Matsumoto 2014.

Methods	Eight‐week multi‐centre randomised double‐blind placebo‐controlled parallel trial
Participants	Forty‐four adults with moderate to severe atopic dermatitis diagnosed according to the criteria of Hanifin and Rajka were recruited. Randomisation was done at a 1:1 ratio: 22 participants were randomised in each arm. Participants continued to use their medications as usual and did not change quantities or levels of corticosteroid medicine during the experimental period. Participants were asked to avoid probiotic supplements, fermented milk, lactic acid bacterial drinks, and fermented soybean (natto) during the experimental period Recruitment took place at 8 dermatology clinics in Japan
Interventions	Participants in the intervention group received capsules containing approximately 6 × 10⁹ CFUs of Bifidobacterium animalis subsp lactis and an excipient that consisted of skim milk, glucose, inulin, dextrin, and silicone dioxide for 8 weeks Control group received capsules containing the excipient only for 8 weeks
Outcomes	• Itch score by behavioural rating scales and by 100‐mm visual analogue scale (VAS) at baseline and at 4 and 8 weeks • Skin severity score using the reference proposed by the Research Group granted by the Japanese Ministry of Health, Labor and Welfare at baseline and at 4 and 8 weeks • Quality of life using Skindex‐29 (Japanese version) at baseline and at 4 and 8 weeks • Faecal levels of B lactis at baseline and at 4 and 8 weeks
Notes	Trial registration: UMIN000005695 Four of the investigators/study authors are employed by the supplier
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "The 44 participants eligible for the study were randomly assigned to receive LKM512 capsule or a placebo by the masked quota director" Judgement: inadequate information on randomisation method; hence judgement of unclear risk of selection bias
Allocation concealment (selection bias)	Unclear risk	Inadequate information for a judgement
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	"Double‐blind" mentioned, but trial registration shows open‐label
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	"Double‐blind" mentioned, but trial registration shows open‐label
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information provided
Selective reporting (reporting bias)	Unclear risk	All outcomes reported but not numerically, and any favourable information/outcome for probiotics particularly analysed, even if not statistically significant
Other bias	High risk	Commercial bias: 4 investigators/study authors employed by supplier; likely that this has influenced the design and outcome of the trial