Xanthan gum is a thickening agent named after the bacteria used to make it through fermentation, Xanthomonas capestris. This common bacterium is the same culprit that causes your cauliflower to turn black when rotting. Although you would not eat rotting cauliflower, xanthan gum is generally safe and only causes mild irritations in some people. Guar gum and cellulose gel are common alternatives to use as thickening agents if you are sensitive to xanthan gum. Since celiac disease and gluten-free diets are becoming more commonplace, xanthan gum is also being used in more baked products to replace gluten.
The most common side effects of xanthan gum are gas and bloating. If you ingest a large quantity of xanthan gum, you may experience severe abdominal pain from gas buildup in your intestines. A clinical study on the effects of xanthan gum on dogs was completed by the World Health Organization. In this study, dogs were fed large amounts of pure xanthan gum and experienced weight loss and chronic diarrhea. A typical 150-lb. person would have to consume over 60 g of xanthan gum daily to replicate this study. Typically, on a gluten-free diet you would consume an average of 0.5 to 4 g of xanthan gum per day from products. No human trials have been done to determine if normal dietary consumption of xanthan gum produces any gastrointestinal effects except gas.
Xanthan gum can be purchased in a powdered form for use in your kitchen. This low-density, fine powder has the ability to create a cloud in the air when being handled roughly. Inhaling xanthan gum may allow it to accumulate in your lungs, according to the World Health Organization. Eventually, xanthan gum may induce respiratory distress by making absorption of oxygen in your lungs difficult. The Xanthan Gum website reports that industrial workers who produce xanthan gum have experienced respiratory problems. You should be careful when handling xanthan gum and try to be gentle when adding it to your recipes. Inhaling small amounts should not cause any problems; however, if you believe you are experiencing any breathing difficulties, consult your doctor.
Manufacturers are not required to list what food the Xanthomonas capestris bacteria eat during production. If you are allergic to any vegetation including soy and corn, you may want to seek an alternative thickening agent. If you only have a slight allergy, you may want to test several individual brands to determine which ones produce the fewest side effects. Allergic reactions can produce severe symptoms, such as difficulty breathing. If you notice swelling or rash developing, talk to your doctor.