J Dent Res 90(10)2011 Mode of Delivery and Oral Microbiota 1185 Table 1. Gender Proportions, Body Weight and Length, and Feeding Method for Infants Delivered Vaginally or by Caesarian Section Caesarian Section n=38 Boys/Girls(numbers) 16/10 19/21 0.264 51.1(50.0-522) 49.2(484-50.0 61.3(60.4-624 60.2(592-60.8) 0.100 Weight (g) 3603{3394-3813) 3425{3190-3660 0.202 at 3 mos of ag 6364(5986-6742) 6069{5807-6331 0.22 Breast-fed at 3 mos of age(%)3 sively or partially 0.836 Not at all 8 le missing values. Oral from four infants, three born by C-section and one vaginally, were not analyzed by microarray, because of low DNA yield 2Mean(95%CI limits). Differences of means were tested with Student's independent t test after confirmation of a normal distribution Differences in proportions were tested with the Chi2-test Table 2. Proportions (%)of Three-month-old Infants with a Positive HOMIM Signal by Genus Phylogenetic Group and Ger Vaginal Delivery(%) Caesarian Section(%) Actinobacteria 92.0 81.6 65.8 Bacteroides 8.0 0.076 16.0 0.0 0.011 0.0 Prevotella Firmicutes Eubacterium 13.2 0.752 Gemella 960 100.0 0.214 granulicatella 36.0 18.4 12.0 Solobacterium 20.0 0.293 0.055 Fusobacterium 44.0 34.2 0.434 Leptotrichia 44.0 0.006 ggregatibacter 0.363 280 8.0 0.0 0.076 5.3 TMZ Division 12.0 0.0 0.029 than in infants delivered by C-section (54 species/clusters) detected more frequently from C-section compared with vagi (p=0.001) Of the species or clusters detected, 31 were detected nally born infants were Slackia exigua (p <0.001)and only in infants born vaginally, compared with 6 species or Lactobacillus Cluster I (p <0.001)(Fig ) Haemophilus parain clusters that were detected only in C-section infants(Appendix fluenzae(p=0.005) was detected more frequently from vagi 1) nally delivered compared with C-section infants (Fig) The detection frequencies of 22 species and 2 clusters dif- Additional species/clusters displayed marginal fered between modes of infant delivery. Species or clusters els(p-values between 0.02 and 0.006; Fig.J Dent Res 90(10) 2011 Mode of Delivery and Oral Microbiota 1185 than in infants delivered by C-section (54 species/clusters) (p = 0.001). Of the species or clusters detected, 31 were detected only in infants born vaginally, compared with 6 species or clusters that were detected only in C-section infants (Appendix Fig. 1). The detection frequencies of 22 species and 2 clusters dif￾fered between modes of infant delivery. Species or clusters detected more frequently from C-section compared with vagi￾nally born infants were Slackia exigua (p < 0.001) and Lactobacillus Cluster I (p < 0.001) (Fig.). Haemophilus parain￾fluenzae (p = 0.005) was detected more frequently from vagi￾nally delivered compared with C-section infants (Fig.). Additional species/clusters displayed marginal significance lev￾els (p-values between 0.02 and 0.006; Fig.). Table 1. Gender Proportions, Body Weight and Length, and Feeding Method for Infants Delivered Vaginally or by Caesarian Section Vaginal Delivery n = 251 Caesarian Section n = 381 p-value Boys/Girls (numbers) 16/10 19/21 0.264 Length (cm)2 at birth 51.1 (50.0−52.2) 49.2 (48.4−50.0) 0.849 at 3 mos of age 61.3 (60.4−62.4) 60.2 (59.2−60.8) 0.100 Weight (g)2 at birth 3603 (3394−3813) 3425 (3190−3660) 0.202 at 3 mos of age 6364 (5986−6742) 6069 (5807−6331) 0.221 Breast-fed at 3 mos of age (%)3 Exclusively or partially 27 32 0.836 Not at all 73 68 1 Numbers vary slightly for various analyses due to single missing values. Oral samples from four infants, three born by C-section and one vaginally, were not analyzed by microarray, because of low DNA yield. 2 Mean (95% CI limits). Differences of means were tested with Student’s independent t test after confirmation of a normal distribution. 3 Differences in proportions were tested with the Chi2 -test. Table 2. Proportions (%) of Three-month-old Infants with a Positive HOMIM Signal by Genus Phylogenetic Group and Genus Vaginal Delivery(%) Caesarian Section(%) p-value Actinobacteria Actinomyces 92.0 81.6 0.247 Rothia 68.0 65.8 0.856 Bacteroidetes Bacteroides 8.0 0.0 0.076 Capnocytophaga 16.0 0.0 0.011 Porphyromonas 4.0 0.0 0.214 Prevotella 40.0 7.9 0.002 Firmicutes Eubacterium 16.0 13.2 0.752 Gemella 96.0 100.0 0.214 Granulicatella 36.0 60.5 0.057 Lactobacillus 16.0 63.2 0.000 Parvimonas 4.0 18.4 0.093 Selenomonas 12.0 10.5 0.856 Solobacterium 20.0 10.5 0.293 Streptococcus 100 100 1.000 Veillonella 84.0 97.4 0.055 Fusobacteria Fusobacterium 44.0 34.2 0.434 Leptotrichia 44.0 13.2 0.006 Proteobacteria Aggregatibacter 4.0 0.0 0.214 Campylobacter 40.0 28.9 0.363 Haemophilus 28.0 7.9 0.033 Kingella 8.0 0.0 0.076 Neisseria 8.0 5.3 0.663 TM7 Division 12.0 0.0 0.029