The Gut Microbiome & Food Allergies: A Black Hole
The gut microbiome refers to the various microbes (especially bacteria) in the GI tract. The specific bacteria and their purposes are still largely unknown (hence the “black hole”). These gut bacteria are constantly changing!
How do bacteria first colonize the gut?
A newborn is first colonized by microbes promptly at birth. The particular bacteria are determined by:
- Mode of delivery
- Colonizing bacteria originate mainly from the mother’s gut and vaginal tract. Interestingly, children born by C-section are colonized later with Bifidobacteria and lactobacilli than children delivered vaginally and these children tend to have more frequent respiratory allergies!
- Early feeding:
- Breast milk contains plenty of indigestible oligosaccharides (small sugars), which pass through the entire intestine and promote the growth and activity of bacteria that live in the gut, especially Bifidobacteria.
- Hygiene conditions around the child (the early environment). The bacteria of the gut can be changed depending on exposures such as antibiotics. foods and supplements.
The major divisions of bacteria (or Superkingdoms) are:
- Firmicutes: 51% of the bacteria
- Bacteroidetes: 48% of the bacteria
- Other 1% include at last 6 common bacteria and many rare ones.
These bacteria in the GI tract break down food that supply us with energy and nutrients. Within days of changing your diet, the bacteria change according to an article published in the journal Nature. Alterations or changes in these microbes has been theorized to be responsible for the development of food allergies or food intolerances.
Why is this important?
- Answers to “why” individuals develop adverse food reactions including food allergy may lie here.
- Treating or preventing adverse food reactions including food anaphylaxis may be developed based on this information.
Allergic children have different gut microbiomes compared to non-allergic, healthy children with higher levels of Clostridia and lower levels of bifidobacteria and lactobacilli.
The data in mice are fairly convincing showing the induction of food allergy was associated with a change in the gut microbiome that was reproducible. Also in these mice, tolerance to food allergy was induced by allergen specific regulatory T-cells (special T lymphocytes). This evidence may help us explain food allergies in humans.
Is there a way to change the gut microbiome to prevent food allergies?
Probiotics: supplementing with bifidobacteria may decrease inflammation in the gut.
- A study published in the journal Pediatrics in 2013 concluded that prenatal and early-life probiotic administration reduces the risk of a positive allergy skin test and decreases the total IgE (allergic antibody) level in children but may not reduce the risk of asthma and wheezing. http://pediatrics.aappublications.org/content/132/3/e666.abstract
While the role of Probiotics seems promising, the benefit of probiotic therapy likely depends upon many factors including the type of bacteria, dose, delivery method and other underlying individual human factors such as the age and diet of the person. Currently, selecting the most beneficial probiotic bacterial strain, the dose and the timing of supplementation still need to be determined before probiotics can be routinely recommended to treat or prevent food allergies. Additional information can be found at: Affects of different probiotic strains
At Family Allergy & Asthma Care of Montana, we try to unlock that “black box” or look into that black hole and decipher the science behind the next wave of clinical recommendations!