Synbiotics and Low Grade Inflammation in Obese Subjects

• Plasmatic Interleukin-6 (IL-6) [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
  Plasmatic IL-6 will be determined after 6 weeks of administration of the synbiotic and compared with the IL-6 values at baseline.
  
  

• Plasmatic LPS-binding protein [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
  Plasmatic LPS-binding protein (LBP) will be determined after 6 weeks of administration of the synbiotic and compared with the LBP values at baseline.
  
  
• Plasmatic sCD14 [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
  Plasmatic sCD14 will be determined after 6 weeks of administration of the synbiotic and compared with the sCD14 values at baseline.
  
  
• glucose tolerance curve [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
  Glucose tolerance will be determined after 6 weeks of administration of the synbiotic and compared with glucose tolerance at baseline.
  
  
• Lipid profile [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
  Lipid profile will be determined after 6 weeks of administration of the synbiotic and compared with the lipid profile at baseline.
  
  
• plasmatic ultrasensitive C-Reactive Protein [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
  Plasmatic ultrasensitive CRP will be determined after 6 weeks of administration of the synbiotic and compared with the usCRP values at baseline.
  
  
• Plasmatic IL-6 [ Time Frame: 10 weeks ] [ Designated as safety issue: No ]
  Plasmatic IL-6 will be determined after a 1-month washout period without synbiotic administration (week 10)and compared with the baseline and post-treatment (6 weeks) values.
  
  
• Plasmatic LBP [ Time Frame: 10 weeks ] [ Designated as safety issue: No ]
  Plasmatic LBP will be determined after a 1-month washout period without synbiotic administration (week 10)and compared with the baseline and post-treatment (6 weeks) values.
  
  
• Plasmatic sCD14 [ Time Frame: 10 weeks ] [ Designated as safety issue: No ]
  Plasmatic sCD14 will be determined after a 1-month washout period without synbiotic administration (week 10)and compared with the baseline and post-treatment (6 weeks) values.
  
  
• Glucose tolerance curve [ Time Frame: 10 weeks ] [ Designated as safety issue: No ]
  Glucose tolerance curves will be determined after a 1-month washout period without synbiotic administration (week 10)and compared with the baseline and post-treatment (6 weeks) values.
  
  
• Lipid profile [ Time Frame: 10 weeks ] [ Designated as safety issue: No ]
  Lipid profile will be determined after a 1-month washout period without synbiotic administration (week 10)and compared with the baseline and post-treatment (6 weeks) values.
  
  
• Plasmatic usCRP [ Time Frame: 10 weeks ] [ Designated as safety issue: No ]
  Plasmatic usCRP will be determined after a 1-month washout period without synbiotic administration (week 10)and compared with the baseline and post-treatment (6 weeks) values.
  
  

Obesity is associated with a spectrum of metabolic disorders including high blood pressure, dyslipidemia, insulin resistance and a state of low grade inflammation that predispose individuals to the development of type-2 diabetes mellitus and cardiovascular diseases. The intestinal microbiota has been recently proposed as a new actor in the development of obesity and its complications. In animal models, high-fat diets have been shown to affect the intestinal microbiota, increasing colonic gram-negative bacteria and lipopolysaccharide (LPS) concentrations, resulting in an impaired gastrointestinal barrier function and in subsequent endotoxinemia in the animals. This phenomenon would trigger chronic inflammatory and metabolic disorders leading to insulin resistance and other complication such as hepatic steatosis. Probiotics and prebiotics are GRAS (Generally recognized as safe) food ingredients which have been proposed to maintain the balance of the intestinal microbiota. Studies in mice fed a high fat diet have shown that the administration of oligofructose increases the counts of Bifidobacterium spp. in the colon and correlatively induced decreases of the endotoxinemia and low-grade inflammation while at the same time improving insulin sensitivity.

On the basis of these antecedents, the aim of this study is to determine whether the intake of a synbiotic product (B. animalis subsp. lactis BB12+ Oligofructose) for six weeks contributes to improve the low grade inflammation and glucose tolerance of obese subjects.

Obese subjects will be randomized into two groups (Synbiotic or Placebo) stratifying by sex and age. Anthropometric data (body composition by Bod-pod, weight, height, waist circumference) and systolic and diastolic blood pressure will be registered. A food survey will be carried out by a trained dietitian to quantify fat consumption. Each subject of the Synbiotic group must ingest one gram of BB12 (containing 1010 CFU) and 5 g of oligofructose twice a day for 6 weeks while those from the Control group will receive the corresponding placebo (maltodextrin). Digestive symptoms as well as stool frequency and consistency will be registered daily during the study using ad hoc forms and the Bristol Chart.

Blood samples will be obtained at baseline, at the end of the six weeks period and one month after the end of the treatment, to determine lipid profiles and ultrasensitive C-reactive protein (CRP); plasmatic biomarkers of inflammation including IL-6, LPS binding protein and sCD14 will be also determined by Elisa using commercial kits. At the same times, a glycemia /insulinemia curve will be performed in the fasted subjects, as well as an intestinal permeability test (lactulose/mannitol/sucralose) to assess their gut barrier function. A fresh stool sample will be also obtained to characterize some bacterial population of their IM (Bifidobacterium, Lactobacillus, F. prausnitzii, Bacteroides and Clostridium cluster) by real-time PCR.