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Infants could be fed 6 probiotics to protect them from food allergies, landmark study finds

Children could be fed a pill containing six probiotics to cure them of food allergies, according to a groundbreaking new study. 

For years, scientists have known that people with allergies or digestive disorders could be treated with doses of ‘friendly’ gut bacteria from healthy people.

But the gut is incredibly complex – we all have millions of bacteria in our guts which change over time – making it hard to work out which are the ‘protective’ microbes, and which fuel allergy. 

Now, a team at Brigham and Women’s Hospital in Boston has identified five or six types of bacteria that seem to be the silver bullets for combating food allergy after using computational models to analyze each microbe closer than ever. 

Testing their theory on mice with egg allergies, it worked: most of those who received the therapy were able to eat eggs compared to those who did not.    

A team at Brigham and Women’s Hospital in Boston has identified five or six types of bacteria that seem to be the silver bullets for combating food allergy after using computational models to analyze each microbe closer than ever

‘This represents a sea change in our approach to therapeutics for food allergies,’ co-senior author Lynn Bry, MD, PhD, director of the Massachusetts Host-Microbiome Center at Brigham and Women’s Hospital, said.

‘We’ve identified the microbes that are associated with protection and ones that are associated with food allergies in patients.

‘If we administer defined combinations representing the protective microbes as a therapeutic, not only can we prevent food allergies from happening, but we can reverse existing food allergies in pre-clinical models.

‘With these microbes, we are resetting the immune system.’  

Scientists have spent decades trying to find something to treat food allergies, which can be incredibly debilitating, and difficult to navigate.

Thirty-two million Americans are allergic to some type of ingredient, mainly nuts, fish, egg, and milk.

While some may outgrow their allergy, many don’t, and, short of experimental therapies, avoiding ingredients is the only option. Though that’s hard, too: in 2017, Natasha Lednan-Laperouse, 15, died after buying a Pret a Manger baguette in London which contained undeclared sesame. 

The only other option that parents turn to – with meager results – is ‘oral immunotherapy’: feeding their child a little bit of the thing they’re allergic to to build up their resilience. 

It’s a strategy that has been hit-and-miss, and can prove very dangerous if the dose is high enough to trigger a severe reaction.  

The new technique developed by Dr Bry and co offers what could be a much simpler and safer alternative to the current options.

It is a type of ‘bacteriotherapy’ and it works the same as a fecal transplant (the increasingly popular technique of transplanting stool of a healthy person into a person with a digestive disorder). 

But Dr Bry’s method does away with the complex logistics of a transplant. 

They studied the stool samples of 56 infants with food allergies and 98 without, and developed a database of all the microbes in each.

Using computational models, they were able to parse out which microbes were more common in which group.

They also compared the stool microbes to each child’s immunological changes, to understand how the microbes might be having an overall beneficial effect. 

They landed on two separate cocktails of five or six species of bacteria derived from the human gut which were protective – all from the species Clostridiales and Bacteroidetes.

In the study, published in the journal Nature Medicine, her team collected fecal samples every four to six months from 56 infants who developed food allergies.

The microbiome – a complex ecosystem of bacteria that live in the gut – is believed play a key role.

By comparing their’s to that of 98 healthy babies infants the researchers found many differences.

Mice sensitized to eggs were protected against a reaction to the food when they received bacteria samples of the infants without allergies. This was not the case after being given those from the allergic children.

Co-first author Dr Georg Gerber, a computational pathologist at the Brigham, said: ‘It’s very complicated to look at all of the microbes in the gut and make sense of what they may be doing in food allergy.

‘But by using computational approaches, we were able to narrow in on a specific group of microbes that are associated with a protective effect.

‘Being able to drill down from hundreds of microbial species to just five or six or so has implications for therapeutics and, from a basic science perspective, means we can start to figure out how these specific bacteria are conferring protection.’ 

By changing the immune system’s wiring it could treat a broad range of allergies rather than desensitizing an individual to a specific food.

Dr Bry said: ‘When you can get down to a mechanistic understanding of what microbes, microbial products, and targets on the patient side are involved, not only are you doing great science, but it also opens up the opportunity for finding a better therapeutic and a better diagnostic approach to disease.

‘With food allergies, this has given us a credible therapeutic that we can now take forward for patient care.’ 

The paper was published in the journal Nature Medicine. 


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