PSII-19 Inclusion of bacillus probiotics in the maternal diet: Effects on microbiome modulation and offspring performance.

Abstract Prenatal transfer of antigenic peptides and microbial DNA/RNA is believed to influence and prime the development of the neonatal immune system. Lactobacillus spp. strains have been shown to modulate ruminant intestinal cells in cell culture models. This study evaluated whether supplementation with Bacillus spp. probiotics in pregnant sheep modulates the vaginal microbiome of the mothers and the growth of their offspring. In the first trial, 14 pregnant Texel ewes were assigned to two groups (Probiotic and Control). Ewes in the Probiotic group received 1 g/day of Bacillus spp. (Bovacillus TM, Novonesis, Denmark) for 50 days prior to parturition. Vaginal swabs were collected at -50, -25, 0, 15, and 30 days relative to parturition. Lambs were monitored through blood samples at birth, and weight and thoracic circumference (TC) were recorded at 0, 30, and 60 days relative to birth. Vaginal swabs were placed in Stuart transport medium and cultured on TSA (for mesophiles), McConkey (for Enterobacteriaceae), and MRS (for Lactobacillus spp.) to count colony-forming units (CFU). In a second trial, 40 ewes of the same breed were fed the probiotic for 50 days prior to parturition. Weight and TC of the lambs were measured at birth, and at weeks 5, 7, 8, 9, 10, and 12. Data were analyzed using SAS software (SAS Institute, Inc., Cary, NC). CFU data were analyzed using PROC GLIMMIX, with treatment, time, and treatment-by-time interaction as fixed effects. Weight and TC data were analyzed as repeated measures using a generalized linear mixed model, considering treatment, time, and treatment-by-time interaction as fixed effects. There was no effect of treatment or treatment-by-time interaction on mesophiles or Enterobacteriaceae (P > 0.05). However, probiotic supplementation increased Lactobacillus spp. CFU at 30 days postpartum (treatmentby-time P < 0.01). No significant effects on offspring growth were observed in either trial. However, there was an effect of treatment on white blood cells counts at birth (3.92 ± 0.99 for control vs. 2.71 ± 0.86 for probiotic, P = 0.02). These results suggest that supplementation with Bacillus spp. in pregnant ewes may influence the proliferation of Lactobacillus spp. in the maternal vaginal microbiome postpartum. Further studies are needed to investigate the effects of this treatment on immune development of neonatal lambs.