The process of natural fermentation is an ancient technique for the production of a variety of community-specific ethnic products such as fermented beverages, foods traditionally prepared from the milk, fish, meat and some agriculture-based resources. Fermented foods make up about 20% of all food consumed worldwide. Consuming traditional fermented meals that are made with various raw materials, microbes and preparation methods, has gained popularity recently. In North and South Asia, Far East Asia and the Indian subcontinent, boiling rice has long been a staple meal accompanied by pickles, vegetables, meat, fish, and fermented and non-fermented legume products (mainly soybeans). In the parts of Europe, North America, Australia and New Zealand, and West Asian continent, breads and loaves are primarily made from wheat or barley that forms a staple diet, followed by milk and some of the fermented milk products. Fermented meats, maize porridges, together with a variety of fermented and non-fermented maize/millets/sorghum/cassava, wild legume seeds, dairy products and meat are the primary healthy meals. The microflora that is naturally present on the raw substrate is typically the microbe responsible for the fermentation process in native fermented foods. One of the most affordable and traditional ways to produce and preserve food is by fermentation, which also has the benefits of destroying unwanted ingredients, improving food quality, flavour and nutritional content, and protecting the final product from harmful microbes. This chapter describes the diversity of microorganisms towards preparation of ethnic fermented food products and beverages.