Whether a mother chooses a natural birth or a caesarean section depends on her individual circumstances, but the method of delivery may affect the baby’s immune system.A study by the Hong Kong Polytechnic University found that babies born by caesarean section have lower levels of probiotic strains in their gut. In particular, levels of ‘Bifidobacterium’ – a probiotic that helps babies develop a strong immune system – were only 1%, more than 30 per cent lower than in babies born vaginally, which may affect the development of the baby’s overall immunity.Paediatricians advise that it is still best for infants to acquire immunity through breast milk; otherwise, they can be supplemented with formula containing probiotics and prebiotics.
A research team from the Hong Kong Polytechnic University was recently commissioned by the food and beverage company Danone Nutricia to study the impact of different delivery methods on the development and nutrition of the infant gut microbiome. Since May last year, researchers have collected faecal samples from 70 newborns within two weeks of birth, using quantitative polymerase chain reaction (qPCR) to detect the number of bacterial species.
Qiu Jiaqi, a PhD student in the Department of Applied Biology and Chemical Technology at the Hong Kong Polytechnic University, pointed out that 38% of babies in Hong Kong are born by caesarean section, which is higher than the 33.7% figure in other Southeast Asian countries.She noted that research has found that the levels of Bifidobacterium in the gut of local babies born by caesarean section are only around 1% during the first two weeks, which is far lower than the approximately 35% found in babies born vaginally, and also lower than the approximately 10% found in Asian babies born by caesarean section.She explained that Bifidobacterium breve is the most common bacterial species found in the mother’s birth canal; consequently, the proportion of probiotics in the bodies of babies born vaginally is higher.
Chiu Ka-ki also cited foreign research stating that the gut microbiome of babies born by Caesarean section generally takes 3 to 5 years to catch up with babies born naturally. A lack of gut probiotics, such as Bifidobacterium, can potentially affect the infant's ability to develop good immunity.
An imbalance in a baby's gut microbiota makes them more prone to allergies.
Paediatric specialist Xu Ziyun stated that an imbalance in an infant’s gut microbiota can easily lead to allergic problems during their development, such as food allergies or eczema.She cited another study which found that babies born by caesarean section who were fed only standard infant formula had an average total count of bifidobacteria in their bodies that was significantly lower than that of babies born vaginally and breastfed; it took 12 weeks for them to catch up to the levels seen in their peers.however, if they are fed formula containing a combination of probiotics and prebiotics, they can reach levels equivalent to or even higher than those of breastfed infants within 3 to 5 days; their risk of developing skin problems and eczema is also 53% and 72% lower, respectively, than that of caesarean-delivered infants fed standard formula.
Xu Zijun pointed out that although newborns can supplement intestinal probiotics by breastfeeding early on, mothers may not be able to breastfeed due to sequelae from surgery such as anaesthesia or poor physical condition. She suggested consulting a doctor to choose a formula milk powder containing probiotics and prebiotics for infants, but noted that dosage and types of probiotics still need attention.
