Immunomodulatory effects of Lactobacillus salivarius on inflammatory pathways and cytokine expression in gastric adenocarcinoma cells

Abstract

Gastric cancer is a leading cause of cancer-related deaths globally, with chronic inflammation, influenced by factors like diet, Helicobacter pylori infection and chronic inflammation. Nuclear factor κ B (NF-κB), a regulator of immune responses, contributes to inflammation and tumour development, with its activation and myeloid differentiation factor 88 (MyD88) signalling influenced by microbial and environmental factors, modulating interleukins like interleukins-8 (IL-8) and interleukins-10 (IL-10). Probiotics such as Lactobacillus salivarius have immunomodulatory effects, potentially impacting cancer progression. This study examined L. salivarius cell-free supernatant (CFS) effects on interleukin expression in a gastric adenocarcinoma cell model (AGS). As results, NF-κB expression decreased at all doses, while MyD88 expression increased. IL-8 gene expression upregulated dose-dependently but was not statistically significant, while IL-10 expression significantly increased at IC20. IL-8 protein levels increased significantly across doses, and IL-10 protein levels showed significant increases except at IC80. Overall, these results indicate that CFS can modulate MyD88, IL-8, and IL-10 in an NF-κB-independent manner.