Oral administration of probiotics increase antimicrobial peptides production by Paneth cells.

SÜLSEN V, CAZORLA SI, LAURELLA L, SELENER M, FRANKFM, MALCHIODI EL, MUSCHIETTI L, CATALÁN C, MARTINO V; LEMME DUMIT J; PERDIGON G; MALDONADO GALDEANO C

Congreso; LXIV Reunión Anual de la Sociedad Argentina de Inmunología; 2016

The huge amountof intestinal bacteria represents a continuing threat to the intestinalbarrier. In order to meet this challenge, gut epithelial produce a lot of antimicrobialpeptides (AMP) that act at the forefront of innate immunity. The aim of thiswork was to explore whether AMP production by Paneth cells is influenced by probioticsadministration, in order to avoidthe imbalance of intestinal microbiota and preserve intestinal barrier.Groups of 45days old BALB/c mice received Lactobacilluscasei CRL 431 (LC 431), Lactobacilluscasei CNCM I-1518 (LC 1518) or water upon 7 and 5 days, respectively. Atthe end of this time mice were sacrificed and samples of intestinal fluids,small and large intestine sections were taken. In mice fedwith the probiotics bacteria, an increase in the number of Paneth cells wereobserved after hematoxylin and eosin stain of small intestine. The increase inthe microbicidal activity against the pathogens S. aureus and S. thyphimuriumby these intestinal fluids was observed respect to the group that receivedconventional diet (p<0.05), after plating dilutions of the incubation mixturesand determinate the number of CFU the next day. Interestingly, a slightlyincrease in the microbicidal activity was observed against the probiotics bacteria.These results were in parallel with those observed by transmission electronmicroscopy. Strong damage of the bacterial cell with leakage of cytoplasmiccontent, and cellular fragmentation were observed in Salmonella and S. aureusafter exposing to intestinal fluids of animals fed with probiotics. Finally, wedetected a slightly higher amount of anaerobes and lactobacillus bacteria, aspart of the colon microbiota in LC 431 and LC 1518 animals compared to mice witha conventional diet.These results support that probiotcs modulateantimicrobial peptides production by Paneth cells to preserved epithelialbarrier. This will be other mechanism by which probiotic protects against infectiousdiseases.