Lactobacillus fermentum AGR1487 cell surface structures and supernatant increase paracellular permeability through different pathways.
Lactobacillus fermentum is commonly found in food products, and some strains are known to have beneficial effects on human health. However, our previous research indicated that L. fermentum AGR1487 decreases in vitro intestinal barrier integrity. The hypothesis was that cell surface structures of AGR1487 are responsible for the observed in vitro effect. AGR1487 was compared to another human oral L. fermentum strain, AGR1485, which does not cause the same effect. The examination of phenotypic traits associated with the composition of cell surface structures showed that compared to AGR1485, AGR1487 had a smaller genome, utilized different sugars, and had greater tolerance to acid and bile. The effect of the two strains on intestinal barrier integrity was determined using two independent measures of paracellular permeability of the intestinal epithelial Caco-2 cell line. The transepithelial electrical resistance (TEER) assay specifically measures ion permeability, whereas the mannitol flux assay measures the passage of uncharged molecules. Both live and UV-inactivated AGR1487 decreased TEER across Caco-2 cells implicating the cell surfaces structures in the effect. However, only live AGR1487, and not UV-inactivated AGR1487, increased the rate of passage of mannitol, implying that a secreted component(s) is responsible for this effect. These differences in barrier integrity results are likely due to the TEER and mannitol flux assays measuring different characteristics of the epithelial barrier, and therefore imply that there are multiple mechanisms involved in the effect of AGR1487 on barrier integrity.
Food Nutrition & Health Team, Food & Bio-based Products Group, AgResearch Grasslands, Palmerston North, 4442, New Zealand.|Riddet Institute, Massey University, Palmerston North, 4442, New Zealand.
Ranjita
R
Sengupta
Food Nutrition & Health Team, Food & Bio-based Products Group, AgResearch Grasslands, Palmerston North, 4442, New Zealand.|Riddet Institute, Massey University, Palmerston North, 4442, New Zealand.
Rachel C
RC
Anderson
Riddet Institute, Massey University, Palmerston North, 4442, New Zealand.|Rumen Microbiology Team, Animal Nutrition & Health Group, AgResearch Grasslands, Palmerston North, 4442, New Zealand.
Eric
E
Altermann
Riddet Institute, Massey University, Palmerston North, 4442, New Zealand.|AgResearch Grasslands, Palmerston North, 4442, New Zealand.
Warren C
WC
McNabb
Bioinformatics Mathematics & Statistics Team, AgResearch Grasslands, Palmerston North, 4442, New Zealand.
Siva
S
Ganesh
Food Nutrition & Health Team, Food & Bio-based Products Group, AgResearch Grasslands, Palmerston North, 4442, New Zealand.
Kelly M
KM
Armstrong
Riddet Institute, Massey University, Palmerston North, 4442, New Zealand.
Paul J
PJ
Moughan
Food Nutrition & Health Team, Food & Bio-based Products Group, AgResearch Grasslands, Palmerston North, 4442, New Zealand.|Riddet Institute, Massey University, Palmerston North, 4442, New Zealand.|Gravida: National Centre for Growth and Development, The University of Auckland, Auckland, New Zealand.
Nicole C
NC
Roy
D018938:Caco-2 Cells; D006801:Humans; D007413:Intestinal Mucosa / Q000502:physiology*; D052197:Limosilactobacillus fermentum / Q000502:physiology*; D010539:Permeability
Inflammatory; Lactobacillus fermentum; germ-free rodents; intestinal barrier integrity; tight junctions