I was recently asked to do an in-service update on the microbiome and birth for a group of midwives. Always excited to dork out on anything birth and baby related, I was eager to accept the offer and wanted to make sure I was prepared with the most up-to-date information I could provide to empower these health professionals with the knowledge needed to support families in their birth decisions. What I intended to be a brief overview turned into a rabbit hole. I spent so much time researching on my computer that I started getting headaches (which I am not prone to) and I came up with over ten pages of notes for a 45-minute talk.
Needless to say, we didn't cover it all. 😉 We focused on GBS and section births in our talk but I accrued so much great information that I wanted to share it with all of you. So here we go!
What is the microbiome?
The human microbiota consists of the 10-100 trillion symbiotic microbial cells harboured by each person. The bulk of it is found as bacteria in the gut but it is also made up of all of the bacteria, viruses, parasites, and fungi all throughout your body. The human microbiome also includes the genes coded within these cells, which are unique and very different from ours, but still impact our health status.
Why does the microbiome matters?
There are 1000 answers to this question and multiple books, articles, and videos created to help explain why. I think this list from Turnbaugh gives a good overview of the impacts of the microbiota that are currently well understood.
The microbiome is important for:
- Harvesting otherwise inaccessible nutrients/energy from the diet and synthesizing vitamins;
- Xenobiotic metabolics and other metabotypes;
- Gut epithelial cell renewal and protection;
- Maturation and maintenance activity of the innate and adaptive immune systems; *This is a big deal! Keep this one in mind as you continue to read my microbiome blog series.
- Cardiac size; and
- Behaviour and association with neurodevelopmental and psychiatric disorders.
Bottom Line: There are implications in absolutely every field of study in human health, from gastroenterology to metabolic to immunology to psychiatric to developmental to perinatal. These bugs matter and we are in this together.
Are there any implications for birth?
Yes! Our in-utero, birth, and early development exposures have arguably the largest impact on our microbiome of any other experiences at any other time. Vaginal versus section birth, antibiotic exposure (in-utero, at birth, or in the first 2 years), and breastfeeding versus formula all have well-established and lasting impacts on our microbiome, and as a result, our metabolic and immune health.
Although there is a growing body of evidence in support of the in-utero transfer of microbiota from the placenta and amniotic fluid to the fetus, many scientists consider birth to be the initial seeding of our microbiome. Your mother’s intestinal and vaginal flora, her diet, any medications she may have been on, your birth environment, and the type of delivery that brought you into this world all played their part on shaping who you are today, as well as your risk factors for many disordered conditions. When a baby is born vaginally, their microbial cultures match those of mom. Within hours of delivery, the newborn’s “sterile” gastrointestinal tract is full of enterococci, staphylococci, streptococci, and enterobacteria. These early settlers set the stage; they alter the oxygen content and pH of the intestine, making it more fertile breeding ground for the anaerobic microbial colonization to come. Eventually, it will be the Bifidobacterium, Lactobacillus, and Bacteroidesfamilies that will take favourable reign over a stable, rich, and diverse kingdom.
Poor maternal diet, prenatal medication use (in particular, antibiotics and antidepressants), teratogenic toxin exposures, Caesarean-section deliveries, and formula-feeding are all commonplace in our modern world today. By no means am I saying that all these are evil. Each one has their place and the potential to save lives. However, there is one defining factor that they all have in common. They all disrupt the development of normal intestinal microbiota, a condition known as dysbiosis.
Intestinal dysbiosis predisposes infants to GI distress (which means more fussing for you), infections, eczema, and allergies. In the long-run, this early imbalance in tiny bugs plays a role in the development of allergies and asthma, susceptibility to infections, inflammatory bowel diseases, autoimmune conditions, diabetes, obesity, and certain types of cancer.
What can you do about it?
Keep reading. My intention is to create a series of overviews and updates on how the microbiota relates to various topics during pregnancy, birth, and early development. If you are impatient, here is a brief consideration. As presented in the documentary Microbirth, there are three big areas of focus at birth that can set baby up for success:
1 – Vaginal Birth
2 – Early Skin-on-skin Contact
3 – Exclusive Breastfeeding
That's obviously not a complete picture, but in a nutshell, those are the biggies that can either work for or against you. We will explore them more in-depth over the next set of blogs.
- Alexander C, Rietschel ET. Bacterial lipopolysaccharides and innate immunity. J Endotoxin Res. 2001;7(3):167-202.
- Bettelheim KA, Breadon A, Faiers MC, O'Farrell SM, Shooter RA. The origin of Oserotypes of Escherichia coli in babies after normal delivery. J Hyg (Lond) 1974; 72:67-70.
- Brook I et al. Aerobic and anaerobic bacterial flora of the maternal cervix and newborn gastric fluid and conjunctiva: a prospective study. Pediatrics 1979; 63:451-5.
- Collado M et al. Human gut colonisation may be initiated in utero by distinct microbial communities in the placenta and amniotic fluid. Scientific Reports. 2016; 6(23129).
- Fanaro S, Chierici R, Guerrini P, Vigi V. Intestinal microflora in early infancy: composition and development. Acta Paediatr Suppl 2003; 91:48-55.
- Favier CF, Vaughan EE, De Vos WM, Akkermans AD. Molecular monitoring of succession of bacterial communities in human neonates. Appl Environ Microbiol 2002; 68:219-26.
- Mackie RI, Sghir A, Gaskins HR. Developmental microbial ecology of the neonatal gastrointestinal tract. Am J Clin Nutr 1999;69:1035S-45S.
- Martinez FD et al. Role of microbial burden in aetiology of allergy & asthma. Lancet.1999; 354: SII12-15.
- Documentary: Microbirth. Microbirth.com
- Salminen S, Gueimonde M. Gut microbiota in infants between 6 and 24 months of age. Nestle Nutr Workshop Ser Pediatr Program 2005;56:43-56.
- Turnbaugh PJ et al. The human microbiome project: exploring the microbial part of ourselves in a changing world. Nature. 2007 Oct 18; 449(7164): 804–810.
- Ursell LK, Metcalf JL, Parfrey LW, & Knight R. Defining the Human Microbiome. Nutr Rev.2012 Aug; 70(Suppl 1): S38–S44.
- Vantanen T. Variation in Microbiome LPS Immunogenicity Contributes to Autoimmunity in Humans. Cell. 2016; 165(4): 842-853.