How to exclude joined table data from query results

Suppose I have the following query,

$results = Listing::select('listings.id', 'listings.slug', 'page_contents.html_title AS name')
    ->join('page_contents', function ($join) {
        $join->on('page_contents.subject_id', '=', 'listings.id')
            ->where('page_contents.subject_type', '=', 'App\Listing');
    });

$results will include the specified select columns (which is all I need), but also, all data for page_contents,

{
"id": 3,
"slug": "omnis-et-harum-atque",
"name": "Omnis et harum atque",
"page_content": {
    "id": 3,
    "subject_type": "App\\Listing",
    "subject_id": 3,
    "html_title": "Omnis et harum atque",
    "meta_title": "Omnis et harum atque",
    ... and a load more stuff I don't want,
    "created_at": "2019-05-23 09:16:37",
    "updated_at": "2019-05-23 09:16:37" 
}

How do I remove page_content from the returned data. The data is being returned for an API and so the page_data info is way over the top.

Laravel 5.8

Cheers

via Chebli Mohamed