Cell viability and immunostimulating and protective capacities of Bifidobacterium longum 51A are differentially affected by technological variables in fermented milks
Article first published online: 28 MAR 2012
© 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 112, Issue 6, pages 1184–1192, June 2012
How to Cite
Souza, T.C., Zacarías, M.F., Silva, A.M., Binetti, A., Reinheimer, J., Nicoli, J.R. and Vinderola, G. (2012), Cell viability and immunostimulating and protective capacities of Bifidobacterium longum 51A are differentially affected by technological variables in fermented milks. Journal of Applied Microbiology, 112: 1184–1192. doi: 10.1111/j.1365-2672.2012.05280.x
- Issue published online: 10 MAY 2012
- Article first published online: 28 MAR 2012
- Accepted manuscript online: 6 MAR 2012 03:07PM EST
- 2011/2181: received 23 December 2011, revised 22 February 2012 and accepted 26 February 2012
- animal survival;
- fermented milks;
- Salmonella infection;
- storage period;
Aim: To investigate the cell viability of Bifidobacterium longum 51A in fermented milks and to study its immunostimulating and protective capacity against Salmonella enterica ssp. enterica serovar Typhimurium infection in mice.
Methods and Results: Bifidobacterium longum 51A was added to milk fermented with different yoghurt starter cultures, before or after fermentation, and viability was monitored during storage (5°C, 28 days). Resistance to simulated gastric acid digestion was assessed. Fermented milks were orally administered to mice for 10 days followed by oral infection with Salmonella Typhimurium. The number of IgA+ cells in the small and large intestine was determined before infection. Survival to infection was monitored for 20 days. Bifidobacterium longum 51A lost viability during storage, but the product containing it was effective for the induction of IgA+ cells proliferation in the gut and for the protection of mice against Salm. Typhimurium infection.
Conclusions: Cell viability of Bif. longum 51A in fermented milks along storage did not condition the capacity of the strain to enhance the number of IgA+ cells in the gut and to protect mice against Salmonella infection.
Significance and Impact of the Study: The uncoupling of cell viability and functionality demonstrated that, in certain cases, nonviable cells can also exert positive effects.