Dilli 2015.

Study characteristics
Methods	RCT
Participants	200 very preterm or VLBW infants
Interventions	Synbiotics (N = 100): Bifidobacterium lactis (5 x 109 colony‐forming units (cfu)) plus inulin (900 mg) added to human milk or formula once daily for 8 weeks (or until hospital discharge) Control (N = 100): maltodextrin powder placebo
Outcomes	NEC Death Invasive infection Length of hospital stay
Notes	Setting: Turkey (5 centres: 2011 to 14) Funding: not stated NB. This was a 4‐arm RCT‐ 2 other groups were probiotic only (N = 100) and prebiotic only (N = 100)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated sequence
Allocation concealment (selection bias)	Low risk	Sealed opaque envelopes
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Masked (placebo‐controlled)
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Masked (placebo‐controlled)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Complete reporting
Selective reporting (reporting bias)	Low risk	Unlikely
Other bias	Low risk	No evidence baseline imbalance