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A model for the induction of autism in the ecosystem of the human body: the anatomy of a modern pandemic?

Bilbo SD, Nevison CD, Parker W - Microb. Ecol. Health Dis. (2015)

Bottom Line: Others are convinced that the disease is not pandemic in nature, but rather that it has been with humanity for millennia, with its biological and neurological underpinnings just now being understood.Finally, the potential role of the microbial flora (the microbiome) in the pathogenesis of autism is discussed, with the view that the microbial flora is a subset of the life associated with the human body, and that the entire human biome, including both the microbial flora and the fauna, has been radically destabilized by modern culture.It is suggested that the unequivocal way to resolve the debate regarding the pandemic nature of autism is to perform an experiment: monitor the prevalence of autism after normalizing immune function in a Western population using readily available approaches that address the well-known factors underlying the immune dysfunction in that population.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology & Neuroscience, Systems & Integrative Neuroscience Group, Duke University, Durham, NC, USA.

ABSTRACT

Background: The field of autism research is currently divided based on a fundamental question regarding the nature of autism: Some are convinced that autism is a pandemic of modern culture, with environmental factors at the roots. Others are convinced that the disease is not pandemic in nature, but rather that it has been with humanity for millennia, with its biological and neurological underpinnings just now being understood.

Objective: In this review, two lines of reasoning are examined which suggest that autism is indeed a pandemic of modern culture. First, given the widely appreciated derailment of immune function by modern culture, evidence that autism is strongly associated with aberrant immune function is examined. Second, evidence is reviewed indicating that autism is associated with 'triggers' that are, for the most part, a construct of modern culture. In light of this reasoning, current epidemiological evidence regarding the incidence of autism, including the role of changing awareness and diagnostic criteria, is examined. Finally, the potential role of the microbial flora (the microbiome) in the pathogenesis of autism is discussed, with the view that the microbial flora is a subset of the life associated with the human body, and that the entire human biome, including both the microbial flora and the fauna, has been radically destabilized by modern culture.

Conclusions: It is suggested that the unequivocal way to resolve the debate regarding the pandemic nature of autism is to perform an experiment: monitor the prevalence of autism after normalizing immune function in a Western population using readily available approaches that address the well-known factors underlying the immune dysfunction in that population.

No MeSH data available.


Related in: MedlinePlus

The three-legged stool analogy. The ecosystem of the human body is stabilized by immune function in concert with distinct and independent components of the biome. In this model, protozoans are placed with the fauna rather than the microbiome because (a) they exert some of the same effects on the immune system as the fauna, and (b) they are not normally considered in most modern studies of the microbiome, being virtually eliminated from the human biome by Western culture. Loss or substantial alteration of any one leg has the potential to destabilize the entire system, although current evidence suggests that the fauna/protozoan leg exists naturally without requirements for specific species. That is, the fauna/protozoan leg is highly variable in the human population in terms of its species composition, although the complete absence of this leg apparently has very detrimental consequences for the ecosystem as a whole (46). The microbiome leg, in contrast, contains many species that are required for normal function, whereas other species may vary from individual to individual depending on diet and other factors. The three-legged stool in the photograph was designed and created by Kim Turk.
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Figure 0001: The three-legged stool analogy. The ecosystem of the human body is stabilized by immune function in concert with distinct and independent components of the biome. In this model, protozoans are placed with the fauna rather than the microbiome because (a) they exert some of the same effects on the immune system as the fauna, and (b) they are not normally considered in most modern studies of the microbiome, being virtually eliminated from the human biome by Western culture. Loss or substantial alteration of any one leg has the potential to destabilize the entire system, although current evidence suggests that the fauna/protozoan leg exists naturally without requirements for specific species. That is, the fauna/protozoan leg is highly variable in the human population in terms of its species composition, although the complete absence of this leg apparently has very detrimental consequences for the ecosystem as a whole (46). The microbiome leg, in contrast, contains many species that are required for normal function, whereas other species may vary from individual to individual depending on diet and other factors. The three-legged stool in the photograph was designed and created by Kim Turk.

Mentions: The factors present in modern society that destabilize immune function are no mystery. These factors, which arise directly from common cultural advances such as food processing equipment, water treatment facilities, and artificial indoor lighting, include inflammatory diets, insufficient exercise, chronic psychological stress, and vitamin D deficiency. However, foremost among the factors that cause modern immune dysfunction is ‘biome depletion’ (44–46), a condition induced by a wide range of technological advancements, including indoor plumbing, hot water heaters, water treatment facilities, and refrigerated storage. In this context, the biome is defined as all life present within the ecosystem of the human body. The immune system and the biome are essentially co-dependent, with the immune system providing support for the biome, while the biome, in turn, provides stimulus necessary for proper immune system development. Importantly for this discussion, the biome can be divided roughly into two components that are, to an extent, independent from one another. One of these two components, the microbial flora, is now referred to universally as the microbiome, although this term obscures the fact that the human biome contains additional components. A second major component of the human biome is the fauna, or animal life, normally present in the intestines and, often less innocuously, in other organs of the body such as the liver and the blood. In viewing the ecosystem of the human body, the analogy of a three-legged stool is helpful (Fig. 1). In this model, the immune system and two components of the biome, the microbial flora and the fauna, interact together, providing stability for the ecosystem as a whole. Protozoans are included with the fauna, since these organisms share some similarities with the fauna in regards to their effects on immune function, and since protozoans are not generally considered in modern studies of the human microbiome. In this model, the loss or substantial alteration of any of the three legs threatens the stability of the entire system.


A model for the induction of autism in the ecosystem of the human body: the anatomy of a modern pandemic?

Bilbo SD, Nevison CD, Parker W - Microb. Ecol. Health Dis. (2015)

The three-legged stool analogy. The ecosystem of the human body is stabilized by immune function in concert with distinct and independent components of the biome. In this model, protozoans are placed with the fauna rather than the microbiome because (a) they exert some of the same effects on the immune system as the fauna, and (b) they are not normally considered in most modern studies of the microbiome, being virtually eliminated from the human biome by Western culture. Loss or substantial alteration of any one leg has the potential to destabilize the entire system, although current evidence suggests that the fauna/protozoan leg exists naturally without requirements for specific species. That is, the fauna/protozoan leg is highly variable in the human population in terms of its species composition, although the complete absence of this leg apparently has very detrimental consequences for the ecosystem as a whole (46). The microbiome leg, in contrast, contains many species that are required for normal function, whereas other species may vary from individual to individual depending on diet and other factors. The three-legged stool in the photograph was designed and created by Kim Turk.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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Figure 0001: The three-legged stool analogy. The ecosystem of the human body is stabilized by immune function in concert with distinct and independent components of the biome. In this model, protozoans are placed with the fauna rather than the microbiome because (a) they exert some of the same effects on the immune system as the fauna, and (b) they are not normally considered in most modern studies of the microbiome, being virtually eliminated from the human biome by Western culture. Loss or substantial alteration of any one leg has the potential to destabilize the entire system, although current evidence suggests that the fauna/protozoan leg exists naturally without requirements for specific species. That is, the fauna/protozoan leg is highly variable in the human population in terms of its species composition, although the complete absence of this leg apparently has very detrimental consequences for the ecosystem as a whole (46). The microbiome leg, in contrast, contains many species that are required for normal function, whereas other species may vary from individual to individual depending on diet and other factors. The three-legged stool in the photograph was designed and created by Kim Turk.
Mentions: The factors present in modern society that destabilize immune function are no mystery. These factors, which arise directly from common cultural advances such as food processing equipment, water treatment facilities, and artificial indoor lighting, include inflammatory diets, insufficient exercise, chronic psychological stress, and vitamin D deficiency. However, foremost among the factors that cause modern immune dysfunction is ‘biome depletion’ (44–46), a condition induced by a wide range of technological advancements, including indoor plumbing, hot water heaters, water treatment facilities, and refrigerated storage. In this context, the biome is defined as all life present within the ecosystem of the human body. The immune system and the biome are essentially co-dependent, with the immune system providing support for the biome, while the biome, in turn, provides stimulus necessary for proper immune system development. Importantly for this discussion, the biome can be divided roughly into two components that are, to an extent, independent from one another. One of these two components, the microbial flora, is now referred to universally as the microbiome, although this term obscures the fact that the human biome contains additional components. A second major component of the human biome is the fauna, or animal life, normally present in the intestines and, often less innocuously, in other organs of the body such as the liver and the blood. In viewing the ecosystem of the human body, the analogy of a three-legged stool is helpful (Fig. 1). In this model, the immune system and two components of the biome, the microbial flora and the fauna, interact together, providing stability for the ecosystem as a whole. Protozoans are included with the fauna, since these organisms share some similarities with the fauna in regards to their effects on immune function, and since protozoans are not generally considered in modern studies of the human microbiome. In this model, the loss or substantial alteration of any of the three legs threatens the stability of the entire system.

Bottom Line: Others are convinced that the disease is not pandemic in nature, but rather that it has been with humanity for millennia, with its biological and neurological underpinnings just now being understood.Finally, the potential role of the microbial flora (the microbiome) in the pathogenesis of autism is discussed, with the view that the microbial flora is a subset of the life associated with the human body, and that the entire human biome, including both the microbial flora and the fauna, has been radically destabilized by modern culture.It is suggested that the unequivocal way to resolve the debate regarding the pandemic nature of autism is to perform an experiment: monitor the prevalence of autism after normalizing immune function in a Western population using readily available approaches that address the well-known factors underlying the immune dysfunction in that population.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology & Neuroscience, Systems & Integrative Neuroscience Group, Duke University, Durham, NC, USA.

ABSTRACT

Background: The field of autism research is currently divided based on a fundamental question regarding the nature of autism: Some are convinced that autism is a pandemic of modern culture, with environmental factors at the roots. Others are convinced that the disease is not pandemic in nature, but rather that it has been with humanity for millennia, with its biological and neurological underpinnings just now being understood.

Objective: In this review, two lines of reasoning are examined which suggest that autism is indeed a pandemic of modern culture. First, given the widely appreciated derailment of immune function by modern culture, evidence that autism is strongly associated with aberrant immune function is examined. Second, evidence is reviewed indicating that autism is associated with 'triggers' that are, for the most part, a construct of modern culture. In light of this reasoning, current epidemiological evidence regarding the incidence of autism, including the role of changing awareness and diagnostic criteria, is examined. Finally, the potential role of the microbial flora (the microbiome) in the pathogenesis of autism is discussed, with the view that the microbial flora is a subset of the life associated with the human body, and that the entire human biome, including both the microbial flora and the fauna, has been radically destabilized by modern culture.

Conclusions: It is suggested that the unequivocal way to resolve the debate regarding the pandemic nature of autism is to perform an experiment: monitor the prevalence of autism after normalizing immune function in a Western population using readily available approaches that address the well-known factors underlying the immune dysfunction in that population.

No MeSH data available.


Related in: MedlinePlus