Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. 
Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was studied
This original research article investigated how probiotics inhibit cadmium absorption, not only by directly binding cadmium but also by reducing intestinal uptake and strengthening the gut barrier. The central hypothesis proposed that probiotics both sequester Cd in the gut and preserve intestinal barrier integrity, thereby lowering Cd accumulation in the body. The study applied complementary models: in vitro (laboratory-based cell culture) and in vivo (animal experiments). In vitro, human intestinal epithelial HT-29 cells were exposed to Cd with and without treatment by Lactobacillus plantarum CCFM8610. Researchers assessed cytotoxicity, oxidative stress, inflammatory responses, and tight junction integrity to evaluate how probiotics inhibit cadmium absorption at the cellular level.
Who was studied
The study involved two main subject groups. In vitro experiments were conducted using the human intestinal epithelial cell line HT-29, a widely accepted model for studying gut barrier function and toxicological responses. For the animal experiments, adult male C57BL/6 mice were used, a standard laboratory mouse strain for toxicology and immunology research. Mice were randomly assigned to five groups: a control group, a Cd-only group, and three groups each receiving Cd plus one of the three L. plantarum strains. Each group contained 10 animals. The probiotic strains administered differed in their abilities to bind Cd and to counteract oxidative stress, providing insight into the relative importance of these probiotic characteristics in mitigating Cd toxicity.
Most important findings
The study provided robust evidence that probiotics, particularly L. plantarum CCFM8610, can reduce Cd absorption through two complementary mechanisms: direct intestinal Cd sequestration and protection of the gut barrier. In HT-29 cells, both intervention (simultaneous) and therapy (post-exposure) treatments with CCFM8610 significantly alleviated Cd-induced cytotoxicity, reduced reactive oxygen species (ROS) and lipid peroxidation, and restored tight junction protein distribution (ZO-1 and claudin-1). Inflammatory cytokine levels (TNF-α, IL-1β, IL-6, IL-8) were also reduced in probiotic-treated cells. In vivo, all three L. plantarum strains increased fecal Cd excretion and reduced Cd accumulation in liver and kidney tissues of mice, but strains with both high Cd-binding and antioxidative activity (especially CCFM8610) were most effective. Cd exposure disrupted gut barrier function, as shown by decreased expression of tight junction genes, increased gut permeability (measured by FITC-dextran and endotoxin translocation), and heightened intestinal inflammation. Probiotic treatment reversed these effects, restoring tight junction gene expression, reducing permeability, and normalizing cytokine and secretory IgA levels. Notably, the antioxidative property of the probiotic strains was crucial: even strains with lower Cd-binding but higher antioxidative activity (CCFM8614) provided significant protection, highlighting multiple modes of probiotic action.
Key implications
For heavy metal certification programs and industry, this study offers critical insights into the mechanisms by which probiotic supplementation can mitigate dietary Cd exposure. The data demonstrate that probiotics can function as a preventive strategy against Cd uptake not solely through biosorption but also by maintaining gut barrier integrity and attenuating oxidative and inflammatory damage induced by Cd. This dual-action approach suggests that probiotic products, particularly those with both strong Cd-binding and antioxidative properties, could be developed as functional food supplements to reduce the bioavailability of Cd from contaminated food or water. For regulatory bodies, these findings support the inclusion of probiotic intervention as a non-invasive, dietary-based strategy in heavy metal risk management and public health guidelines. The research further underscores the importance of characterizing probiotic strains for both metal-binding and antioxidative capacities when certifying or recommending them for heavy metal mitigation.
Citation
Zhai Q, Tian F, Zhao J, Zhang H, Narbad A, Chen W. Oral administration of probiotics inhibits absorption of the heavy metal cadmium by protecting the intestinal barrier. Applied and Environmental Microbiology. 2016;82(14):4429-4440. doi:10.1128/AEM.00695-16.
Cadmium is a persistent heavy metal that accumulates in kidneys and bones. Dietary sources include cereals, cocoa, shellfish and vegetables, while smokers and industrial workers receive higher exposures. Studies link cadmium to kidney dysfunction, bone fractures and cancer.
Heavy metals are high-density elements that accumulate in the body and environment, disrupting biological processes. Lead, cadmium, arsenic, mercury, nickel, tin, aluminum, and chromium are of greatest concern due to persistence, bioaccumulation, and health risks, making them central to the HMTC program’s safety standards.
