Bacteria
Bacteria are microscopic, single-celled organisms that thrive in diverse environments. These organisms can live in soil, water and inside the human gut.
Humans' relationship with bacteria is complex. Sometimes bacteria lend us a helping hand, such as by curdling milk into yogurt or helping with our digestion.
In other cases, bacteria are destructive, causing diseases like pneumonia or Staphylococcus aureus infections.







