Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Participants were randomized into either the study or control groups (probiotic vs. placebo supplementation) with a random‐number sequence allocated to each participant number"
Allocation concealment (selection bias)	Low risk	Quote: "No differences in the colour and appearance of the probiotic and placebo were noted. The probiotic and placebo were blinded with the use of a colour‐coded label (orange or purple)"
Blinding of participants and personnel (performance bias)	Low risk	Quote: "The attending physician, nurses, researcher, research assistant and study participants were blinded to the group assignment"
Blinding of outcome assessment (detection bias)	Low risk	Quote: "The attending physician, nurses, researcher, research assistant and study participants were blinded to the group assignment"
Incomplete outcome data (attrition bias)	Low risk	Minimal loss to follow up
Selective reporting (reporting bias)	Low risk	Authors seem to report all the relevant outcomes
Other bias	Low risk	No other bias was noted