Some civilizations had to rely on meat only for their source of food during the winter time. But fortunately we arent under those conditions. A healthy human is designed to eat a wide variety of foods. Carbs/fiber is the preferred food of flora, but can also be the preferred food for candida. Each one of us has to adjust our diets depending whats going on in our digestive tract.
I agree, A high protein diet might not be good for people that have bacterial/gut ecology imbalnces because it can produce to much ammonia and protein by products. But for healthy people it might not be as much of a problem. Extreme diets of any kind of food can be unhealthy-- even greens. The key is balanced nutrition. Unfortunately candida robs us of much needed nutrition.