Investigating the effect of a paraprobiotic on sleep quality, stress, and gut health in people with insomnia and elevated stress levels

The intervention consists of tablets containing heat-inactivated Lactobacullus sp. (1 x 10^10 bacterial cells per two tablets). The active tablet will be composed of maltose, dextrin, starch, heat-inactivated lactic acid bacteria powder, and vegetable oil. The study duration is a nominal total of 12 weeks, with a two-week lead-in phase, eight-week intervention phase, and follow-up two-weeks after the end of the intervention. The 2-weeks lead-in phase requires participants to complete weekly questionnaires about their sleep patterns, and record their bowel motion, mood, and perception of sleep quality every day on an app designed for this trial. During the second week of the lead-in period they will complete a non-consecutive 3-day food diary, wear an actigraphy device for seven days to measure sleep and activity levels, and wear an electroencephalogram headband for three nights (at their home) to measure brainwave patterns during sleep. Participants will collect a faecal and saliva sample one day prior to their baseline visit (end of 2nd week of lead-in phase). At their baseline visit (beginning of intervention phase) participants will have height and weight measured, complete a set of questionnaires about their mental and physical health, general well-being, and clinical variables. During the eight-week intervention phase, participants will consume two of their assigned tablets each day (with or without water or food), complete their daily bowel motion and mood/sleep app and complete weekly sleep questionnaires and two-weekly mental health questionnaires. The tablets will be packaged in sachets containing two-weeks supply. Compliance will be monitored by checklist and counting returned tablets. Participants will attend the study clinic at weeks 2, 4 and 6 to return unused tablets, and pick up their next two weeks of tablets. At the final clinic visit (end of intervention phase), the aforementioned baseline visit procedures will be repeated. Prior to the final visit, participants will again complete the same set of questionnaires, 7-day actigraph, 3-night EEG, and non-consecutive 3-day food diary, and collect a faecal sample and saliva sample. Participants will receive their reimbursement ($300 grocery vouchers). Attendance of clinic visits and completion of questionnaires will be assessed to measure the adherence of participants. Two-weeks after the final clinic visit, participants will complete an online survey regarding their mental and physical health, general well-being, and gastrointestinal symptoms; the link to this survey will be sent to the participant by email.