Gut Microbiome
          •  The Human Microbiome Project, NIH 2007
             • Goal
               • Catalogue microbial genes and species found 
                 within and on the human body
             • Sequenced
               • 60 million predicted genes
               • 600 microbial reference genomes
               • 700 metagenomes
             • Microbiome
               • 10 trillion to 100 trillion cells
               • 10 times the number of eukaryotic cells in the 
                 human body
                 • Most of which reside in our GI tract
          Gut Microbiome
      • Gut Microbiota
       • Complex, diverse and vast microbial community
       • 10 conserved bacterial phyla
        • Firmicutes and Bacteroidetes comprise more than 
         90%
        • Actinobacteria and proteobacteria
        • Fusobacteria, Verrucomicrobia, Cyanobacteria
       • Species vary widely between individuals
        • Populated starting at birth
         • Affected by mode of delivery
        • Fostered by method of feeding
         • Breast milk vs formula
         • Protein and animal fat vs carbohydrate 
          predominant diets
        • Modified by Age 
                         Gut Microbiome
            •   In the absence of major dietary changes or 
                antibiotics, the microbiota is remarkably stable
            •   Significant role in health and disease
                • Eubiotic State
                  • Energy harvest from otherwise inaccessible starches
                  • Regulation of metabolism
                  • Production of micronutrients and vitamins
                  • Metabolism of xenobiotics
                  • Gut epithelial-cell renewal
                  • Immune system development
                  • Protection from pathogenic organisms
                         Gut Microbiome
            •   In the absence of major dietary changes or 
                antibiotics, the microbiota is remarkably stable
            •   Significant role in health and disease
                • Eubiotic State
                • Dysbiotic State
                  • Asthma and atopic diseases
                  • Obesity and metabolic syndrome
                  • Colorectal cancer
                  • Enteric infections
                  • Irritable bowel syndrome
                  • Inflammatory bowel disease
                  Clostridium difficile 
                         infection (CDI)
          •  Acquired after antibiotic treatment and 
             ingestion of environmental spores
          •  Public health problem
             • Prevalence of 13.1 per 1,000 patients
             • 100,000 people dying annually
             • Strains with increased virulence
               • Resistance to fluoroquinolones
               • Increased toxin production