Lactobacillus rhamnosus GG and its SpaC pilus adhesin modulate inflammatory responsiveness and TLR-related gene expression in the fetal human gut

Kriston Ganguli, Maria C. Collado, Jaana Rautava, Lei Lu, Reetta Satokari, Ingemar von Ossowski, Justus Reunanen, Willem M. de Vos, Airi Palva, Erika Isolauri, Seppo Salminen, W. Allan Walker, Samuli Rautava*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review


BACKGROUND: Bacterial contact in utero modulates fetal and neonatal immune responses. Maternal probiotic supplementation reduces the risk of immune-mediated disease in the infant. We investigated the immunomodulatory properties of live Lactobacillus rhamnosus GG and its SpaC pilus adhesin in human fetal intestinal models.

METHODS: Tumor necrosis factor (TNF)-alpha mRNA expression was measured by qPCR in a human fetal intestinal organ culture model exposed to live Lactobacillus rhamnosus GG and proinflammatory stimuli. Binding of recombinant SpaC pilus protein to intestinal epithelial cells (IECs) was assessed in human fetal intestinal organ culture and the human fetal intestinal epithelial cell line H4 by immunohistochemistry and immunofluorescence, respectively. TLR-related gene expression in fetal ileal organ culture after exposure to recombinant SpaC was assessed by qPCR.

RESULTS: Live Lactobacillus rhamnosus GG significantly attenuates pathogen-induced TNF-alpha mRNA expression in the human fetal gut. Recombinant SpaC protein was found to adhere to the fetal gut and to modulate varying levels of TLR-related gene expression.

CONCLUSION: The human fetal gut is responsive to luminal microbes. Lactobacillus rhamnosus GG significantly attenuates fetal intestinal inflammatory responses to pathogenic bacteria. The Lactobacillus rhamnosus GG pilus adhesin SpaC binds to immature human IECs and directly modulates IEC innate immune gene expression.

Original languageEnglish
Pages (from-to)528-535
Number of pages8
JournalPediatric Research
Issue number4
Publication statusPublished - Apr 2015
MoE publication typeA1 Journal article-refereed



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