Your sexual partners can change your microbiome, mouse study finds

Scientists are beginning to understand the influence of the gut microbiome on the body’s immune system, but a new mouse studysuggests there may be another link in the chain: sexual partners. Mice that received stool from men who had anal intercourse had different microbiomes than mice whose stool donors only had vaginal intercourse. And looking at the mice’s immune systems, researchers found that the mice whose stool donors had anal intercourse also had a higher number of a subtype of T cell — a sign that these mice, had they been human, could be at increased risk for HIV infection.

Although this study does not show a link between the microbiome and HIV transmission in humans, “the data strongly suggests that there could be a link, and provides a strong rationale for doing those studies in humans,” Sam Li, the first author on the paper, tells STAT.