translation.en: Sometimes what's going on is that the microbes are helping them digest food more efficiently from the same diet, so they're taking more energy from their food, but other times, the microbes are actually affecting their behavior.
translation.zh: 这是因为，有时候微生物 帮助它们更有效的消化同样的食物， 因此它们从食物中汲取了更多的能量， 但是其他时候， 微生物会影响寄主的行为。