CONICET | Buscador de Institutos y Recursos Humanos

We demonstrated that probiotics oral administration increase Paneth cells, the mainintestinal cell responsible of antimicrobial peptides (AMPs) production. Currently we explore, in amurine model of inflammatory bowel disease (IBD), whether lactobacillus modify the alteredproduction of AMPs reported in the disease, in order to preserve intestinal barrier.IBD were induced in Balb/c mice by subcutaneous doses of 7.5mg/kg/day indomethacin, ondays 6 and 7. Animals were supplemented with: Group 1: Lactobacillus casei CRL 431 (LC 431), G2:Lactobacillus paracasei CNCM I-1518 (LP 1518), or G3: water, upon 7 and 5 days, respectively.Additional controls fed with LC 431, LP 1518 or water, respectively, received 2 injection of PBS. Atday 8, mice were sacrificed.A 2.27± 1.32% body weight loss was observed in G3 after indomethacin injection, whilegains of 1.30±0.98, and 2.14±0.80 were observed for G1 and G2, respectively, and 3.79 ±1.84 forcontrol animals. Fur appearance of each mouse showed a Score of: 3 (smooth Coat) for G1 and G2,and Score: 1 (majority of back is piloerected) for G3.In vitro, an increase microbicidal activity against S. aureus and S. thyphimurium wereobserved in the intestinal fluids of G1 and G2 comparing animals treated with indomethacin thatreceived water in their beverage (G3). Hematoxylin-eosin studies showed severe mononuclear cellinfiltrates in the lamina propria and thickening of small intestinal wall on G3. Besides, serummarkers of inflammatory process (LDH and PCR) were increase in G3 comparing with G1 and G2(p˂0.05).Finally, a slightly increase of anaerobes and lactobacillus and decrease of totalenterobacteria were observed as part of colon microbiota in G1 and G2 animals compared to G3.Probiotics can be promising microorganisms for the stimulation of intestinal antimicrobialactivity in pathologies such as IBD, contributing to preserved intestinal barrier and protect againstpathogens.