Phages, viruses that attack bacteria but don't affect humans, are one promising new avenue to combat bacterial infections.

噬菌体，一种能攻击细菌但不感染人体的病毒，是一个很有前景的对抗细菌感染的新途径。

Then, they added bacteria. They found that the lung cells were better protected from bacteria than those without the added phage virus.

然后加入细菌，他们发现与那些没有加入噬菌体病毒的细胞相比，这样的肺细胞能够得到的更好地保护来抵御细菌的侵入。