Purpose: Probiotics may confer health benefits for the host. Although Lactobacillus has demonstrated to stimulate the immune response, only a few strains have demonstrated immunomodulatory properties. The newly identified Lactobacillus plantarum strains CECT7315 and CECT7316 (LP3457) seem to boost the immune system in individuals that immune decline. We aimed to investigate whether LP3457 protects against inflammation and the mechanism behind.
Methods: LP3457 potential anti-inflammatory effects were assessed in an acute model LPS-induced inflammation in healthy rats and in a chronic model of low-grade inflammation in Zucker diabetic fatty (ZDF) rats. Wistar rats received LP3457 or placebo control for 20 days. Lipopolysaccharide (LPS; 1 mg/kg) was injected intraperitoneally at day 14, and animals were sacrificed 6 days after. Blood was collected at baseline (day 0) and consecutively at day 7, 14, 17, and 20 for haematological evaluation and assessment of anti-inflammatory/pro-inflammatory systemic markers. Myeloperoxidase activity was investigated in the ileum. ZDF rats received LP3457 or placebo control during 8 weeks, and changes in inflammasome-related transcripts were assessed in the ileum.
Results: LPS induced a comparable and significant leucocytosis 3 days post-injection (day 17) in both LP3457-treated and LP3457-untreated rats. However, the probiotic supplementation attenuated IL-1β, IL-6, and CRP release and increased anti-inflammatory IL-10 levels 6 days post-LPS induction (p < 0.05 vs. placebo). LP3457-supplemented animals also displayed lower intestinal myeloperoxidase activity (p < 0.05 vs. placebo). Chronic administration of LP3457 to ZDF rats resulted in a significant downregulation of the inflammasome signalling pathway (p < 0.05 vs. placebo).
Conclusions: Intake of LP3457 attenuates both acute endotoxemia-induced and chronic metabolically induced inflammatory reactions and the inflammasome signalling pathway. The stabilization and regulation of the gut microbiota is an important target for reducing the impact of organ-related inflammatory reactions.
Keywords: Inflammasome; Inflammation; Lactobacillus plantarum; Probiotic.