2nd Summit on the Health Effects of Yogurt -San Diego- Gut microbiota & health - Pr O.Goulet
Channel: yogurtinnutrition
Date: 2014-07-29

Olivier Goulet, MD, PhD - Necker Hospital - enfants malades, Paris, France

Microorganisms are introduced into the human gut early after birth. The microbial composition of the microbiota varies with delivery methods, feeding (i.e., breast vs. bottle), infant care environment and antibiotic use. Post natal development of the human gut is largely influenced by the intestinal microbiota. Today, it is an increasing evidence that the early phases of microbiota implementation may influence the occurrence of later diseases.  As for “metabolic programming”, one might consider nowadays, “microbiotical programming”. Conventional culture techniques detect only a small number of the species of intestinal bacteria. During the last decade, the diversity of gut microbiota has been revealed by genetic or metagenomic studies. It has been clearly evidenced that microbes are represented by more than 1500 microbial species. The vast majority of microbial species give rise to symbiotic host-bacterial interactions that are fundamental for human health. 
Obesity has become one of the most prevalent health issues of our time with over 1.5 billion overweight adults in the world and, of these, approximately 500 million are clinically obese.  As a matter of fact, more deaths are caused worldwide by excessive weight than those caused by being underweight. Obesity is a multifactorial condition but it can be most simply described as being the result of a long-term imbalance between energy intake and energy expenditure. While modern eating habits and ever increasingly sedentary lifestyles are contributory factors in this burden, the link between obesity and the composition and functionality of the microorganisms in the gut is nowadays pointed as a major factor.  
Metagenomic analysis and 16S ribosomal RNA gene sequencing, have shown that Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria are the predominant bacterial phyla among the intestinal bacteria in adults. Changes in the composition of the diverse gut microbiota (dysbiosis) are associated with several clinical conditions, including obesity, autoimmune diseases, and allergy.  Current research involve the comparison of gut microbiota of lean and obese animals, the metagenomic study of the gut microbiota of lean and obese humans,   the impact of diet on the gut microbiota,   and by manipulating the gut microbiota to understand the mechanisms by which the gut microbiota might impact on body weight gain and adiposity. 
Recent studies indicated that obesity and diet could be associated with altered gut microbiota characterized by a high Firmicutes to Bacteroidetes ratio and a dramatic fall in overall microbial diversity. The altered gut microbiota could, in turn, alter the host metabolic potential. Therefore, the gut microbiota might contribute to obesity through increases in the harvest of energy from diet, gut permeability, and fat deposition in adipose tissue and the liver. 
According to these recent advances, modulation of gut microbiota has been suggested as a treatment for obesity, using fermented dairy products, probiotics, or prebiotics. 

About The Yogurt in Nutrition Initiative (YINI)
The Yogurt in Nutrition Initiative for a Balanced Diet is a multi-year global, collaborative project led by the Danone Institute International (DII) in collaboration with the American Society for Nutrition (ASN) and the International Osteoporosis Foundation (IOF) which aims to evaluate the current evidence base on the nutritional impact of yogurt. The mission of the project is to uncover scientific data related to yogurt, stimulate new research and identify gaps in our understanding of the health effects of this food category in order to share this information with professionals and the public.  http://yogurtinnutrition.com; @YogurtNutrition