Number of microbial cells, number of species and total mass in gastrointestinal tract

Range total population ~10^14cells: Num. of species ~500-1,000: total mass ~1.5kg
Organism Human Homo sapiens
Reference Rubio CA. The Natural Antimicrobial Enzyme Lysozyme is Up-Regulated in Gastrointestinal Inflammatory Conditions. Pathogens. 2014 Jan 16 3(1):73-92. doi: 10.3390/pathogens3010073. p.74 2nd paragraphPubMed ID25437608
Primary Source [1] Kaper, J.B. Sperandio, V. Bacterial cell-to-cell signaling in the gastrointestinal tract. Infect. Immun. 2005, 73, 3197–3209.PubMed ID15908344
Comments P.74 2nd paragraph:"The density of the bacterial flora in the GI tract is huge: it varies from 10^3/mL near the gastric outlet, to 10^10/mL at the ileo-cecal valve, to 10^11 to 10^12/mL in the colon. The total microbial population (ca. 10^14) [primary source] exceeds the total number of cells in the GI tract. About 500 to 1,000 different species exist, a biomass that weights about 1.5 kg [primary source]."
Entered by Uri M
ID 112308