Gut-brain health effects of prebiotics in older adults with suspected cognitive decline (LWV22109)

The primary objective of PRECODE is to investigate the effect of 26 weeks of supplementation with three different dietary fibres (chicory inulin, resistant dextrin, and seaweed polysaccharide) compared to a placebo (maltodextrin) on microbiota gut-brain health effects in 164 older adults (aged 60-79) with Subjective Cognitive Decline Plus (SCD+) by assessing changes in brain function and working memory by blood oxygen level dependant (BOLD) signal activity and task accuracy during n-back task functional magnetic resonance imaging (fMRI) assessment. This is a randomised, double-blinded, placebo-controlled intervention study with parallel design and four arms (n=41 each). The secondary objectives are the following parameters related to potential gut-brain pathways: (1) neuropsychological test battery scoring, (2) other relevant brain health parameters (amyloid-beta biomarkers, tryptophan metabolites, BDNF measures), (3) relevant intestinal health parameters (intestinal barrier function, microbiota composition, SCFA/BCFA analyses), and (4) immune and metabolic parameters (inflammatory marker panel, fasting glucose and insulin, HbA1c, lipogram). Tertiary outcomes relate to physiological parameters as determined by wearable smartwatches (heart rate, physical activity, mood).
PRECODE is the first study in its kind in which prebiotics are tested for improvement of cognitive functioning in older adults at risk of conversion to Alzheimer’s disease. SCD+ is a predecessor stage of AD, but at which stage the cognitive deficits can still be reversed. Thereby a substantial health benefit can still be gained. The partners within the project who deliver the dietary fibres will gain a wealth of knowledge concerning their product in terms of effectiveness (for brain health), potential repurposed use, digestibility, potential side effects and palatability.