Human connection with the surrounding world has developed evolutionarily and is a system of symbiont relationships. Symbiont bacteria live in our intestines, mucous membranes, skin. What role do they play in the human digestive tract?
1) do not allow the development of putrefactive and pathogenic bacteria;
2) help to digest fiber;
3) produce some vitamins.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.