From: mha23x@gmail.com   
      
   Friday, 23 September 2016 12:25    
      
   “I CAN’T EAT THAT” OR HOW OUR MICROBIOME INFLUENCES OUR DIETARY   
   RESTRICTIONS    
      
   Written by  Monika Buczek    
      
      
   Allergy Testing ImageFigure 1. Food allergen patch testing. In this technique   
   the allergen is placed on the upper back under a bandage and removed in 48   
   hours. The skin is observed for reaction 48-72 hours later. Source    
      
      
      
   Microbes of all kinds influence our body’s immune system and most readers   
   are likely familiar with the example of a pathogen invading the body and being   
   met with an army of innate and adaptive immune cells. The pathogen is   
   identified and killed. Boom.    
   The body did its duty, no more threat. However, our benign microbes have a   
   surprisingly big influence our immune system. Out of the frenzy of new   
   microbiome research, a link has emerged between overactive immune responses   
   (such as those in autoimmune    
   diseases we read about last week) and gastrointestinal bacteria. It appears   
   that an imbalance of microbes in the GI tract can adversely affect how the   
   immune system functions. In fact, we are learning more and more how normal   
   human development is    
   dependent on the microbes that have coevolved with us. Research to date has   
   revealed several examples of food-centric autoimmune disorders that,   
   surprisingly, are linked to the composition of microbes in and on our bodies.   
   While we have only just    
   investigated the tip of the iceberg, I’ll go over a few examples of these   
   disorders including type-1 diabetes, allergies, and celiac disease.    
      
        
      
   insulin moleculeFigure 2. Human Insulin hexamer. Source    
   The Rise of Antimicrobials and Food Allergies    
      
   If you haven’t heard, food allergy rates are on the rise, and are now so   
   common that schools and airlines have enacted regulations on certain foods.   
   Children are no longer allowed to bring peanut butter sandwiches to school,   
   bake sales have banned    
   homemade food, and several airlines are participating in allergy-free travel   
   to protect afflicted passengers. The first peanut allergy in modern times was   
   officially reported in 1920 by J. D. Blackfan, and since then, reports of food   
   and airborne    
   allergies have become more and more common. The World Health Organization   
   estimates that 1-3% of adults and 4-6% of children have an allergy to at least   
   1 of 70 reported foods. Symptoms of food allergies range from a mild itchiness   
   in and around the    
   mouth, vomiting, and gastrointestinal distress to anaphylaxis and possible   
   death. There is no treatment for food allergies; those who suffer must abstain   
   from eating foods that cause allergic reactions and often must carry around a   
   life-saving    
   epinephrine injector (such as the EpiPen® of recent controversy) that can   
   prevent anaphylaxis by delivering a jolt of epinephrine to the body.    
      
   Allergies are caused by an overactive immune response to a foreign particle or   
   protein that the body mistakes as a threat. There are a few theories on why   
   this happens, but the the Hygiene Hypothesis is the most prevalent, and posits   
   that the root of    
   increasing allergy rates is due to modern access to antimicrobials and an   
   obsession with disinfectants. Being “too clean” has ultimately led to too   
   little microbial colonization early in life. Microbes are necessary for the   
   development of a normal    
   immune system (and thus, a normal immune response to non-pathogens). Some data   
   suggest that commensal microbes acquired during vaginal birth and shortly   
   thereafter are needed for the development of immune “tolerance” to   
   themselves and other antigens.    
   In studies done on infants that later developed allergies, fewer   
   Bifidobacteria were detected during the first weeks of life. Colonization is   
   so important, in fact, that developing allergies within the first year of life   
   was correlated with less    
   colonization by commensals in the first week of life. Not only that, but   
   interaction with microbes is required for T-cell maturation in newborn   
   infants. Unfortunately, we have yet to discover the exact species required for   
   immune system maturation, and    
   only have general trends to go on. In adults, it was reported that there was   
   an inverse relationship between orofecal infections and prevalence of   
   allergies; the sicker you were, the fewer allergies you developed. Altogether,   
   colonization by microbes    
   both early-on and later in life appears to be extremely important in   
   preventing allergies, but is a hard pill to swallow for a generation raised to   
   believe that cleaner is better, and sterile is best.    
      
        
      
   celiac-disease-imgFigure 3. Normal (left) and celiac (right) duodenal mucosa   
   samples from the New England Journal of Medicine. Source    
   Viral Causes of Type 1 Diabetes Mellitus    
      
   Another example of an autoimmune disease linked to microbes is type 1   
   diabetes. Insulin is an essential hormone normally secreted by the pancreas in   
   response to high levels of glucose in the blood, and signals the cellular   
   uptake of glucose by recruiting    
   glucose transporter molecules to cell membranes. But in the case of type 1   
   diabetes, also known as juvenile diabetes, the immune system malfunctions and   
   causes CD4+ and CD8+ T-cells to misidentify insulin as an antigen and destroy   
   insulin-producing β-   
   cells in the pancreas. Insulin keeps blood glucose levels steady by ensuring   
   that the liver is releasing sufficient amounts of glucose: if there is   
   insufficient insulin in the liver, the liver releases glucose into the   
   bloodstream faster than tissues can    
   metabolize it, causing hyperglycemia. In the case of diabetes, high levels of   
   glucose remain in the blood and put a serious strain on blood vessels and can   
   damage them. Unmanaged hyperglycemia increases the risk of heart disease and   
   stroke, as well as    
   renal, vision, and nerve disorders. As a result, people with diabetes must   
   inject themselves with insulin (commercially made today by E. coli and   
   sometimes yeast) after meals to ensure that blood glucose levels remain   
   constant.    
      
   Sources of GlutenFigure 4. Sources of gluten include wheat flour, spelt,   
   barley, rye (Clockwise from top). Source   
      
   [continued in next message]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)