Gut microbiota in preterm infants receiving breast milk or mixed feeding

Table 2 Comparison of relative abundances of classes and phyla between the initial and final samples

	Type of feeding
	Breast milk, n = 21			Mixed, n = 19
	Initial, mean ± SD	Final, mean ± SD	P value	Initial, mean ± SD	Final, mean ± SD	P value
Class
Bacteroidia	7.468 ± 15	6.835 ± 14	0.782	1.890 ± 3	2.872 ± 11	0.612
Flavobacteria	0.245 ± 10	0.008 ± 0.004	0.106	0.404 ± 1	0.005 ± 0.005	0.041
Sphingobacteria	0.030 ± 0.09	0.001 ± 0.001	0.155	0.055 ± 0.1	0.002 ± 0.006	0.100
Cytophagia	0.030 ± 0.10	0.001 ± 0.002	0.208	0.0004 ± 0.001	0.063 ± 0.268	0.320
Actinobacteria	2.270 ± 2.0	4.519 ± 9	0.261	1.396 ± 2	3.520 ± 10	0.398
Bacilli	14.975 ± 17	17.794 ± 17	0.539	19.112 ± 29	20.131 ± 26	0.875
Clostridia	1.664 ± 30	3.525 ± 6	0.177	1.517 ± 2	5.084 ± 15	0.326
Mollicutes	4.334 ± 17	0.054 ± 0.076	0.274	4.424 ± 19	4.607 ± 20	0.324
Erysipelotrichia	0.0001 ± 0.0005	0.0006 ± 0.001	0.253	0.028 ± 0.06	0.0002 ± 0.0008	0.063
Negativicutes	1.038 ± 3.0	2.440 ± 5	0.138	0.387 ± 1	0.337 ± 0.813	0.857
Alphaproteobacteria	0.989 ± 1.0	0.017 ± 0.011	0.005	0.570 ± 1	0.237 ± 0.623	0.103
Betaproteobacteria	23.550 ± 27.0	0.643 ± 0.290	0.001	18.517 ± 28	12.789 ± 28	0.509
Deltaproteobacteria	1.585 ± 4.0	0.200 ± 0.593	0.081	0.163 ± 0.4	0.103 ± 0.168	0.582
Epsilonproteobacteria	0.130 ± 0.4	0.001 ± 0.002	0.179	0.009 ± 0.02	0.0009 ± 0.002	0.218
Gammaproteobacteria	40.831 ± 30.0	64.381 ± 24	0.004	51.063 ± 36	50.182 ± 34	0.921
Phylum
Bacteroidetes	7.775 ± 15	6.786 ± 14	0.667	2.350 ± 3	2.943 ± 11	0.762
Actinobacteria	2.282 ± 2	4.131 ± 9	0.373	1.396 ± 2	3.520 ± 10	0.391
Firmicutes	17.678 ± 19	23.761 ± 17	0.219	21.046 ± 29	25.553 ± 28	0.558
Proteobacteria	67.087 ± 24	65.243 ± 24	0.772	70.324 ± 31	63.314 ± 31	0.403