FPIES protocols do not yet exsit. Doctors are too unfamiliar with the multiple mechanisms for this illness. Allergists treat it under IgE protocols, which primarily work, especially when you think of this Non-IgE allergy as an anaphyalaxis of the gut. GI's treat it under EoE protocols, which are helpful and resourceful- especially in the beginning stages when the treatment is to remove all foods, give the gut rest and find a baseline, and then trial foods. Ideally, FPIES needs to be a multi-disciplinary approach driven protocols that are individualized to the specific needs of the child.
The goal of treatments plans should be to develop oral tolerances and control inflammatory responses, while managing gut dysbiosis to achieve homeostasis.
To understand FPIES, it is helpful to understand where current thinking of the root mechanisms are, which are multi-factorial:
- Genetics- immune responses (via cytokines) driven my genetic markers
- Environmental influences- how the immune system is influenced by the digestive tract (birth environment, breast milk, formula, antibiotics,etc...)
- Gut Micro flora - digestion (GALT) and gut homeostasis can influence the degree and severity of the protein intolerance's (increased intestinal permeability- or also referred to as leaky gut).
- Other factors still to be determined (more research needed).
Th2- IgE antibodies are produced in response to antigens. Some FPIES kids can have co-existing IgE (Th2) and Non-IgE (Th1) responses.
Understanding Digestion and Gut Microflora:
Intestinal flora forms a natural barrier to pathogens and also work together with the GALT (intestinal immune system within the GI tract made of lymphoid cells), Food allergic response in the gut activated by the immune system (via the GALT), is thought to lead to increased intestinal permeability, which can lead to further intolerance's and dysbiosis. One of the roles of gut micro flora is to help regulate the immune system. Disturption of microflora disrupts Treg responses (which regulates the cytokine responses- which regulates inflammation or anti-inflammatory mediators). When the antigenic presenting dendritic cell (where micro flora have their role) activates the lymphocytes, it leaves the mucousa via the lymph and enters the blood stream via the thoracic duct. The activated lymphocytes then travel back to the gut and can colonize in the same mucousa or other mucousal sites along the GI tract. This is where the Tmemory cells are then stored and activated upon re-exposure to trigger (antigen) proteins (and likely why the re-exposure can be a more intense response because of the recognition from previous activated lymphocytes. Probiotics can help manage the gut homeostasis and further reduce the mechanism of allergy responses and restore the natural barrier.