Babies born by caesarean section (also known as caesarean section) miss a smear of bacteria from their mother’s vagina as they pass through the birth canal, which affects the newborn’s microbiome and may or may not affect their future health and development as Good.
As scientists try to find out, a small new study led by researchers at China’s Southern Medical University suggests the practice of sow vaginally‘, in which a cotton pad is doused with a mother’s vaginal fluid and smeared on the newborn baby, can be an effective way to rebalance the gut bacteria after a cesarean section.
Vaginal seeding could even have a positive impact on a child’s short-term brain development, at least during the first six months of life, researchers argue, though much more research is needed before the practice can be properly recommended.
In the current experiment, the lips, skin, and hands of 32 newborns born by caesarean section were treated with a carefully screened vaginal swab taken from their mothers 2 hours before birth. Babies were wiped for about 15 seconds and were not bathed for the first 12 hours.
Six weeks later, these babies’ poop contained more of their mother’s bacteria and more adult bacteria than 36 other babies born by cesarean section who had only been wiped with simple saline.
Six months after birth, children who received the vaginal swab scored higher on a brain development survey completed by their parents, compared to those smeared with saline. Their scores were similar to the development of babies born vaginally, researchers say.
All parents were blind to their baby’s treatment.
“We don’t know exactly how early gut bacteria affect their neurological development,” admits Yan He, who studies the microbiome at Southern Medical University, “but there is some circumstantial evidence showing that some microbial metabolites are linked to disease.”
For example, some bacteria, such as lactobacilli, were more dominant
the stool of babies who have had a vaginal smear. This is interesting if Lactobacillus is shown improvement of a neurological condition in an animal model.
However, it is not clear whether the Lactobacillus levels detected in the current study have long-term effects on baby brains.
While caesarean babies show a different array of bacteria in their guts compared to babies born vaginally, some studies to suggest the differences disappear after about 9 months. The current study tested babies’ microbiomes for just 42 days.
It is true that at a population level, some studies have linked C-sections to an increased risk of childhood obesity, asthma and diabetes later in life.
But whether that association is directly driven by gut bacteria in babies or can be alleviated with vaginal seeding remains unclear.
To date, there simply isn’t enough evidence to recommend vaginal seeding after cesarean delivery. The proposed benefits are based on uncertain science and there are potentially serious and fatal consequences if babies are accidentally exposed to harmful pathogens.
The British medical journal and the American College of Obstetricians and Gynecologists in the United States both warn against the practice.
That doesn’t mean there’s no point in studying the effects in a highly controlled clinical trial. But there is reason to remain sceptical.
In 2018, a major review of vaginal seeding studies found no support for the practice.
Instead, researchers argued that vaginal seeding studies should compare babies born via cesarean section to babies born via vagina, which the current study did not.
“If babies get vaginal bacteria through the vagina, we would expect to find these bacteria in babies born this way, but this is not the case,” said microbiologist Lisa Stinson of the University of Western Australia in 2018.
“Microbes that become unbalanced in babies born by cesarean section are very similar to the microbes that become unbalanced in babies born to mothers who receive antibiotics but deliver vaginally. This is an underlying problem.”
What’s more, in 2020, the authors of a Pilot study argued that what cesarean babies really missed was not exposure to their mother’s vaginal bacteria, but exposure to her gut bacteria.
By comparing the microbiomes of babies born vaginally and by caesarean section, researchers found that “vaginal swabs [C-section-induced] imbalance in the microbiota,” compared to vaginally born babies.
But a poop transplant does.
Yan He and his colleagues plan to continue studying the potential effects on neurodevelopment of vaginal seeding, but it’s worth bearing in mind that there may be more to the story than missing bacteria in part of the body. body.
The study is published in Cell Host & Microbe.