Consume Product

I'm not sure what terrain theory is but in your example you're talking about inflammation which doesn't necessarily include infection. There are many non infectious inflammatory responses.

Edit: I quickly read over terrain theory and they seem to go hand in hand, and the distinction would be more a threshold of body health that needs to be overcome by a germ to make someone sick. So weakened people, or immunocompromised, would allow opportunistic infections that are able to penetrate and reproduce and create infection.