Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization was done using an online service (www.randomization.com)"
Allocation concealment (selection bias)	Low risk	Quote: "Serially numbered opaque sealed envelopes with the allocation were available with the in‐charge nurse of the NICU, who dispensed the intervention in a syringe for oral administration"
Blinding of participants and personnel (performance bias)	Low risk	Quote: "All probiotic and sterile water mini bottles were coded and labels concealed"
Blinding of outcome assessment (detection bias)	Low risk	Quote: "All the investigators were blinded to the intervention"
Incomplete outcome data (attrition bias)	Low risk	Minimal loss to follow up
Selective reporting (reporting bias)	Low risk	Authors seem to report all the outcomes irrespective of their statistical significance
Other bias	Low risk	No other risk of bias was noted