Gut bacteria play essential roles in regulating what nutrients the human body receives from ingested food and they also manufacture and secrete various vitamins and other nutrients the human body needs. They have also been shown to directly modulate immune function and to play essential roles in protection against food allergies. Premier Allergy will discuss the role of gut bacteria in food allergies further in this article.
Immune modulation
A recent study conducted at children’s hospitals in Boston found that certain species of gut bacteria could retrain the immune system to tolerate food antigens. This finding is of particular interest because it suggests that simply providing a patient with the proper gut bacteria could eliminate any and all food allergies with one simple treatment. Previous studies had shown that people with and without food allergies had differences in their gut bacteria profile, but no one was sure exactly why or how it was linked to food allergies. This new study provides a direct mechanistic link between gut bacteria and food allergies.
Can gut bacteria explain the increase in allergies?
Food allergies used to be quite rare, but over the past few decades their incidence, especially among children, has been increasing rapidly. Normally, infants acquire their first dose of gut bacteria during vaginal birth and then continue to acquire them from people around them and from the environment. Prior to the onset of modern plumbing and hygiene and the emphasis on constant hand washing, young children were exposed to human fecal matter containing gut bacteria on a regular basis; although modern hygiene has saved large numbers of children from dying from intestinal diseases, it has also resulted in children with limited numbers of species of bacteria in their guts.
What can be done to improve the gut bacteria in young children?
A research group in Spain found that breast-feeding of infants for the first year, especially infants delivered by C-sections, improved their gut bacteria profile. They also found that avoiding unnecessary antibiotic use during pregnancy and during childhood had a profound effect on the gut bacteria profile; obviously, antibiotics are sometimes necessary, but they are heavily over-prescribed. For example, many studies have shown that childhood ear infections generally do not need to be treated with antibiotics because they just go away on their own.
What about in older children and adults?
Premier Allergy suggests that both children and adults regularly take high-quality, active probiotics and prebiotics in order to improve their gut bacteria health. One species of gut bacteria, in particular, Anaerostipes caccae, seems to be particularly important in protecting against food allergy. A study found that administering just this one species as a probiotic was protective against nut allergies and possibly other food allergies.
In the future, it may be possible for allergists to deliver a cocktail of the most important species of gut bacteria for the prevention and treatment of food allergies, but further research and testing in humans is still necessary to identify the most optimal species and the best method of delivering them to the gut.