University of Nebraska scientists are exploring how to make milk even healthier by enhancing its infection-fighting properties.

“We know that different parts of a person’s diet can have potential impacts on their microbiome, and this may influence susceptibility to infections with different gastrointestinal pathogens,” said Jennifer Auchtung, assistant professor of food science and technology at the University of Nebraska and one of the main investigators on a new research project led by the Nebraska Center for the Prevention of Obesity-Related Diseases (NPOD). “One of the questions we asked was whether the molecules that are found in dairy products, especially milk, can change the microbiome and influence this susceptibility to infections.”

Auchtung is working with University of Nebraska professor of nutrition and health sciences and lead investigator Janos Zempleni on a four-year research project, funded by a $500,000 grant from the U.S. Department of Agriculture’s National Institute of Food & Agriculture, to study how milk enhances or diminishes pathogenic bacteria.

The new research builds on work Zempleni’s lab has been doing since 2013 to study how nutritional nanoparticles affect the human gut, the university said.

“No matter what you do diet-wise, you’re always going to change the gut microbiome,” said Zempleni, director of NPOD and Willa Cather professor of molecular nutrition.

Through natural nanoparticles known as exosomes, milk delivers bioactive compounds to people. Exosomes facilitate cell-to-cell communication through the transfer of regulatory “cargos” from donor to recipient cells. Some of the exosomes and their RNA cargos from milk are absorbed, but some escape absorption and interact with the gut microbiome, encouraging certain virulent gut bacteria, the scientists explained.

Of specific concern in this research are two antibiotic-resistant bacteria that can wreak havoc in the body: vancomycin-resistant Enterococcus faecalis (VRE) and Clostridioides difficile, which together cause infections in about 500,000 Americans annually. Over the past 30 years, infection rates of C. difficile and VRE have increased considerably, the university said.

VRE can cause severe infections in people who are immunocompromised, such as those who have received organ transplants or are undergoing chemotherapy, Auchtung said. C. difficile is one of the leading causes of hospital-acquired infections and antibiotic-associated diarrhea.

This project builds on the University of Nebraska-Lincoln’s previous research into the gastrointestinal tract, where trillions of microbes — bacteria, viruses, fungi and more — make up the gut microbiome. The gut normally acts in concert with the body to regulate organs, develop the immune system, fight disease and metabolize foods; however, abnormalities in the gut microbiome are being discovered as factors in many diseases, the researchers said.

At Nebraska and elsewhere, previous research into diet-microbiome interactions has focused largely on the effects of diet on microbial communities without considering genomic changes within these communities. This will be the first study to assess the effects of exosomes and their RNA cargos on the selection of trait diversity and mutations that alter the virulence of pathogens such as VRE and C. difficile.

Ultimately, Auchtung said, the research could result in targeted ways to modify diets of people taking antibiotics, perhaps through dietary supplements. Zempleni said the research also could lead to nutritional supplements for infant formulas that improve the health of babies in developing countries.