The Placental Microbiome and Preterm Birth: An Evolutionary Life History Perspective

This work sequenced the placental microbiome of preterm and full-term pregnancies, and related preterm/full-term variations in placental microbiome composition and function to maternal inflammation in order to evaluate the proximate roles of the placental microbiome in responding to maternal immune stress and determining gestation length. These findings were situated in an evolutionary life history framework based on reproductive-immune trade-offs in order to develop an ultimate explanation for why natural selection has left us vulnerable to preterm birth, and why some populations are more affected than others. The preterm placental microbiome was found to be characterized by an inflammatory microbiome, dominated by bacteria that multiply in the context of energetic stress. The presence of such high numbers of these bacteria at the preterm placenta suggests that energetic and immune stresses are occurring in preterm birth, and that there may be a bidirectional relationship between stressful conditions and the microbiome. That is, inflammation or other stressors that contribute to energy imbalance may encourage shifts in the microbiome, which in turn creates more inflammation and energy imbalance. When that happens, pregnancy may become unsustainable before reaching term. Conversely, term pregnancies were characterized by greater numbers of beneficial, anti-inflammatory bacteria, hinting at possible roles for a healthy placental microbiome in nourishing and protecting the fetus. These findings underscore the need for a more holistic view of the role of microbes in pregnancy, as well as the need for health interventions that identify and address root sources of energetic and immune stress.

Grantor dc:publisher

Temple University. Libraries

Year dc:date.issued

2019

Author dc:creator

• Almskaar, Kristin

Advisor dc:contributor.advisor

• Rockwell, Christie

Committee members dc:contributor.committeemember

• Weitz, Charles A.
• Newman, Jessica
• Taylor, Brandie DePaoli

• Evolution and development

Statement dc:rights

• IN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available.

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/20.500.12613/2069

OAI identifier oai:identifier

oai:scholarshare.temple.edu:20.500.12613/2069