The intestinal microbiota consists of approximately 1013 to 1014 microorganisms, a global microbial community dominated by bacteria, mainly strict anaerobes, but also including viruses, protozoa, archaea, and fungi (1). Although several studies have investigated the bacterial communities in infants, our understanding of the microbiota in children of different ages remains limited because only 20% of the bacterial species have been successfully cultured (2). The limitation of these quantitative and qualitative descriptions reflects the methodological difficulty encountered when trying to delineate and enumerate the constituents of a normal microbiota. Traditional culture-based analyses are adequate only for the minority of the gut microbes that are amenable to cultivation. As new culture-independent techniques, such as genome sequencing and metagenomic techniques, become available and less expensive, the likelihood of a more comprehensive analysis will increase (3). Although gut microbiota comprises a wide variety of bacterial species and strains whose composition and density vary along the gastrointestinal (GI) tract, it is largely defined by 2 bacterial phylotypes, Bacterioidetes and Firmicutes, with Proteonacteria, Acinobacteria, Fusobacteria, and Verrucomicrobia phyla present in relatively low numbers. The size of 1 microbial metagenome, also called microbiome, is 150 times larger than the human genome and encodes 100 times more genes than our own genome. This extensive gene catalogue may enable us to study potential associations between microbial genes and human phenotypes and even environmental factors throughout our lifetime. Indeed, the microbiota acts as a personalized organ that can be modified by diet, lifestyle, prebiotics, probiotics, and antibiotics.

MICROBIOTA INVOLVEMENT IN THE GUT-BRAIN AXIS

Indrio F
;
2013-01-01

Abstract

The intestinal microbiota consists of approximately 1013 to 1014 microorganisms, a global microbial community dominated by bacteria, mainly strict anaerobes, but also including viruses, protozoa, archaea, and fungi (1). Although several studies have investigated the bacterial communities in infants, our understanding of the microbiota in children of different ages remains limited because only 20% of the bacterial species have been successfully cultured (2). The limitation of these quantitative and qualitative descriptions reflects the methodological difficulty encountered when trying to delineate and enumerate the constituents of a normal microbiota. Traditional culture-based analyses are adequate only for the minority of the gut microbes that are amenable to cultivation. As new culture-independent techniques, such as genome sequencing and metagenomic techniques, become available and less expensive, the likelihood of a more comprehensive analysis will increase (3). Although gut microbiota comprises a wide variety of bacterial species and strains whose composition and density vary along the gastrointestinal (GI) tract, it is largely defined by 2 bacterial phylotypes, Bacterioidetes and Firmicutes, with Proteonacteria, Acinobacteria, Fusobacteria, and Verrucomicrobia phyla present in relatively low numbers. The size of 1 microbial metagenome, also called microbiome, is 150 times larger than the human genome and encodes 100 times more genes than our own genome. This extensive gene catalogue may enable us to study potential associations between microbial genes and human phenotypes and even environmental factors throughout our lifetime. Indeed, the microbiota acts as a personalized organ that can be modified by diet, lifestyle, prebiotics, probiotics, and antibiotics.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11369/393736
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