John Bienenstock, MD – McMaster University, Canada
Advances in technology have brought about a revolution in microbiology. The gut microbiome alone contains at least 100 times the genome of the host. It can now be a legitimate question as to whether we or the microbiome are the hosts. It is certainly becoming clear that the microbiome has a major role to play in the physiological homeostasis of the gut and the various systems it contains, including epithelial and immune function and metabolic and endocrinologic activities. Most recently attention has been drawn to the role of the normal gut microbiome in determining the development and function of both the enteric and central nervous systems. The rapidly accumulating experimental evidence points to the possibility that gut microbes and their products including those of fermentation, play a significant role in these changes. Ingestion of communities of bacteria and even specific bacteria such as certain bifidobacteria or lactobacilli have now been shown to attenuate stress responses of the HPA axis, and even reduce anxiety-like behavior. Most recently the gut-brain axis has been implicated in preventing behavioral changes associated with autistic behavior in an experimental model. The signals responsible for communication between bacteria in the lumen of the gut and the brain are just beginning to be understood. For example, vagotomy has been shown to abrogate many of these effects. Some of the pathways responsible for transduction of these signals are becoming a focus of research and range from the production of neuroactive gases such as carbon monoxide, nitric oxide and hydrogen sulfide, neurotransmitters such as GABA, bacterial membrane components such as exopolysaccharides and products of fermentation such as butyrate. These experimental results are only just starting to be applied to the clinical situation and early experimental data, while showing great promise, have yet to be confirmed.
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