Gut Microbiota Signatures Associated with Weight Loss and Insulin Resistance in an Elderly Mediterranean Population with Overweight/Obesity and Metabolic Syndrome

Identifier:  TDX:3845

Handle: https://hdl.handle.net/20.500.11797/TDX3845

Authors:  Atzeni, Alessandro

Abstract:
Alterations in gut microbial composition and functionality may contribute to the development of obesity and insulin resistance. The identification of specific gut bacteria and metabolic pathways associated with obesity and related metabolic disorders represents a promising novel perspective to tailor personalized interventions. The main objectives of this doctoral thesis, designed within the frame of the PREDIMED (PREvención con DIeta MEDiterránea)-Plus clinical trial, are: (i) Explore the association between fecal microbiota, body mass index and changes in total body weight after 12-month lifestyle intervention in elderly subjects (aged 55–75 years) with overweight/obesity and metabolic syndrome; (ii) explore the association between fecal microbiota and insulin resistance, estimated by HOMA-IR index, in non-diabetic subjects from the same cohort. Results shown specific fecal microbiota genera associated with lower body mass index and higher weight loss at 12-month follow-up. Specific genera and related metabolic pathways were negatively associated with higher HOMA-IR index and linked with improved glucose homeostasis via increased amino acid breakdown and sulfate reduction. Besides, specific genera and related metabolic pathways were positively associated with HOMA-IR index and linked to increased saccharide degradation inducing abnormal butyrate production. Our results support the identification of specific gut microbiota taxa to predict obesity treatments’ success, but also to target potential bacterial candidates for the development of therapies for insulin resistance. These findings encourage further investigation especially in terms of deepen taxonomic exploration and metabolomics profiling.