all rice is gluten free
Gluten is a protein mixture found in rye, wheat and barley and makes dough rise.
Rice contains no gluten and fits anyone with gluten allergy or sensitivity such as celiac disease.
Glutinous is a synonym for sticky or sweet rice. Starch is made of amylopectin and amylose, two slightly differently linked chains of glucose.
Sticky rice is high in amylopectin.
black rice is a whole grain with a glycemic index below 50
Diabetes is not my medical specialty, I'm a physician with a background in emergency medicine but I try to educate myself more in this direction. In the end, if you are a diabetic, it's your call, you decide what's best for your health.
That said, most black rice varieties have a glycemic index just below 50 (due to high fiber content).
That's a low-moderate GI and therefore, yes, a rather safe choice for someone with a fairly well controlled DM type 2.
Note that GI can only be measured in a clinical setting, so this is a test that we cannot do ourselves for our variety, but scientific papers about Thai black rice have consistently shown values under 50.