Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	No clear data is available to support the assessment however the two groups were comparable after randomizations and allocation seems to be concealed. So less likely that randomizations was not done properly
Allocation concealment (selection bias)	Low risk	Quote: "To blind the trial the probiotic and placebo sachets were set in similar indistinguishable packages"
Blinding of participants and personnel (performance bias)	Low risk	Quote: "The control group was fed with milk and a placebo that was physically indistinguishable from the probiotic powder"
Blinding of outcome assessment (detection bias)	Low risk	Quote: "After starting the feeding, infants were observed continuously by a chart containing basic information like daily weight, feeding volume, abdominal girth, appearance of erythema of abdominal wall, loose stools with blood, vomiting, and orogastric tube suction volume. The amount of feeding was advanced slowly, if tolerated, with no more than a 20 ml/kg/d"
Incomplete outcome data (attrition bias)	Low risk	Quote: "Feeding was discontinued if there was any sign of feeding intolerance (defined as the presence of gastric aspirate in the amount that was more than a half of the previous feeding or abdominal distension)"
Selective reporting (reporting bias)	Low risk	Authors seem to report all the relevant outcomes
Other bias	Low risk	No other risk of bias was noted