I'm sure you're talking about the no-sugar type, as opposed to the sugary, flavored oatmeal packets. Like other grains, it's a starchy food that can feed candida, but many candida guides have no problem with moderate consumption of whole grains. One prominent alternative med guide (I have to revisit the book store and write down the exact quote and post it here) states that the digestive bowel chemistry behind whole grains is somewhat different than what happens with refined flours, and that the former is much more acceptable to candida folks than the latter. Stevia might make an excellent and healthy sweetener for oatmeal, and possibly that "Xy____" sweetener I haven't familiarized myself with yet.
One thing to keep in mind is that a candida-related "leaky gut" often brings about food allergies, sometimes to glutens ("wheat allergy"). If so, as happened with me, the grains wheat, rye, barley, triticale, and oats should be avoided, and the non-grass family of "grains" buckwheat and millet avoided as well for some folks since their prolamines are similar to wheat protein.
Hi (new to forum) I've read that gluten in grains such as wheat and wheat's cousins, as well as oats, rye, barley, etc feed candida. I've been recently diagnosed with sensitivity to potatoes, rye, oats, and all wheat products. I'm not sure if that makes me a celiac case...but I know that some people can tolerate certain combinations of grains differently. I'm not sure if candida caused my sensitivity or if my sensitivity was always there and allowed for candida to colonize my body...I'd see if I were sensitive to certain foods via a homeopath/nutritionist's test - because I had no idea that wheat was a problem...always thought it was something else I had eaten with it - before you try and survive on grains that might be feeding candida and/or a food sensitivity. (ps. my candida resluted after many courses of antibiotics over the past year for respiratory infections).