Methyl mercury decomposition in mice treated with antibiotics

Area of Science:

• Environmental Toxicology
• Microbiology
• Pharmacology

Background:

• Intestinal flora plays a role in the metabolism and excretion of xenobiotics.
• Methylmercury (MeHg) is a toxic environmental pollutant whose metabolic fate is not fully understood.
• The impact of gut microbiota on mercury biotransformation warrants further investigation.

Purpose of the Study:

• To investigate the role of intestinal flora in the decomposition and fecal excretion of methyl mercury (MeHg).
• To quantify the effects of antibiotic-induced gut microbiota reduction on mercury metabolism in mice.

Main Methods:

• Mice were treated with neomycin sulfate and chloramphenicol to reduce intestinal microorganisms.
• Methyl mercuric chloride (MMC) was administered intraperitoneally.
• Inorganic and organic mercury levels were measured in feces, intestinal contents, and organs.

Main Results:

• Antibiotic treatment significantly reduced the percentage of inorganic mercury in cecal and large intestinal contents compared to controls.
• Fecal excretion of inorganic mercury was reduced to 26% and total mercury to 60% in antibiotic-treated mice.
• Reduced intestinal microorganisms correlated with decreased mercury decomposition in the gut and lower fecal excretion.

Conclusions:

• Intestinal flora is crucial for the decomposition of methyl mercury in the gut.
• Reducing gut microbiota alters mercury metabolism, leading to decreased fecal excretion.
• These findings highlight the importance of the gut microbiome in methylmercury detoxification pathways.