Lactose-fermenting bacteria are microorganisms that can break down lactose, a sugar found in milk and dairy products. These bacteria convert lactose into lactic acid through fermentation, which helps in the production of various dairy products like yogurt and cheese. Common examples include Lactobacillus and Streptococcus species. These bacteria play a crucial role in the digestive health of individuals who are lactose intolerant. By fermenting lactose, they can help reduce symptoms associated with lactose intolerance, making dairy products more digestible for some people. Additionally, they contribute to the preservation and flavor of fermented foods.