ECE2016 Guided Posters Obesity (10 abstracts)
Introduction: Changes in the gut microbiome have been associated with the development of obesity. The aim of the present study was to examine i) the effect of a formula based very-low-calorie weight loss diet (VLCD) on the gut microbiome of obese humans and ii) whether if potential changes are sustained during weight maintenance.
Patients and methods: The study consisted of 3 months VLCD (~800 kcal/d) followed by 3 months of weight maintenance. 18 obese humans were examined (BMI 42.3 kg/m2 (35.247.7)). A lean and an obese control group were included. Microbiome was characterized by performing high-throughput dual-indexed 16S rDNA amplicon sequencing of stool samples and subsequent analyses.
Results: At baseline, a difference in the Firmicutes/Bacteroidetes ratio was observed (P=0.047). The VLCD resulted in alterations in diversity from baseline to 3 months (P=0.0053). Acinetobacter is an indicator species for the observed effect (IndVal=0.998, P=0.006). Metabolic analysis revealed significant alterations of the bacterial riboflavin pathway from baseline to 3 months (P=0.039). However, the changes in diversity and bacterial metabolism induced by the VLCD diminished during the weight maintenance phase, despite sustained reductions in body weight and sustained improvements of insulin sensitivity.
Discussion: In obese humans a VLCD is able to beneficially alter both, gut microbiome diversity and metabolism, but these changes are not sustained during weight maintenance. This finding might in part explain the significant weight regain after VLCD- based therapies and might suggest additional measures to target the microbiome, e.g. fecal transplantation.