After reading the article Gut Microbes for Life by Ed Young that discussed the relative long term stability of our gut flora I wondered if the way a mother chooses to feed her baby had any effect on the bacterial make-up of an infant’s gut and if that had any effect on long term health related to gastrointestinal diseases. All major medical associations recommend exclusive breastfeeding for 6 months followed by continued breastfeeding with the addition of age appropriate foods until at least 1 year of age. The health benefits of breastfeeding to both mom and baby have been researched extensively and are now accepted by much of the general population. Healthy People 2020 goals are to have 81.9% of moms initiate breastfeeding, 46.2% exclusively breastfeeding at 3 months, 60.6% breastfeeding at 6 months, 25.5% exclusive breastfeeding at 6 months, and 34.1% breastfeeding at 1 year. Even with the research highlighting the benefits of breastfeeding many mothers choose to formula feed their infants. The CDC 2012 Breastfeeding Report card shows only 76.9% of mothers initiating breastfeeding, 36% exclusive at 3 months, 47.3% breastfeeding at 6 months, 16.3% exclusive breastfeeding at 6 months, and only 25.2% at 1 year.
The intestinal flora is important for the development of the immune system and normal intestinal structure and function. Bifidobacteria. Bifidobacteria inhibits the growth of harmful bacteria and pathogens. The gut of a breastfed baby has a lower pH which promotes the growth of Bifidobacteria and also inhibits the growth of harmful bacteria. Formula fed infants have more harmful bacteria such as coliforms, enterococci and bacteroides. As formula fed infants age, they also will get more Bifidobacteria but the breastfed infants level remain many times higher.
Another way that breastfeeding helps promote gut health is through the development of biofilms that form a barrier against pathogens and infections. This is especially important for infants since the junctions of the gut mucosa are pretty open and allow pathogens to pass through easily. This is further augmented by sIgA that the mother produces and passes on through the breastmilk. These antibodies are specific to pathogens in the infant environment that have the potential to cause disease. This sIgA coats the gut and provides another layer of protection.
Breastmilk also contains human milk oligosaccharides, complex carbohydrates that are not in formula. These oligosaccharides help to promote healthy gut bacteria that initially protect the infant from infections. As the infant gets older, the oligosaccharides change and produce different fatty acids that help the immune system develop that provides protection against food allergies and asthma.
Research is just beginning to look at how the difference in bacteria, pH, biofilms and immunologic development from breastfeeding is affecting different intestinal disease. One study looked specifically at infants who had a high-risk for the development of Celiac Disease. Breastfeeding was shown to decrease the bacteria that were associated with the development of Celiac Disease. Breastfeeding increased the prevalence of B. uniformis bacteria that was more often seen in the low-risk group. A meta-analysis of research showed that breastfeeding was associated with a decreased risk of both Crohn's Disease and Ulcerative Colitis.