Foods such as cheese and yoghurt are made by bacterial or yeast fermentation. In Asia and Africa cooked soya beans and cereals are fermented to make a number of important foods, including koji, miso, sufu, and tofu. Fermented foods contain the bacteria or moulds which helped to produce them. These can improve the taste of bland foods and may provide valuable nutrients that are especially difficult for vegans to obtain. In addition, some bacteria (e.g. Lactobacillus in natural yoghurt) can take up residence in the intestine where they may produce enzymes, vitamins, and other chemicals beneficial to the health of their host (see also gut bacteria). Fermented milk products (e.g. yoghurt) are tolerated by people lacking the enzyme lactase who cannot tolerate fresh milk (see lactose), but fermented milk products are no use for people who cannot tolerate milk because of an allergy to milk proteins.
Subjects: Medicine and Health.