Which of these following factors affect the existence of useful bacteria in human body?
Usage of Antibiotics.
Change in Food Habits.
Human body consists of an ecosystem for a collective group of bacteria and other microorganisms. Bacteria are present in our skin, trachea, alimentary canal, urethra etc. Although some bacteria are harmful, there are bacteria that are helpful for us. For example, the bacteria present in our alimentary canal is our primary source for vitamin K. Several factors such as usage of antibiotics, food habits, damage of tissues, etc. will directly affect the existence of these useful bacteria.