Final answer:
While some microorganisms can be harmful, most are beneficial, aiding in digestion, nutrient production, and environmental processes. The Human Microbiome Project has expanded our understanding of the diverse roles microbes play in human health and the ecosystem.
Step-by-step explanation:
Microorganisms can be both beneficial and harmful to humans and the environment. While some microorganisms are known pathogens that can cause diseases, the majority are helpful and crucial to sustaining life. In the human body, for example, beneficial microbes assist with digestion, produce essential nutrients like vitamin K, and protect against harmful pathogens. The Human Microbiome Project has highlighted the diversity of microbes that live in and on us, some of which were previously unknown, and even amongst these, many perform life-sustaining functions. Outside the human body, microorganisms are integral in processes such as decomposition, nutrient cycling, and the production of foods like bread, cheese, and beer.