Environmental cadmium exposure alters the internal microbiota and metabolome of Sprague–Dawley rats Original paper
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Metals
Metals
Heavy metals influence microbial pathogenicity in two ways: they can be toxic to microbes by disrupting cellular functions and inducing oxidative stress, and they can be exploited by pathogens to enhance survival, resist treatment, and evade immunity. Understanding metal–microbe interactions supports better antimicrobial and public health strategies.
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Microbes
Microbes
Microbes are microscopic organisms living in and on the human body, shaping health through digestion, vitamin production, and immune protection. When microbial balance is disrupted, disease can occur. This guide explains key microbe types—bacteria, viruses, fungi, protozoa, and archaea—plus major pathogenic and beneficial examples.
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Divine Aleru
Read MoreI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
I am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.
What was studied?
This study explored the effects of environmental cadmium exposure on the microbiota and metabolome of Sprague-Dawley rats. The researchers aimed to understand how cadmium (Cd) exposure, particularly from environmental sources, affects the intestinal and blood microbiomes and their corresponding metabolites. The study used a 30-day exposure model with cadmium chloride (CdCl₂) administered to rats, and analyzed the changes in microbial composition and serum metabolites through high-throughput sequencing and liquid chromatography-mass spectrometry (LC-MS).
Who was studied?
The study involved Sprague-Dawley female rats aged 6-8 weeks. These rats were divided into two groups, one receiving daily cadmium exposure through CdCl₂, and the other receiving a control solution. The rats were exposed for 30 days, during which the effects on their intestinal and blood microbiomes were monitored. Inflammatory factors, tight junction protein expression, and metabolic profiles were assessed to identify the impact of cadmium on microbiome-related metabolic changes.
Most important findings
The study showed that cadmium exposure significantly altered the microbiome composition in both the blood and gut of rats. In the gut, cadmium exposure increased the abundance of harmful bacteria such as Clostridia_UCG_014, which is associated with proinflammatory responses. The blood microbiome also showed an increase in Corynebacterium and Muribaculaceae, bacteria that are typically not abundant in the blood under normal conditions. These changes were linked to alterations in inflammatory factors like TNF-α and IL-6, which were significantly elevated in both the blood and intestine. Additionally, serum metabolomics revealed significant changes in metabolic pathways, including lipid metabolism, amino acid metabolism, and oxidative stress markers. Notably, metabolites such as indoxyl sulfate and p-cresol sulfate were upregulated, while compounds like δ-tocopherol were downregulated, indicating potential oxidative damage. These findings suggest that cadmium exposure triggers microbial translocation from the gut to the blood, leading to systemic inflammation and metabolic disturbances.
Key implications
The results underscore the crucial role of gut microbiota in mediating the toxic effects of cadmium exposure. The translocation of gut bacteria into the bloodstream can exacerbate systemic inflammation, potentially leading to more severe health issues, including cardiovascular diseases and metabolic disorders. The study also highlights the importance of monitoring not only the gut microbiome but also the blood microbiome as a key indicator of exposure to environmental toxins. The identified metabolic biomarkers provide valuable insights for early detection of cadmium toxicity and for developing intervention strategies to mitigate its effects. The findings also suggest that interventions targeting gut microbiota modulation could help alleviate the health impacts of cadmium exposure, especially in areas with high environmental cadmium contamination.