Specifically what did you eat? Low carb meaning elimination of anything withs carbs, like vegetables? I am sorry but I don't agree with your reasoning. If you eliminate grains then that is beneficial. Above ground vegetables, especially green vegetables, are necessary and won't contribute to whatever nonsense you say about body fermentation. Lactic acid is a product of waste production and exercise regardless of what you eat so this theory does not hold water. If anyone changes their diet dramatically AND suddenly then the body's acid balance will swing in the opposite direction to balance itself out. This is called homeostasis. A gradual approach to changing one's diet is what is needed.
I don't mean to disparage your feelings, not my intention. But trying to tell people not to eat lo carb or use fermented foods because it destroys the bowels and is killing them is, IMO, utter nonsense.