Exopolysaccharides of Lactobacillus rhamnosus GG form a protective shield against innate immune factors in the intestine
Article first published online: 16 AUG 2010
© 2010 The Authors. Journal compilation © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd
Special Issue: Lactic Acid Bacteria. Editors: Michiel Kleerebezem and Willem M. de Vos.
Volume 4, Issue 3, pages 368–374, May 2011
How to Cite
Lebeer, S., Claes, I. J. J., Verhoeven, T. L. A., Vanderleyden, J. and De Keersmaecker, S. C. J. (2011), Exopolysaccharides of Lactobacillus rhamnosus GG form a protective shield against innate immune factors in the intestine. Microbial Biotechnology, 4: 368–374. doi: 10.1111/j.1751-7915.2010.00199.x
- Issue published online: 25 APR 2011
- Article first published online: 16 AUG 2010
- Received 5 May, 2010; accepted 30 June, 2010.
Probiotic bacteria are administered as live microorganisms to provide a health benefit to the host. Insight into the adaptation factors that promote the survival and persistence of probiotics in the gastrointestinal tract (GIT) is important to understand their performance. In this study, the role of the long galactose-rich exopolysaccharides (EPS) of the prototypical probiotic strain Lactobacillus rhamnosus GG (LGG) was investigated. In a competition experiment with wild type, the isogenic EPS mutant CMPG5351 exhibited a reduced persistence in the murine GIT, especially in the lower parts of the intestine. This was surprising as our previous in vitro studies had shown an increased adhesion capacity for this EPS mutant. Follow-up assays indicated that this mutant is more sensitive towards host innate defence molecules, such as the LL-37 antimicrobial peptide and complement factors. This suggests that EPS forms a protective shield for LGG against these molecules in the GIT. Moreover, culturing LGG wild-type in subinhibitory concentrations of host defence factors such as LL-37 resulted in increased production of EPS, indicating that bacterial EPS production is modulated in the host to fine-tune the balance between adhesion and immune evasion. These observations are of interest in understanding the dynamics of adaptation of probiotics to the host environments.