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The human gut microbiota with reference to autism spectrum disorder: considering the whole as more than a sum of its parts.

Toh MC, Allen-Vercoe E - Microb. Ecol. Health Dis. (2015)

Bottom Line: The human gut microbiota is a complex microbial ecosystem that contributes an important component towards the health of its host.This highly complex ecosystem has been underestimated in its importance until recently, when a realization of the enormous scope of gut microbiota function has been (and continues to be) revealed.One of the more striking of these discoveries is the finding that the gut microbiota and the brain are connected, and thus there is potential for the microbiota in the gut to influence behavior and mental health.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada.

ABSTRACT
The human gut microbiota is a complex microbial ecosystem that contributes an important component towards the health of its host. This highly complex ecosystem has been underestimated in its importance until recently, when a realization of the enormous scope of gut microbiota function has been (and continues to be) revealed. One of the more striking of these discoveries is the finding that the gut microbiota and the brain are connected, and thus there is potential for the microbiota in the gut to influence behavior and mental health. In this short review, we outline the link between brain and gut microbiota and urge the reader to consider the gut microbiota as an ecosystem 'organ' rather than just as a collection of microbes filling a niche, using the hypothesized role of the gut microbiota in autism spectrum disorder to illustrate the concept.

No MeSH data available.


Related in: MedlinePlus

Pictorial representation of the routes for, and blockages of, microbial colonization of Westernized humans during early life. On the left of the figure, routes of natural colonization are depicted, while on the right, impediments to natural colonization are shown.
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Figure 0002: Pictorial representation of the routes for, and blockages of, microbial colonization of Westernized humans during early life. On the left of the figure, routes of natural colonization are depicted, while on the right, impediments to natural colonization are shown.

Mentions: Having established the importance of microbial community diversity, it is not surprising that a growing body of literature indicates that many chronic diseases are associated with less diverse gut ecosystems (35, 36). At the moment, this phenomenon is mainly associative, as it is difficult to ascertain whether reduced diversity occurs as a result of disease or vice versa. However, in some cases (e.g. Clostridium difficile infection, CDI), disease certainly results from a loss of gut microbiota diversity and robustness (36). It is undoubtedly true (both on the micro and macro scale) that ecosystems which lack functional redundancy are more prone to collapse under perturbational stress. An imbalance within the microbial ecosystem (‘dysbiosis’) of the human gut microbiota could result from many different scenarios (Fig. 2), including: insufficient colonization of an infant (e.g. due to Caesarean section) and/or inadequate nursing with breastmilk; exposure to antibiotics, both as short-term therapy as well as long-term pervasive exposure through the food chain; infection with pathogenic microbes; and consumption of a refined, Western-style diet with little fiber [which is an important food source for colonic bacteria (29, 37–40)]. Recently, proponents of the ‘missing microbiota hypothesis’ have warned that modern lifestyles do not sustain a diverse human microbiome, and that the extinction of important ‘keystone’ microbes could lead to the loss of fundamental functional abilities, which would ultimately contribute to dysbiosis and disease (41).


The human gut microbiota with reference to autism spectrum disorder: considering the whole as more than a sum of its parts.

Toh MC, Allen-Vercoe E - Microb. Ecol. Health Dis. (2015)

Pictorial representation of the routes for, and blockages of, microbial colonization of Westernized humans during early life. On the left of the figure, routes of natural colonization are depicted, while on the right, impediments to natural colonization are shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4310852&req=5

Figure 0002: Pictorial representation of the routes for, and blockages of, microbial colonization of Westernized humans during early life. On the left of the figure, routes of natural colonization are depicted, while on the right, impediments to natural colonization are shown.
Mentions: Having established the importance of microbial community diversity, it is not surprising that a growing body of literature indicates that many chronic diseases are associated with less diverse gut ecosystems (35, 36). At the moment, this phenomenon is mainly associative, as it is difficult to ascertain whether reduced diversity occurs as a result of disease or vice versa. However, in some cases (e.g. Clostridium difficile infection, CDI), disease certainly results from a loss of gut microbiota diversity and robustness (36). It is undoubtedly true (both on the micro and macro scale) that ecosystems which lack functional redundancy are more prone to collapse under perturbational stress. An imbalance within the microbial ecosystem (‘dysbiosis’) of the human gut microbiota could result from many different scenarios (Fig. 2), including: insufficient colonization of an infant (e.g. due to Caesarean section) and/or inadequate nursing with breastmilk; exposure to antibiotics, both as short-term therapy as well as long-term pervasive exposure through the food chain; infection with pathogenic microbes; and consumption of a refined, Western-style diet with little fiber [which is an important food source for colonic bacteria (29, 37–40)]. Recently, proponents of the ‘missing microbiota hypothesis’ have warned that modern lifestyles do not sustain a diverse human microbiome, and that the extinction of important ‘keystone’ microbes could lead to the loss of fundamental functional abilities, which would ultimately contribute to dysbiosis and disease (41).

Bottom Line: The human gut microbiota is a complex microbial ecosystem that contributes an important component towards the health of its host.This highly complex ecosystem has been underestimated in its importance until recently, when a realization of the enormous scope of gut microbiota function has been (and continues to be) revealed.One of the more striking of these discoveries is the finding that the gut microbiota and the brain are connected, and thus there is potential for the microbiota in the gut to influence behavior and mental health.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada.

ABSTRACT
The human gut microbiota is a complex microbial ecosystem that contributes an important component towards the health of its host. This highly complex ecosystem has been underestimated in its importance until recently, when a realization of the enormous scope of gut microbiota function has been (and continues to be) revealed. One of the more striking of these discoveries is the finding that the gut microbiota and the brain are connected, and thus there is potential for the microbiota in the gut to influence behavior and mental health. In this short review, we outline the link between brain and gut microbiota and urge the reader to consider the gut microbiota as an ecosystem 'organ' rather than just as a collection of microbes filling a niche, using the hypothesized role of the gut microbiota in autism spectrum disorder to illustrate the concept.

No MeSH data available.


Related in: MedlinePlus