How can the body of the character not pass through the clothes during animations?

Hello, for my character, I made a blender file for the body and others blender files for clothes (pants, tee-shirt…) so I can change clothes when I want. I made animations with blender and I import them in unity. But during animations, the body pass through the clothes. How can I make sure it doesn’t get through the clothes?

Nice tutorial from Sebastion Lague:

RPG graphics E06: Clothes [Blender] - YouTube

It works
Thank you so much