Abstract
The human body is home to complex communities of microorganisms. Their total number is estimated to be 1014; 10 times the number of human cells per individual [1]. These microbial communities are found on our skin, in the mouth, nose, ears, vagina, and in the intestinal tract. Similar to environmental sources in which microbes are found, such as seawater and soil, the human body could be considered as an ecosystem consisting of different niches, or a meta-community consisting of many local communities. Each anatomical site has its own physiochemical characteristics, and each location is occupied with a specialized set of microbes. The majority of the human-associated microbes and the largest diversity are found in the intestinal tract, where microbial abundance increases from the stomach to the colon, with the highest number of microbes found in stools (1011 per mL). This complex ecosystem consists of bacteria, archaea, yeasts and other eukaryotes [1, 2].
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Bengmark S. Ecological control of the gastroinstinal tract: the role of probiotic flora. Gut, 1998, 42: 2–7.
Elisabeth M B. Composition and function of the human-associated microbiota Nutr Rev, 2009, 67(suppl 2): 164–171.
Gronlund M M, Lehtonen O P, Eerola E, et al. Fecal microflora in healthy infants born by different methods of delivery:permanent changes in intestinal flora after cesarean delivery. J Pediatr Gastroenterol Nutr, 1999, 28:19–25.
Backhed F, Ley R E, Justin L, et al. Host-bacterial mutualism in the human intestine. Science, 2005, 307: 1915–1920.
Zoetendal E G Akkermans ADL, Akkermans-van vliet WM, et al. The host genotype affects the bacterial community in the human gastro-intestinal tract. Microb. Ecol Health Dis, 2001, 13: 129–134.
Simon G L, Gorbach S L. Intestinal flora in health and disease. Gastroenterology, 1984, 86: 174–193.
Guarner F, Malagelada J R. Gut flora in health and disease, Lancet, 2003, 361: 512–519.
Palmer C, Bik E M, Digiulio D B, et al. Development of the human infant intestinal microbiota. PLoS Biol, 2007, 5: e177.
Suau A, Bonnet R, Sutren M, et al. Direct rDNA community analysis reveals a myriad of novel bacterial lineages within the human gut. Appl Environ Microbiol, 1999, 65: 4799–4807.
Tannock G W. Molecular assessment of intestinal microflora. Am J Clin Nutr, 2001, 73 (suppl): S410-S414.
Kimura K, McCartney A I, McConnell M A, et al. Analysis of fecal populations of bifidobacteria and lactobacilli and investigation of the immunological responses of their human hosts to the predominant strains. Appl Environ Microbiol, 1997, 63: 3394–3398.
Sghir A, Gramet G, Suau A, et al. Quantification of bacterial groups within human fecal flora by oligonucleotide probe hybridization. Appl Environ Microbiol, 2000, 66: 2263–2266.
Cummings J H, Beatty E R, Kingman S M, et al. Digestion and physiological properties of resistant starch in the human large bowel. Br J Nutr, 1996, 75: 733–747.
Smith E A, Macfarlane G T. Enumeration of human colonic bacteria producing phenolic and indolic compounds: Effects of pH, carbohydrate availability and retention time on dissimilatory aromatic amino acid metabolism. J Appl Bacteriol, 1996, 81: 288–302.
Fallingborg J. Intraluminal pH of the human gastrointestinal tract. Dan Med Bull 1999, 46: 183–196.
Hill M J. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prey 1997, 6 (suppl): S43-S45.
Miyazawa E, Iwabuchi A, Yoshida T. Phytate breakdown and apparent absorption of phosphorus, calcium and magnesium in germfree and conventionalized rats. Nutr Res, 1996, 16: 603–613.
Younes H, Coudray C, Bellanger J, et al. Effects of two fermentable carbohydrates (inulin and resistant starch) and their combination on calcium and magnesium balance in rats. Br J Nutr, 2001, 86: 479–485.
Wang Z N, Klipfell E, Brian J, et al. Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease Nature, 2011, 472 (7341): 57–63.
Hill J. Understanding and addressing the epidemic of obesity: An energy balance perspective. Endocr Rev, 2006, 27: 750–761.
Backhed F, Ding H, Wang T, et al. The gut microbiota as an environmental factor that regulates fat storage. Proc Natl Acad Sci USA, 2004, 101: 15718–15723.
Ley R E, Backhed F, Turnbaugh P, et al. Obesity alters gut microbial ecology. Proc Natl Acad Sci USA, 2005, 102: 11070–11075.
Ley R E, Turnbaugh P J, Klein S, et al. Microbial ecology: Human gut microbes associated with obesity. Nature, 2006, 444:1022–1023.
Turbaugh P J, Ley R E, Mahowald M A, et al. An obesity-associated gut microbiome with increased capacity for energy harvest. Nature, 2006, 444: 1027–1031.
Marko K, Collado M C, Salminen S, et al. Early differences in fecal microbiota composition in children may predict overweight. Am J Clin Nutr, 2008, 87:534–538.
Bajzer M, Seeley R J. Physiology: Obesity and gut flora. Nature, 2006, 444: 1009–1010.
Cani P D, Neyrinck A M, Maton N, et al. Oligofructose promotes satiety in rats fed a high-fat diet: Involvement of glucagon-like peptide-1. Obes Res, 2005, 13: 1000–1007.
Kolida S, Meyer D, Gibson G R. A double-blind placebo-controlled study to establish the bifidogenic dose of inulin in healty humans. Eur J Clin Nutr, 2007, 61: 1189–1195.
Alam M, Midtvedt T, Uribe A. Differential cell kinetics in the ileum and colon of germfree rats. Scand J Gastroenterol, 1994, 29: 445–451.
Gordon J I, Hooper L V, McNevin M S, et al. Epithelial cell growth and differentiation. III. Promoting diversity in the intestine: Conversations between the microflora, epithelium, and diffuse GALT. Am J Physiol, 1997, 273: G565-G570.
Krinos C M, Coyne M J, Weinacht K G, et al. Extensive surface diversity of a commensal microorganism by multiple DNA inversions. Nature, 2001, 414: 555–558.
Kagnoff M F, Eckmann L. Epithelial cells as sensors for microbial infection. J Clin Invest, 1997, 100: 6–10.
Aderem A, Ulevitch R J. Toll-like receptors in the induction of the innate immune response. Nature, 2000, 406: 782–787.
Borruel N, Carol M, Casellas F, et al. Increased mucosal TNF_production in Crohn’s disease can be downregulated ex vivo by probiotic bacteria. Gut, 2002, 5: 659–664.
Ling Z, Liu X, Luo Y, et al. Pyrosequencing analysis of the human microbiota of healthy Chinese undergraduates. BMC Genomics 2013, 14: 390.
Ling Z, Liu X, Wang Y, et al. Pyrosequencing analysis of the salivary microbiota of healthy Chinese children and adults. Microb Ecol, 2013, 65: 487–495.
Taguchi H, Takahashi M, Yamaguchi H, et al. Experimental infection of germ-free mice with hyper-toxigenic enterohaemorrhagic Escherichia coli O157:H7, strain 6. J Med Microbiol, 2002, 51: 336–343.
Lievin V, Peiffer I, Hudault S, et al. Bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity. Gut, 2000, 47: 646–652.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 Zhejiang University Press, Hangzhou and Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Li, Y. (2014). Human Microbiota and Its Function. In: Li, L. (eds) Infectious Microecology. Advanced Topics in Science and Technology in China. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-43883-1_2
Download citation
DOI: https://doi.org/10.1007/978-3-662-43883-1_2
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-662-43882-4
Online ISBN: 978-3-662-43883-1
eBook Packages: Biomedical and Life SciencesBiomedical and Life Sciences (R0)