Bulgarian yogurt relieved symptoms and distress and increased fecal short-chain fatty acids in healthy constipated women: A randomized, blinded crossover controlled trial

Abstract

Background: Probiotic yogurt containing both starter culture and additional beneficial bacteria was shown to promote bowel movement and improve mood. The present study aimed to investigate the effect of Bulgarian yogurt containing only starter culture on defecation, constipation symptoms, mood, and fecal short-chain fatty acids in healthy constipated women. Method: A randomized, double-blinded, crossover-controlled trial was conducted in thirty-one healthy constipated women without irritable bowel diseases. After randomized into two groups, each group received an inverse order of Bulgarian yogurt (made by S. thermophilus and L. bulgaricus) and lactic-acidified milk curd for three weeks each with three-week washout period between interventions. Outcome included defecation frequency and fecal characteristics (Bristol stool scale), constipation symptoms (Constipation Assessment Scale and ROME IV criteria), mood (distress thermometer), and constipation-related quality of life (CRQoL questionnaire). Short-chain fatty acids were measured by GC–MS analysis of stool. Results: Constipation symptoms (rectal pain, separate hard or lumps stool, and inability to pass stool) were relieved (p < 0.001); mood scores associated with emotional distress and constipation were reduced (p < 0.05); number of participants with fecal short-chain fatty acids (butyrate, propionate and acetate) were increased after taking Bulgarian yogurt but not the milk curd. Defecation frequency, CRQoL, and fecal characteristics were improved by both interventions. Conclusions: The findings of this study suggested that continuous intake of Bulgarian yogurt with no additional probiotic bacteria for three weeks may relieve constipation symptoms and distress in healthy constipated women. The simultaneous increase in short-chain fatty acids suggests that the improved symptoms and mood may result from stimulation of gut-brain axis.