Arunachalam K, Gill H, Chandra R. Enhancement of natural immune function by dietary consumption of Bifidobacterium lactis (HN019). Eur J Clin Nutr 2000;54(3):263-267.

Objective

To determine the effects of dietary consumption of Bifidobacterium lactis (strain HN019, DR10) on natural immunity.

Design

A randomized, double blind, placebo-controlled clinical trial. Setting:: Janeway Medical Centre, Memorial University, St Johns, Newfoundland. Subjects: Twenty-five healthy elderly volunteers (median age 69 y; range 60-83 y). Interventions: Twelve control subjects consumed 180 ml low-fat/low-lactose milk twice daily for a period of 6 weeks; 13 test subjects consumed milk supplemented with 1.5 × 1011 colony-forming units of B. lactis twice daily. Indices of natural immunity, including interferon production, phagocytic capacity and phagocyte-mediated bactericidal activity, were determined via peripheral blood at 0, 3, 6 and 12 weeks post-trial commencement.

Results

Subjects who consumed milk containing B. lactis for 6 weeks produced significantly enhanced levels of interferon-alpha, upon stimulation of their peripheral blood mononuclear cells in culture, in comparison to the placebo control group who received milk alone. There were also significant increases in polymorphonuclear cell phagocytic capacity among test group subjects, following consumption of milk supplemented with B. lactis, while individuals who consumed B. lactis-supplemented milk or milk alone showed enhanced phagocyte-mediated bactericidal activity.

Conclusions

The results demonstrate that dietary consumption of B. lactis HN019 can enhance natural immunity in healthy elderly subjects, and that a relatively short-term dietary regime (6 weeks) is sufficient to impart measurable improvements in immunity that may offer significant health benefits to consumers. 

Hatakka K, Ahola AJ, Yli-Knuuttila H, et al. Probiotics reduce the prevalence of oral candida in the elderly–a randomized controlled trial. J Dent Res, 2007;86:125-130.

 
Overgrowth of oral yeast is a common problem among the elderly. Probiotic bacteria are known to inhibit the growth of pathogenic microbes.
We tested the hypothesis that cheese containing probiotic bacteria can reduce the prevalence of oral Candida. During this 16-week, randomized, double-blind, placebo-controlled study, 276 elderly people consumed daily 50 g of either probiotic (n = 136) or control cheese (n = 140).

The primary outcome measure was the prevalence of a high salivary yeast count (>or= 10(4) cfu/mL) analyzed by the Dentocult method. The prevalence decreased in the probiotic group from 30% to 21% (32% reduction), and increased in the control group from 28% to 34%.

Probiotic intervention reduced the risk of high yeast counts by 75% (OR = 0.25, 95%CI 0.10-0.65, p = 0.004), and the risk of hyposalivation by 56% (OR = 0.44, 95%CI 0.19-1.01, p = 0.05).

Thus, probiotic bacteria can be effective in controlling oral Candida and hyposalivation in the elderly.

PMID: 17251510

Turchet P et al. Effect of fermented milk containing the probiotic Lactobacillus casei DN-114001 on winter infections in free-living elderly subjects: A randomized, controlled pilot study. Journal of Nutrition, Health, and Aging, 2003;7(2):75-77.

Probiotics are being increasingly studied for their ability to enhance host resistance to, and recovery from, infection. The probiotic strain Lactobacillus casei DN-114001 has previously been shown to reduce the incidence and duration of episodes of diarrhoea in children.

Our controlled pilot study aimed to evaluate the effect of supplementation for 3 weeks with milk fermented with yoghurt cultures and L. casei DN-114001 on the incidence and severity of winter infections (gastrointestinal and respiratory) in elderly people. We found no difference in the incidence of winter infections between groups. However, duration of all pathologies was significantly lower in the treatment group (7.0 3.2 days, n=180) than in the control group (8.7 3.7 days; n=180) (p=0.024), as was maximal temperature (38.3 0.5 C treatment group vs. 38.5 0.6 C control; p=0.01).

The potential for a 20% reduction in the duration of winter infections that we have found warrants further investigation on a larger scale.

PMID: 12679825

Gill et al. Enhancement of immunity in the elderly by dietary supplementation with the probiotic Bifidobacterium lactis HN019. American Journal of Clinical Nutrition. 2001 Dec;74(6): 833-839.

BACKGROUND: The aging process can lead to a decline in cellular immunity. Therefore, the elderly could benefit from safe and effective interventions that restore cellular immune functions.

OBJECTIVE: We determined whether dietary supplementation with the known immunostimulating probiotic Bifidobacterium lactis HN019 could enhance aspects of cellular immunity in elderly subjects.

DESIGN: Thirty healthy elderly volunteers (age range: 63-84 y; median: 69 y) participated in a 3-stage dietary supplementation trial lasting 9 wk. During stage 1 (run-in), subjects consumed low-fat milk (200 mL twice daily for 3 wk) as a base-diet control. During stage 2 (intervention), they consumed milk supplemented with B. lactis HN019 in a typical dose (5 x 10(10) organisms/d) or a low dose (5 x 10(9) organisms/d) for 3 wk. During stage 3 (washout), they consumed low-fat milk for 3 wk. Changes in the relative proportions of leukocyte subsets and ex vivo leukocyte phagocytic and tumor-cell-killing activity were determined longitudinally by assaying peripheral blood samples.

RESULTS: Increases in the proportions of total, helper (CD4(+)), and activated (CD25(+)) T lymphocytes and natural killer cells were measured in the subjects’ blood after consumption of B. lactis HN019. The ex vivo phagocytic capacity of mononuclear and polymorphonuclear phagocytes and the tumoricidal activity of natural killer cells were also elevated after B. lactis HN019 consumption. The greatest changes in immunity were found in subjects who had poor pretreatment immune responses. In general, the 2 doses of B. lactis HN019 had similar effectiveness.

CONCLUSION: B. lactis HN019 could be an effective probiotic dietary supplement for enhancing some aspects of cellular immunity in the elderly.

PMID: 11722966