How to apply Boostrap style on ajax return?

I have a list of checkbox (a list of filters), when i check one, it makes an ajax call to reload the content below, but it also reload the list of checkboxes (to update number of items displayed near each checkbox per example) At the first load of the page, no problem, bootstrap well style the checkboxes, but not the ones reloaded after ajax call.

How could I do to apply bootstrap on my ajax result before inserting it in the DOM

Tried to add both css and js in the returned list, but no success

Thank you for your time