What does the term 'nonpathogenic' refer to?

The term 'nonpathogenic' specifically refers to microorganisms that do not cause disease in their host. These microorganisms can be harmless and may even provide beneficial functions, such as aiding in digestion or contributing to the body's immune response. Nonpathogenic bacteria are often an important part of the normal flora in various environments, including the human body, where they can play a role in maintaining health and preventing infections by outcompeting harmful pathogens.

While some microorganisms do reside in the human body, this characteristic does not inherently make them nonpathogenic, as some can be pathogenic. Similarly, harmful microorganisms directly refer to pathogens, which is the opposite of nonpathogenic. Therefore, the most accurate definition of 'nonpathogenic' is the description of organisms that are harmless and potentially beneficial.