I've read some recipes/blogs that say that overnight oats can be made with milk substitutes such as almond milk. Other recipes/blogs I've read say that enzymes found in milk help to break down the oats, which allows for the long soaking process to serve as an alternative to cooking them with high heat.
Clearly many people make overnight oats using milk substitutes, so it works to some extent, but does using actual milk make a notable difference in how the oats end up? Does the choice between milk versus milk substitute affect their nutritional profiles (as one can break down more/different substances in them than the other)? Does the choice between milk versus milk substitute affect their texture?
Perhaps the claims about enzymes in milk being important for the oats are simply incorrect. After all, processing techniques commonly used for milk (e.g. heat treatment) destroys/deactivates many of the enzymes in milk.