Bioremediation and Tolerance of Humans to Heavy Metals through Microbial Processes: a Potential Role for Probiotics?. App Environ Microbiol

The food and water we consume are often contaminated with a range of chemicals and heavy metals, such as lead, cadmium, ar-senic, chromium, andmercury, that are associated with numerous diseases. Although heavy-metal exposure and contamination are not a recent phenomenon, the concentration of metals and the exposure to populations remain major issues despite efforts at remediation. The ability to prevent andmanage this problem is still a subject of much debate, with many technologies ineffective and others too expensive for practical large-scale use, especially for developing nations where major pollution occurs. This has led researchers to seek alternative solutions for decontaminating environmental sites and humans themselves. A number of en-vironmental microorganisms have long been known for their ability to bindmetals, but less well appreciated are human gastro-intestinal bacteria. Species such as Lactobacillus, present in the humanmouth, gut, and vagina and in fermented foods, have the ability to bind and detoxify some of these substances. This review examines the current understanding of detoxicationmecha-nisms of lactobacilli and how, in the future, humans and animals might benefit from these organisms in remediating environ-mental contamination of food. Heavy metals are a unique group of naturally occurring com-pounds released into the environment by various processes (15, 107). The recent expansion of human industrial activity, in-cluding mining, smelting, and synthetic compound creation, has led to an exponential increase in the amounts of heavy metal