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Open AccessVollständige AnalyseJun 16, 2026

Prebiotics and cognitive decline in older adults: design of the PRECODE randomised controlled trial

This paper describes only the protocol of an incomplete RCT; no efficacy data are available to determine direction of effect.

The question (PICO)
PopulationOlder adults (≥60 years) with subjective cognitive decline (SCD), no established dementia
InterventionDaily prebiotic supplementation (chicory inulin, resistant dextrin, seaweed beta-glucans mixture) for protocol-defined duration
VergleichPlacebo (inactive control)
EndpunktWorking memory assessed by fMRI and neuropsychological testing (primary); gut microbiota composition, metabolites, inflammatory biomarkers, quality of life (secondary)
DEvidenz
Studie
Study
Effekt
Unzureichend
Zusammenfassung der Ergebnisse nach Endpunkt
EndpunktGradRichtungEffektStudien
Working memory (fMRI and neuropsychological)D Unzureichendnão disponível — protocolo sem resultados
Gut microbiome compositionD Unzureichendnão disponível — protocolo sem resultados
Plasma metabolites (SCFAs, indoles)D Unzureichendnão disponível — protocolo sem resultados
Inflammatory biomarkersD Unzureichendnão disponível — protocolo sem resultados
Quality of lifeD Unzureichendnão disponível — protocolo sem resultados
Working memory (fMRI and neuropsychological)D
Richtung Unzureichend
Effektnão disponível — protocolo sem resultados
Studien
Gut microbiome compositionD
Richtung Unzureichend
Effektnão disponível — protocolo sem resultados
Studien
Plasma metabolites (SCFAs, indoles)D
Richtung Unzureichend
Effektnão disponível — protocolo sem resultados
Studien
Inflammatory biomarkersD
Richtung Unzureichend
Effektnão disponível — protocolo sem resultados
Studien
Quality of lifeD
Richtung Unzureichend
Effektnão disponível — protocolo sem resultados
Studien

Kontext

The microbiota-gut-brain axis is a biologically plausible target for prevention of age-related cognitive decline. Prebiotic fibres (chicory inulin, resistant dextrin, seaweed beta-glucans) may modulate microbial composition and metabolites linked to cognition. Robust clinical evidence in subjective cognitive decline populations is lacking, and the PRECODE trial aims to address this gap.

Was die Studie zeigte

No efficacy results are presented — this is solely a protocol paper. No primary or secondary outcome data are available. No effect estimates, confidence intervals, or p-values can be reported.

Wie es durchgeführt wurde

Protocol publication for a double-blind, randomised, placebo-controlled trial (NCT06433037) targeting older adults with SCD. Methods include functional MRI, gut microbiome analysis, plasma metabolomics, and neuropsychological batteries. Final sample size and duration were not specified in the provided text.

Effektgröße

No effect size is calculable — trial is not yet completed. Power calculation parameters were not detailed in the available text.

Einschränkungen

Complete absence of outcome data makes efficacy appraisal impossible. The provided text is fragmented (introduction and discussion repeated without full methods or results), precluding RoB 2 risk-of-bias assessment. Clinical applicability remains undetermined until results are published.

In der klinischen Praxis

No practice change is supported by this paper. Clinicians should await PRECODE trial results before recommending this intervention for cognitive decline prevention in older adults.

Was noch fehlt

Primary and secondary outcome data from PRECODE (NCT06433037) must be published. Subsequent work should confirm whether microbiome changes translate into measurable, clinically meaningful cognitive benefit.

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