Saturday, April 28, 2007

Food, bacteria, yeast & the leaky gut meet probiotics & gluten free diet in the fight against Crohn's disease and Celiac

Food, bacteria and yeast in the gut are increasingly being acknowledged by doctors to have a role in the development of a variety of chronic diseases. For years alternative and complementary health practitioners have been advocating various elimination diets and supplements for treatment of a myriad of illnesses and symptoms. Recently more medical researchers are seriously looking into science of food and gut bacteria and yeast causing illness. This research is more common in Europe than in the West because in the U.S. most of the research funding is linked to drug development. Since dietary treatment is not a drug pharmaceutical companies are generally not interested. Their deep pockets are not available to the research scientists working on food related illness who depend on pharmaceutical company funds to survive in academic medicine.

However, Celiac disease affects 1%, food allergies 8%, gluten sensitivity 10% and various food intolerance 30-60%, so what we eat is important. Our genetics play an important role as well. Between 35-45% of people are genetically at risk to develop Celiac disease. Many of these people are gluten sensitive. The majority of people with Crohn’s disease have detectable antibodies in their blood to a variety of proteins that come from bacteria and common dietary yeast. It is believed that these proteins trigger abnormal immune responses in the gut in genetically predisposed people.

Around seventy percent of people with Crohn’s disease have elevated levels of antibodies to the dietary yeast Saccharomyces cerevisiae,more commonly known as Baker's or Brewer's yeast. These anti-Saccharomyces cerevisiae (ASCA) antibodies are rarely present in blood in people without Crohn’s but may be detectable in the stool in people sensitive to dietary yeast. Though touted as very sensitive and specific for Crohn's disease and rarely present in blood in normal people, ASCA antibodies can be detectable in other digestive conditions including Celiac disease.

I have found many of my Celiac disease, non-celiac gluten sensitive, and various microscopic colitis (lymphocytic, collagenous, eosinophilic and mastocytic enterocolitis) patients have detectable to elevated ASCA levels. Often they are combined with other antibodies to intestinal bacteria and food proteins. Gut bacteria proteins from the outer membrane protein (OmpC) and flagella (CBir1) of certain bacteria are also present in many Crohn’s patients. Antibodies to the toxic protein gliadin produced from wheat gluten digestion are often detectable. The specific antibodies for Celiac disease, endomysial (EMA) and tissue transglutaminase (tTG), are by definition only detectable in the blood in Celiac disease. However, gliadin and tTG antibodies are usually present in the stool in people sensitive to gluten and are always present in untreated Celiac disease.

As a gastroenterologist who specializes in Crohn’s, colitis, Celiac disease, gluten sensitivity and various food allergies and intolerance, I test as many of my patients as possible for these antibodies. I find many patients with gastrointestinal symptoms who fail to meet the strict diagnostic criteria for Crohn’s disease, ulcerative colitis or Celiac disease have detectable levels of antibodies to these proteins in their blood or stool. Not all people with detectable ASCA antibodies have Crohn’s disease. Often, though they have digestive symptoms, I am unable to definitely diagnose Crohn’s disease by colonoscopic biopsies of the intestine or wireless capsule endoscopy (the swallowed pill camera). However, most respond to standard medications used to treat Crohn’s disease and colitis.

Even more interesting is that many also respond to probiotics and elimination diets, especially the gluten free diet. I believe some of these people have very early Crohn’s while others have various forms of increased gut permeability or leaky gut but have not yet developed irreversible Crohn's disease or other chronic intestinal dieases. Because I believe altered gut bacteria or dysbiosis is a critical factor in the development of abnormal intestinal permeability or leaky gut leading I recommend a probiotic. For those who I believe have severely altered gut bacteria or yeast (dysbiosis), I may first prescribe a course of an antibiotic or an anti-fungal medication. Though there are many probiotics available, I prefer the probiotic bacteria preparations VSL#3, Ultimate Flora, and Flora Q, based on their large numbers of multiple strains of good gut bacteria and absence of gluten.
In patients with elevated ASCA, Crohn’s disease, antibiotic associated diarrhea, or C. difficile infection, I frequently now recommend the probiotic yeast Saccharomyces boulardii.

With these new antibody tests and the recognition that the gut can be irritated at the microscopic level when it appears normal is resulting in the ability to detect earlier signs of gut injury. Such injury results in increase permeability or leaky gut resulting in the ability of food and gut bacteria and yeast proteins tranlocating or moving through the intestine wall. Once these foreign proteins get through the gut wall they encounter white blood cells that especially in the genetically predisposed can activate an self perpetuating abnormal immune activation response and gut inflammation leading to more gut injury. The resulting further leaky gut can allow more foreign proteins to get access into the blood stream where they can travel to other parts of the body and cause injury and a host of other non-digestive symptoms.

As the result of these antibody tests to food, bacteria and yeast proteins combined with microscopic examination of the gut we are identifying more people with symptoms that may respond to treatment before they have enough damage to establish a definitive diagnosis of Crohn’s disease, ulcerative colitis, or Celiac disease. Some have various forms of microscopic enterocolitis, intestinal conditions where the surface appears to be normal visually but under the microscope there inflammation or irritation indicating an abnormal response to food, bacteria and yeast.

I am preparing a presentation on nutrition in inflammatory bowel disease I was invited to give at a conference for Crohn’s and colitis patients and their families sponsored by the Rocky Mountain Chapter of Crohn’s and Colitis Foundation of America (CCFA). I wanted to share some of my thoughts with those following my blog that has had to take a brief hiatus due to family health issues. See my Food Journal Report post tomorrow about neurological symptoms and possible link of herniated discs to Celiac disease and gluten. To your "Healthy Gut, Healthy Life", the Food Doc.

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1 comment:

Judy said...

Dr. Lewey,

I'm interested in your use of S. boulardii in treating people with ASCA antibodies and celiac disease. I have both. But I am afraid of using it because my understanding is that S. boulardii is actually a subtype of S. cerevisiae, and I notice systemic reactions (headache, brain fog) even to small ingestions of it, like in a small serving of communion wine. Would not a capsule containing a large number of these organisms trigger an even more severe reaction? I'm finding it counter-intuitive to use this as someone with a severe S. cerevisiae senstivity, but if you're seeing success in these patients and can explain the mechanism, I'm open to trying it. I'm a physician assistant, by the way. Thanks!

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