M. M. Elbahrawy1, C. E. Pisano1, R. D. Shelby1, J. B. Navarro2, S. D. Goodman2, G. E. Besner1 1Center for Perinatal Research, The Research Institute at Nationwide Children’s Hospital,,Department Of Pediatric Surgery,Nationwide Children’s Hospital,,Columbus, OH, USA 2Center for Microbial Pathogenesis, The Research Institute at Nationwide Children’s Hospital,Columbus, OH, USA
Introduction: We have previously shown that enteral administration of the probiotic Lactobacillus reuteri (Lr) in its biofilm state to premature rat pups exposed to experimental necrotizing enterocolitis (NEC) protects the intestines from injury. In the current study, we investigated whether administration of the probiotic biofilm enterally to the pregnant mother can protect the intestines of the progeny from NEC.
Methods: For administration in its planktonic (free-living) state, Lr was pelleted and resuspended in sterile 0.9% saline. For administration in its biofilm state, dextranomer microspheres were loaded with maltose (DM-maltose) by overnight incubation to reach equilibrium, followed by Lr incubation with the loaded microspheres at room temperature for 30 minutes to induce biofilm formation. For 7 days prior to delivery, dams received a daily gavage dose of: (1) 0.2 ml of sterile water, (2) 0.2 ml of Lr (2×108 CFU), or (3) 0.2 ml of Lr (2×108 CFU) + DM-maltose (2 mg). Pups were delivered prematurely via Cesarean section on day 21 of gestation and subjected to experimental NEC via repeated exposure to hypoxia/hypothermia/hypercaloric feeds. Additional pups from untreated dams were delivered by C-section, placed with surrogate dams, unstressed, and breast fed. After 4 days, all pups were sacrificed and intestinal samples were collected. Intestinal histologic injury was graded blindly by two independent investigators.
Results: None of the unstressed breast-fed control pups developed NEC, whereas 63.2% of pups delivered from untreated dams and exposed to experimental NEC developed histologic injury. Compared to the progeny from untreated dams, 27.3% of pups from dams treated with Lr (p=0.030), and only 10.5% of pups from dams treated with Lr + DM-maltose developed NEC (p=0.0009) (see Figure). Furthermore, progeny of dams who were treated with Lr + DM-maltose and exposed to experimental NEC had significantly decreased mortality (20.5%) compared to pups from untreated dams (61.9%) (p < 0.001).
Conclusion: Prenatal Lactobacillus reuteri in its biofilm state administered enterally to pregnant rats is most effective in reducing NEC incidence and mortality in offspring exposed to experimental NEC and may represent a novel method of reducing clinical NEC in the future.
