1
|
Rusch JA, Layden BT, Dugas LR. Signalling cognition: the gut microbiota and hypothalamic-pituitary-adrenal axis. Front Endocrinol (Lausanne) 2023; 14:1130689. [PMID: 37404311 PMCID: PMC10316519 DOI: 10.3389/fendo.2023.1130689] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 05/25/2023] [Indexed: 07/06/2023] Open
Abstract
Cognitive function in humans depends on the complex and interplay between multiple body systems, including the hypothalamic-pituitary-adrenal (HPA) axis. The gut microbiota, which vastly outnumbers human cells and has a genetic potential that exceeds that of the human genome, plays a crucial role in this interplay. The microbiota-gut-brain (MGB) axis is a bidirectional signalling pathway that operates through neural, endocrine, immune, and metabolic pathways. One of the major neuroendocrine systems responding to stress is the HPA axis which produces glucocorticoids such as cortisol in humans and corticosterone in rodents. Appropriate concentrations of cortisol are essential for normal neurodevelopment and function, as well as cognitive processes such as learning and memory, and studies have shown that microbes modulate the HPA axis throughout life. Stress can significantly impact the MGB axis via the HPA axis and other pathways. Animal research has advanced our understanding of these mechanisms and pathways, leading to a paradigm shift in conceptual thinking about the influence of the microbiota on human health and disease. Preclinical and human trials are currently underway to determine how these animal models translate to humans. In this review article, we summarize the current knowledge of the relationship between the gut microbiota, HPA axis, and cognition, and provide an overview of the main findings and conclusions in this broad field.
Collapse
Affiliation(s)
- Jody A. Rusch
- Division of Chemical Pathology, Department of Pathology, University of Cape Town, Cape Town, South Africa
- C17 Chemical Pathology Laboratory, Groote Schuur Hospital, National Health Laboratory Service, Cape Town, South Africa
| | - Brian T. Layden
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL, United States
- Department of Medicine, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States
| | - Lara R. Dugas
- Division of Epidemiology and Biostatistics, School of Public Health, University of Cape Town, Cape Town, South Africa
- Public Health Sciences, Parkinson School of Health Sciences and Public Health, Loyola University Chicago, Maywood, IL, United States
| |
Collapse
|
2
|
Jones RP, Ponomarenko A. Roles for Pathogen Interference in Influenza Vaccination, with Implications to Vaccine Effectiveness (VE) and Attribution of Influenza Deaths. Infect Dis Rep 2022; 14:710-758. [PMID: 36286197 PMCID: PMC9602062 DOI: 10.3390/idr14050076] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/15/2022] [Accepted: 09/15/2022] [Indexed: 08/29/2023] Open
Abstract
Pathogen interference is the ability of one pathogen to alter the course and clinical outcomes of infection by another. With up to 3000 species of human pathogens the potential combinations are vast. These combinations operate within further immune complexity induced by infection with multiple persistent pathogens, and by the role which the human microbiome plays in maintaining health, immune function, and resistance to infection. All the above are further complicated by malnutrition in children and the elderly. Influenza vaccination offers a measure of protection for elderly individuals subsequently infected with influenza. However, all vaccines induce both specific and non-specific effects. The specific effects involve stimulation of humoral and cellular immunity, while the nonspecific effects are far more nuanced including changes in gene expression patterns and production of small RNAs which contribute to pathogen interference. Little is known about the outcomes of vaccinated elderly not subsequently infected with influenza but infected with multiple other non-influenza winter pathogens. In this review we propose that in certain years the specific antigen mix in the seasonal influenza vaccine inadvertently increases the risk of infection from other non-influenza pathogens. The possibility that vaccination could upset the pathogen balance, and that the timing of vaccination relative to the pathogen balance was critical to success, was proposed in 2010 but was seemingly ignored. Persons vaccinated early in the winter are more likely to experience higher pathogen interference. Implications to the estimation of vaccine effectiveness and influenza deaths are discussed.
Collapse
Affiliation(s)
- Rodney P Jones
- Healthcare Analysis and Forecasting, Wantage OX12 0NE, UK
| | - Andrey Ponomarenko
- Department of Biophysics, Informatics and Medical Instrumentation, Odessa National Medical University, Valikhovsky Lane 2, 65082 Odessa, Ukraine
| |
Collapse
|
3
|
Noppert GA, Stebbins RC, Dowd JB, Hummer RA, Aiello AE. Life Course Socioeconomic Disadvantage and the Aging Immune System: Findings From the Health and Retirement Study. J Gerontol B Psychol Sci Soc Sci 2021; 76:1195-1205. [PMID: 32880643 DOI: 10.1093/geronb/gbaa144] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVES Previous research has documented a consistent association between current socioeconomic status (SES) and cytomegalovirus (CMV). Early life is likely a critical period for CMV exposure and immune development, but less is known about early-life socioeconomic factors and CMV, particularly in older age populations. Using data from the Health and Retirement Study, we investigated the association between life course socioeconomic disadvantage and immune response to CMV among older adults. METHODS Using ordered logit models, we estimated associations between several measures of socioeconomic disadvantage and the odds of being in a higher CMV Immunoglobulin G (IgG) response category in a sample of 8,168 respondents aged older than 50 years. RESULTS We found a significant association between educational attainment and CMV IgG response. Those with less than a high school education had 2.00 (95% confidence interval [CI]: 1.67-2.40) times the odds of being in a higher CMV category compared to those with a college degree or greater. In addition, we also observed a significant association with parental education and CMV response. Individuals with parents having 8 years or less of schooling had 2.32 (95% CI: 2.00-2.70) times the odds of higher CMV response compared to those whose parents had greater than high school education. DISCUSSION CMV IgG levels in older adults are associated with both early-life and adult SES. Life course socioeconomic disadvantage may contribute to disparities in immunological aging.
Collapse
Affiliation(s)
- Grace A Noppert
- Carolina Population Center, University of North Carolina at Chapel Hill
| | | | - Jennifer B Dowd
- Department of Global Health and Social Medicine, King's College London, UK.,CUNY Graduate School of Public Health and Health Policy, City University of New York
| | - Robert A Hummer
- Carolina Population Center, University of North Carolina at Chapel Hill.,Department of Sociology, University of North Carolina at Chapel Hill
| | - Allison E Aiello
- Carolina Population Center, University of North Carolina at Chapel Hill.,Department of Epidemiology, University of North Carolina at Chapel Hill
| |
Collapse
|
4
|
Lu Y, Tan CTY, Gwee X, Yap KB, Fulop T, Pan F, Larbi A, Ng TP. Pathogen Burden, Blood Biomarkers and Functional Ageing in Community-Dwelling Older Adults. J Gerontol A Biol Sci Med Sci 2021; 76:1864-1873. [PMID: 33640984 DOI: 10.1093/gerona/glab057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Lifelong accumulation of latent or persistent or repeated infections may be a contributing factor to the deterioration of physical and cognitive function associated with functional ageing, but the evidence is limited and the biological underpinnings are unclear. METHODS We profiled the seropositivity for common viral, bacterial and plasmodial pathogens of local importance in community-living older adults in two studies involving 745 older adults (mean age 67.0, SD: 7.7 years), and 142 older adults (mean age 72.7, SD: 8.3 years). Pathogen load was related to different sets of age-related physical and cognitive measures of functional ageing and the frailty index, and plasma levels of biomarkers of inflammation, innate and adaptive immunity, and other physiological functions. RESULTS High pathogen load was associated with impaired gait speed (GS), (p<0.015), functional mobility (POMA) (p<0.029), cognitive function (MMSE) (p<<0.05), and increased frailty index (FI) (p<<0.05). High pathogen load was significantly associated with C3a complement activity (p<0.001), matrix metalloproteinase-7, macrophage inflammatory protein-1α (p<0.05), and monocyte chemoattractant protein 2 (p=0.028). Blood biomarkers did not fully explain the observed association between pathogen load and functional ageing measures. CONCLUSIONS The present study provides novel evidence linking lifelong cumulated numbers of latent, persistent or repeated infection to functional ageing, plausibly via inflammatory and immune and other biological factors.
Collapse
Affiliation(s)
- Yanxia Lu
- Department of Medical Psychology and Ethics, School of Basic Medical Sciences, Shandong University, China
| | - Crystal Tze Ying Tan
- Biology of Ageing Laboratory, Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore
| | - Xinyi Gwee
- Gerontology Research Programme, Department of Psychological Medicine, National University Health System, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Keng Bee Yap
- Geriatric Medicine and Palliative Medicine Department, Ng Teng Fong General Hospital
| | - Tamas Fulop
- Geriatrics Division, Department of Medicine, Research Center on Aging, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Fang Pan
- Department of Medical Psychology and Ethics, School of Basic Medical Sciences, Shandong University, China
| | - Anis Larbi
- Biology of Ageing Laboratory, Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore.,Geriatrics Division, Department of Medicine, Research Center on Aging, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Tze Pin Ng
- Gerontology Research Programme, Department of Psychological Medicine, National University Health System, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| |
Collapse
|
5
|
Gicas KM, Jones AA, Thornton AE, Petersson A, Livingston E, Waclawik K, Panenka WJ, Barr AM, Lang DJ, Vila-Rodriguez F, Leonova O, Procyshyn RM, Buchanan T, MacEwan GW, Honer WG. Cognitive decline and mortality in a community-based sample of homeless and precariously housed adults: 9-year prospective study. BJPsych Open 2020; 6:e21. [PMID: 32043436 PMCID: PMC7176832 DOI: 10.1192/bjo.2020.3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Homeless and precariously housed individuals experience a high burden of comorbid illnesses, and excess mortality. Cross-sectional studies report a high rate of cognitive impairment. Long-term trajectories have not been well investigated in this group. AIMS To longitudinally assess risks for premature and/or accelerated cognitive ageing, and the relationship with early mortality in homeless and precariously housed people. METHOD This is a 9-year community-based study of 375 homeless and precariously housed individuals from Vancouver, Canada. Annual cognitive testing assessed verbal learning and memory, and inhibitory control. Linear mixed-effects models examined associations between clinical risk factors (traumatic brain injury, psychotic disorders, viral exposure, alcohol dependence) and cognitive change over 9 years. Cox regression models examined the association between cognition and mortality. RESULTS Traumatic brain injury and alcohol dependence were associated with decline in verbal memory. Inhibitory control declined, independent of risk factors and to a greater extent in those who died during the study. Better inhibitory control was associated with a 6.6% lower risk of mortality at study entry, with a 0.3% greater effect for each year of life. For each one-point increase in the Charlson Comorbidity Index score at study entry, the risk of mortality was 9.9% higher, and was consistent across age. Adjusting for comorbidities, inhibitory control remained a significant predictor of mortality. CONCLUSIONS Findings raise the possibility of a premature onset, and accelerated trajectory, of cognitive ageing in this group of homeless and precariously housed people. Traumatic brain injury, alcohol dependence and cognition could be treatment priorities.
Collapse
Affiliation(s)
- Kristina M Gicas
- Department of Psychology, York University, Toronto, Canada.,Department of Psychiatry, University of British Columbia, Canada
| | - Andrea A Jones
- Department of Psychiatry, University of British Columbia, Canada
| | | | - Anna Petersson
- Department of Psychology, Simon Fraser University, Canada
| | | | | | | | - Alasdair M Barr
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Canada
| | - Donna J Lang
- Department of Radiology, University of British Columbia, Canada
| | | | - Olga Leonova
- Department of Psychiatry, University of British Columbia, Canada
| | - Ric M Procyshyn
- Department of Psychiatry, University of British Columbia, Canada
| | - Tari Buchanan
- Department of Psychiatry, University of British Columbia, Canada
| | | | - William G Honer
- Department of Psychiatry, University of British Columbia; and British Columbia Mental Health and Substance Use Services Research Institute, Canada
| |
Collapse
|
6
|
Noppert GA, Aiello AE, O'Rand AM, Cohen HJ. Race/Ethnic and Educational Disparities in the Association Between Pathogen Burden and a Laboratory-Based Cumulative Deficits Index. J Racial Ethn Health Disparities 2020; 7:99-108. [PMID: 31642044 PMCID: PMC6980710 DOI: 10.1007/s40615-019-00638-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 09/02/2019] [Accepted: 09/13/2019] [Indexed: 11/25/2022]
Abstract
BACKGROUND Disparities in adult morbidity and mortality may be rooted in patterns of biological dysfunction in early life. We sought to examine the association between pathogen burden and a cumulative deficits index (CDI), conceptualized as a pre-clinical marker of an unhealthy biomarker profile, specifically focusing on patterns across levels of social disadvantage. METHODS Using the data from the National Health and Nutrition Examination Survey 2003-2004 wave (aged 20-49 years), we examined the association of pathogen burden, composed of seven pathogens, with the CDI. The CDI comprised 28 biomarkers corresponding to available clinical laboratory measures. Models were stratified by race/ethnicity and education level. RESULTS The CDI ranged from 0.04 to 0.78. Nearly half of Blacks were classified in the high burden pathogen class compared with 8% of Whites. Among both Mexican Americans and other Hispanic groups, the largest proportion of individuals were classified in the common pathogens class. Among educational classes, 19% of those with less than a high school education were classified in the high burden class compared with 7% of those with at least a college education. Blacks in the high burden pathogen class had a CDI 0.05 greater than those in the low burden class (P < 0.05). Whites in the high burden class had a CDI only 0.03 greater than those in the low burden class (P < 0.01). DISCUSSION Our findings suggest there are significant social disparities in the distribution of pathogen burden across race/ethnic groups, and the effects of pathogen burden may be more significant for socially disadvantaged individuals.
Collapse
Affiliation(s)
- Grace A Noppert
- Carolina Population Center, University of North Carolina, 123 West Franklin St, Chapel Hill, NC, 27516, USA.
- Duke University Population Research Institute, Duke University, Durham, NC, USA.
- Center for the Study of Aging and Human Development, Duke University, Durham, NC, USA.
| | - A E Aiello
- Carolina Population Center, University of North Carolina, 123 West Franklin St, Chapel Hill, NC, 27516, USA
- Department of Epidemiology Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - A M O'Rand
- Duke University Population Research Institute, Duke University, Durham, NC, USA
| | - H J Cohen
- Center for the Study of Aging and Human Development, Duke University, Durham, NC, USA
- Claude D. Pepper Older Americans Independence Center, Durham, NC, USA
| |
Collapse
|