Canadian Research has "smoking gun" linking c-section babies to health problems later in life
C-sections alter baby‚Äôs gut bacteria, may affect newborn‚Äôs lifelong health, Canadian study shows
A new study carried out by Canadian researchers claims that babies delivered via C-sections have a higher risk of lifelong health problems.
Photograph by: File photo , Postmedia News
Caesarean section births may put babies at higher risk for lifelong health problems by altering the amount of ‚Äúgood‚ÄĚ bacteria in an infant‚Äôs gut, Canadian researchers are reporting.
Appearing this week in Canada‚Äôs top medical journal, the finding may help explain why babies delivered via C-sections are at increased risk of allergies and asthma, obesity, inflammatory bowel disease, diabetes and other illnesses.
The study is based on sophisticated DNA testing of 24 babies born in Winnipeg. After analyzing the babies‚Äô fecal samples, researchers found that infants born by C-section lacked a specific group of bacteria found in babies delivered vaginally.
Babies that were exclusively formula fed also had significant differences in their gut bacteria compared with breastfed babies.
‚ÄúThe infant gut microbiota plays a crucial role in lifelong health,‚ÄĚ the researchers write in the Canadian Medical Association Journal Among other things, bacteria prime a baby‚Äôs immune system, providing protection against disease-causing organisms.
‚ÄúWe want parents (and physicians) to realize that their decisions regarding C-section and breastfeeding can impact their infant‚Äôs gut microbiome and this can have potentially lifelong effects on the child‚Äôs health,‚ÄĚ first author Meghan Azad, of the University of Alberta, said in a statement released with the study.
In Canada, nearly 27 per cent of all babies are delivered via C-section, and fewer than 15 per cent of infants are exclusively breastfed for the recommended six months. Doctors say most surgical births are performed for medically valid reasons. But there are concerns too many C-sections are being ordered because labour isn‚Äôt progressing quickly enough, and that to many ‚Äúroutine‚ÄĚ but unnecessary interventions are now being done that increase the odds of a woman needing a surgical delivery.
In some parts of the world, ‚Äúelective‚ÄĚ C-sections are performed on demand at the mother‚Äôs request, often because women are worried about the pain of childbirth, and sometimes purely out of convenience for the woman and her doctor, the authors write.
Babies, like all mammals, ‚Äúare naturally inoculated as they pass through the birth canal,‚ÄĚ researchers from the University of Colorado and New York University School of Medicine write in a related commentary.
Yet C-sections are rising globally. In the U.S., more than 30 per cent of babies are now born by caesarean. In China and Brazil, nearly half of babies are born by C-section.
‚ÄúThe human body harbours trillions of microbes, known collectively as the ‚Äėhuman microbiome,‚Äô ‚ÄĚ the Canadian team writes in the CMAJ.
‚ÄúSome people call it the forgotten organ, because it protects us from pathogens and also helps in the absorption of nutrients,‚ÄĚ said Dr. Anita Kozyrskyj, research chair and an associate professor at the University of Alberta.
‚ÄúIncreasingly we‚Äôre learning that these good bacteria are quite important to the development of the immune system in the infant,‚ÄĚ she said. Among other functions, ‚ÄúThey train the immune cells not to overreact.‚ÄĚ
The gut microbiome is developed during the first year of life after birth. ‚ÄúWe start off with almost a clean slate,‚ÄĚ Kozyrskyj said. ‚ÄúDuring (vaginal) delivery, babies acquire mum‚Äôs microbes from her vagina and also from her GI (gastrointestinal) tract.‚ÄĚ These so-called ‚Äúfirst colonizers‚ÄĚ lay the foundation for other beneficial bacteria to colonize, she said.
For their study, stool samples were collected from the babies when they were three to four months old. Six, or one-quarter of the babies, were born via caesarean.
Using high-throughput gene sequencing technology, the team found that C-section babies had undetectable amounts of a Bacteroides species, an important gut bacteria involved in priming the immune system. They also had lower abundances of Escherichia-Shigella, one of those first colonizers.
Compared with breastfed babies, formula-fed infants had higher amounts of C. difficile, which has been linked to allergies and asthma later in life.
The study was based on only a small number of babies (the researchers are now testing 200 more infants; the hope is to sample more than 2,000 in the years ahead). It‚Äôs also not clear exactly what makes up the ‚Äúideal‚ÄĚ infant gut microbiome, or how much it influences health and disease later in childhood.
However, ‚Äúthere‚Äôs certainly lots of evidence to promote breastfeeding and vaginal delivery,‚ÄĚ said Kozyrskyj. Much of the focus on the rising number of C-sections has been on the risks to the mother, she said, but not babies.
‚ÄúThis evidence provides information on the harmful effects of caesarean section delivery on the infant.‚ÄĚ