New Research Finds Healthy Microbiome Protects Against Listeria

The Rockefeller University Press announce a new research demonstrating that bacteria residing naturally in the gut can protect against Listeria symptoms. Researchers are hoping that the bacteria can be produced as a probiotic to provide cancer patients and pregnant women with extra support in defending against the disease.

Listeria monocytogenes is the major pathogen associated with food-borne illnesses like meningitis, septicemia, and chorioamnionitis. Most humans and animals can effectively fend off the pathogen after a few days of gastrointestinal stress. People who are immunocompromised such as infants, cancer patients, or pregnant women are immensely more susceptible and can have sometimes have fatal outcomes. Cancer patients undergoing chemotherapy have a more suppressed immune system because it disrupts the community of bacteria in the gut.

The animal study, published June 6 in the Journal of Experimental Medicine found that depleting the microbiome in mice using antibiotics made them more susceptible to L. monocytogenes  infection. Immunodeficient mice treated with chemotherapy drug became even more susceptible when given antibiotics, further depleting their microbiome.

Researchers also identified four species of gut bacteria (C. saccharogumia, C. ramosum, C. hathewayi, and B. producta) that limited L. monocytogenes  growth in lab cultures. Transferring these bacteria to germ-free mice protected them from Listeria infection, inhibiting the pathogen’s ability to colonize the gastrointestinal tract.