The in Vitro Wound Healing System Detects Differences in the Quality of Probiotic Formulations.

Introduction:Disruption of the intestinal barrier function and repeated intestinal epithelial damage are key features of IBD, as well as other intestinal disorders. A number of factors modulate intestinal epithelial wound repair, including bacteria which play an essential role in the maintenance of gut homeostasis. A high concentration 8-strains probiotic formulation has shown efficacy in pouchitis and ulcerative colitis reducing inflammation and restoring the barrier function. However, recently, under the same brand, a formulation produced by manufacturers different from the previous one, has been commercialized in some European countries. Th is study was aimed to compare the in vitrowound healing activities of the “original” and the “redesigned” probiotic formulation considering that diff erences in production and manufacturing methods may significantly change the properties of the probiotic strains present in the formulation, so to invalidate the previous in vivostudies on human subjects. Methods:Wound healing activities of bacterial lysates from “original” and “redesigned” probiotic formulations were tested using in vitroassays including cell proliferation and migration assays, collagen production, nitric oxide generation, and H2O2-induced oxidative stress in 3T3 fibroblasts, HaCAT keratinocytes, and HUVEC cells. Th e cellular ROS detection assay kit was used to compare antioxidant activity of bacterial lysates from both probiotic formulations. Moreover, the ability of endothelial cells to differentiate into capillary-like tubular structures was analyzed through a standard tube formation assay. Results:Using the in vitrowound healing assay, the “original” formulation, as compared to the “redesigned” formulation, more significantly accelerated in vitrohealing process of scratched monolayers. Th ese results well correlated with anti-oxidative effect, stimulation of cell proliferation and migration as well as increased collagen production. Th e tube formation assay also revealed a significantly higher ability of bacterial lysate from “original” probiotic formulation to stimulate the angiogenic activity of HUVEC in vitro as compared to the “redesigned” probiotic. Conclusion:Our data show that there are marked differences among the “original and the “redesigned” formulations, in terms of wound healing properties. Gastroenterologists should be informed that the previous studies and clinical experiences might not apply at all or in part to the “redesigned” product.