Lactiplantibacillus plantarum associated to fermented foods: in vitro evidences for its beneficial role in ameliorating intestinal inflammation

Fermented food microbes have recently recovered scientific interest for their health-promoting potential. Among them, Lactiplantibacillus (Lpb.) plantarum strains, with a long history as starter cultures in the production of a wide variety of fermented foods, showed the potential to affect host health in several in vitro and in vivo studies. Our study was aimed to investigate selected Lpb. plantarum strains, isolated from fermented foods, to face oxidative stress and related inflammatory damage at intestinal level, in order to be considered a promising strategy in intestinal inflammatory diseases. For this purpose, we examined food- and human- associated Lpb. plantarum strains for their in vitro capacity to tolerate oxidative stress as well as for their antioxidant potential by three different chemical assays (DPPH, ABTS and FRAP). In addition, the specific ability of each strain to modulate reactive oxygen species (ROS) levels in response to either oxidative or inflammatory stress and to reduce IL-17A, IL-17F and IL-23 release in an inflamed intestinal cell model was investigated. Overall, the results show that Lpb. plantarum endure high levels of induced oxidative stress through partially neutralizing ROS, whereas they elicit their production when co‑cultured with normal mucosa intestinal cells (NCM460). Moreover, pre‑treatment with food‑borne Lpb. plantarum significantly reduces pro ‑inflammatory cytokines IL‑17F and IL‑23 levels in inflamed NCM460 cells. Both IL-23 and IL-17 are pro-inflammatory cytokines with an active role in the pathophysiology of chronic inflammatory disorders, thus targeting the IL23/IL17 axis could be a considerable way to treat intestinal inflammatory diseases. Our results suggest that food‑vehicled Lpb. plantarum strains might reduce inflammatory response in intestinal cells by directly modulating local ROS production and by triggering the IL‑23/IL‑17 axis with future perspectives on health benefits derived by the consumption of functional foods enriched with selected strains.