Cellulose is vegetable fibre and the rice flour would be a negligible amount that’ll likely be readily absorbed in your small intestine in any case. I think the same would hold for dextrose, which is basically just glucose. Some people with SIBO and other bacterial infections use simple (glucose) sugars like dextrose and rice syrup for carbs for this reason.
Things to watch for might be GMO soy oil and other allergens, including wheat and yeasts, and artificial colourings, e.g. caramel. There are some other crappy fillers used by some brands with chemical names that you’d need to lookup case-by-case. Generally, good brands like Solgar and NOW Foods don’t contain trash, but it’s worth looking around for a good price as long as you can see the full ingredients list.