According to Subways website....
Do your breads contain animal products?
SUBWAY® Italian bread contains no animal-derived ingredients. The wheat bread and deli roll contain honey, which may be considered an animal-derived ingredient. The Parmesan Oregano and other cheese-topped breads do contain milk-derived ingredients.
Do any of your breads contain milk/milk-derived ingredients?
Only the breads that contain a cheese topping like the Parmesan Oregano bread.
What is the origin of sodium stearoyl-2-lactylate and the mono- and diglycerides found in the bread?
These ingredients are plant-derived.
What is the origin of enzymes (rennin) used in the cheese?
The bulk of rennet used in processing is microbial however there could be a chance of calf rennin in the cheese due to production variables. The cheese contains no porcine (pig) derived rennet.
What menu items at SUBWAY® restaurants are vegan/do not contain animal-derived ingredients?
The menu items that do not contain any animal-derived ingredients are the Veggie Delite® on Italian bread and the Veggie Delite® salad. Also these individual items also do not contain animal-derived ingredients: all vegetables, oil, vinegar, mustard, sweet onion sauce and Fruizle. The wheat bread and deli roll contain honey but no other animal-derived ingredients.