Ren 2010.

Study characteristics
Methods	RCT
Participants	150 preterm infants (most participants were very preterm)
Interventions	Probiotics (N = 79): Bifidobacterium infantis, Lactobacillus acidophilus, Bacillus cereus, and Enterococcus faecalis in milk feeds twice daily from day 7 after birth for 7 days (route translated as "oral or nasal"‐ presumed to refer to oro‐gastric or naso‐gastric tube) Control (N = 80): unsupplemented milk feeds
Outcomes	NEC
Notes	China (single centre, 2006‐2008) Translation from Chinese courtesy of Yuan Chi
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Drawing lots"
Allocation concealment (selection bias)	Unclear risk	Safeguards unclear
Blinding (performance bias and detection bias) All outcomes	High risk	Unmasked
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unable to assess
Selective reporting (reporting bias)	Unclear risk	Mortality and infection not reported