Clinical and psychological responses to synbiotic supplementation in obese or overweight adults: A randomized clinical trial

Highlights

• We examined the clinical and psychological responses to synbiotic supplementation in obese or overweight adults.

• Synbiotic supplementation can decrease body weight, TG, TC, LDL-c, stress, anxiety, and depression in overweight or obese adults.

• Supplementation with synbiotics did not affect the HDL-c, SBP, DBP, FBG and fasting insulin concentrations, as well the BMI and WC.

Abstract

Background

Obesity is highly prevalent worldwide. Emerging clinical studies suggest that pre- and pro- biotic formulations may be effective interventions for the management of obesity and associated metabolic complications. The current trial was conducted to assess the effect of synbiotic supplementation on anthropometric indices, glycemic and lipid profile, blood pressure, and psychological status of adults with overweight or obesity.

Methods

This randomized double-blind, placebo-controlled trial was conducted on 60 adults with overweight or obesity. Participants were randomly assigned into two groups to receive either synbiotics (n = 30) in form of a 500 mg capsule (containing Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium bifidum plus inulin) or placebo (n = 30) for 8 weeks. The level of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting blood glucose (FPG), insulin, body weight, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), stress, anxiety, and depression were measured at the baseline and end of the study.

Results

In total, 59 subjects (39 men and 20 women) completed the present study. A significant between-group decrease in body weight (P = 0.03), TC (P = 0.01), TG (P = 0.02), LDL-C (P = 0.01), stress (P < 0.001), anxiety (P = 0.03), and depression (P = 0.03) was found in the synbiotic group compared to the placebo. However, synbiotics had no significant effect on HDL-C, SBP, DBP, FPG and fasting insulin concentrations, as well the BMI and WC (P < 0.05).

Conclusion

The present study showed that synbiotic supplementation can confer a number of health benefits including improvements in TG, TC, LDL-C, body weight, stress, anxiety, and depression to subjects that are overweight or obesity.

Trial registration

Iranian Registry of Clinical Trials IRCT20180201038585N3.

Introduction

Obesity is one of the most widespread chronic diseases around the world, resulting from a complex interaction between eating habits as well as environmental and genetic factors1., 2., 3. Based on World Health Organization statistics, more than 1.9 billion adults are overweight and approximately 650 million people are suffering from obesity.⁴ If present trends continue, 2.16 and 1.12 billion adults will be overweight or obese by 2030, respectively.⁵ Furthermore, individuals with obesity have a higher risk of numerous metabolic derangements including type 2 diabetes, atherosclerosis, cardiovascular diseases, non-alcoholic fatty liver disease, osteoarthritis, reproductive problems and some forms of cancer.^1,6., 7., 8. Obesity also has a negative effect on self-esteem and is bi-directionally associated with depression.^9,10 Lifestyle and pharmacological interventions are two of the most important strategies for obesity management.11., 12., 13. However, stringent lifestyle changes are often only accepted by limited numbers of people and anti-obesity medications may exert some adverse effects while their efficacy is often attenuated after prolonged use.¹⁴ Thus, an important unmet need is the lack of convenient and effective adjuvant therapies for obesity management.

Emerging evidence indicates that adverse changes in the composition of the gut microbiome may play a pivotal role in progression of obesity.15, 16., 17. Probiotic interventions may therefore contribute to the management of obesity and associated complications by influencing the abundance and function of gut microbiota.^15,16,18 Prebiotics can enhance the proliferation of probiotics, resulting in sustainable changes in the human microbiome. Therefore, the combination of pre- and pro- biotic (synbiotic) interventions may provide a synergistic and effective therapy for metabolic disorders.19., 20., 21., 22. Furthermore, the positive role of synbiotic supplementation in mental diseases such as major depressive disorder have been documented.23., 24., 25. Probiotics might improve symptoms of depression through enhancing tryptophan metabolism and decreasing dopamine metabolite concentrations in the amygdaloid cortex.²⁶ Based on the current evidence, there is a general lack of research investigating the effects of synbiotics on psychological status in these patients. Therefore, the aim of this study was to assess the effects of synbiotic supplementation on clinical and metabolic response among overweight or obese adults.