(P22-028-23) A Study Protocol To Determine the Effect of a Probiotic on Gastrointestinal Symptoms Due to the Menstrual Cycle in Healthy Adult Women Taking an Oral Contraceptive

Objectives: Previous studies have reported that gastrointestinal (GI) symptoms in healthy women significantly differ by the day of the menstrual cycle. Specifically, on the first day of bleeding, women report significantly increased abdominal pain, diarrhea, constipation, reflux, indigestion, stress, stool frequency, and alterations in stool form as measured by the Bristol stool form scale. Because probiotic supplementation has been shown to normalize GI function in stressed individuals, probiotics may also be a beneficial strategy for decreasing symptoms of abdominal pain and other GI symptoms related to menstruation in healthy females.

Methods: 186 healthy women on an oral contraceptive (OC) aged 18 to 35 y will consume either a probiotic containing a Bifidobacterium species or a placebo for 9 weeks in a randomized, double-blind, controlled clinical trial. Women on OCs will be included to decrease variability and allow for a more predictable cycle. The primary outcome is the change in the daily Visual Analog Score for abdominal pain for the average of the first 3 days of menstruation when on the intervention for 4 weeks minus the average of the first 3 days of menstruation prior to initiating the intervention between women on the probiotic versus the placebo interventions. Secondary outcomes will examine the probiotic on GI symptoms, quality of life, stool form and frequency, food cravings, and menstrual symptoms. In a subgroup of 40 women (20 on the probiotic and 20 on placebo), gut and vaginal microbiota samples will be obtained weekly to understand how the microbiome may fluctuate during the menstrual cycle. Data will be collected prospectively based on individual menstrual cycles to decrease recall bias.

Results: To date, the average age of the participants is 21.9 ± 0.3 and average BMI is 23.6 ± 0.4. Initial compliance assessments show that data from 176 women will be included in primary outcome analysis with 79.1% of women on a monophasic or biphasic OC and 20.9% on a triphasic OC. 40 women completed the subgroup tasks.

Conclusions: This study hopes to demonstrate that an oral probiotic supplement may decrease GI symptoms related to menstruation and maintain a healthy gut and vaginal microbiome throughout the menstrual cycle.

Funding Sources: Lallemand Health Solutions Inc.