I would call your veterinarian immediately if they do eat that and let them know what they ate, when they ate it, and how much they ate. Depending on what it is, we can go from there.

I would avoid most fruits, meats, and simple carbs. Stay away from human foods aside from certain veggies and rare foods.

Vitamin C supplementation is absolute, but they should be getting everything else from their hay.

Give them a little biscuit supplement, and make sure they're getting enough of the peppers. We have care guides we give out when you first get your guinea pig, and you should bring them to the veterinarian for evaluation so we can give you more specifics of how much they should be getting based on their body weight.