People of the 21st century have lost empathy, as well as experiencing more social isolation, divorce, and suicide than prior decades--but why? Psychologists talk about lack of community, the dissolution of traditional families, over-reliance on technology, all of which are undoubtedly important contributors. But could there be a physical factor that could contribute to these social phenomena? And, if so, can it be remedied? I talk about how modern humans have lost a crucial microbial species from our intestinal microbiomes that, when replaced, restores the hormone oxytocin, the hormone of love, empathy, social connection, and youthfulness.