I also changed my toothpaste recently and I am sure that it was causing that white line inside my lips.
When I think about it, I saw real improvement after changing my toothpaste which had a ton of ingredients although it was an ayurvedic toothpaste.The toothpaste had antimicrobial ingredients which I think was not letting good bacteria to grow.
I have discontinued the diet and it has not affected my lips much. But, I do believe that *my* ec is because of candida/gut flora imbalance as I saw similar improvements when I had taken antifungal for 12 days few months back.
The diet will not cure your lips if candida is not the cause of your EC so please don't say that the diet doesn't work. Lees cured his lips twice with anticandida diet and his case was similar to mine he and I both took accutane