Maternal undernutrition concerns 10-19% of women of reproductive age globally, the vast majority of which live in sub Saharan Africa and south Asia. Recommendations for nutritional interventions to tackle the problem range from per-pregnancy supplementation to upstream interventions targeting women of reproductive age before conception. To render the latter interventions cost-effective and sustainable, experts recommend to focus on food processing that leads to an enhanced nutrient content. One such method, which has been known and practiced for centuries in diverse societies, is fermentation. Traditionally fermented foods are diverse, widespread and highly appreciated in Burkina Faso. The present study aims to investigate the effect of fermented millet porridge on gut microbiota diversity, stool short chain fatty acid concentration and inflammation markers level in women of reproductive age living in rural Burkina Faso.