Even a single remedy with antibiotics adjustments the intestinal flora completely, generally for a few years. However, some treatments have longer-term penalties than others.
https://www.spiegel.de/wissenschaft/medizin/studie-zu-spaetfolgen-antibiotika-koennen-mikrobiom-im-darm-fuer-acht-jahre-schaedigen-a-59c5344a-d693-4c37-809a-53dacc22fb9d#ref=rss