How do you protect a population from a foodborne illness such as E. coli?
You have four options: limit or eliminate exposure; create a medication that cures it; create a vaccine that gives people immunity; or make the food resistant to the bacteria so those who eat it won’t get sick.
Nomad Bioscience, a German firm founded in 2008, has chosen the fourth option.
This month its researchers unveiled an engineered spinach and other edible plants capable of inhibiting the growth of enterohemorrhagic Escherichia coli.
Yuri Gleba, Ph.D., is the founder and CEO of Nomad Bioscience.
“I’m a scientist first and then a businessman,” he told Healthline from his office in Germany. “We have done experiments that show it kills 99.9 percent of the bacteria.”
How the Plants Fight E. coli
The process involves growing colicins, which are non-antibiotic proteins produced by E. coli strains, to kill or inhibit the growth of other E. coli strains. They are then used like an antibiotic.
The plant-produced proteins significantly reduced the amount of pathogenic bacteria present in meat spiked with E. coli O157:H7, Gleba said in a press release.
“It’s more focused and more efficient than an antibiotic,” he told Healthline. “You cannot use antibiotics on most animals or on food before you consume it.”
And since it’s not an antibiotic, Gleba added, “You don’t have to worry about antibiotic resistance.”
E. coli is a leading cause of foodborne illness worldwide. Every year in the United States, it accounts for approximately 100,000 cases and 90 deaths. Heating food has been the only proven method of eliminating the pathogens.
Gleba’s team studied whether tobacco and common edible plants such as spinach and leafy beets could be modified to produce colicins. The other question was if these proteins would prevent contamination in food.
The Nomad Bioscience report says that most colicins can operate at high levels in plants and retain full function. And mixtures of colicins, applied at low concentrations to bacterial cultures, greatly reduced the growth of all major pathogenic strains of E. coli.
Research Still in Early Stages
Although the research is still in its early days, Gleba sees plenty of potential in his discovery.
“Early data tell us it kills salmonella,” he said. “It would be good news if we could show it also kills salmonella. We could use the same cocktail to treat chicken as well as meat and vegetables.”
Other scientists are less enthusiastic. They said the findings are interesting, but it’s too early for the cheering.
At the Center for Science in the Public Interest, Greg Jaffe, the organization’s biotech director, told Healthline, “What it shows is there’s a lot of good research going on. But it’s hard to tell at this stage if it will be valuable.”
European consumers do not want genetically modified food, Jaffe noted, making Gleba’s project all the more intriguing.
“It’s good to see researchers in Europe doing these interesting and unique things,” he said.
Because the findings are preliminary, “It’s hard in my mind to tell what exactly they’ve done,” Jaffe said. “I don’t know how many E. coli need to be on a fruit before you can get sick.”
From Jaffe’s point of view, there’s a lot more work ahead.
“Any time we’re producing new proteins, we want to make sure it’s not an allergen,” he said. “We’d have to go through food safety procedures and see, does it kill other beneficial things?”
“There’s no unique downside here,” he added. “As with other genetically engineered crops, it has to be assessed on a case-by-case basis and make sure there’s no harm to humans. And besides food safety, there’s the environmental angle.”
Doug Gurian-Sherman, Ph.D., is an expert on genetically modified organisms (GMOs) who has even stronger words about the German development. Gurian-Sherman is a senior scientist and director of sustainable agriculture at the Center for Food Safety.
“It’s hard to know what will become of this,” he told Healthline. “My experience is when companies talk about their own results, you need to take it with a grain of salt.”
Gurian-Sherman echoed Jaffe, saying, “It’s a long way to commercialization.”
A lot of things can go wrong, he said. “There have been thousands of field tests of different crops and virtually none have come to market.”
He does not agree that the field has been stifled by overregulation, ticking off some of the potential problems. Among other things, the bacteria could develop resistance, or the product doesn’t work well enough to be commercially viable, or it’s too expensive compared to the cheaper products it will compete against.
Testing all these things will take years. The regulatory process, which Gurian-Sherman agrees is often cumbersome, nevertheless helps to ensure that a new product is safe.
“It needs to be shown to be effective. What is the problem it is trying to solve? Is this an answer looking for a problem?” he asked.
In this case, he suggests the problem is more systemic than technological.
“There’s a problem with the bagging and distribution of greens,” he said, so “the solution might not require plant engineering.”