Study design
Nelson
NELSON, RECRUITMENT
Participants who met the inclusion criteria were randomly assigned to either the GSM or placebo group, stratified by age (55–64, 65–75 years) and BMI (25–29⋅9 kg/mBoth GSM powder and placebo were encapsulated in hard-shell capsules by a commercial facility (Alaron, Nelson, NZ) and stored under nitrogen in the dark at room temperature or lower until use. The GSM and placebo capsules were identically matched in the shape, size and colour of the hard-shell encapsulant. Activated carbon sachets for absorbing moisture and odour were put in bottles to conceal any ‘fishy’ odour.A randomisation list was generated by Excel and maintained by the project's supervising investigator, who did not interact with the study subjects or conduct the primary data analysis. Both the primary researcher and participants were blinded to treatment group allocation until all analyses were completed. Data were collected during participants’ visits at the baseline and the end of the study (week 12). All participants self-reported an omnivorous diet and the majority had the intake of probiotic products at least once a week in their diet before the study and were instructed to maintain their normal diet and physical activity throughout the trial. Recruitment, screening and data collection took place at the Human Nutrition Research Unit (HNRU) at Massey University, Palmerston North, New Zealand from August 2020 to September 2021.