Iterate through users and display users meta info at front-page

Sometimes it is more useful to look at the task outside of the WordPress field, but from true programming.
You can use custom SQL query to get your users ids and then do what you want with them.

Place the code below into functions.php

function wpse_177536_get_user_ids(){
    global $wpdb;
    $sql = "SELECT user_id FROM $wpdb->usermeta WHERE meta_key='columnista-destacado' AND  meta_value="1" LIMIT 6";
    $user_ids = $wpdb->get_col($sql);
    return $user_ids;
}

Now anywhere, for example, in front-page.php you can call this function like this:

$user_ids = wpse_177536_get_user_ids();