Gluten is a protein found in grains such as wheat, barley and rye. It is present in wheat and other flours and therefore in many baked goods. Gluten intolerance causes digestive inflammation, the most severe form is Celiac Disease.
Oats do contain similar proteins to wheat but are not thought to develop gluten. Some people report a reaction to eating oatmeal but research shows this is likely to be caused by cross-contamination. Oatmeal products are often processed in equipment that also processes wheat flour.
Only grains contain gluten. Maple syrup and brown sugar are both suitable for use in a gluten-free diet. Pure, tree-tapped maple syrup is less likely to have come into contact with gluten during processing than a manufactured syrup.
A package of microwave-ready maple and brown sugar oatmeal is unlikely to contain gluten. If you are very sensitive to small traces of gluten, you can reduce the risk of cross-contamination by preparing oatmeal at home. Some suppliers of oats offer a guaranteed gluten-free product.