Copper and mercury exposure alters rectum microbiota in female adult mice

Abstract

Objectives: Copper (Cu) and mercury (Hg) are major pollutants worldwide, but the gastrointestinal damage caused by copper and mercury exposure is unclear. We are committed to scientific research on the harm and transformation of copper and mercury exposure to the rectal microbial population of female mice. Methods: Kunming mice (n = 24) were randomly divided into four equal groups, i.e., 1) Rectal Colon Control (RCK) group, 0 mg/kg of Cu and Hg), 2) Rectal Copper (RCu group), 5 mg/kg weight of Cu), 3) Rectal Mercury (RHg) group, 2 mg/kg weight of Hg) and 4) Rectal copper-mercury (RCH) group, 2.5 and 1 mg/kg weight of Cu and Hg. On the 90th day, the rectal and intestinal tissues were analyzed for pathophysiology, and quantitative analysis by PCR, then a library was prepared, and sequencing was carried out. Results: The rectal tissue of the RCu and RCH group had histopathological and physiological damage, including low weight, low pH value, increased thickness of the outer muscle layer, smooth muscle tissue, widening of the submucosal layer, reduction of goblet cells, blunt intestinal villi and severe aging of the central mammary duct. In addition, Sequencing results of 16S rRNA genes compared with RCK showed that the abundance of the Treponema, Coprococcus, and Dehalobacterium in RCu was more significant than the RCK. Still, the bacillus, Jeotgalicoccus, Salinicoccus, Staphylococcus, and Ignatzschineria was just the opposite. The abundance of Butyricimonas, Streptococcus, Dehalobacterium, Coprococcus, Oscillospira, and Helicobacter in RHg was more significant than in the RCK. Still, Corynebacterium, Bacillus, Jeotgalicoccus, Salinicoccus, Staphylococcus, Lactococcus, and Ignatzschineria were the opposite. We found some similar exciting things. The abundance of the Dehalobacterium, Coprococcus, and Oscillospira was significantly more significant than the RCK. Still, the Corynebacterium, Salinicoccus, Jeotgalicoccus, Staphylococcus, Lactococcus, Sutterella, and Ignatzschineria were the opposite. In addition, the Staphylococcus in RCu was increased than in the RCH, and the Streptococcus in RCu was increased than in the RCH. Conclusion: The results of the present study furnish a source for a more precise validation of the risk of digestive tract diseases driven by Cu and Hg.

Keywords

• Mice
• Intestinal microbiota
• Copper
• Mercury
• Rectum
• 16S rRNA