What's the definition of feeling your using?

And ultimately sentience is a really vague poorly defined term which makes any answer difficult.

So perhaps if we, rephrased it to could a microorganism develop intelligence comparable to a human.

In which case no not with conventional neurons as we understand them.

Perhaps you could engineer something that did processing on the atomic level that could meet the size and processing requirements.

I'm not sure sapient is a better choice to be fair.

- wise, or attempting to appear wise.

- relating to the human species

I think he's asking about consciousness but unfortunately given we don't really understand it or have a rigid definition, the only answer to his question we can give reasonably give is we don't know.

Depends on your definition of sentient.

the definition found on google was - able to perceive or feel things.

So by that definition yes, lots of microorganism already meet that criteria.