For the second time in a relatively short period I am having issues with the search function on my macbook.

Whether in spotlight, Mail app, or Finder search results return nothing. If I reboot the search works fine again. Unfortunately this now seems to be a recurring problem. It's also a recent problem that I never had before, first noted it a few weeks ago.

Macbook on macOS Sierra 10.12.3.

Any one has this experience? What could it be? How can I prevent it or fix it, without having to restart everytime?

-- edit --

Following the feedback in the comments, I ran Disk Utility. Disk utility indicates there are errors but doesn't seem to repair them. Final message in DU: "file system check exit code is 8" I have already tried to reindex Spotlight, that didn't solve the problem.