Croutons are not a gluten free item, as they are made from wheat. I decided to analyze a few popular brands of croutons. Here is the list of ingredients:
Crouton brand 1:
Enriched Wheat Flour (Wheat Flour, Niacin, Reduced Iron, Thiamin Mononitrate, Riboflavin, Folic Acid), Canola Oil, Salt, Sugar, Dehydrated Onion, Yeast, Herbs, Natural Butter Flavor (a Milk Ingredient), BHT Added to Package to Maintain Freshness.
Crouton brand 2:
Enriched flour, (wheat flour, barley malt, niacin, reduced iron, thiamine mononitrate, folic acid), canola and/or sunflower oil, whey, salt yeast.
Crouton brand 3:
Potato Starch, White Rice Flour, Non-GMO Canola Oil, Tapioca Flour, Defatted Soy Flour, Egg Whites, Navy Bean Flour, Water, Yeast, Salt, Orange Peel, Xanthan Gum, Garlic*, Spices, Onion*, Parsley*, Lemon Juice Solids, Red Pepper Flake, *Dehydrated
As you can see, sometimes croutons can have more inflammatory ingredients than just gluten, such as corn, table salt, and white sugar.
If you love croutons and do not have an issue with gluten, consider making your own, as this will reduce the amount of additives. There are several recipes online.
If gluten is an issue for your body, some alternatives for adding crunchiness to your salads are cut zucchini, cut yellow squash, diced red/orange/yellow bell peppers, nuts and seeds (almonds, chopped walnuts, chopped pecans, sunflower seeds). These alternatives also pack a lot more nutrition than croutons, always a plus.