Courtesy of Yale News

A new study finding that bacteria and antioxidants present in the human body may help lead to enhanced diagnostics and therapies for microbial infections and cancer-causing bacteria.

Researchers at the Yale Microbial Science Institute published a paper in November about how a widespread and life-threatening stomach bactrim, Helicobacter pylori, or H. pylori, maintains its survival in the gut of its hosts. A key finding to this study was the discovery of how the molecule ergothioneine, or EGT, assists this bacteria to survive exposure to oxidative stress in the host.

“H. pylori infection is associated with the development of cancer and other stomach pathologies,” said Daniel G. Dumitrescu GRD ’23, a graduate student in the Yale chemistry department who led this study. “This project started in 2018. We had a really simple question: What small molecules do bacteria like Helicobacter pylori use to survive oxidative stress inside the gut?” 

According to Dumitrescu, the specific molecules used by H. pylori have long remained a mystery. By using mass spectrometry to investigate H. pylori, the researchers found that H. pylori can maintain homeostasis within the host by transporting EGT. EGT is an antioxidant found in many food sources and is associated with longevity and anti-inflammatory properties.

Dumitrescu highlighted the significance of EGT, which is known as a beneficial antioxidative molecule in humans. According to him, EGT might be contributing to disease, as the molecule is being imported and broken down to sustain H. pylori in the host environment. 

Furthermore, the preliminary findings and comprehensive study of EGT in H. pylori serves as an excellent benchmark to discover other specific links between bacteria and the molecules they use to survive in hosts. 

“We infected animals with strains of bacteria that can and cannot import EGT,” said Elizabeth Gordon GRD ’24, another graduate student involved in this research. 

In doing so, the researchers were able to monitor how well the bacteria survived in the host environment. This experiment utilized mutated and non-mutated bacteria in mice that were or weren’t able to import EGT, finding that bacteria unable to transport EGT were outcompeted for survival in the stomach environment. 

Following these experiments, Gordon said, “it seems like EGT is really important for the bacteria to competitively survive in the stomach.” 

Gordon highlighted that these research findings will be crucial in further investigating the gut microbiota, as many bacterias that import EGT live throughout the gastrointestinal tract. Further studies investigating whether bacteria and humans compete for EGT will increase our understanding of the complex interactions between microbial communities and humans. Because EGT is believed to play a vital role to promote longevity and overall health. 

“Ergothioneine is widely associated with positive health effects in humans, so one area we are interested to explore in the future is how bacterial consumption of ergothioneine influences host physiology,” Stavroula Hatzios, assistant professor of molecular, cellular and developmental biology and of chemistry, told the News.

The success of this biological discovery came through efforts that were short of identifying the genes involved in assisting H. pylori to obtain an antioxidant status. 

Hatzios expressed the benefits of an interdisciplinary approach to better understanding biological processes. 

“One interesting aspect of this work is that it highlights how chemistry can serve as an engine of biological discovery,” noted Hatzios. “In this work, we used chemical approaches to identify ergothioneine in H. pylori, and that ultimately led us to discover the unique protein used by this microbe to ingest ergothioneine from the host.

Researchers at the MSI use interdisciplinary approaches to study factors that contribute to the relationship between our bodies and microbes. For example, MSI researchers study microbial mechanisms of disease, ecology of the gut, microbiome and the structures of proteins that bacteria produce to maintain homeostasis within host environments.

The Yale Microbial Sciences Center is located in West Haven at 840 West Campus Drive.