Indeed, we now know that intestinal flora plays an important role in health: stimulating the immune system, protecting the host from invading bacteria and viruses, aiding digestion and assimilation of food. Yet, the importance of these bacteria in the gastro-intestinal “GI” tract has been neglected for a long time, while the focus was merely placed on enteric pathogens and other factors leading to gastrointestinal "disorders".Custom Probiotics
Gut microflora is specific to each individual, established at birth- resident flora does not change substantially from birth. However, many things in life can change the density,numbers/concentration, and ratio of good to bad microflora. These things include: diet, antibiotics, illness, stress, infection, the list goes on but these are the main effectors. To achieve homeostasis, there needs to be a balance of good gut flora to bad. "Lactobacilli and Bifidobacteria, should predominate, presenting a barrier to invading organisms. Around 85% of the intestinal microflora in a healthy person should be good bacteria and 15% bad bacteria. The greater the imbalance, the greater the symptoms" Custom probiotics
You'll notice my above links, a fellow FPIES mom shared the link in her search for probiotics for her child. I typically don't quote websites that are also selling something and proceed with caution with their information (as I just need to re-research it to be sure it is medically sound information) but the above information is good information from their site, which I found easy to read through (although they are selling something and although it looks like a promising probiotic, as always check with the manufacturer for safe ingredients first!). The reason I have bookmarked their site is because they have a GREAT illustration of the intestines and it's tie to the immune system. So, if you'd like a look at that- visit this site and scroll down the page a few paragraphs.
It shows the villi and crypt of the intestines. The villi and crypt can be damaged in severe/chronic FPIES inflammation, therefore causing further cascading problems of illness from increased intestinal permeability (leaky gut) due to the inflammation opening "holes" in the intestine, thereby causing further damage, deficiencies and mostly allergies/intolerance's as proteins "leak" into the blood stream (via the lymph). Villi damage can also lead to nutritional deficiencies and weight loss as this is where nutrients are picked up from the broken down food molecules.
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), comprised of Peyer's Patches (which facilitate the beginning of the immune response in the GI tract), Paneth cells (control microbes) and dendritic cells (micro flora communication). 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 that balance once it has been established (past infancy). Probiotics have antimicrobial effects (pathogens, toxins), maintain intestinal epithelium (barrier), and regulate the immune system via the GALT (inflammatory responses to allergens and other inflammatory substances).
It is clear the balance (homeostasis) of micro flora in the gastrointestinal tract is important to immune responses.