Pretreatment With Pro- and Synbiotics Reduces Peritonitis-Induced Acute Lung Injury in Rats

To study whether enteral pretreatment with a synbiotic composition of lactic acid bacteria and bioactive fibers can reduce peritonitis-induced lung neutrophil infiltration and tissue injury in rats.Rats were divided into five groups, and subjected to induction of peritonitis-induced lung injury using a cecal ligation and puncture model (CLP). All animals were pretreated for 3 weeks prior the CLP by daily gavage with either (1) a synbiotic composition (10(10) CFU of Pediococcus pentosaceus 5-33:3, 10(10) CFU of Leuconostoc mesenteroides 77:1, 10(10) CFU of L. paracasei subspecies paracasei, 10(10) CFU of L. plantarum 2362 plus fermentable fibers), (2) fermentable fibers alone, (3) nonfermentable fibers, (4) a probiotic composition (10(10) CFU of P. pentosaceus 5-33:3, 10(10) CFU of L. mesenteroides 77:1, 10(10) CFU of L. paracasei subsp. paracasei, 10(10) CFU of L. plantarum 2,362), or (5) a heat-killed probiotic composition. All animals were killed 24 hours after CLP and lung tissue samples were studied for degree of neutrophil infiltration and levels of tumor necrosis factor (TNF)-alpha, Interleukin (IL)-1beta. In addition the lung wet-to-dry tissue weight ratio, the myeloperoxidase activity, and malondialdehyde content were also assessed.No mortality was encountered in any of the groups. Histologic signs of lung injury (number of neutrophils and TNF-alpha, IL-1beta staining) were observed in all groups except the synbiotic and probiotic treated groups. Myeloperoxidase activity and malondialdehyde content were significantly lower in the two lactobacillus- pretreated groups, with no difference between them. Heavy infiltration of lung tissue with neutrophils was observed only in fiber-treated (302.20 +/- 7.92) and placebo-treated (266.90 +/- 8.92) animals. This was totally abolished in the synbiotic-treated group (34.40 +/- 2.49). Lung edema (wet-to-dry lung weight ratio) was significantly reduced in the synbiotic-treated group (4.92 +/- 0.13 vs. 5.07 +/- 0.08 and 5.39 +/- 0.10, respectively).Three weeks of preoperative enteral administration of a synbiotic composition reduced peritonitis-induced acute lung injury in rats in a CLP model.