01 Feb Microbiome Can Be Partially Restored in C-Section Delivered Babies
MedicalResearch.com Interview with:
Maria Dominguez-Bello, PhD
Associate Professor, Department of Medicine, Division of Translational Medicine
NYU Langone Medical Center and
Jose Clemente, PhD
Assistant Professor, Departments of Genetics and Genomic Sciences, and Medicine
Icahn School of Medicine at Mount Sinai
Medical Research: What is the background for this study? What are the main findings?
Response: Humans and animals are a composite of their own cells and microbes.
But where they get their microbes from? For mammals, labor and birth are major exposures to maternal vaginal bacteria, and infants are born already with a microbiota acquired from the mother.
Mom’s birth canal is heavily colonized by bacteria that are highly related to milk: some will use milk components and become dominant during early development, an important window for maturation of the immune system, the intestine and the brain. Thus, the maternal vaginal microbiota is thought to be of high adaptive value for newborn mammals. Indeed, studies in mice confirm that microbes acquired at birth are important to develop adequate immune and metabolic responses, and the mature adult microbiome will continue to modulate host metabolism and immunity.
Humans are the only mammals that interrupt the exposure to maternal vaginal microbiota, by delivering babies by Cesarean section. C-sections save lives of babies and moms, and they are estimated necessary in 10-15% of the cases. But most Western countries have rates above 30%, with the notable exception of the Scandinavian countries, Holland and Japan, which have excellent health systems and low maternal-infant mortality rates.
Previous work by us an others has shown that infants born by C-section acquire different microbiota at birth, and those differences are sustained over time, altering the normal age-dependent maturation of the microbiome. The fundamental questions are then, can we restore the microbiota of Cesarean delivered babies? And if we can, does that reduce the associated disease risks? In relation to the first question, we present here the results of a pilot study in which infants born by Cesarean delivery were exposed to maternal vaginal fluids at birth.
A total of 18 infants were recruited for the study. Seven of them were vaginally delivered, the remaining 11 were born by scheduled C-section. Among the C-section infants, 4 were exposed to maternal vaginal fluids at birth and 7 were not. We sampled all infants and their mothers for the first month of life across different body sites (oral, skin, anal, maternal vagina) and determined the microbiome composition on a total of over 1,500 samples.
Medical Research: What should clinicians and patients take away from your report?
Response: The microbiota of C-section babies exposed to maternal vaginal fluids was more similar to that of vaginally born infants than of unexposed C-section infants. In particular, we observed an enrichment in Lactobacillus and Bacteroides in the anal and skin samples vaginally delivered babies and exposed C-section babies, which were nearly absent in unexposed C-section babies.
Despite the small number of subjects, our study shows significant differences in the bacterial communities of C-section infants exposed to their maternal vaginal fluids, whose microbiota is partially restored and more similar to vaginally delivered infants.
Medical Research: What recommendations do you have for future research as a result of this study?
Response: We’d like to emphasize that labor is a complex process beyond the mere transfer of microbes, and that cannot be fully recaptured by our procedure. Our results establish feasibility but not health outcomes, and larger studies in populations at risk will be needed to determine if transferring of vaginal microbes to the newborn can be translated into reducing disease risks associated with C-section birthing.
Maria G Dominguez-Bello, Kassandra M De Jesus-Laboy, Nan Shen, Laura M Cox, Amnon Amir, Antonio Gonzalez, Nicholas A Bokulich, Se Jin Song, Marina Hoashi, Juana I Rivera-Vinas, Keimari Mendez, Rob Knight, Jose C Clemente. Partial restoration of the microbiota of cesarean-born infants via vaginal microbial transfer. Nature Medicine, 2016; DOI:10.1038/nm.4039
Maria Dominguez-Bello, PhD, & Jose Clemente, PhD (2016). Microbiome Can Be Partially Restored in C-Section Delivered Babies