Gut Microbial Carbohydrate Metabolism Hinders Weight Loss in Overweight Adults Undergoing Lifestyle Intervention With a Volumetric Diet.

Mayo Clinic proceedings. 2018;93(8):1104-1110

Plain language summary

Recent research suggests that the human gut microbiome has a role to play in the development and maintenance of obesity, by influencing metabolism, fat deposition, brain-hormone signalling and insulin sensitivity. This pilot study of 26 participants, aimed to assess whether the composition and functional aspects of the gut microbiome influence outcomes of a comprehensive weight loss programme in overweight and obese individuals in America. A success criteria of 5% weight loss over a 3 month period was established. Comparisons in the gut microbiome using fecal samples at baseline and at 3 months were made between those successfully achieving the weight loss with those that did not. Achieving the weight loss success criteria was positively associated with the presence of Phascolarctobacterium. In contrast, an increased abundance of Dialister and of genes encoding gut microbial carbohydrate-active enzymes was positively associated with a failure to lose 5% of baseline body weight after 3 months. Interestingly, Phascolarctobacterium and Dialister both belong to the same bacterial family, which suggests that a compositional shift in this family may be responsible for host carbohydrate metabolism and obesity outcomes. This study highlights the potential of influencing the gut microbiome as part of an individualised obesity management programme. However the findings need to be confirmed in a larger, cohort study over a longer duration.

Abstract

The rising incidence of obesity requires the reevaluation of our current therapeutic strategies to optimize patient outcomes. The objective of this study was to determine whether compositional and functional characteristics of the gut microbiota in adults predict responses to a comprehensive lifestyle intervention program in overweight and obese adults. We recruited 26 participants from the Mayo Clinic Obesity Treatment Research Program between August 6, 2013, and September 12, 2013, to participate in a lifestyle intervention program for weight loss. Adults aged 18 to 65 years with a body mass index of 27 to 39.9 kg/m2 and able to provide informed consent were included in the study. Fecal stool samples were obtained at baseline and after 3 months. Loss of at least 5% of baseline weight after 3 months was defined as success. Clinical characteristics and gut microbial composition and function were compared between those who achieved at least 5% and those who achieved less than 5% weight loss. After 3 months, 9 of 26 participants lost at least 5% of their weight. The mean weight loss was 7.89 kg (95% CI, 6.46-9.32 kg) in the success group and 1.51 kg (95% CI, 0.52-2.49 kg) in the less than 5% weight loss group. An increased abundance of Phascolarctobacterium was associated with success. In contrast, an increased abundance of Dialister and of genes encoding gut microbial carbohydrate-active enzymes was associated with failure to lose 5% body weight. A gut microbiota with increased capability for carbohydrate metabolism appears to be associated with decreased weight loss in overweight and obese patients undergoing a lifestyle intervention program.

Lifestyle medicine

Fundamental Clinical Imbalances : Digestive, absorptive and microbiological
Patient Centred Factors : Antecedents/Gut microbiome/genetics
Environmental Inputs : Microorganisms
Personal Lifestyle Factors : Nutrition ; Exercise and movement
Functional Laboratory Testing : Stool
Bioactive Substances : Phascolarctobacterium ; Dialister

Methodological quality

Allocation concealment : Not applicable

Metadata

Nutrition Evidence keywords : Gut microbiome ; Weight loss ; Obesity ; Carbohydrate metabolism