The DOI matches its Crossref record; 48 of the 48 references it cites were found in a registry or an index.
Increased Intestinal Permeability Correlates with Sigmoid Mucosa alpha-Synuclein Staining and Endotoxin Exposure Markers in Early Parkinson's Disease
Open accessAbstract
UNLABELLED: Parkinson's disease (PD) is the second most common neurodegenerative disorder of aging. The pathological hallmark of PD is neuronal inclusions termed Lewy bodies whose main component is alpha-synuclein protein. The finding of these Lewy bodies in the intestinal enteric nerves led to the hypothesis that the intestine might be an early site of PD disease in response to an environmental toxin or pathogen. One potential mechanism for environmental toxin(s) and proinflammatory luminal products to gain access to mucosal neuronal tissue and promote oxidative stress is compromised intestinal barrier integrity. However, the role of intestinal permeability in PD has never been tested. We hypothesized that PD subjects might exhibit increased intestinal permeability to proinflammatory bacterial products in the intestine. To test our hypothesis we evaluated intestinal permeability in subjects newly diagnosed with PD and compared their values to healthy subjects. In addition, we obtained intestinal biopsies from both groups and used immunohistochemistry to assess bacterial translocation, nitrotyrosine (oxidative stress), and alpha-synuclein. We also evaluated serum markers of endotoxin exposure including LPS binding protein (LBP). Our data show that our PD subjects exhibit significantly greater intestinal permeability (gut leakiness) than controls. In addition, this intestinal hyperpermeability significantly correlated with increased intestinal mucosa staining for E. coli bacteria, nitrotyrosine, and alpha-synuclein as well as serum LBP levels in PD subjects. These data represent not only the first demonstration of abnormal intestinal permeability in PD subjects but also the first correlation of increased intestinal permeability in PD with intestinal alpha-synuclein (the hallmark of PD), as well as staining for gram negative bacteria and tissue oxidative stress. Our study may thus shed new light on PD pathogenesis as well as provide a new method for earlier diagnosis of PD and suggests potential therapeutic targets in PD subjects. TRIAL REGISTRATION: Clinicaltrials.gov NCT01155492.
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“A leaky gut barrier has been linked to PD pathogenesis involving local flux of bacterial toxins, microbes, and potentially molecules like α-synuclein across the gastrointestinal epithelium [29–31]”
From The gut–brain axis in early Parkinson’s disease: from prodrome to prevention (2025) · cites this paper as [31]
Experimental — accuracy not yet measuredThe source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“Increased intestinal permeability is associated with increased bacteria and exposure to the bacterial endotoxin in Parkinson's disease, while increased intestinal a-synuclein and 3nitrotyrosine staining (associated with oxidative stress) leads to high intestinal permeability.127”
From The role of gut dysbiosis in Parkinson’s disease: mechanistic insights and therapeutic options (2021) · cites this paper as [127]
Experimental — accuracy not yet measuredIn the citing paper
“Intestinal permeability increases early in Parkinson’s disease”
From The endotoxin hypothesis of neurodegeneration (2019) · cites this paper as [92]
In the citing paper
“PD patients have increased gastrointestinal permeability [92] and LPS binding protein (LBP) [92], and a proportion of PD patients have elevated blood endotoxin [93].”
From The endotoxin hypothesis of neurodegeneration (2019) · cites this paper as [92]
In the citing paper
“serum from PD patients contains low levels of LPS binding protein [145,146], which are indicative of a chronic systemic exposure to LPS and gram negative endobacteria [147,148,149]”
From The Interplay between Gut Microbiota and Parkinson’s Disease: Implications on Diagnosis and Treatment (2022) · cites this paper as [146]
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Cites
Hughes, A. J., Daniel, S. E., Kilford, L., & Lees, A. J. (1992) · Journal of Neurology, Neurosurgery & Psychiatry · doi:10.1136/jnnp.55.3.181 · Cited by 10,378
Metagenomic Analysis of the Human Distal Gut Microbiome
Gill, S. R., Pop, M., DeBoy, R. T., Eckburg, P. B., Turnbaugh, P. J., Samuel, B. S., Gordon, J. I., Relman, D. A., Fraser-Liggett, C. M., & Nelson, K. E. (2006) · Science · doi:10.1126/science.1124234 · Cited by 4,699
The Effect of Diet on the Human Gut Microbiome: A Metagenomic Analysis in Humanized Gnotobiotic Mice
Turnbaugh, P. J., Ridaura, V. K., Faith, J. J., Rey, F. E., Knight, R., & Gordon, J. I. (2009) · Science Translational Medicine · doi:10.1126/scitranslmed.3000322 · Cited by 3,058 · cited 1×
“The composition of this bacterial community is influenced by both genetic and environmental factors like diet [10].”
BackgroundProjected number of people with Parkinson disease in the most populous nations, 2005 through 2030
Dorsey, E. R., Constantinescu, R., Thompson, J. P., Biglan, K., Holloway, R. G., Kieburtz, K. D., Marshall, F. J., Ravina, B. M., Schifitto, G., Siderowf, A. D., et al. (2006) · Neurology · doi:10.1212/01.wnl.0000247740.47667.03 · Cited by 2,479
Systemic LPS causes chronic neuroinflammation and progressive neurodegeneration
Qin, L., Wu, X., Block, M. L., Liu, Y., Breese, G. R., Hong, J., Knapp, D. J., & Crews, F. T. (2007) · Glia · doi:10.1002/glia.20467 · Cited by 2,144
Neuroinflammation in Parkinson’s disease: A target for neuroprotection?
Hirsch, E. C., & Hunot, S. (2009) · The Lancet Neurology · doi:10.1016/s1474-4422(09)70062-6 · Cited by 1,984
Lees, A. J., Hardy, J., & Revesz, T. (2009) · The Lancet · doi:10.1016/s0140-6736(09)60492-x · Cited by 1,956
Braak, H., R�b, U., Gai, W. P., & Del Tredici, K. (2003) · Journal of Neural Transmission · doi:10.1007/s00702-002-0808-2 · Cited by 1,683
Parkinson's disease: a dual‐hit hypothesis
Hawkes, C. H., Del Tredici, K., & Braak, H. (2007) · Neuropathology and Applied Neurobiology · doi:10.1111/j.1365-2990.2007.00874.x · Cited by 1,021
Kim, W., Mohney, R. P., Wilson, B. C., Jeohn, G., Liu, B., & Hong, J. (2000) · Journal of Neuroscience · doi:10.1523/jneurosci.20-16-06309.2000 · Cited by 881
Research works printed but not linked: 3
- K Shannon, 2011, Alpha-synuclein in Colonic Submucosa in Early Untreated Parkinson Disease., Movement Disorders
- WJ Kupsky, 1987, Parkinson's disease and megacolon: concentric hyaline inclusions (Lewy bodies) in enteric ganglion cells., Neurology, 37, 1253, 10.1212/WNL.37.7.1253 · DOI
- K Wakabayashi, 1997, Neuropathology of autonomic nervous system in Parkinson's disease., Eur Neurol, 38, 2, 10.1159/000113469 · DOI
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Rusch, C., Beke, M., Tucciarone, L., Nieves, C., Ukhanova, M., Tagliamonte, M. S., Mai, V., Suh, J. H., Wang, Y., Chiu, S., et al. (2021) · Frontiers in Neurology · doi:10.3389/fneur.2021.794640 · Cited by 63
Pal, G. D., Shaikh, M., Forsyth, C. B., Ouyang, B., Keshavarzian, A., & Shannon, K. M. (2015) · Frontiers in Neuroscience · doi:10.3389/fnins.2015.00306 · Cited by 57
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Gonzalez-Riano, C., Saiz, J., Barbas, C., Bergareche, A., Huerta, J. M., Ardanaz, E., Konjevod, M., Mondragon, E., Erro, M. E., Chirlaque, M. D., et al. (2021) · npj Parkinson's Disease · doi:10.1038/s41531-021-00216-4 · Cited by 49
Endres, K., & Schäfer, K.-H. (2018) · Journal of Innate Immunity · doi:10.1159/000488629 · Cited by 52
Zhu, Y., Huan, F., Wang, J., Xie, X., Yu, G., Wang, X., Jiang, L., Gao, R., Xiao, H., Ding, H., et al. (2020) · ACS Chemical Neuroscience · doi:10.1021/acschemneuro.0c00475 · Cited by 48
Torres, E. R. S., Akinyeke, T., Stagaman, K., Duvoisin, R. M., Meshul, C. K., Sharpton, T. J., & Raber, J. (2018) · Frontiers in Behavioral Neuroscience · doi:10.3389/fnbeh.2018.00140 · Cited by 38
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Metadata
- Authors
- Forsyth, C. B., Shannon, K. M., Kordower, J. H., Voigt, R. M., Shaikh, M., Jaglin, J. A., Estes, J. D., Dodiya, H. B., & Keshavarzian, A.
- Affiliations
- Rush University Medical Center (US)
- National Cancer Institute (US)
- Corresponding author
- Forsyth, Christopher B.
- ORCID
- Venue
- PLoS ONE
- Publisher
- Public Library of Science (PLoS)
- Published
- 2011-12-01
- Volume
- 6
- Issue
- 12
- Pages
- e28032
- ISSN
- 1932-6203 (ISSN-L)
- PMC
- PMC3228722
- OpenAlex
- W1992780204
- Cited by
- 974
- References
- 48
- Citations by year
- 2026: 72 · 2025: 73 · 2024: 86 · 2023: 108 · 2022: 108 · 2021: 132 · 2020: 96 · 2019: 72 · 2018: 66 · 2017: 44 · 2016: 33 · 2015: 36 · 2014: 20 · 2013: 13 · 2012: 14
- FWCI
- 9.55
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Locations
- PLoS ONE (publishedVersion, cc-by)
- Europe PMC (PubMed Central) (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Figshare (submittedVersion, cc-by)
- Funders
- Parkinson's Disease Foundation
- Topics
- Health Sciences › Medicine › Clinical Neurology › Parkinson's Disease Mechanisms and Treatments
- Health Sciences › Medicine › Gastroenterology › Gastrointestinal motility and disorders
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gut microbiota and health
- Keywords
- Parkinson's disease, intestinal permeability, alpha-synuclein, Lewy bodies, endotoxin exposure, bacterial translocation, nitrotyrosine, oxidative stress, LPS-binding protein, Escherichia coli, intestinal barrier integrity, early diagnosis, gut-brain axis
- MeSH terms
- Lipopolysaccharide-Binding Protein, Acute-Phase Proteins, Aged, Carrier Proteins, Endotoxins, Escherichia coli, Escherichia coli Infections, Female, Humans, Immunoenzyme Techniques, Intestinal Mucosa, Intestines, Male, Membrane Glycoproteins, Middle Aged, Neurons, Parkinson Disease, Permeability, Sucrose, Tyrosine, Biomarkers, Oxidative Stress, alpha-Synuclein
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