Celiac.com 12/03/2008 - Xanthan Gum is a polysaccharide used as a binder in many gluten-free products. In the production of xanthan gum, sucrose or glucose is fermented by a bacterium, Xanthomonas campestris. After a four-day fermentation period, the polysaccharide is precipitated from a corn-based growth medium with isopropyl alcohol, dried, and ground into a fine powder. When added to a liquid medium, a slippery, sticky gum is formed, and this substance works well in holding baked goods together, or keeping separate liquid ingredients in suspension in salad dressings and sauces.
A xanthan reaction can also precipitate migraine headaches, skin itchiness, and for those exposed to large amounts, such as bakery workers, nose and throat irritation. Symptoms of xanthan sensitivity become more prevalent with increasing exposure, so that can be one important clue. If you've suddenly started baking alot, or become addicted to a new brand of gluten-free cookies, and you start to have increased gastrointestinal symptoms, you may want to consider ruling out an adverse reaction to xanthan gum.
What's a body to do? Guar gum makes a good substitute, and it is also less expensive.
How did I become aware of this? Well, actually I have known about this for quite awhile, but since xanthan gum is in so many gluten-free products, I thought that sensitivity to xanthan must be a rare and isolated occurrence. Then two things happened to change my mind. I began baking a lot of gluten-free products for a business venture, and suddenly started having some gastro-intestinal problems, after being healthy for so long. I didn't have the severe pain of a gluten reaction, but otherwise my symptoms were eerily similar, particularly the bloating. I had already decided to lay off the baking (and tasting) as much as I could, and had narrowed the possibilities down to either tapioca starch or xanthan gum. Then, a student in one of my cooking classes let me know that she had a severe allergy to xanthan, and described her symptoms. They were identical, except in severity.
I reformulated my recipes using only guar gum for my next stretch of gluten-free baking, and I had no problem at all. I certainly hope that I do not develop a reaction to Guar gum, which is the ground carbohydrate storage portion of the guar bean. I have not seen reports of allergy or sensitivity to guar gum, but will do a little more research for my own knowledge, which I will share in the future.
By no means am I advocating that all people following a gluten-free diet give up products made with Xanthan gum. But, if you do not feel that the diet is helping you, and are still symptomatic, a sensitivity to Xanthan gum is one possibility that needs to be ruled out.