Calorie restriction in combination with prebiotic supplementation in obese women with depression: effects on metabolic and clinical response

Background: Major depressive disorder (MDD) is a common psychiatric disorder, closely associated with obesity. This study aimed to assess the effects of prebiotics combined with calorie restriction on clinical and metabolic response in obese women with MDD. Methods: In an 8-week double-blind placebo-controlled randomized clinical trial, 62 obese women with MDD were equally allocated into either prebiotic (10 g/day Inulin) or placebo (10 g/day Maltodextrin) group. In addition, all the participants were also prescribed a 25% calorie-restricted diet (registration ID: IRCT20100209003320N15). Depression was assessed by Hamilton depression rating scale (HDRS) and Beck depression inventory (BDI-II) pre- and post-intervention. Anthropometric measures, fasting serum levels of glucose, insulin and lipid profile were assessed, and dietary assessments were performed pre- and post-intervention. Insulin resistance was estimated by homeostasis model assessment of insulin resistance (HOMA-IR). Results: 45 patients completed the trial. There were no significant between-group differences for MDD symptoms and other study outcomes, post-intervention. Weight, waist and hip circumferences, systolic blood pressure, and HDRS score significantly decreased in both groups, while fat mass and total cholesterol (TC) declined only in the prebiotic arm. Those who had ≥1.9 kg weight loss showed significantly improved HDRS score, compared to women with <1.9 kg weight reduction, irrespective of the supplement they took. Conclusion: Although prebiotic supplementation had some beneficial metabolic effects, calorie restriction and weight loss seem to play a more important role in improving depressive symptoms among obese women with MDD.