than 0.05). This study confirms that TNBS-induced colitis in CD-1 mice is useful for studying the mechanisms involved in IBD pathogenesis, and pre-treatment with Citogenex prevents the intestinal damage induced by TNBS.

Objective: The aim of this study was to evaluate the performance of the overall antioxidant of Lactobacillus fermentum LF31 bacterium with prebiotic supplement in human colon cultured cells., Methods: The antioxidant capability of L. fermentum LF31 has been assayed in vitro on human colon adenocarcinoma HT-29 cell line using the oxygen radical absorbance capacity method., Results: The analysis revealed that the interaction of probiotic strain cells supplemented with a prebiotic exerts a remarkable antioxidant capacity., Conclusion: The L. fermentum used in the present study exhibited significant in vitro antioxidant capacity, increasing the total antioxidant potential., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Probiotics (PB) are living microorganisms that act as a commensal population in normal intestines and confer numerous beneficial effects on the host. The introduction of probiotics in the treatment of inflammatory bowel disease (IBD) prolongs remission. The aim of this study was to investigate the intestinal and hepatic effects of PB supplementation in an experimental IBD model in mice induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). In the first step of the experimental procedure, CD-1 male mice, 5 to 6 weeks old, were randomly divided into 3 groups and inoculated intrarectally with, respectively, saline, alcohol, or TNBS to assess the experimental IBD model. In the second step, mice treated, or not, with TNBS inoculation, were treated with PB (Lactobacillus Casei, Bifidobacterum Lactis) for 1, 2 or 3 weeks, on a daily basis. Large bowel (colon and rectum) and liver were processed for histological alterations, according to a scoring system. Large bowel was also assessed for apoptosis by TUNEL assay. TNBS induced, as expected, severe damage and inflammation in the large bowel, including nuclear alterations and apoptosis, and, to a lesser extent, to the liver. Administration of PB determined significant reduction of both histological alterations and apoptosis. PB administration in advance protects from inflammation. In conclusion, supplementation with Lactobacillus casei, Bifidobacterum lactis PB is able to ameliorate the colitis by reversing the histological changes caused by TNBS in mice. Experimentation in human subjects in needed to prove their efficacy in reducing histological alterations that may be present in subjects with IBD.