Be my biological Valentine: Do microbes define physical attraction?

Small heart-shaped ornaments are displayed for Valentine's Day in a shop in Beirut February 13, 2009. REUTERS/Cynthia Karam (LEBANON) - RTXBKZM

Roses are red, violets are blue, and your microbiome makes me love you. Does it really? Well, according to one researcher, it does.

In an article published by the British Columbia Medical Journal, Bill Miller, a medical doctor who serves as a scientific advisor to OmniBiome Therapeutics, writes that sexual attraction between two people is determined by the microorganisms that make up each individual’s microbiome. So, what is a microbiome, you may ask? Think of it as a tiny microscopic ecosystem made up of microorganisms – or microbial cells – that exist in and on all of us. According to Miller, these cells actually outnumber our own innate cells by a factor of ten to one, and they may be able to influence emotional responses to stress, depression, and fittingly for Valentine’s Day, love.

“Nature sees you as an ecological collaborative of different types of things that are working together seamlessly,” Miller told Fox News.com. “The fact that these microbes outnumber your own cells 10-1 – well, the implication is really profound. These microbes impact things that we consider innately human.”

These microbes have an intimate connection to our bodies, and Miller asserted that we would not survive without them. Apparently, we wouldn’t be able to find a significant other without them either. Forget online dating or apps like Tinder. Our microbes are the ultimate matchmakers.

For instance, when two people kiss, microbes are shared between each individual’s mouth. The frequency of kisses does not necessarily drive attraction. Miller writes that there “is a shared linkage in microbial composition between the mouths of sexual partners that operates regardless of kissing frequency.” Essentially, a person’s microbial makeup might subconsciously influence who he or she is sexually attracted to.

When asked whether the idea that microscopic organisms could be influencing human behavior is discomfiting for people, Miller said that he finds this revelation “empowering.”

“There is this general idea that people need to change themselves to become more attractive. Maybe they will have to look for a significant other more actively, they have to figure out what will click for them and what won’t. There is this ‘I need to make myself more appealing’ aspect in all human relationships,” Miller said. “We are really only at the beginning of exploring the attractional effects on an immunological basis. It might be a little disturbing to some, but it’s true. What does this teach us about ourselves and our sexual attractions? What does it mean to look at this from a purely biological basis?”

For Miller, this all goes back to evolution. He said that attraction between people is all about a person finding another individual who is an “immunological complement.”

This research into microbial-based sexual compatibility ties into the hologenome theory of evolution, of which Miller is a proponent. This theory moves Darwinian theory away from an individual organism, and instead suggests that natural selection is based on an organism’s symbiotic relationship with its related microbial communities. The theory originated from studies on coral reefs, organic structures that contain abundant microbial communities. It’s certainly a theory that is not without its critics. However, Miller said that this theory takes Darwinism a step further.

“This theory accepts that the Darwinism that is fundamentally based on entire organisms in competition with each other is incomplete,” Miller said. “The real narrative that really counts is unseen to our eyes. You have two moose locking horns over a female. It seems like that is the full depiction of the story of evolution, right there. It’s really just a side show. The real narrative is immunology, the cellular dynamics within the organisms, the collaborative relationships between all of our cells. These cells have their own cognitive capacity, with the linkages and partnerships between microbes.”

“These things live and thrive,” he added. “It’s a combination of the seen and the unseen that defines sexual attraction.”