Fig. 1.

The detail procedures for animal experiments in neonatal maternal separation (NMS) model (n = 8/group) and pseudo germ-free (GF) model (n = 6/group). a Neonatal pups were separated with mothers for 3 h daily (9 a.m. to 12 a.m) from postnatal days (PD) 1 to 14, while other pups staying with mother are controls. The GI motility of rats was elevated by defecation frequency and gut transit time at adulthood. Feces were collected from both groups for metabolomic and metagenomic analysis. In addition, 150 mg/kg of neomycin was twice daily treated to NMS rats from PD 56 to 70 for confirming the relationship between SLCFA-produced bacteria and host bowel motility. b The pseudo GF rats model was induced by intaking water of antibiotic cocktails (ABX) for ten consecutive days. Fecal microbiota from NMS or control donors were prepared as PBS suspension for oral gavage to GF rats from day 10 to 14. The stool frequency was monitored weekly 1 week after fecal microbial transplantation. Fecal samples were collected from day 0, 10, 21 and 35 for observing dynamic changes of fecal microbiota at duration of the experiment