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Microbial Changes during Pregnancy, Birth, and Infancy
Meital Nuriel-Ohayon1, Hadar Neuman1, Omry Koren1
1Faculty of Medicine, Bar-Ilan University Safed, Israel.
Insights
The maternal microbiome undergoes significant changes during pregnancy, influencing fetal development. Understanding these healthy microbial shifts is crucial for maternal and infant health outcomes.
Area of Science:
- Microbiology
- Developmental Biology
- Immunology
Background:
- Pregnancy involves significant physiological changes, including weight gain, hormonal shifts, and immune system alterations.
- The microbiome, a collection of microbes, plays an integral role in influencing and being influenced by these developmental processes.
Purpose of the Study:
- To review and summarize the known changes in microbiota composition across various body sites during pregnancy, fetal development, and early childhood.
- To highlight emerging research on the microbiome's role in healthy gestation and its potential impact on pregnancy complications.
Main Methods:
- Literature review summarizing existing research on microbiome composition and function during key developmental stages.
- Analysis of studies investigating microbial colonization in the placenta and fetus.
- Review of factors influencing the infant microbiome, such as delivery mode, feeding, and antibiotic exposure.
Main Results:
- The maternal microbiome composition changes significantly at sites including the gut, vagina, oral cavity, and placenta throughout gestation.
- Evidence suggests early microbial colonization of the placenta and fetus, challenging previous assumptions of a sterile environment.
- Factors like delivery mode, infant feeding practices, and antibiotic exposure are key determinants of the infant microbiome's development.
Conclusions:
- Understanding the dynamic changes in the maternal and infant microbiome during development is essential for distinguishing healthy microbial patterns from those associated with adverse outcomes.
- Emerging evidence indicates the microbiome plays a critical role from the earliest stages of life, potentially influencing long-term health.
- Further research is needed to elucidate the precise mechanisms by which the microbiome interacts with maternal physiological changes during pregnancy.
Abstract:
Several healthy developmental processes such as pregnancy, fetal development, and infant development include a multitude of physiological changes: weight gain, hormonal, and metabolic changes, as well as immune changes. In this review, we present an additional important factor which both influences and is affected by these physiological processes-the microbiome. We summarize the known changes in microbiota composition at a variety of body sites including gut, vagina, oral cavity, and placenta, throughout pregnancy, fetal development, and early childhood. There is still a lot to be discovered; yet several pieces of research point to the healthy desired microbial changes. Future research is likely to unravel precise roles and mechanisms of the microbiota in gestation; perhaps linking the metabolic, hormonal, and immune changes together. Although some research has started to link microbial dysbiosis and specific microbial populations with unhealthy pregnancy complications, it is important to first understand the context of the natural healthy microbial changes occurring. Until recently the placenta and developing fetus were considered to be germ free, containing no apparent microbiome. We present multiple study results showing distinct microbiota compositions in the placenta and meconium, alluding to early microbial colonization. These results may change dogmas and our overall understanding of the importance and roles of microbiota from the beginning of life. We further review the main factors shaping the infant microbiome-modes of delivery, feeding, weaning, and exposure to antibiotics. Taken together, we are starting to build a broader understanding of healthy vs. abnormal microbial alterations throughout major developmental time-points.
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