Obesity in children has become a significant social problem considering that nowadays 4 to 5 % of all children are obese in the industrialized countries with increased incidence in Europe by 10 to 50% over the past 10 years. Obesity is associated with the metabolic syndrome in 30% of the children and is considered as a state of chronic inflammation inducing the production of pro-inflammatory cytokines which determine metabolic and endocrine alterations on the organism. It has been observed that obesity is also linked to a change in the intestinal microflora with a reduction of Bacterioides and bifidobacteria and a decrease of Firmicutes and Staphylococcus aureus. The qualitative and quantitative analysis of the metabolites may provide us with a characterization of the existing phenotypes and variations in relation to the changes of the physiological state, in particular when supplemented or not with a probiotic preparation.

Inclusion Criteria:

• age 6-12
• parents or tutors able to give the written consent and follow the study procedures Value of BMI>90°

Exclusion Criteria:

• - Any severe or concomitant clinical or psychiatric condition that, in the investigator's opinion, could affect the treatment, the evaluations and the inclusion in the protocol;
• Evidence of active liver disease due to other causes;
• Steroid treatment; immuno suppressive therapies, chemotherapy agents within 2 month from screening;
• Pregnancy or breastfeeding;
• Abuse of alcohol and drugs clinically relevant;
• Diabetes.