This second image shows Staphylococcus epidermidis living on human skin and hair, where it eats dead skin cells.

This is an example of a commensal relationship.

Here’s why:

• The bacteria benefit by getting nutrients (dead skin cells).

• The human host is neither helped nor harmed in this situation—our bodies naturally shed skin cells anyway.

• Since only one organism benefits and the other is unaffected, this is called commensalism.

So, to summarize:

• Image 1: Mutualism (both benefit)

• Image 2: Commensalism (one benefits, one unaffected)

Let me know if you’d like a quick comparison table or to explain these for a class post!

Microbiota