Environmental cadmium exposure alters the internal microbiota and metabolome of Sprague–Dawley rats

Abstract

Cadmium (Cd) is a toxic element that can negatively affect both humans and animals. It enters the human and animal bodies through the respiratory and digestive tracts, following which it tends to accumulate in different organs, thereby seriously affecting human and animal health, as well as hampering social and economic development. Cd exposure can alter the composition of intestinal microbiota. In addition, it can damage the peripheral organs by causing the translocation of intestinal microbiota. However, the relationship between translocation-induced changes in the composition of microbiome in the blood and metabolic changes remains unclear. In the present study, we investigated the effects of Cd exposure on microbiota and serum metabolism in rats by omics analysis. The results demonstrated that Cd exposure disrupted the balance between the blood and intestinal flora in Sprague–Dawley (SD) rats, with a significant increase in gut microbiota (Clostridia_UCG_014, NK4A214_group) and blood microbiome (Corynebacterium, Muribaculaceae). However, Cd exposure caused the translocation of Corynebacterium and Muribaculaceae from the gut into the blood. In addition, Cd exposure was associated with the up-regulation of serum indoxyl sulfate, phenyl sulfate, and p-cresol sulfate; down-regulation of δ-tocopherol and L-glutamine; and changes in blood microbiome and metabolites. In conclusion, we identified novel metabolic biomarkers for Cd toxicity, which will also expand our understanding of the role of blood microbiome in Cd-induced injury.

Cadmium exposure induces changes in gut microbial composition and metabolic function in long‐tailed dwarf hamsters, Cricetulus longicaudatus

“…Despite extensive investigations into the toxicity of Cd on various model animals, primarily focusing on Cd exposure‐induced intestinal damage and organ‐specific accumulation in R. norvegicus , M. musculus , etc. (Li et al., 2019 ; Liu et al., 2023 ; Wong et al., 1980 ), there remains a dearth of comprehensive research on the impact of this heavy metal on wild mammals. Previous studies have demonstrated that the gut serves as the primary barrier following oral ingestion of Cd, and organs directly exposed to Cd, which play crucial roles in nutrient metabolism and energy acquisition, ultimately resulting in weight loss (He et al., 2020 ).…”

“…Rodents, which are widely distributed in the natural environment, the own characteristics, and external environment, can influence the structure and composition of host–gut microbiota (Suzuki, 2017 ). The inevitable extensive exposure to heavy metal pollutants can disrupt the diversity and composition of the gut microbiota, resulting in a significant decrease in microbial richness, which may profoundly impede associated gene pathways (He et al., 2020 ; Li et al., 2019 ; Liu et al., 2023 ). The study has demonstrated that Cd exposure significantly enhanced the relative abundances of Alistipes and Odoribacter in mice, while inducing notable reductions in Mollicutes and unclassified Ruminococcaceae, but no discernible alteration in microbial diversity (Zhai et al., 2017 ).…”

Exposure to Environmental Toxins: Potential Implications for Stroke Risk via the Gut– and Lung–Brain Axis

“…Recent studies have revealed exposure to environmental toxins shifts the relative abundance of bacteria and alters microbial profiles in animal models. Dietary exposure to heavy metals and PCBs has been shown to reduce the abundance of Proteobacteria while simultaneously increasing the presence of Bacteroidetes [25,26,30]. Chronic exposure to PAHs (BaP and TCDD) also shifts the bacterial ratios, increasing the relative abundance of Bacteroidetes while reducing the abundance of Firmicutes [12,162].…”