Patients will be recruited among the outpatient population of the National Center for
Endometriosis, Department of Gynecological Surgery and Urology, Gynecology Department,
University Hospital Center Zagreb following the inclusion and exclusion criteria.
To participate in the study all patients will be required to sign the Informed Consent
form.
All patients will undergo a complete anamnesis via a digital form to investigate their
lifestyle (occupation, stress, diet, physical activity level).
The study period will be 6 months: eight weeks on either option (verum/placebo), with an
eight week washout period in between. The purpose of the washout period is to allow the
gut microbiome to return to baseline. The washout period was determined based on previous
gut microbiota studies with a similar design (reference), based on the fact that the gut
microbiota can change rapidly (< 7 days) r.
The outcome measures (gut microbiome, quality of life) will be assessed in four distinct
time points in context of the planned intervention.
T1 - before the intervention (start-of-study)
T2 - after the first intervention cycle/phase 1 (verum/placebo) of two months
T3 - after the wash-out phase of two months
T4 - after the second intervention cycle/phase 2 (verum/placebo) of two months
(end-of-study)
Stool sampling will be performed with the aid of specific kits indepently by the
patients. Lifestyle and quality of life will be evaluated by an online form designed
specifically for the purpose of this study in Microsoft Office Forms (Microsoft, San
Francisco, USA), short Online Form.
Through the process of randomization, patients will be allocated to either first receive
the verum (probiotic) or the placebo (maltodextrin), and second the placebo or verum
inversely.
Both patients and researchers involved will be blinded (double-blind study), the patients
will be informed that they are going to take a probiotic twice for two months with a
two-month time division. The intervention will consist of treatment with a multistrain
probiotic formulation (Omni Biotic Stress) and the placebo which is identical in all its
characteristics and packaging. Patients will be instructed to consume one sachet a day of
each (probiotic) for 8 weeks and to report any symptoms or side effects related to its
use. Adherence control will be carried out through the patient's notes on a separate
online form provided, and also by checking the number of sachets used.
Since this is a cross-over study, data will be compared between time-points T1 and T2,
and time-points T3 and T4, with the goal of minimizing the potential effect if we find
that the effect of the probiotics lasted longer than eight weeks in those randomized into
the intervention arm first.