The small intestine microbiota, nutritional modulation and relevance for health.

The intestinal microbiota plays a profound role in human health and extensive research has been dedicated to identify microbiota aberrations that are associated with disease. Most of this work has been targeting the large intestine and fecal microbiota, while the small intestine microbiota may also have a profound impact on various aspects of the host's physiology, including immune, metabolic and endocrine functions. This review highlights the recent advances made in the study of the human small intestine microbiota. In addition, it describes recent human and animal studies that underpin the importance of this part of the intestine for health of the host organism.