Jafari 2013.

Methods	Trial design: RCT. Trial grouping: parallel group. Randomisation method: not specified, "randomly divided".
Participants	Inclusion criteria CF with a positive elevated sweat chloride concentration (> 60 mEq/L), clinical symptoms and common mutations. Aged 2 ‐ 12 years. Absence of chronic illnesses other than CF. Informed consent by parents. Exclusion criteria Congenital heart disease. Abnormalities of the central nervous system. Intolerance to the medication. No parental consent. Inability to consume probiotic because of severe disease. Baseline characteristics Overall Participants: n = 37. Gender distribution, number (%) males: 20 (54.1%). Pancreatic insufficient (number; %): 37 (100%). Probiotic Participants: n = 20. Age, median (range) years: 5.36 (2.66). Gender distribution, number (%) males: 13 (65%). Pancreatic insufficient (number; %): 20 (100%). Placebo Participants: n = 17. Age, median (range) years: 5.50 (2.55). Gender distribution, number (%) males: 7 (41.2%). Pancreatic insufficient (number; %): 17 (100%).
Interventions	Probiotic Preparation: Protexin capsule containing L casei, L rhamnosus, S thermophilus, B breve, L acidophilus, B infantis, and L bulgaricus. Dose (probiotic): 2 x 109 CFU/day (2 capsules). Frequency of administration: daily. Duration: 1 month. Placebo Preparation: capsule (contents not specified). Dose (probiotic): 0. Frequency of administration: daily. Duration: 1 month.
Outcomes	Primary outcome measures HRQoL measured using the PedsQLTM 4.0 SF 15, post treatment absolute mean 3 and 6 months after completing the intervention period. Number of pulmonary exacerbations (defined using CF Foundation Criteria), post treatment absolute mean 3 months after completing the intervention period. Duration (days) of hospitalisation for pulmonary exacerbations. Time points for measurements: baseline, 1 month (end intervention), 4 months (3 months post treatment) and 7 months (6 months post treatment). Length of follow‐up: 30 weeks.
Identification	Country: Iran. Setting: Dr. Sheikh Pediatric Hospital CF clinic, Mashhad, Iran. Author's name: Atieh Mehdizadeh‐Hakkak. Institution: Cystic Fibrosis Clinic, Dr. Sheikh Pediatric Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. Email: aty_mehdizadeh@yahoo.com. Address: Number 21, 12th Felestin Street, Mashhad, Iran.
Funding Source	Research Chancellor of Mashhad University of Medical Sciences.
Declaration of Interest Among the Primary Researchers	No conflicts of interest.
Notes	The authors have compared probiotic participants with themselves in the previous year instead of against the placebo cohort; these data were not included in our review.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Patients were randomly divided into two groups of probiotic and placebo". Judgement comment: randomisation process not specified.
Allocation concealment (selection bias)	Unclear risk	Judgement comment: not specified.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "placebo capsules which contained all ingredients of probiotic capsules except the effective substance". Judgement comment: participants were blinded. Protocol states investigators were not blinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The questionnaires were filled out by a trained nurse who was unaware about the principles of study". Judgement comment: HRQoL assessment blinded. Pulmonary exacerbation assessment not blinded but defined based on consensus criteria.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "All patients enrolled in both groups (placebo group: 7 females, 13 males, mean age 5.36±2.66 years; placebo group: 10 females, 7 males, mean age 5.50±2.55 years) completed the study period". Judgement comment: all participants completed.
Selective reporting (reporting bias)	High risk	Judgement comment: growth outcomes (weight, height, head circumference and arm circumference) included in protocol (IRCT201205219823N1 ‐ this differs from registration number listed in the article which cannot be found) and not reported in paper. Also unclear why pulmonary exacerbations were not compared between probiotic and placebo groups. Adverse events not reported.
Other bias	Unclear risk	Judgement comment: unclear if Probiotics International Company, UK also provided the placebo product and if they had any influence on the study.