VSL#3 probiotic differently influences IEC-6 intestinal epithelial cell status and function

The data here reported introduce the wound-healing assay as a tool for testing probiotics aimed at protecting gastrointestinal mucosal surfaces and to verify the consistency of their manufacturing. At the scope, we compared the in vitro effects of two multi-strain high concentration formulations both commercialized under the same brand VSL#3 but sourced from different production sites (USA and Italy) on a non-transformed small-intestinal epithelial cell line, IEC-6. The effects on cellular morphology, viability, migration, and H2O2-induced damage, were assessed before and after the treatment with both VSL#3 formulations. While the USA-sourced product (USA-made) VSL#3 did not affect monolayer morphology and cellular density, the addition of bacteria from the Italy-derived product (Italy-made) VSL#3 caused clear morphological cell damage and strongly reduced cellularity. The treatment with USA-made lysate led to a higher rate of wounded monolayer healing, while the addition of Italy-made bacterial lysate did not influence the closure rate as compared to untreated cells. While lysates from USA-made VSL#3 clearly enhanced the formation of elongated and aligned stress fibers, Italy-made lysates had not similar effect. USA-made lysate was able to cause a total inhibition of H2O2-induced cytotoxic effect whereas Italy-made VSL#3 lysate was unable to protect IEC-6 cells from H2O2-induced damage. ROS generation was also differently influenced, thus supporting the hypotesis of a protective action of USA-made VSL#3 lysates, as well as the idea that Italy-made formulation was unable to prevent significantly the H2O2-induced oxidative stress.