There are different kinds of Cheetos but...
Enriched Corn Meal (Corn Meal, Ferrous Sulfate, Niacin, Thiamin Monoitrate, Riboflavin, and Folic Acid), Vegetable Oil (Contains one or more of the following: corn, soybean, or sunflower oil), Whey, Salt, Cheddar Cheese, (Cultured Milk, Salt, Enzymes). Partially Hydrogenated Soybean Oil, Maltodextrin, Disodium Phosphate, Sour Cream (Cultured Cream, Nonfat Milk), Artificial Flavor, Monosodium Glutamate, Lactic Acid, Artificial Colors (Including Yellow 6), and Citric Acid. Contains Milk Ingredients.
I was gonna say that how O acts when he has red dyes - but I didn't see red dye listed for the Cheetos.
But here -
http://www.cheetos.com/retro/parents_products.php - you can click "Nutrition info" for the info on each kind they make to see what was in the ones DS got.
The MSG perhaps?