Hi folks, intrigued by the debate. food intolerances do cause bad breath, but it depends on the makeup of you're bowel flora. We all expel methane, co2 and oxygen from the colon via the lungs. several litres a day in fact, but these are all odorless gases. If you are fermenting sugars in your colon you disrupt the bowel flora and increase production of odorous gases, which are also expelled via the lungs. pS meat only rots in the gut if you eat larger serves than your body can digest, which goes for all protein.