Statistical analysis
cognitive and mood
The postdose cognitive and mood outcome measures, as well as microbiota identified as changing significantly, were modeled using the MIXED procedure in SPSS (version 26.0, IBM Corp.). This included the respective baseline values and the terms Treatment and Visit as fixed factors and Participant as a random factor. Significant interaction effects were followed up with Bonferroni corrected pairwise comparisons exploring the differential effects of treatment across visits and differential effects across visits within treatments. Further exploratory analysis was conducted on recognition measures to ascertain whether effects were specific to novel or original stimuli. Partial bivariate Pearson correlations were conducted on change from baseline values to assess any relation between significant changes in the gut microbiota and cognition following nut consumption adjusting for the potential confounding effects of age, sex, years in education, and BMI.