Answer
Mutualism is the type of symbiosis best represented by the relationship between humans and E.coli.
Work Step by Step
E.coli is able to thrive in the large intestine because it is provided with the nutrients to survive. But they do not live for free. E.coli synthesize vitamin K and B which are used by our body. Both humans and E.coli are benefitted in this symbiotic relationship. Hence, mutualism is the type of symbiosis that best represents this relationship.
