Anti-inflammatory potential via the MAPK signaling pathway of Lactobacillus spp. isolated from canine feces

Area of Science:

• Microbiology
• Immunology
• Gastroenterology

Background:

• Lactobacillus reuteri and Lactobacillus acidophilus possess known antioxidant, anti-inflammatory, immune-enhancing, and anti-cancer properties.
• These probiotic species have demonstrated beneficial effects in both human and animal models.
• Identifying novel strains with robust probiotic characteristics is crucial for therapeutic applications.

Purpose of the Study:

• To evaluate the probiotic potential of two canine-isolated strains: Lactobacillus reuteri C1 and Lactobacillus acidophilus C5.
• To investigate the anti-inflammatory mechanisms of these strains in vitro.
• To assess their ability to modulate key inflammatory pathways.

Main Methods:

• Assessed tolerance to acid and bile salts.
• Evaluated adhesion to HT-29 cell monolayers.
• Determined antibiotic sensitivity.
• Measured nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells.
• Analyzed the expression of inducible NO synthase (iNOS), Interleukin-10 (IL-10), and Interleukin-1 beta (IL-1β).
• Investigated the involvement of the mitogen-activated protein kinase (MAPK) signaling pathway.

Main Results:

• Strains C1 and C5 exhibited tolerance to acid/bile salts and effective HT-29 cell adhesion, confirming probiotic traits.
• Both strains downregulated inducible NO synthase (iNOS) expression, reducing NO production in LPS-stimulated cells.
• C1 and C5 significantly reduced pro-inflammatory IL-1β and increased anti-inflammatory IL-10 expression.
• The anti-inflammatory effects were strongly correlated with the modulation of the MAPK signaling pathway.

Conclusions:

• Lactobacillus reuteri C1 and Lactobacillus acidophilus C5 possess significant probiotic characteristics.
• These strains effectively attenuate LPS-induced inflammation through the MAPK signaling pathway.
• The anti-inflammatory potential of C1 and C5 suggests their utility as novel probiotics.