Your mother's DNA may have determined your eye color, but some traits that you thought came from her may instead have come from the DNA of bacteria she passed on to you soon after birth
, a new study finds.
The study found that a mother mouse can pass along to her offspring a susceptibility to intestinal disorders, such as inflammatory bowel disease
, by way of a gut-residing bacterium called Sutterella,
the researchers reported in the journal Nature
Scientists have long speculated that a mother can transfer beneficial bacteria to her offspring through the birthing process and then through breast-feeding and kissing. These myriad bacteria species quickly spread and cover an infant's skin, mouth and digestive tract.
Inflammatory Bowel Disease
This new finding, however, is the first identification of a specific trait that an offspring can inherit — in this case, a deficiency of a blood protein called immunoglobulin A, or IgA,
which is the source of the bowel condition — caused by a specific bacterium that can be transferred from the mother to her offspring. IgA helps the body fight infection.
"The implications for mouse experiments are profound, and could help us cut through some persistent sources of confusion," in genetic research, said Dr. Thaddeus Stappenbeck, an immunologist at Washington University School of Medicine in St. Louis and a co-author of the new study.
Until now, most doctors have thought that IgA deficiency, seen in people with diseases such as chronic diarrhea, Crohn's disease and ulcerative colitis, is primarily hereditary, meaning the deficiency is inherited through one's genes. The new finding suggests that bacterial forces transmitted from mother to infant also are at play, perhaps to a significant extent.