What treats are best for picky eaters or sensitive stomachs?

Single-ingredient or limited-ingredient options come up most often in sensitive-stomach discussions, because there are fewer suspects if a dog reacts. Threads in r/DogFood and r/puppy101 also flag that very rich treats (filet mignon-style soft chews, bacon strips) can trigger loose stools in sensitive dogs, so starting with a small bag is usually advised.