It’s unlikely that eating naturally fermented foods like homemade pickles would “overgrow” a certain bacteria in a harmful way... especially if your overall diet is diverse. The gut is a complex ecosystem that thrives on balance and variety. When that microbial harmony is maintained, it actually helps keep any one strain from dominating. Problems usually arise not from too much of one good bacteria, but from a lack of diversity or an overgrowth of harmful microbes... often caused by processed foods, antibiotics, or chronic inflammation. Fermented foods tend to support that balance, not disrupt it.