I haven't seen any aliens in my life - does it imply aliens exists?

Alien could be any word. "I haven't seen any aliens in my life". Does saying like this imply interlocutor thinks aliens exists?

difference between "can do nothing" and "cannot do anything" Just in case: "I have seen no aliens." - same meaning?

P.S. That might look like question on language in general, however AFAIK different cultures can interpret phrases differently, so I asked here.

I haven't seen any aliens in my life - does it imply aliens exists?

No. As it stands, it is a simple statement about the speaker's experience.

Compare

"I haven't seen any viruses/bald eagles/ in my life."