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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

Independent alteration of the two compartments of the biome by modern culture. Depletion of biome diversity is much less profound when assessing the microbial flora (a) than the fauna (b). Data from the microbiome (a) compared the US population with two pre-industrial populations, and are taken from Yatsunenko et al. (47, 48) The average number of ‘operational taxonomic units’ (OTUs), an indicator of biological diversity, is shown on the X-axis. In graph b, IgE concentrations (shown on the Y-axis) are plotted against an index of measured colonization with helminths and protozoans (X-axis). Although high levels of IgE in post-industrial populations are indicative of allergy, IgE can be used as a biomarker for helminth and protozoal colonization in pre-industrial populations. The colonization index and IgE concentrations are taken from Scaglia et al. (48), who assessed IgE levels in pre-industrial groups from Rwanda. Scaglia's colonization index was calculated as the sum of parasitosis scores for individual parasites (both helminths and protozoans), and the population (n=161) was divided into eight groups according to their colonization index. The juxtaposition of these two diagrams illustrates how two important parts of the biome are depleted essentially independently of each other.
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Figure 0002: Independent alteration of the two compartments of the biome by modern culture. Depletion of biome diversity is much less profound when assessing the microbial flora (a) than the fauna (b). Data from the microbiome (a) compared the US population with two pre-industrial populations, and are taken from Yatsunenko et al. (47, 48) The average number of ‘operational taxonomic units’ (OTUs), an indicator of biological diversity, is shown on the X-axis. In graph b, IgE concentrations (shown on the Y-axis) are plotted against an index of measured colonization with helminths and protozoans (X-axis). Although high levels of IgE in post-industrial populations are indicative of allergy, IgE can be used as a biomarker for helminth and protozoal colonization in pre-industrial populations. The colonization index and IgE concentrations are taken from Scaglia et al. (48), who assessed IgE levels in pre-industrial groups from Rwanda. Scaglia's colonization index was calculated as the sum of parasitosis scores for individual parasites (both helminths and protozoans), and the population (n=161) was divided into eight groups according to their colonization index. The juxtaposition of these two diagrams illustrates how two important parts of the biome are depleted essentially independently of each other.

Mentions: There is little doubt that alteration of the microbial flora using broad-spectrum antibiotics can destabilize immune function, leading to a range of inflammatory conditions that include allergic and autoimmune diseases. Indeed, the failure to preserve the microbial flora via use of probiotics, autotransplants, and, when necessary, allotransplants during medical interventions that place the microbiome at risk (e.g. use of broad-spectrum antibiotics or delivery by C-section) probably represents one of the most costly and most easily avoidable failures of modern medicine. However, evaluation of the biome in modern versus pre-industrial cultures suggests that the effects of modern culture on the microbial flora pale in comparison to the effects on the fauna (Fig. 2). Although the average diversity of the microbial flora in the US society was 15–30% less than that found in two pre-industrial societies, the differences between individuals were greater than the differences between populations (47). More importantly, most of the differences between populations could be accounted for by diet and the known effects of diet on the microbial flora (47). In stark contrast, using a biomarker for the presence of fauna, it is apparent that the fauna in modern society has been virtually annihilated (Fig. 2). This destruction of a large swath of the biome was essential in order to prevent the spread of infectious diseases, but a large body of research, including numerous studies in animal models and several clinical studies, points toward this biome depletion as the leading cause of immune dysfunction in modern society (44–46). As such, the failure to enrich the biome in order to compensate for this depletion is probably the single most costly shortcoming of modern medicine.


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)

Independent alteration of the two compartments of the biome by modern culture. Depletion of biome diversity is much less profound when assessing the microbial flora (a) than the fauna (b). Data from the microbiome (a) compared the US population with two pre-industrial populations, and are taken from Yatsunenko et al. (47, 48) The average number of ‘operational taxonomic units’ (OTUs), an indicator of biological diversity, is shown on the X-axis. In graph b, IgE concentrations (shown on the Y-axis) are plotted against an index of measured colonization with helminths and protozoans (X-axis). Although high levels of IgE in post-industrial populations are indicative of allergy, IgE can be used as a biomarker for helminth and protozoal colonization in pre-industrial populations. The colonization index and IgE concentrations are taken from Scaglia et al. (48), who assessed IgE levels in pre-industrial groups from Rwanda. Scaglia's colonization index was calculated as the sum of parasitosis scores for individual parasites (both helminths and protozoans), and the population (n=161) was divided into eight groups according to their colonization index. The juxtaposition of these two diagrams illustrates how two important parts of the biome are depleted essentially independently of each other.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4310853&req=5

Figure 0002: Independent alteration of the two compartments of the biome by modern culture. Depletion of biome diversity is much less profound when assessing the microbial flora (a) than the fauna (b). Data from the microbiome (a) compared the US population with two pre-industrial populations, and are taken from Yatsunenko et al. (47, 48) The average number of ‘operational taxonomic units’ (OTUs), an indicator of biological diversity, is shown on the X-axis. In graph b, IgE concentrations (shown on the Y-axis) are plotted against an index of measured colonization with helminths and protozoans (X-axis). Although high levels of IgE in post-industrial populations are indicative of allergy, IgE can be used as a biomarker for helminth and protozoal colonization in pre-industrial populations. The colonization index and IgE concentrations are taken from Scaglia et al. (48), who assessed IgE levels in pre-industrial groups from Rwanda. Scaglia's colonization index was calculated as the sum of parasitosis scores for individual parasites (both helminths and protozoans), and the population (n=161) was divided into eight groups according to their colonization index. The juxtaposition of these two diagrams illustrates how two important parts of the biome are depleted essentially independently of each other.
Mentions: There is little doubt that alteration of the microbial flora using broad-spectrum antibiotics can destabilize immune function, leading to a range of inflammatory conditions that include allergic and autoimmune diseases. Indeed, the failure to preserve the microbial flora via use of probiotics, autotransplants, and, when necessary, allotransplants during medical interventions that place the microbiome at risk (e.g. use of broad-spectrum antibiotics or delivery by C-section) probably represents one of the most costly and most easily avoidable failures of modern medicine. However, evaluation of the biome in modern versus pre-industrial cultures suggests that the effects of modern culture on the microbial flora pale in comparison to the effects on the fauna (Fig. 2). Although the average diversity of the microbial flora in the US society was 15–30% less than that found in two pre-industrial societies, the differences between individuals were greater than the differences between populations (47). More importantly, most of the differences between populations could be accounted for by diet and the known effects of diet on the microbial flora (47). In stark contrast, using a biomarker for the presence of fauna, it is apparent that the fauna in modern society has been virtually annihilated (Fig. 2). This destruction of a large swath of the biome was essential in order to prevent the spread of infectious diseases, but a large body of research, including numerous studies in animal models and several clinical studies, points toward this biome depletion as the leading cause of immune dysfunction in modern society (44–46). As such, the failure to enrich the biome in order to compensate for this depletion is probably the single most costly shortcoming of modern medicine.

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