Characterizing probiotic Lactobacillus bioactive compounds

Lactobacillus spp are a diverse group of lactic-acid producing bacteria that are important constituents of a healthy gastrointestinal and urogenital microbiota of animals. Lactobacillus spp are vastly used in food production and preservation including yoghurt, cheese and fermented foods. They have also been added as food supplements for health and wellbeing. The health promoting and commensal activity is believed to be due to antibacterial and immuomodulating properties, however the exact mechanisms are not well defined.

The purpose of this project is to identify the specific lactobacilli substances that influences cellular responses to bacteria and determine their function and activity. We have previously identified 10 released proteins produced by Lactobacillus rhamnosus GR-1 in a cell-active fraction. In addition we have identified closely related lactobacilli with similar properties to L. rhamnosus. We aim to analyze these 10 proteins using bioinformatics and compare them to the other Lactobacillus strains to identify the bioactive substance. Purified substances may have therapeutic potential.

Selected references

Karlsson, M., Jass, J (2012) Lactobacilli differently regulate expression and secretion of CXCL8 in urothelial cells. Beneficial Microbes 3:195-203.

Karlsson M, Scherbak N, Reid G, Jass, J. (2012) Lactobacillus rhamnosus GR-1 enhances NF-kB activation in E. coli – stimulated urinary bladder cells through TLR4. BMC Microbiol. 12:15.

Abuabaid H, Jass J. (2010) An in vitro model of human epithelial cell and macrophage co-cultures. In Vivo 24:345.

Reid, G., Jass, J., Sebulsky, M.T. and McCormick, J.K. (2003) Probiotics in Clinical Practice.  Clinical Microbiology Reviews 16:658-672.