Antibodies from it can neutralize short RNA molecules in the baby’s intestines
Russian biologists have found that breast milk has antibodies that can break down short RNA molecules. This can affect the immune system of the baby’s intestines. The results of the study are published by the Journal of Dairy Science, briefly written about it “Science in Siberia.”Everyone believes that breast milk is just a biological liquid consisting of water, sugar, vitamins, and protein. In fact, it includes a huge amount of proteins performing different functions, and therefore very different from different milk mixtures. Including it has antibodies that protect the child from a variety of infections,” said one of the authors of the paper, a researcher at the Institute of Chemical Biology and Fundamental Medicine of so RAS Sergey Sedykh
Studies show that infants who are fed breast milk suffer from intestinal infections in a very different way than newborns who eat artificial mixtures. This effect persists even in adulthood. Scientists believe that this is due to the gut microbiome, which is formed also due to bacteria and antibodies that are found in breast milk.
Unlike antibodies in the blood, which fight against various infections, the antibodies in milk only remove the pathogens from the baby’s intestines outwards. At the same time, they begin to work only in the intestines, and not in the milk itself. Previous studies show that the nursing woman has more antibodies with catalytic activity in the blood and milk. Scientists suggest that such antibodies can not only bind and neutralize pathogens but also cut into pieces of DNA and RNA.
In a new study, Russian biologists have proven that this is true on microRNA molecules. Their length is only about 20 nucleotides, “letter” of the genetic code. During the experiments, the scientists isolated antibodies from breast milk and mixed them with specially created microRNAs. It turned out that antibodies neutralize such molecules.
Two different types of antibodies from breast milk (IgG and sIgA) can neutralize short RNA, the tasks of which have not yet been fully understood. Perhaps it is some unknown function of the immune system of the intestines, which is necessary for the entire immune system to work in a complex,” explained another author of the work, a Ph.D. student at IHBFM SO RAS Ivan Kompaneets.
Thus, antibodies from breast milk limit the amount of short RNA that can reach the baby’s gut receptors. At the same time, the experiments revealed that antibodies act the same on all types of microRNAs, without becoming specific to any particular molecules.
So far, the results of the study are purely fundamental. However, scientists are trying to understand how they can be applied in practice. In particular, they can be used in the production of infant formula: they can be further enriched with antibodies from breast milk, or artificially create antibodies with the specific properties of protective antibodies from breast milk.