Objective: To determine the effects of dietary consumption of Bi®dobacterium lactis (strain HN019, DR10 TM ) on natural immunity. Design: A randomized, double blind, placebo-controlled clinical trial. Setting:: Janeway Medical Centre, Memorial University, St Johns, Newfoundland. Subjects: Twenty-®ve healthy elderly volunteers (median age 69 y; range 60 ± 83 y). Interventions: Twelve control subjects consumed 180 ml low-fatalow-lactose milk twice daily for a period of 6 weeks; 13 test subjects consumed milk supplemented with 1.5610 11 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 signi®cantly 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 signi®cant 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 phagocytemediated 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 suf®cient to impart measurable improvements in immunity that may offer signi®cant health bene®ts to consumers.

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Abstract:In this experiment, green-synthesized silver and gold nanoparticles were produced rapidly by treating silver and gold ions with an extract of Memecylon umbellatum leaf. The reaction process was simple and easy to handle, and was monitored using ultraviolet-visible spectroscopy. The effect of the phytochemicals present in M. umbellatum, including saponins, phenolic compounds, phytosterols, and quinones, on formation of stable silver and gold nanoparticles was investigated by Fourier-transform infrared spectroscopy. The morphology and crystalline phase of the nanoparticles were determined by transmission electron microscopy and energy-dispersive x-ray spectroscopy. The results indicate that the saponins, phytosterols, and phenolic compounds present in the plant extract play a major role in formation of silver and gold nanoparticles in their respective ions in solution. The characteristics of the nanoparticles formed suggest application of silver and gold nanoparticles as chemical sensors in the future. Given the simple and eco-friendly approach for synthesis, these nanoparticles could easily be commercialized for large-scale production.