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Abstract

Background: Gut microbiota is involved in the modulation of host immunity, and the inflammatory status associated with obesity, and it is also an important factor affecting energy disposal and storage in adipocytes. However, the precise mechanisms by which alterations in microbiota affect obesity and associated disorders are still unclear. Diets based on a high fat, high protein and/or low carbohydrate intake, may alter microbial composition and activity in the large intestine impacting on gut health. Gut microbial glycoside-hydrolases (GH) activity is higher in obese and correlates with fasting glucose, insulin resistance and body mass index (BMI) in obese. We hypothesized that a functional approach is needed to characterize the functionality of the microbial community that transmits this metabolic capacity. We studied the modulation of this functionality induced by a multidisciplinary approach including a calorie restriction intervention (EVASYON). Methods: GH activity data, represented by �²-galactosidase and �±-glucosidase, were systematically collected in fecal bacterial proteins from obese adolescents (n=13) that followed a dietary intervention for 1 year and lean (n=8) ones. Comparative and correlation analyses, involving activity levels, anthropometric and biochemical parameters, were performed. Results: Levels of �²-galactosidase and �±-glucosidase activity were significantly different between lean and obese subjects. A sigmoid association between BMI and �²-galactosidase was found, where BMI>24.5 acts as a functional frontier. Positive correlations between �²-galactosidase activity and insulin levels (Sp-Rho=0.43, p<0.01), HOMA-IR (Sp-Rho=0.36, p<0.05) and LDL (Sp-Rho=0.35, p<0.05) were established. �±-glucosidase activity was also correlated with BMI (Sp-Rho=0.65, p<0.0001) and HOMA-IR (Sp-Rho=0.34, p<0.05). Conclusions: Anabolic capacity of the human gut microbiota seems to be associated to BMI, insulin resistance and lipids plasma levels. The dietary intervention slightly improved the anthropometric and biochemical parameters, and the functionality of the microbiota remains higher since the BMI did not reach values under 25. So, different functionality levels depend on host BMI. Potential future individual approaches may be designed based on these results.

Biography

Email: ccampoy@ugr.es