1.
Consumption of Bifidobacterium lactis LKM512 yogurt reduces gut mutagenicity by increasing gut polyamine contents in healthy adult subjects.
Matsumoto, M, Benno, Y
Mutation research. 2004;(2):147-53
Abstract
The possible role of probiotic metabolites on human health effects of probiotics has received little research attention. In this study, we investigated the effects of consumption of Bifidobacterium lactis LKM512-containing yogurt (LKM512 yogurt) on fecal probiotic metabolites (polyamines, lactate, and acetate) and mutagenicity in seven healthy adults (one male and six females; average age: 30.5 years). Each volunteer was provided with 100g/day of LKM512 yogurt or placebo for 2 weeks. Fecal polyamines and mutagenicity were measured by HPLC and the umu-test, respectively. Consumption of LKM512 yogurt increased fecal spermidine levels, but not fecal lactate and acetate contents. The mutagenicity level significantly reduced to 79.2% (10-91.1%) and 47.9% (0-86.8%) following consumption of LKM512 yogurt (P=0.0293) and placebo (P=0.0314), respectively. LKM512 yogurt consumption significantly reduced the mutagenicity level compared with consumption of a placebo (P=0.0489). These results suggest that increased gut spermidine level by LKM512 yogurt was responsible for the reduction of mutagenicity in the gut of healthy adults. We suggest that spermidine produced by LKM512 yogurt consumption contributes to host health as a bioantimutagenic factor; to our knowledge, these substances have not been previously reported as antimutagens from probiotics or fermented milk.
2.
Uranium gastrointestinal absorption: the f1 factor in humans.
Limson Zamora, M, Zielinski, JM, Meyerhof, D, Moodie, G, Falcomer, R, Tracy, B
Radiation protection dosimetry. 2003;(1-4):55-60
Abstract
The present investigation was undertaken by the Department of Health, Canada, to determine the most appropriate value to use for uranium gastrointestinal absorption (f1) in setting the guideline for drinking water. Fifty participants, free from medical problems, were recruited from two communities: a rural area where drinking water, supplied from drilled wells, contained elevated levels of uranium and an urban area where the water supplied by the municipal water system contained < 1 microg l(-1). Uranium intake through food, drinking water and other beverages was monitored using the duplicate diet approach. Intake and excretion were measured by inductively coupled plasma-mass spectrometry (ICP-MS) in samples collected concurrently from the same individuals over a 3 d period. The range of f1 values was between 0.001 and 0.06, with a median of 0.009. These values were independent of gender, age, duration of exposure, daily total uranium intake and allocation of intake between food and water. Consistent with the recommendation of ICRP Publication 69, 78% were below 0.02.