The Influence of Different Maternal Microbial Communities on the Development of Infant Gut and Oral Microbiota

Very few studies have analyzed how the composition of mother's microbiota affects the development of infant's gut and oral microbiota during the first months of life. Here, microbiota present in the mothers' gut, vagina, breast milk, oral cavity, and mammary areola were compared with the gut and oral microbiota of their infants over the first six months following birth. Samples were collected from the aforementioned body sites from seven mothers and nine infants at three different time points over a 6-month period. Each sample was analyzed with 16S rRNA gene sequencing. The gut microbiota of the infants harbored distinct microbial communities that had low similarity with the various maternal microbiota communities. In contrast, the oral microbiota of the infants exhibited high similarity with the microbiota of the mothers' breast milk, mammary areola and mouth. These results demonstrate that constant contact between microbial communities increases their similarity. A majority of the operational taxonomic units in infant gut and oral microbiota were also shared with the mothers' gut and oral communities, respectively. The disparity between the similarity and the proportion of the OTUs shared between infants' and mothers' gut microbiota might be related to lower diversity and therefore competition in infants' gut microbiota.Peer reviewe

The Effect of Maternal Microbial Communities and Preterm Birth on the Development of Infant Gut Microbiota. Ema mikroobikoosluste ja enneaegse s\ufcnni m\uf5ju imiku seedetrakti mikrobioota kujunemisele

Doctoral thesis 46/2019 Doktorit\uf6\uf6 46/201

Mean (±SD) values of selected parameters of vaginal environment within bacterial community groups.

<p>Mean (±SD) values of selected parameters of vaginal environment within bacterial community groups.</p

The distribution of 10 most relatively abundant OTUs in determined vaginal bacterial community groups.

<p>The distribution is presented based on mean relative abundance values (x-axis) of these OTU-s among bacterial community groups (y-axis).</p

Relative abundance of bacterial OTUs found in the vaginal communities of healthy Estonian women (n = 432).

<p>Bacterial taxonomic assignments are indicated on the right of the heatmap at the Genus and Species level. The relative abundance is color coded and indicated by the color key on the left top of the map. The tree on the top of the heatmap characterizes the similarity of analyzed samples based on OTU composition of vaginal microbiota.</p

Relative abundance of the most abundant bacterial and fungal OTUs found in the vaginal communities of 181 women.

<p>Taxonomic assignments are indicated on the right of the heatmap at the Genus and Species level. The relative abundance is color coded and indicated by the color key on the left top of the map. The tree on the top of the heatmap characterizes the similarity of analyzed samples.</p

The prevalence and summarized relative abundance of predominant fungal taxa.

<p>The prevalence and summarized relative abundance of predominant fungal taxa.</p

Distribution of 432 samples according to number of sequences and number of OTUs.

<p>The cutoff value is set to 400 sequences. Round and square brackets in the figure indicate to the exclusion and inclusion of adjacent value, respectively.</p

Two-dimensional (2D) plots describing the principal component analysis (PCA) of OTU composition among analyzed samples.

<p>The plots represent 2D projections of a multidimensional analysis where the relative abundance of each specific OTU defines a dimension. Both plots are the projection of the same analysis viewed at a different angle. The plots visualize the clustering and variability of studied vaginal bacterial communities. First (a) 2D plot of the first two PCA components describes the clustering of groups I–V. Second (b) 2D plot of third and fourth PCA component confirms that the samples belonging to non-classifiable group (0) are not clustering into separate or any other entity. The variance described by the respective PCA components (Axis-1 and Axis-2) is written in brackets.</p