Humans are highly adapted to consuming probiotics. Trehalose ("mushroom" sugar) is probably an important reserve compound and stress-responsible metabolite (increases bile and gastric acid resistance) of probiotic bacteria's and trehalase activity, in contrast to lactase activity, is preserved in all human populations, even those not consuming mushrooms. Among traditional Melanesian horticulturists, of whom 4/5 are daily smokers, the diet is rich in pre- and probiotics and there is absence of cancer and cardiovascular disease. Indoor air pollution is an important cancer risk factor. Over thousands of years, the controlled use of fire for preparing meals has resulted in exposure to smoke pollution (biomass fuels produce up to 100 times more respirable particles compared to gas ovens). Simultaneously, up until the 20th century, the only commonly available and inexpensive way of preserving food was fermentation and drying. Probiotics may protect the detoxification function of the kidney and liver. Furthermore, it can be speculated that probiotics may help in adaptation to smoke pollution generated during cooking, heating but also tobacco smoking. Smoking is the most important lifestyle risk factor for bladder cancer and the consumption of probiotic foods reduces the risk of this cancer in humans. Probiotics may restore natural killer cell activity which is lowered in smokers. In one study it was observed that a diet supplemented with Lactobacillus plantarum could be also useful in the prevention of cardiovascular disease in smokers. There is no sufficient data from clinical trials to recommend the routine use of probiotics in prevention of smoking-related diseases. More research is needed to investigate the role of probiotics in this area.