"a fellow human" is a valid expression in English, and can be used in both spoken and written contexts.
For example: "As a fellow human, I understand the struggles you are going through right now."
Except that she's a fellow human being occupying planet Earth, I don't care about your wife".
As a fellow human being, I had to feel a little sorry for Rick Perry.
Abdul, on an individual level, is a fellow human in a tragic situation.
He was there because he never recognized Lazarus as a fellow human being.
The psychiatrist meant that a fellow human being should not be defined by an illness.
To Lena, such concern for a fellow human being was the natural instinct of a socialist.
Mr. Barenboim led his orchestra, and his audience, as a fellow human being.
Remember, email is just another way to communicate with a fellow human being.
To actively isolate a fellow human being is nothing short of structural violence".
"You just don't do this to a fellow human being," he said, "especially a place that publicly preaches brotherhood".
He is neither "sane" nor "insane" but a fellow human being who speaks to us with courage and honesty.
