Maternal & Child Health Series
July 17, 2017
Pregnancy is a dynamic event where a mother's body changes in unbelievable ways, including physiologically, immunologically, hormonally and metabolically. The most amazing event is the change in the immune system from the aggressive infection fighting TH1 baseline to a TH2 mediated baby protecting mode. This occurs because the baby has 50% of dad's genes prompting the immune system to change in order to prevent the baby from being attacked and aborted. This effect is also highlighted by women with autoimmune diseases like Crohns that spontaneously improve once they become pregnant. Unfortunately, many become ill again after the child is born. The complexities of the immune system are still beyond complete understanding for us, however, we are learning.
The microbiome is the latest area of research that is shedding light on how pregnancy outcomes are determined. The maternal microbiome is defined as the community of organisms that inhabit a woman's mucosal and skin surfaces. These organisms are bacteria, fungi, archae and viruses. These opportunistic players affect us in ways previously thought impossible. "We hypothesize that an appropriate microbiota is essential for healthy early development, pregnancy maintenance, and the first years of childhood." (3)
What is becoming clear now is that alterations in the maternal microbiome can alter the events of pregnancy including the timing and normalcy of labor as well as inflammation and glucose metabolism. Any alteration that can negatively affect a pregnancy and healthy birth is of profound interest to us. We also know that the maternal microbiome directly affects a newborn's microbiome and in turn her health long term. The infant's microbiota at any time in infancy is most similar to the mother's microbiota during the first trimester despite the fact that her microbiome changes dramatically over the 10 months of pregnancy toward a reduced biodiversity (less species) and a metabolic storage/weight gain pattern. The reasons behind this shift are still unknown but thought to be related to energy storage in preparation for breastfeeding. (2) This change in microbes is very similar to the dynamic shifts that a mother's breast milk undergoes over the course of the first year to suit the babies growth and ever changing needs.
Another interesting finding is that the microbiota of the third trimester pregnant female is very similar to a patient with metabolic syndrome defined as a person with obesity, elevated blood sugar, high blood pressure and abnormal lipids. Clearly, these microbes have the ability to enhance energy extraction and storage for defined events like starvation, pregnancy and lactation. (2) While these changes are highly beneficial for pregnancy, they are devastating for a child or adult that consumes a standard American high fat, refined carbohydrate diet.
A 2012 study published in the Journal Cell by a group led by Dr. Koren studied the effects of transferring intestinal microbes from the first and third trimesters of pregnancy into germ free mice to assess the microbes metabolic effects in a non pregnant state. What they found is as follows: "The transfer of specific gut microbiota to otherwise healthy germ-free wildtype mice is sufficient to induce symptoms of metabolic syndrome, which, in addition to inflammation, include reduced insulin sensitivity and excess weight gain" (2)
This study proves that the microbes are the cause of the change in metabolism to a storage energy profile. The consequences of this effect are fabulous if you are consuming a healthy diet that is based on whole foods and anti-inflammatory principles. Unfortunately, we see mothers-to-be eating a standard American diet that causes these microbiome effects to become deleterious causing increased inflammation and poor glucose control signs constant with early metabolic syndrome. Subsequently, these events affect the infants long term health.
When asking the question as to whether these changes affect labor and delivery outcomes, the early evidence seems to point to the answer being yes.
In summary, from previous articles and research, it is well known that the healthiest and most diverse human gut microbiome comes from a diverse anti-inflammatory predominantly plant based diet like the Mediterranean type. If the current research is correct, then a mother-to-be should heed this advice to alter the long-term outcome of not only her pregnancy, but also the health of her bundle of joy.
Mothers are awesome,
Drs. Grey and Magryta