New research from the University of Chicago in the US shows that a class of bacteria known as Clostridia can block peanut allergies in mice, and suggests it could be used to treat similar conditions in humans.
Clostridia is one of the types of bacteria killed off by antibiotic use in early childhood, and this research supports the emerging theory that increased antibiotic use is one of the factors that has caused food allergies in kids to rise by 50% since 1997.
Cathryn Nagler, an immunologist at the University of Chicago, and her team have spent the past decade investigating the link between antibiotics and allergies. Back in 2004, they wiped out all gut bacteria in mice and found that this caused food allergies, as Science Magazine reports. But they weren't sure which bacteria in particular were key to protecting against allergies.
In their latest study, Nagler and her team raised mice in a completely sterile environment so that they had no bacteria in their guts at all, and found they were allergic to peanuts. They then gave these mice solutions containing different bacteria. While most had little effect on the allergy, the solution containing Clostridia bacteria caused peanut sensitisation to disappear. The results are published in the Proceedings of the National Academy of Sciences.
So what’s so special about the Clostridia bacteria? The team discovered that these bacteria are actually interacting with the intestinal lining and keeping peanut proteins, which can cause allergic reactions, out of the bloodstream.
“The bacteria are maintaining the integrity of the [intestinal] barrier,” Nagler told Jennifer Couzin-Frankel, a journalist for Science Magazine.
The team is now looking into whether a probiotic containing Clostridia could help treat allergies in humans, or whether they can replicate the bacteria’s allergy-blocking effects with a drug.
Colin Hill, a microbiologist at University College Cork in the UK, who wasn't involved in the study, told the BBC: "This is really interesting. This paper identifies a group of bacteria which could be important in protecting against these prevalent diseases. While we have to be careful not to extrapolate too far from a single study, and we also have to bear in mind that germ-free mice are a long way from humans, it is a very exciting paper and puts this theory on a much sounder scientific basis."