Effect of Lactobacillus rhamnosus GR-1 supernatant and fetal sex on lipopolysaccharide-induced cytokine and prostaglandin-regulating enzymes in human placental trophoblast cells: implications for treatment of bacterial vaginosis and prevention of preterm labor.

OBJECTIVE: The objective of the study was to determine the effect of fetal sex on the output of cytokines and prostaglandin-regulating enzymes in lipopolysaccharide (LPS) and probiotic lactobacilli-treated placental trophoblast cells.

STUDY DESIGN: We examined the effect of LPS and Lactobacillus rhamnosus GR-1 supernatant in placental trophoblast cells on tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-10 using enzyme-linked immunosorbent assay and on prostaglandin-endoperoxide synthase 2 (PTGS2), 15-hydroxy prostaglandin dehydrogenase (PGDH), and toll-like receptor-4 (TLR-4) using Western blotting. Comparisons were performed using one-way analysis of variance and Student t test.

RESULTS: LPS increased the output of TNF-alpha, IL-10, and PTGS2 with a greater response in male placentae. L rhamnosus GR-1 supernatant inhibited the LPS-stimulated TNF-alpha and increased IL-10. It also up-regulated expression of PGDH in female placentae and partially reduced the LPS-stimulated PTGS2 in male placentae. There was no change in IL-1beta. Expression of TLR-4 was greater in placentae of male fetuses.

CONCLUSION: These findings suggest an underlying mechanism for the sex difference in the incidence of preterm birth and provide potential evidence for a therapeutic benefit of lactobacilli in reducing preterm labor.