Basic genetics, as many school children know, shows how certain traits like eye color and height are passed from one generation to the next through the parents’ DNA. This process is well-established, but new research adds a surprising twist: DNA of bacteria that live in the body appear to be able to pass a trait to offspring in a way similar to the parents’ own DNA.
In terms of the kinds of traits, these, according to the authors, are linked to health and well-being. Previous studies suggest that commensal bacteria influence traits like weight and behavior. Up until now, it has been assumed that these bacteria are acquired through life. The new study argues that at least a proportion of these are passed from mother to child and that this process can influence immunity and inflammation.
The position is based on experiments conducted on mice. Here, scientists have shown that mice with a population of inherited bacteria are susceptible to a particular injury of the gut when they are exposed to a certain chemical. These bacteria, which increase the risk of the injury occurring, were shown to only be passed from the mother to the pup. The researchers think that the phenomenon could extend to such conditions as Crohn’s disease and ulcerative colitis.
The studies were triggered when researchers began questioning why strange results were occurring on studies with genetically modified mice. This led to an investigation into the possibility of mother-to-child gene transfer and the role of bacteria.
At present, the effect has only been observed with mice. Nonetheless, the researchers argue, there is no reason to think that the effect won’t occur with all animals. If the results are verified, then the revelation could mean that medics need to consider a significant new factor in putting together how genes influence health: the DNA of bacteria passed from mother to child.
The research has been reported to the science journal Nature, in a paper titled “Vertically transmitted faecal IgA levels determine extra-chromosomal phenotypic variation.”
