© 2018 LP-DG® Science

Exit.st0{fill:none;stroke:#FFFFFF;stroke-width:2;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:10;} .st1{fill:none;stroke:#00d9ff;stroke-width:1;enable-background:new;} .st2{fill:none;stroke:#FFFFFF;stroke-width:1;enable-background:new;}
A Novel Rhamnose-Rich Hetero-exopolysaccharide Isolated from Lactobacillus paracasei DG Activates THP-1 Human Monocytic Cells.
Appl Environ Microbiol 2017, 83(3):e02702-16.

Lactobacillus paracasei DG is a bacterial strain with recognized probiotic properties and is used in commercial probiotic products. However, the mechanisms underlying its probiotic properties are mainly unknown. In this study, we tested the hypothesis that the capability of strain DG to interact with the host is, at least partly, associated with its ability to synthesize a surface-associated exopolysaccharide (EPS). Comparative genomics revealed the presence of putative EPS gene clusters in the DG genome; accordingly, EPS was isolated from the surface of the bacterium. A sample of the pure EPS from strain DG (DG-EPS), upon nuclear magnetic resonance (NMR) and chemical analyses, was shown to be a novel branched hetero-EPS with a repeat unit composed of L-rhamnose, D-galactose, and Nacetyl-D-galactosamine in a ratio of 4:1:1. Subsequently, we demonstrated that DG-EPS displays immunostimulating properties by enhancing the gene expression of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), and, particularly, that of the chemokines IL-8 and CCL20, in the human monocytic cell line THP-1. In contrast, the expression of the cyclooxygenase enzyme COX-2 was not affected. In conclusion, DG-EPS is a bacterial macromolecule with the ability to boost the immune system either as a secreted molecule released from the bacterium or as a capsular envelope on the bacterial cell wall. This study provides additional information about the mechanisms supporting the cross talk between L. paracasei DG and the host.

The consumption of food products and supplements called probiotics (i.e., containing live microbial cells) to potentially prevent or treat specific diseases is constantly gaining popularity. The lack of knowledge on the precise mechanisms supporting their potential health-promoting properties, however, greatly limits a more appropriate use of each single probiotic strain. In this context, we studied a well-known probiotic, Lactobacillus paracasei DG, in order to identify the constitutive molecules that can explain the documented health-promoting properties of this bacterium. We found a novel polysaccharide molecule, named DG-EPS, that is secreted by and covers the bacterium. We demonstrated that this molecule, which has a chemical structure never identified before, has immunostimulatory properties and therefore may contribute to the ability of the probiotic L. paracasei DG to interact with the immune system.

Balzaretti S, Taverniti V, Guglielmetti S, Fiore W, Minuzzo M, Ngo HN, Ngere JB, Sadiq S, Humphreys PN, Laws AP.

Cookie Policy

This website uses technical and profiling cookies collecting data in aggregate form. By closing this banner, scrolling this page or clicking any of its elements you consent to the use of cookies.

Healthcare professionals

Part of the information contained in this website is exclusively addressed to healthcare professionals. Please confirm that you are a healthcare professional. Are you a healthcare professional?

Yes, I am
No, I am not
Content to third part

This website contains links/references to third-party websites. By such links, SOFAR does not provide any guarantee nor gives its approval to their contents and quality. SOFAR does not have and does not accept any responsibility for the contents or the availability of such websites; SOFAR does not accept any liability for damage or injury resulting from the use of such contents, of whatever form. Users access such websites at their own risk. The information contained in this website is for information purposes only and not for diagnostic or therapeutic purposes. Thus, it does not substitute in any way medical and /or expert or other healthcare professionals or specialists ‘advice.

Duly noted