Passage Summary: A new treatment successfully reduces Salmonella in young chickens, but surprisingly, those same chickens end up with more total bacteria a week later than chickens that weren't treated at all.

Reasoning: Chicks treated for Salmonella showed lower infection rates than untreated chicks, yet a week later, the treated group had higher overall concentrations of various bacteria.

Analysis: We are looking for a way to reconcile a successful treatment with an increase in total bacteria. This is a classic biological trade-off scenario. If the treatment wipes out Salmonella, it might be clearing out the 'neighborhood,' allowing other, perhaps less harmful, bacteria to move in and multiply without competition. Look for an answer that explains how the reduction of one specific bacterial strain creates an opening for others to flourish.