Synbiotic combination of prebiotic grape pomace extract and probiotic Lactobacillus sp. reduced important intestinal inflammatory markers and in-depth signalling mediators in lipopolysaccharide-treated Caco-2 cells.

Inflammatory bowel diseases (IBD) are a major problem for public health, with an increased incidence and impact on life quality. The effect of pre- and probiotic combination has been less studied in IBD. Using genomic and proteomic array technologies, this study examined the efficacy of a new combination of natural alternatives: prebiotics (grape pomace extract, GP) and probiotics (lactobacilli mixture, Lb mix) on inflammation and intracellular signalling routes in a cellular model of inflammation. Caco-2 cells challenged with lipopolysaccharide (LPS) for 4 h were treated with GP extract (50 μg/ml gallic acid equivalent) and Lb combination (3 × 108 colony-forming units/ml total Lb) for 24 h. The profile expressions of forty key inflammatory markers and twenty-six signalling kinases were analysed. Other markers involved in inflammation were also investigated (NF-κB/RELA, Nrf2, aryl hydrocarbon receptor, Cyp1A1, Cyp1B1); 57·5 and 60 % of investigated genes and proteins, respectively, were down-regulated by the synbiotic combination. Relevant cytokines and chemokines involved in response to microbial infection and inflammation were reduced under the level induced by LPS treatment and toward the unchallenged control. As expected, the reduction effect seems to imply mitogen-activated protein kinase and NF-κB pathway. Most of the signalling molecules activated by LPS were decreased by GP extract and Lb mix. Our study indicates that the synbiotic combination of GP extract and Lactobacillus sp. mixture exerted anti-inflammatory properties, which are able to decrease the majority of inflammatory genes, their proteins and associated signalling markers. Due to protective role of GP compounds on lactobacilli probiotic, this synbiotic combination might serve as a promising adjunctive therapy in intestinal inflammations.