Nisin, a colorless, tasteless, naturally occurring food preservative that grows on dairy products, has been found to kill deadly, antibiotic-resistant bacteria as well as cancer cells.
A new study from the University of Michigan found that feeding rats a "nisin milkshake" killed 70-80 percent of head and neck tumor cells after nine weeks and extended survival, according to Yvonne Kapila, DDS, PhD, a professor at the University of Michigan School of Dentistry. Kapila has studied nisin in cancerous tumors and as an antimicrobial to combat diseases of the mouth and found that after nine weeks of nisin treatment, tumors were comparable to tumors at three weeks. She and her team of researchers have published positive results with less potent nisin, but the highly purified nisin ZP used in this particular study nearly doubled its effectiveness. While nisin is typically added to food at the rate of 0.25 to 3.75 mg/kg, the authors reported 800 mg/kg is needed to kill cancer cells.
Nisin is lethal to bacteria because it bunds to a static area of bacteria, which gives nisin the opportunity to work before bacteria changes into an antibiotic-resistant superbug, and because it kills biofilms, which are bacteria that group together to thwart antibiotics.
"To date, nobody had found bacteria from humans or living animals that is resistant to nisin, "Kapila said in a news release. She noted though, that although the results are promising, they are also small and only in mice, so it's too early to say if nisin will act the same way in humans.
"The application of nisin has advanced beyond its role as a food biopreservative," Kapila said. "Current findings and other published data support nisin's potential use to treat antibiotic resistant infections, periodontal disease and cancer."
For more, see the study in the Journal of Applied Microbiology, published online ahead of print Dec. 18, 2015.