A team from Pennsylvania State University has conducted research indicating that gut microbes could be used to block our bodies from absorbing harmful metals like mercury and aid in absorbing beneficial ones such as iron. This research was shared at the American Society for Microbiology’s annual meeting, ASM Microbe 2023.
Daniela Betancurt-Anzola, a graduate student at Penn State who headed the study, pointed out the dangers of methylmercury, a nerve-damaging substance. She mentioned that it has various harmful effects and is especially harmful for brain development in pregnant women and children, particularly in communities heavily dependent on fish in their diet. She said, “It accumulates in living things, in plants and fish. We eat those things, and it accumulates in us.”
To start, Betancurt-Anzola and her team studied thousands of genomes from gut bacteria, specifically looking at the genetic factors linked to the ability to interact with metals. They focused on genes that allow bacteria to convert dangerous mercury into less harmful forms and absorb the heavy metal.
The team then used metagenomic sequencing to understand how these genes function and affect the host by studying how human and mouse microbes reacted to mercury exposure. Using this knowledge, they developed a specially designed probiotic to detoxify a harmful type of mercury commonly found in human diets. They did this by adding genes from a bacteria known for its resistance to methylmercury, Bacillus megaterium, into strains of Lacticaseibacillus, a type of lactic acid bacteria.
Betancurt-Anzola mentioned, “It’s a perfect probiotic for this because we have previously shown it works in humans, and now we are engineering it to make it even better. It is inside the gut, it grabs the methylmercury, then it goes out.”
Currently, the team is mainly studying how gut microbes interact with mercury, but they plan to extend their research to other metals as well. Their ultimate goal is to develop ways to lower levels of harmful metals like mercury in the body and enhance the absorption of beneficial ones. “We are interested in studying how the entire microbial community reacts to different metals,” said Betancurt-Anzola.