|LEZIONI SUL METABOLISMO|
|Rassegna stampa:||Diet and the human gut microbiota - modulation of chronic disease risk|
|Thursday 24-03-2011 Roma Edificio di Igiene, aula B, p.le Aldo Moro 5
Università di Roma “La Sapienza” Inizio ore 12:00|
Relatore: Kieran M. TUOHY | Group leader of the Nutrition and Nutrigenomics Group, IASMA Research and Innovation Centre - Fondazione Edmund Mach in San Michele all’Adige, Trento - Coordinatori: Alfredo Miccheli, professore di Chimica Fisica per Scienze Biologiche, facolta' di Scienze MM.FF.NN. “Sapienza” Università di Roma- Paola Mastromarino, professore di Microbiologia, facolta' di Medicina “Sapienza” Università di Roma. Free entrance.
|Diet and the human gut microbiota - modulation of chronic disease risk|
|Although there is a strong genetic contribution to coronary vascular disease (CVD) and certain cancers, disease risk is also strongly governed by environmental factors. Diet and nutrition are important environmental contributors to chronic disease risk and play key roles in the morbidity and mortality associated with CVD, cancer, diabetes and premature dementia. Epidemiological data suggest that Western style diets high in animal protein, fat and refined sugars increase the risk of these chronic diseases often in association with increased body fat and obesity. |
Conversely, such studies also show that diets rich in whole plant foods, dietary fiber and plant secondary metabolites or polyphenols, protect against these diseases. Therefore dietary modulation with those foods shown to chronic disease lower could provide real benefit in reducing their socioeconomic and quality of life impact. The human microbiome is now seen as an important and modifiable contributor to host health and recent post-genomic studies have highlighted the fact that an aberrant gut microbiota and microbial metabolite profile is characteristic of many disease states, both chronic diseases of the gut (e.g. inflammatory bowel disease and colon cancer) and more systemic diseases (e.g. allergy, diabetes and obesity). Many studies are showing that the gut microbiota in health is typified by a mainly saccharolytic microbiota and one with relatively high populations of bifidobacteria and reduced numbers of bacteria known to cause disease e.g. certain clostridia and the Enterobacteriaceae. In any given individual, the composition and metabolic activity of the gut microbiota is strongly influenced by diet and comparative studies between modern Western style diets and traditional pre-industrial or hunter gatherer diets, show that Westernisation is associated with a significant reduction in dietary components active on the gut microbiota.
Although it is appreciated that the majority of the putative health promoting components in whole plant foods, must first interact with the human gut microbiota before becoming biologically available or active, their underlying mechanisms of effect remain poorly understood. In this presentation I will discuss how dietary fiber and whole plant foods including fruit, vegetables and whole grain cereals impact on the gut microbiota and give examples from both in vitro and in vivo studies.
I will also discuss the role of the gut microbiota in governing the metabolic fait and biological activity of plant polyphenolic compounds which reach the colon and how microbial transformation of plant fiber and polyphenols leads to important changes in host physiological processes involved in protection from chronic disease. I will also discuss how the enabling technologies of genomics, metagenomics and metabolomics have provided for the first time a tool-kit capable of measuring at the systems level human metabolic flux in response to dietary intervention.
Such technologies hold great promise to elucidate the underlying mechanisms linking health promoting foods or food components with measurable health parameters. It is becoming apparent that at the regulatory level, only foods which show a reproducible, statistically and mechanistically sound, clear dose-response in clinically recognised disease parameters (e.g. blood pressure, blood cholesterol and lipid profiles, blood glucose and insulin levels, systemic inflammation and liver function) will be accepted to have a “health claim” in the EU. It is also apparent that our current nutritional environment is out of step with our closely co-evolved gut microbiome, and that this malfunctioning relationship is contributing to increased morbidity and mortality from chronic diet associated disease.
Redressing this imbalance will require close collaboration between nutritionists, microbiologists, food chemists and medics, and there is a clear mandate for large-scale multidisciplinary studies to help turn the toxic tide of diet associated disease.