Probiotics and newborn immunity

January 30th 2020

Candice Leblanc

Véronique Flamand (IMI) and her research partners have recently been awarded funds as part of the Win2Wal programme. This will enable them to study the impact of a probiotic on the immune system during the neonatal period.

Probiotics are living microorganisms that, when ingested in sufficient quantities, provide health benefits. Exposing pregnant mothers and newborns to certain strains of probiotics could lower the risk of developing pathologies involving the immune system—especially infectious and allergic respiratory diseases—, which are surging worldwide. ‘The goal of the ImmuProMat study is to identify the impact of four purified strains, including lactobacillus rhamnosus GG, on immunity in the earliest stages of life’, explains Professor Véronique Flamand, a researcher in neonatal immunology at the IMI and leader of the study. ‘This is why we will study the mechanisms involved, at the scale of the host’s metabolism and immune system.’


Dendritic cells in the newborn

The neonatal period is a unique opportunity to ‘educate’ an immune system that is very susceptible to factors that could influence its development. ‘Dendritic cells(1), which are present in lungs among other places, contribute to this modulation,’ explains Professor Flamand. ‘They are a gateway to the immune system. Dendritic cells in newborns respond to most stimuli in different ways than those of adults. These differences must be studied, as dendritic cells are what trigger an adaptive immune response and immunological memory.’


Microbiota and immunity

Dendritic cells in newborns can also receive signals sent from bacteria in the commensal flora(2) via the products of digestion (metabolites) carried by the blood. ‘We will first identify a number of candidate metabolites in the digestive tract of animals treated with probiotics,’ continues Professor Flamand. ‘Then, we will study the dendritic cells as well as the gamma delta T cells found in the lungs. Our goal is to analyse the impact of probiotics on how they react to allergens and respiratory viruses.’


A series of analyses

Researchers(3) will carry out analyses of three types:

  • Metabolomic analyses, using spectrometry to study metabolites.
  • Cytometric analyses of neonatal dendritic cells and T lymphocytes that express a specific receptor (TCRgd), which should enable the researchers to isolate and identify biomarkers that these cells express after being exposed to probiotics.
  • Metagenomic analyses using high-throughput sequencing of the commensal flora of newborns, in order to evaluate the impact of probiotics administered during pregnancy on the microbiota.

Project ImmuProMat’s final goal is to determine the identity and mechanism of action of the probiotic, as well as the exact dose in which it must be administered to the mother in order to boost the child’s defences against infection and allergy.



  1. Dendritic cells trigger adaptive immune responses.
  2. The commensal flora includes the microbiotas of the intestine, mouth, vagina, skin, etc.
  3. Project ImmuProMat gathers two academic partners (ULB’s Doctor David Vermijlen and UCLouvain’s Professor Amandine Everard) and an industry partner (Vésale Pharma) that provides the probiotics studied.