Database integration of Rails and Laravel apps

I have some very small apps on a VPS running ruby on rails and a co-worker also have some of his own apps running on laravel at another VPS. So far we dont needed to share any data among the apps, but we are currently developing something that would have some overlaping database tables like a Users table. How would you make that integration? Create a mysql database for all apps to connect? Is there someway to "replicate" Userupdates on a database to another one?