Table 1.

Body weight and brain size in perinatal conventionally colonized (CC) and germ-free (GF) mice.

Age	Microbiota Status
	CC	GF
Body weight (g)
E18.5	1.35 ± 0.02	1.43 ± 0.03
P0	1.56 ± 0.03	1.59 ± 0.07
P3	2.28 ± 0.06	2.58 ± 0.07***
Forebrain volume (mm3)
P3	12.67 ± 0.36	14.89 ± 0.40**

Mean ± SEM. N = 17 – 27 mice per group for body weight; N = 7 – 10 mice per group for forebrain volume.

^**p = 0.001,

^***p= 0.0002.