The Relationship Between Phenolic Compounds from Diet and Microbiota

All multicellular organisms live in a strong bond with the microorganisms from around the world, and the humans are not the exceptions. Human microbiota (a complex bacterial community) contains about 1014 microbial cells, 10 times more than the content of the cells from our body and the microbial genome named microbiome, 1000 more that the human genome. It colonises any surface of the human body, above our skin, in the genitourinary tract, gut and airways. From all this, the gut is the most colonised organ, with an amount of almost 70% of the human microbes. Considering the large size of the gut, compared with a tennis terrain, filled with substances that plays a key, nutritive role for the microbes, polyphenols are micronutrients from our diet, with an emerging role in the modulation of the colonic microbial population composition and activity. Therefore, many studies underline that long-term consumption of diets rich in plants polyphenols offers protection against cancer, cardiovascular diseases, diabetes, osteoporosis and neurodegenerative diseases. This chapter reviews the biological effects of plant polyphenols in the context of relevance to human health, especially considering the food functionality area, together with the complexity of the human microbiota and the bioavailability highly dependent on their intestinal absorption.