title: Human gut colonisation may be initiated in utero by distinct microbial communities in the placenta and amniotic fluid.
abstract: Interaction with intestinal microbes in infancy has a profound impact on health and disease in later life through programming of immune and metabolic pathways. We collected maternal faeces, placenta, amniotic fluid, colostrum, meconium and infant faeces samples from 15 mother-infant pairs in an effort to rigorously investigate prenatal and neonatal microbial transfer and gut colonisation. To ensure sterile sampling, only deliveries at full term by elective caesarean section were studied. Microbiota composition and activity assessment by conventional bacterial culture, 16S rRNA gene pyrosequencing, quantitative PCR, and denaturing gradient gel electrophoresis revealed that the placenta and amniotic fluid harbour a distinct microbiota characterised by low richness, low diversity and the predominance of Proteobacteria. Shared features between the microbiota detected in the placenta and amniotic fluid and in infant meconium suggest microbial transfer at the foeto-maternal interface. At the age of 3-4 days, the infant gut microbiota composition begins to resemble that detected in colostrum. Based on these data, we propose that the stepwise microbial gut colonisation process may be initiated already prenatally by a distinct microbiota in the placenta and amniotic fluid. The link between the mother and the offspring is continued after birth by microbes present in breast milk.
authors.affiliation: Functional Foods Forum, University of Turku, Itäinen Pitkäkatu 4A, 20520, Turku, Finland.|Department of Biotechnology, Institute of Agrochemistry and Food Technology, National Research Council (IATA-CSIC), Av Agustin Escardino 7, 49860, Paterna, Valencia, Spain.
authors.forename: Maria Carmen
authors.initials: MC
authors.lastname: Collado
authors.affiliation: Department of Paediatrics, University of Turku and Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland.
authors.forename: Samuli
authors.initials: S
authors.lastname: Rautava
authors.affiliation: Functional Foods Forum, University of Turku, Itäinen Pitkäkatu 4A, 20520, Turku, Finland.|Food Chemistry and Food Development, Department of Biochemistry, University of Turku, Vatselankatu 2, 20500, Turku, Finland.
authors.forename: Juhani
authors.initials: J
authors.lastname: Aakko
authors.affiliation: Department of Paediatrics, University of Turku and Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland.
authors.forename: Erika
authors.initials: E
authors.lastname: Isolauri
authors.affiliation: Functional Foods Forum, University of Turku, Itäinen Pitkäkatu 4A, 20520, Turku, Finland.
authors.forename: Seppo
authors.initials: S
authors.lastname: Salminen
mesh_terms: D000653:Amniotic Fluid / Q000382:microbiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007422:Intestines / Q000196:embryology / Q000382:microbiology*; D008297:Male; D064307:Microbiota; D010920:Placenta / Q000382:microbiology*; D011247:Pregnancy