New research by a team at Pennsylvania State University shows that microbes in the human gut can be used to help the body absorb beneficial nutritional metals like iron, which is crucial to red blood cells, and inhibit or even eliminate the absorption of toxic metals. such as mercury The Group presents its findings at ASM Microbe 2023, the annual meeting of the American Society for Microbiology.

Methyl mercury is particularly worrying, said Daniela Betancourt-Anzola, a Penn State graduate student who led the new study. It is a neurotoxin that can cause blindness, organ damage, and even death if left untreated. Pregnant women are particularly vulnerable to mercury poisoning, and prenatal exposure can lead to blindness, seizures, and brain damage.

The greatest exposure to mercury occurs in fish or shellfish, but it can happen elsewhere, too. “It accumulates in living things, plants and fish,” he said. “We eat these and it builds up in us.”

Betancourt-Anzola and colleagues analyzed for the first time thousands of gut bacterial genomes, focusing on genetic markers associated with the ability to interact with metals. Many genes are known to be associated with resistance to metals, but the group focused on those that allow the bacteria to absorb methylmercury and prevent it from entering the gut.

To understand how these genes work and affect the host, the team used metagenomic sequencing to examine how human and mouse microbes respond to mercury exposure. Finally, the researchers used this knowledge to develop a probiotic specifically designed to detoxify the harmful type of mercury often found in the human diet. They inserted genes from the bacteria Bacillus megaterium, known to be highly resistant to methylmercury, into strains of Lacticaseibacillus, a lactic acid bacteria genus.

“It’s an excellent probiotic for this because it can survive in the gut, but it doesn’t colonize very well in the body,” said Betancourt-Anzola. “In the gut, the methyl takes up the mercury and then it goes out.”

The group began pilot studies in mice exposed to mercury, and early results showed that mice that received probiotics did better than those that did not.

For now, he said, the group is focused on understanding how gut microbes interact with mercury, but they also plan to investigate other metals. Their ultimate goal is to develop interventions that can help lower levels of dangerous metals such as mercury and speed up the absorption that the human body needs. “We are interested in studying how the entire microbial community responds to different metals,” Betancourt-Anzola said. Said. Source