British Journal of Nutrition

Nutritional Immunology

Evaluation of the immune benefits of two probiotic strains Bifidobacterium animalis ssp. lactis, BB-12® and Lactobacillus paracasei ssp. paracasei, L. casei 431® in an influenza vaccination model: a randomised, double-blind, placebo-controlled study

Giuliano Rizzardinia1, Dorte Eskesena2, Philip C. Caldera3, Amedeo Capettia1, Lillian Jespersena2 c1 and Mario Clericia4a5

a1 Department of Infective Diseases, Luigi Sacco Hospital, Via GB Grassi 74, 20157 Milan, Italy

a2 Chr. Hansen A/S, Bøge Alle 10-12, DK-2970 Hørsholm, Denmark

a3 School of Medicine, Institute of Human Nutrition, University of Southampton, MP887 Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK

a4 Department of Biomedical Science and Technology, University of Milan, Via Flli Cervi, 93, 20090 Segrate-Milano, Italy

a5 Don C. Gnocchi Foundation, IRCCS, Piazza Morandi, 3, 20100 Milano, Italy


The present study investigated the ability of Bifidobacterium animalis ssp. lactis (BB-12®) and Lactobacillus paracasei ssp. paracasei (L. casei 431®) to modulate the immune system using a vaccination model in healthy subjects. A randomised, double-blind, placebo-controlled, parallel-group study was conducted in 211 subjects (56 % females, mean age 33·2 (sd 13·1) years). Subjects consumed a minimum of 109 colony-forming units of BB-12® (capsule) or L. casei 431® (dairy drink) or a matching placebo once daily for 6 weeks. After 2 weeks, a seasonal influenza vaccination was given. Plasma and saliva samples were collected at baseline and after 6 weeks for the analysis of antibodies, cytokines and innate immune parameters. Changes from baseline in vaccine-specific plasma IgG, IgG1 and IgG3 were significantly greater in both probiotic groups v. the corresponding placebo group (L. casei 431®, P = 0·01 for IgG; P < 0·001 for remaining comparisons). The number of subjects obtaining a substantial increase in specific IgG (defined as ≥ 2-fold above baseline) was significantly greater in both probiotic groups v. placebo (BB-12®, P < 0·001 for IgG, IgG1 and IgG3; L. casei 431®, P < 0·001 for IgG1 and IgG3). Significantly greater mean fold increases for vaccine-specific secretory IgA in saliva were observed in both probiotic groups v. placebo (BB-12®, P = 0·017; L. casei 431®, P = 0·035). Similar results were observed for total antibody concentrations. No differences were found for plasma cytokines or innate immune parameters. Data herein show that supplementation with BB-12® or L. casei 431® may be an effective means to improve immune function by augmenting systemic and mucosal immune responses to challenge.

(Received February 11 2011)

(Revised June 07 2011)

(Accepted July 06 2011)

(Online publication September 07 2011)


c1 Corresponding author: L. Jespersen, fax +45 4574 8888, email


Abbreviations: AE, adverse events; MFI, mean fold increase; Th, T-helper cells