Obesity is a major, public health concern that affects at least 400 million individuals and
is associated with severe disorders including diabetes and cancers. Worldwide, the prevalence
of overweight and obesity combined in children, adolescents and youth, between 1980 and 2013,
increased to 47.1%, with alarming data also in developing countries. Obesity is often caused
by imbalance between excessive caloric intake and reduced physical activity.
Recently, microbial changes in the human gut was proposed to be another possible cause of
obesity and it was found that the gut microbes from fecal samples contained 3.3 million
non-redundant microbial genes. However, it is still poorly understood how the dynamics and
composition of the intestinal microbiota are affected by diet or other lifestyle factors.
Moreover it has been difficult to characterize the composition of the human gut microbiota
due to large variations between individuals.
The role of the digestive microbiota in the human body is still largely unknown, but the
bacteria of the gut flora do contribute enzymes that are absent in humans for food digestion.
Moreover, the link between obesity and the microbiota is likely to be more sophisticated than
the simple phylum-level Bacteroidetes: Firmicutes ratio that was initially identified, and it
is likely to involve a microbiota-diet interaction.
Obese and lean subjects presented increased levels of different bacterial populations. It is
hypothesized that the obese microbiome is set up to extract more calories from the daily
intake when compared to the microbiome of lean counterparts. In addition, a caloric diet
restriction impacted the composition of the gut microbiota in obese/overweight individuals
and weight loss.
In lean subjects there are Coriobacteriaceae, Lactobacillus, Enterococcus, Faecalibacterium
prausnitzii, Prevotella, Clostridium Eubacterium, E. coli and Staphilococcus. By contrast,
Bifidobacterium, Methanobrevibacter, Xylanibacter, Bacteroides characterize the composition
of lean gut microbiota.
For this reason, in a cohort of obese paediatric subjects with visceral adiposity, the aim of
the study is to assess the efficacy of a supplementation with probiotic bifidobacteria with
respect to a conventional treatment on weight loss and improvement of cardio-metabolic risk
factors.
Phase:
Phase 4
Details
Lead Sponsor:
Azienda Ospedaliero Universitaria Maggiore della Carita