From:  Systematic review of probiotic supplementation in Alzheimer’s patients with results on cognitive function, health biomarkers, and microbiota

 PICOS-based eligibility criteria for study inclusion and exclusion.

CriteriaInclusion criteriaExclusion criteria
Population ‘P’Adult men and/or women over the age of 18 who are Alzheimer’s patients.Participants diagnosed with any other neurodegenerative disease (Parkinson’s), psychiatric disorders, depression, or alcoholism other than Alzheimer’s. Patients were diagnosed with chronic gastrointestinal diseases.
Participants who received any type of medication or treatment: immunosuppressants, steroids, antibiotics, chemotherapy, and probiotics in at least the last 4 weeks. Participants with a history of recreational drug abuse.
Intervention ‘I’To include a supplementation intervention that involves the use of probiotics as monotherapy, with clear information on the dose and duration of supplementation.Administration together with other nutritional supplements. Studies in which probiotics were administered in combination with other nutritional interventions (e.g., specific diets or non-probiotic supplements) were excluded. This decision was made to isolate the effects attributable specifically to probiotic supplementation and to avoid confounding effects that could obscure the independent contribution of probiotics to the observed outcomes.
Comparison ‘C’To include a placebo, control, or sham treatment group (parallel group study design).Patients receiving other doses of probiotics or other nutritional supplements.
Outcomes ‘O’Any biomarker related to biological, cognitive, or physical health in Alzheimer’s patients.None.
Study design ‘S’Randomized controlled trials.Observational studies and studies using a specific analytical approach.
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PICOS: Population, Intervention, Comparison, Outcomes, and Study design.