Immunobiotic Lactiplantibacillus plantarum MPL16 and CRL1506 enhance resistance to Enterococcus faecalis infection in vivo

VERA, DANIELA; BLANCO, HECTOR; ARCE, LORENA; RAYA TONETTI, FERNANDA; SACUR, JACINTO; DALMEIDA ROMINA; ORTIZ MOYANO, RAMIRO; MÜLLER, MELISA; KITAZAWA, HARUKI; JULIO VILLENA; VIZOSO-PINTO, GUADALUPE

Roma

Congreso; 12th Probiotics, Prebiotics & New Foods; 2023

Italian Academy for the Study of Human Microbiota

Objective: To evaluate the impact of Lactiplantibacillus plantarum MPL16 and CRL1506 feeding on the longevity of Caenorhabditis elegans and their ability to enhance resistance against Enterococcus faecalis infection in malnourished mice. Methods: Caenorhabditis elegans were fed with probiotics for 24 hours and then infected with E. faecalis 102. Survival rate was monitored daily, and bacterial counts were assessed. Intestinal distention was examined using transmission electron microscopy. BALB/c mice were subjected to a hypo-proteic diet for 21 days, followed by 7 days of re-nourishment with a conventional balanced diet or a diet supplemented with probiotics. Subsequently, mice were intraperitoneally challenged with E. faecalis 102. After 48h, CFUs were counted in various tissue samples. Results: Feeding C. elegans with L. plantarum MPL16 or CRL1506 increased their lifespan by approximately 20%, while E. faecalis feeding reduced their survival and affected their offspring. Pre-treatment of nematodes with CRL1506 and MPL16 delayed the onset of infection-related lethality (L50) by 24 hours and 48 hours, respectively, compared to the control group. MPL16 treatment resulted in a 1 log reduction in enterococci CFU/mL and restored reproductive capacity affected by enterococcal infection. In malnourished mice, probiotic supplementation significantly improved resistance to E. faecalis infection, evident from reduced CFU counts in intestinal lavage, feces, liver, spleen, and blood samples. Conclusions: The immunobiotic strains MPL16 and CRL1506 hold promise in preventing E. faecalis infections in susceptible hosts, as demonstrated in both the C. elegans and malnourished mouse models. These strains are potential candidates for future therapeutic interventions.