A tiny orgy has taken over the human stomach. To live, the microorganisms in our digestive tract engage in regular'sex' with one another, all in the name of exchanging secrets on how to withstand lethal dosages of antibiotics.
Of course, bacteria lack genitals, but in biology,'sex' refers to any procedure that involves the exchange of genetic material.
A germ may transmit its DNA to another microbe in our gut by creating a 'temporary marriage' with another bacterium - it doesn't have to be the same species.
The research focused on the Bacteroidetes phylum of gut microorganisms, which account for up to 80% of the human microbiome and are essential digesters.
"Without these bacteria, the huge, lengthy molecules from sweet potatoes, beans, whole grains, and vegetables would flow right through our systems," says scientist Patrick Degnan of the University of California, Riverside.
Because most gut microorganisms lack the capacity to generate these essential substances on their own, they must rely on what they can get from their surroundings.
"This discovery excites us because it demonstrates that this mechanism isn't just for antibiotic resistance," explains Degnan.
"Anything that boosts a microbe's capacity to survive, including exchanging [genes for the transport of] vitamin B12, is presumably employed for horizontal gene exchange across microorganisms."
Researchers studied the genome of the receiving bacteria, which was still alive, after the procedure and discovered that it had integrated an additional band of DNA from the donor.
Something similar appears to occur with live mice. After giving a mouse two types of Bacteroidetes, one with the genes for transferring B12 and the other without, researchers discovered that the genes of the former had 'jumped' to the genes of the latter after five to nine days.
The findings show that when it comes to bacterial sex, there may be a slight'species barrier.' Although, unlike mammals, where a species may only reproduce with another of its kind, there is no such barrier.
Bacteria, it appears, aren't nearly as choosy about their mates as we are, and our stomachs thank them for it.