How does bacteria affect humans?

Hint: Microscopic, single-celled species called bacteria can live in complex environments. Bacteria are found in the soil, the ocean, and within the human gut. The relationship of human beings with bacteria is complex.

Complete answer:
Bacteria are strong and complex, but small, and they can live in severe conditions. Bacteria have a tough protective coating which increases their resistance in the body to white blood cells. Bacteria can be beneficial to human health as well as harmful. "Friendly" bacteria, inside our bodies, share space and resources and appear to be helpful. There are about 10 times more microbial cells in our bodies than human cells. The intestine contains the largest number of microbial organisms. The human gut is a comfortable environment for bacteria, with plenty of nutrients available for their sustenance. Gut bacteria and other microorganisms, such as helpful E. coli and Streptococcus strains, aid in digestion, prevent harmful pathogens from colonizing, and help the immune system to develop. Certain bacteria help to digest food, kill cells that cause illness, and provide the essential vitamins for the body. In addition, some disease disorders have been associated with the destruction of gut bacteria. Infections may be caused by other bacteria. Sometimes referred to as flesh-eating bacteria, aureus can cause a rare but serious infection of soft tissue called necrotizing fasciitis. In the body, they replicate easily. Many give off toxins called chemicals, which can cause tissue damage and make you sick.

Note:
Usually, antibiotics are used to treat bacterial infections. In producing nutritious foods like yogurt and cheese, bacteria are also used.Bacteria improve soil fertility and provide the soil with nutrients that are useful for plant growth. Bacillus thuringiensis is a bacterium used in agriculture that is gram-positive.