Update exiting booking

Hi, how can I update many bookings in one method? I'm finding bookings where email is the same as logged in user and I want to add the id of that user into user_id column.

I tried $bookings->save(), but that didn't work. Any ideas?

public function getBookings()
	{
		$bookings = Booking::where('email', '=', \Auth::user()->email)->get();

		if (request()->wantsJson()) {
			return $bookings;
		}

		return $bookings;
	}