The present study is aimed at exploring whether positive expectations of receiving a three-week treatment with a probiotic supplement (in fact a placebo) improve symptoms of gastrointestinal distress and promote physical and emotional well-being in healthy individuals with mild gastrointestinal symptoms. At first, a comparison is planned between (1) a classic deceptive placebo manipulation (Deceptive Placebo group, DP), and (2) a control condition (Control group, C), in which no placebo substance will be administered. After the three-week waiting list, the Control group will be invited to take the placebo probiotic pills in an "open-label" fashion (Open Label Placebo, OLP). Specifically, participants will be informed that the pills are inert placebos. An exploratory analysis will help to clarify whether the OLP paradigm leads to significant effects, based on a within-group (C- OLP) and between-group comparison (DP-OLP).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
30
Three-week consumption of placebo probiotic capsules passed off as being actual probiotics
Participants of the Control group will be switched to this condition after three weeks and receive placebo probiotic capsules for the following three-weeks of no intervention. Specifically, they will be honestly informed that the capsules are inert placebos.
For the first three weeks, the Control group will not be exposed to any intervention.
Catholic University of the Sacred Heart
Milan, Italy
RECRUITINGChange from Baseline in the Gastrointestinal Symptom Rating Scale (GSRS) total score at 3 weeks.
Time frame: Baseline and 3 weeks
Change from Baseline in the Digestion-Associated Quality Of Life Questionnaire (DQLQ) total score at 3 weeks.
Time frame: Baseline and 3 weeks
Change from Baseline in Stool Form as assessed by means of the Bristol Stool Scale
The Bristol stool scale is a diagnostic medical tool designed to classify the form of human stool into seven categories.
Time frame: Day 2/3 and day 19/20 from Baseline
Change from Baseline in Fatigue Levels as assessed by means of the Multidimensional Fatigue Inventory (MFI-20) at 3 weeks.
Items are scored 1-5, with 10 \[fatigue-\]positively phrased items reverse scored (items 2, 5, 9, 10, 13, 14, 16, 17, 18, 19). In the final score, high scores represent more fatigue.
Time frame: Baseline and 3 weeks
Change from Baseline in Sleepiness Levels as assessed by means of the The Epworth sleepiness scale at 3 weeks.
Final total score ranges from 0 to 24. Scores from 0 to 10 show average (normal) daytime sleepiness. A result from 11 to 24 indicates excessive (abnormal) daytime sleepiness.
Time frame: Baseline and 3 weeks
Change from Baseline in Positive and Negative affect as assessed by means of the Positive and Negative Affect Schedule (PANAS) at 3 weeks.
Time frame: Baseline and 3 weeks
Change from Baseline in Stress Levels as assessed by means of the Perceived Stress Scale (PSS) 3 weeks.
The scale comprises of 10 items, with scores ranging from 0 ( = Never) to 4 ( = Very Often). Scores ranging from 0-13 would be considered low stress. Scores ranging from 14-26 would be considered moderate stress. Scores ranging from 27-40 would be considered high perceived stress.
Time frame: Baseline and 3 weeks
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.