Wheat — Food safety facts
Safe to share · Cats · full breakdown on the linked food page
Plain cooked wheat is safe, though some pets are sensitive to gluten.
Short answer
Both plain wheat bread and plain pasta are safe for cats in small amounts. They're essentially the same ingredient—cooked wheat—so neither is safer than the other. Just offer it plain, watch for any digestive upset, and call your own vet if anything seems off.