Carriage of microbial taxa at the genus level associated with skin to skin (STS) and non-STS exposure at grouped corrected gestational ages. Proportion of microbes in infant oral microflora in infants exposed to STS care and unexposed non-STS infants at sampling. STS (N = 22) at sampling gestational age ≤32 weeks (N = 10); 33–34 weeks (N = 7), and >35 weeks (N = 5) corrected age. Non-STS (N = 20), at sampling gestational age ≤32 weeks (N = 10); 33–34 weeks (N = 6), and >35 weeks (N = 4) corrected age. The predominant genera are Streptococcus (dark blue), Staphylococcus (red), Pseudomonas (green), and unclassified genus (tan).