Modified probiotics, the beneficial bacteria touted for their role in digestive health, could one day decrease the risk of Listeria infection in people with susceptible immune systems, according to Purdue University research.
Arun Bhunia, a professor of food science; Mary Anne Amalaradjou, a Purdue postdoctoral researcher; and Ok Kyung Koo, a former Purdue doctoral student, found that the same Listeria protein that allows the bacteria to pass through intestinal cells and into bloodstreams can help block those same paths when added to a probiotic.
"Based on the research, it looks very promising that we would get a significant reduction in Listeria infections," said Bhunia, whose findings were published this month in the journal PLoS One.
Bhunia's earlier work showed that Listeria triggers intestinal cells to express heat shock protein 60 on their surfaces. That allows Listeria to bind to the intestinal cells using an adhesion protein and pass into them, acting as a sort of gateway to the bloodstream.
Once in the bloodstream, even small doses of Listeria can cause fever, muscle aches, nausea
and diarrhea, as well as headaches
, stiff neck, confusion, loss of balance and convulsions if it spreads to the nervous system. It can also cause abortion and stillbirth in pregnant women.
According to the U.S. Centers for Disease Control and Prevention, it sickens about 1,500 and kills 255 people each year in the United States and primarily affects pregnant women, newborns, older adults and those with weakened immune systems.
"We're seeing fewer Listeria infections, but the severity of those infections is still high," Amalaradjou said.
The researchers found that probiotics alone were ineffective in combatting Listeria, so they stole a trick from the bacteria's own playbook. By adding the Listeria adhesion protein to the probiotic Lactobacillus paracasei, they were able to decrease the number of Listeria cells that passed through intestinal cells by...