What type of association is formed by bacteria with many other organisms, including humans?

symbiotic association

Explanation:

The simbiosis can be:

Mutualist: Mutualism is defined as a symbiotic relationship in which organisms are of different species  provided benefits to each other.Mutualism between bacterias and animals  is very important for example in their digestive system In  herbivores, bacteria are the ones that digest the plant cell wall.

Another example is In the large intestine humane, the E.coli bacteria synthesizes vitamins. The large intestine in turn provides it nutrients

Commensalism: one species benefits and the other neither benefits nor harms. For example, the micobacterias that inhabit the human ear, they live from secretions and cause no harm to human guests

Parasitic: like the many bacteria that cause diseases