Oral administration of certain probiotics reduced uptake of the heavy metal, cadmium, in the intestines of mice, and in a laboratory experiment using human intestinal cells. The research, which might ultimately be applied to improving public health in areas of heavy metal contamination, is published ahead of print May 20 in
Applied and Environmental Microbiology, a journal of the American Society for Microbiology.
In earlier work, these investigators, led by Wei Chen, PhD, confirmed that the
probiotic bacterium Lactobacillus plantarum, could inhibit cadmium absorption in mouse intestines by binding cadmium. In the new study, the goal was to determine whether probiotics inhibited cadmium absorption by other means.
Cadmium damages the intestinal tract, which is usually the first internal organ to be exposed, said Chen, Dean and Professor, School of Food Science and Technology, Jiangnan University, Wuxi, Peoples Republic of China. The new study
provides evidence that this heavy metal induces inflammation, increases intestinal permeability, disrupts "tight junctions,"-areas where cells are so closely bound that they form a barrier that is virtually impermeable to fluid—and generally damages the gut barrier. As barrier cells are killed, permeability increases further.
The investigators fed the mice the probiotic L. plantarum, as well as drinking water laced with cadmium, for eight weeks. They measured cadmium in the feces weekly during the eight weeks. The quantity of cadmium excreted in the feces rose steadily during the study period, as the bacteria became established in increasing numbers in the mice' intestines. Mice that excreted greater cadmium in the feces had less cadmium in their tissues, although that burden needs further reduction before such probiotics can be commercialized.
The probiotics reduced the inflammation, reversed the disruption of tight junctions, and reduced intestinal permeability in the mice. The authors suggest that these benefits arise from mitigation of oxidative stress caused by cadmium.
Comment: Sott.net has been publishing detailed information on this fact for years.