I am making a wood cutting board need to fill some cracks what's safe

This kind of question has come up before on this site. I have searched all over the Internet and have not as of yet, been able to come up with a definitive answer. Maybe it is there somewhere, and I just haven't been using the correct search terms.

As such, as of right now, I don't think that there is a wood filler that would be like wood and be safe to be used on something where food might be prepared. There are clear fills and finishes that would be safe. But, then we are talking about plates, bowls and similar food containers. If there were to be a wood filler used on one of those, then it would be covered by something clear that would be food safe.

If you are making a cutting board, what kind of wood is it that you are using, and how are you putting it together, please? I am wondering why you are having cracks. Thanks!