Prebiotic Inulin for Late-Reproductive Individuals

Inclusion Criteria: * Body mass index: 25 - 40 kg/m2; * Menstrual cycle irregularity (cycle length outside 21 - 35 days or variation \> 7 days) or/and ≥ 2 skipped cycles and interval of ≥ 60 days of amenorrhea; with or without hot flashes or/and night sweats; * Weight stable within the last 3 months (body weight fluctuations within the 5% of their habitual body weight); * Spending ≥ 6 hours sitting; * \< 150 minutes per week (50 minutes per day, 3 days per week OR 30 minutes per day, 5 days per week) of moderate to vigorous structured physical activity (i.e., planned intentional physical activity, not incidental movement). Exclusion Criteria: * Recent antibiotic use oral or vaginal (≥ 6months); * Diagnosed with any chronic disease (e.g., any gastrointestinal condition like IBD, type 2 diabetes, or cancer); * Prescription of hormone replacement therapy, hormonal contraceptives, probiotics, GLP-1 medications, or weight loss medications * Smoking; * Recent blood donation (within the past 8-12 weeks); * Significant weight changes (≥5%) in the last 4 weeks; * Use of dietary supplements (unless discontinued 4 weeks prior); * Participants taking long-term, stable medications for chronic conditions such as hypertension or hyperlipidemia will not be excluded if their medication regimen has been unchanged for at least 2 years, as these treatments are part of their usual health status. Recent medication changes (within the past 6 months), initiation of new prescriptions, or use of me…