Full Papers

Human and Clinical Nutrition

Consumption of a fermented dairy product containing the probiotic Lactobacillus casei DN-114 001 reduces the duration of respiratory infections in the elderly in a randomised controlled trial

E. Guillemard^a1 c1, F. Tondu^a1, F. Lacoin^a2 and J. Schrezenmeir^a3

^a1 Danone Research, Centre de Recherche Daniel Carasso, RD 128, 91767 Palaiseau Cedex, France

^a2 Quintiles/MGRecherches, Levallois Perret, France

^a3 Department of Physiology and Biochemistry of Nutrition, Max Rubner Institute, Karlsruhe, Germany

Abstract

Common infectious diseases (CID) of the airways and the gastrointestinal tract are still a considerable cause of morbidity and mortality in elderly. The present study examined the beneficial effect of a dairy product containing the probiotic strain Lactobacillus casei DN-114 001 (fermented product) on the resistance of free-living elderly to CID. The study was multicentric, double blind and controlled, involving 1072 volunteers (median age = 76·0 years) randomised for consumption of either 200 g/d of fermented (n 537) or control (non-fermented) dairy product (n 535) for 3 months, followed by an additional 1 month's follow-up. The results showed that, when considering all CID, the fermented product significantly reduced the average duration per episode of CID (6·5 v. 8 d in control group; P = 0·008) and the cumulative duration of CID (7 v. 8 d in control group; P = 0·009). Reduction in both episode and cumulative durations was also significant for all upper respiratory tract infections (URTI; P < 0·001) and for rhinopharyngitis (P < 0·001). This was accompanied with an increase of L. casei species in stools throughout the fermented product consumption (2–3·8 × 10⁷ equivalents of colony-forming unit/g of stools, P < 0·001). The cumulative number of CID (primary outcome) was not different between groups nor was the CID severity, fever, pathogens' occurrence, medication, immune blood parameters and quality of life. The fermented product was safe and well tolerated. In conclusion, consumption of a fermented dairy product containing the probiotic strain L. casei DN-114 001 in elderly was associated with a decreased duration of CID in comparison with the control group, especially for URTI such as rhinopharyngitis.

(Received March 18 2009)

(Revised June 16 2009)

(Accepted June 30 2009)

(Online publication September 14 2009)

Key Words:

• Probiotics;
• Lactobacillus casei DN-114 001;
• Respiratory and gastrointestinal infections;
• Elderly

Correspondence:

^c1 Corresponding author: E. Guillemard, fax +33 1 69 35 76 46, email eric.guillemard@danone.com

Footnotes

Abbreviations: AGGIR, Gerontological Autonomy Iso-resource Group; CID, common infectious diseases; eq. CFU, equivalent of colony-forming unit; GITI, gastrointestinal tract infections; ITT, intention to treat; LRTI, lower respiratory tract infections; URTI, upper respiratory tract infections