How does a person use bacteria in their activities?

In the 21st century, bacteria are very actively used by mankind. In the food industry, lactic acid bacteria help create products: kefir, yogurt, cottage cheese. Some substances used in food production create genetically engineered bacteria. These are microbes in which the DNA is altered. Because of this change, bacteria acquire new properties. Bacteria are actively used in medicine. During the use of antibiotics, the intestinal microflora is disrupted. In this case, drugs containing beneficial bacteria are used.