The human body is home to trillions of bacteria, known as the . These "good" bacteria aid in digestion and protect against harmful pathogens. However, pathogenic bacteria cause diseases such as strep throat, tuberculosis, and urinary tract infections. These are typically treated with antibiotics , though the overuse of these drugs has led to the rise of "superbugs"—bacteria that are resistant to standard medical treatments.
Bacteria are microscopic, single-celled organisms that exist in virtually every environment on Earth, from deep-sea vents to the human digestive tract. They are , meaning they lack a nucleus and membrane-bound organelles. While often associated with disease, the vast majority of bacteria are either harmless or essential to life. 1. Structure and Classification bacterium
They break down organic matter, recycling carbon and nutrients back into the ecosystem. The human body is home to trillions of
Engineered bacteria produce insulin, vaccines, and enzymes used in detergents. 4. Human Health and the Microbiome These are typically treated with antibiotics , though