The Microbiota and Microbiome in Aging: Potential Implications in Health and Age‐Related Diseases
Open accessAbstract
Advances in bacterial deoxyribonucleic acid sequencing allow for characterization of the human commensal bacterial community (microbiota) and its corresponding genome (microbiome). Surveys of healthy adults reveal that a signature composite of bacteria characterizes each unique body habitat (e.g., gut, skin, oral cavity, vagina). A myriad of clinical changes, including a basal proinflammatory state (inflamm‐aging), that directly interface with the microbiota of older adults and enhance susceptibility to disease accompany aging. Studies in older adults demonstrate that the gut microbiota correlates with diet, location of residence (e.g., community dwelling, long‐term care settings), and basal level of inflammation. Links exist between the microbiota and a variety of clinical problems plaguing older adults, including physical frailty, Clostridium difficile colitis, vulvovaginal atrophy, colorectal carcinoma, and atherosclerotic disease. Manipulation of the microbiota and microbiome of older adults holds promise as an innovative strategy to influence the development of comorbidities associated with aging.
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Increased gut dysbiosis has been postulated to increase mucosal barrier permeability, allowing bacteria and their products into the circulatory system and contributing to a chronic pro-inflammatory state.
“Increased gut dysbiosis has been postulated to increase mucosal barrier permeability, thereby allowing bacteria and their products — including pathogen-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs), and microbial-associated molecular patterns (MAMPs)— into the circulatory system. Together, these factors contribute to a chronic pro-inflammatory state71.”
From Inflammageing: chronic inflammation in ageing, cardiovascular disease, and frailty (2018) · cites this paper as [71]
Changes in microbiota composition occur alongside changes in microglial physiology with age.
“Gradual changes in microbiota composition have been observed as normal features of aging, including changes in microbial resilience, stability, and diversity, which are features that occur alongside changes in microglial physiology with age (Zapata and Quagliarello, 2015; Buford, 2017).”
From Microbiome–microglia connections via the gut–brain axis (2019) · cites this paper as Zapata and Quagliarello, 2015
Gradual changes in microbiota composition, including changes in microbial resilience, stability, and diversity, are normal features of aging.
“Gradual changes in microbiota composition have been observed as normal features of aging, including changes in microbial resilience, stability, and diversity, which are features that occur alongside changes in microglial physiology with age (Zapata and Quagliarello, 2015; Buford, 2017).”
From Microbiome–microglia connections via the gut–brain axis (2019) · cites this paper as Zapata and Quagliarello, 2015
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Cites
Structure, function and diversity of the healthy human microbiome
The Human Microbiome Project Consortium (2012) · Nature · doi:10.1038/nature11234 · Cited by 11,726 · see citing works
Human gut microbiome viewed across age and geography
Yatsunenko, T., Rey, F. E., Manary, M. J., Trehan, I., Dominguez-Bello, M. G., Contreras, M., Magris, M., Hidalgo, G., Baldassano, R. N., Anokhin, A. P., et al. (2012) · Nature · doi:10.1038/nature11053 · Cited by 7,815 · see citing works
Turnbaugh, P. J., Ley, R. E., Hamady, M., Fraser-Liggett, C. M., Knight, R., & Gordon, J. I. (2007) · Nature · doi:10.1038/nature06244 · Cited by 6,091 · see citing works
Inflamm‐aging: An Evolutionary Perspective on Immunosenescence
FRANCESCHI, C., BONAFÈ, M., VALENSIN, S., OLIVIERI, F., DE LUCA, M., OTTAVIANI, E., & DE BENEDICTIS, G. (2000) · Annals of the New York Academy of Sciences · doi:10.1111/j.1749-6632.2000.tb06651.x · Cited by 5,358 · see citing works
Dominguez-Bello, M. G., Costello, E. K., Contreras, M., Magris, M., Hidalgo, G., Fierer, N., & Knight, R. (2010) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1002601107 · Cited by 4,774 · see citing works
Recognition of Commensal Microflora by Toll-Like Receptors Is Required for Intestinal Homeostasis
Rakoff-Nahoum, S., Paglino, J., Eslami-Varzaneh, F., Edberg, S., & Medzhitov, R. (2004) · Cell · doi:10.1016/j.cell.2004.07.002 · Cited by 4,251 · see citing works
Phylogenetic structure of the prokaryotic domain: The primary kingdoms
Woese, C. R., & Fox, G. E. (1977) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.74.11.5088 · Cited by 4,131 · see citing works
Duodenal Infusion of Donor Feces for Recurrent <i>Clostridium difficile</i>
van Nood, E., Vrieze, A., Nieuwdorp, M., Fuentes, S., Zoetendal, E. G., de Vos, W. M., Visser, C. E., Kuijper, E. J., Bartelsman, J. F. W. M., Tijssen, J. G. P., et al. (2013) · New England Journal of Medicine · doi:10.1056/nejmoa1205037 · Cited by 3,708 · see citing works
Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk
Tang, W. H. W., Wang, Z., Levison, B. S., Koeth, R. A., Britt, E. B., Fu, X., Wu, Y., & Hazen, S. L. (2013) · New England Journal of Medicine · doi:10.1056/nejmoa1109400 · Cited by 3,402 · see citing works
Gut microbiota composition correlates with diet and health in the elderly
Claesson, M. J., Jeffery, I. B., Conde, S., Power, S. E., O’Connor, E. M., Cusack, S., Harris, H. M. B., Coakley, M., Lakshminarayanan, B., O’Sullivan, O., et al. (2012) · Nature · doi:10.1038/nature11319 · Cited by 3,314 · see citing works
Bacterial Community Variation in Human Body Habitats Across Space and Time
Costello, E. K., Lauber, C. L., Hamady, M., Fierer, N., Gordon, J. I., & Knight, R. (2009) · Science · doi:10.1126/science.1177486 · Cited by 3,231 · see citing works
Treg induction by a rationally selected mixture of Clostridia strains from the human microbiota
Atarashi, K., Tanoue, T., Oshima, K., Suda, W., Nagano, Y., Nishikawa, H., Fukuda, S., Saito, T., Narushima, S., Hase, K., et al. (2013) · Nature · doi:10.1038/nature12331 · Cited by 2,872 · see citing works
Kostic, A. D., Chun, E., Robertson, L., Glickman, J. N., Gallini, C. A., Michaud, M., Clancy, T. E., Chung, D. C., Lochhead, P., Hold, G. L., et al. (2013) · Cell Host & Microbe · doi:10.1016/j.chom.2013.07.007 · Cited by 2,718 · see citing works
Succession of microbial consortia in the developing infant gut microbiome
Koenig, J. E., Spor, A., Scalfone, N., Fricker, A. D., Stombaugh, J., Knight, R., Angenent, L. T., & Ley, R. E. (2011) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1000081107 · Cited by 2,540 · see citing works
<i>Fusobacterium nucleatum</i> infection is prevalent in human colorectal carcinoma
Castellarin, M., Warren, R. L., Freeman, J. D., Dreolini, L., Krzywinski, M., Strauss, J., Barnes, R., Watson, P., Allen-Vercoe, E., Moore, R. A., et al. (2012) · Genome Research · doi:10.1101/gr.126516.111 · Cited by 2,043 · see citing works
Genomic analysis identifies association of <i>Fusobacterium</i> with colorectal carcinoma
Kostic, A. D., Gevers, D., Pedamallu, C. S., Michaud, M., Duke, F., Earl, A. M., Ojesina, A. I., Jung, J., Bass, A. J., Tabernero, J., et al. (2012) · Genome Research · doi:10.1101/gr.126573.111 · Cited by 1,960 · see citing works
Composition, variability, and temporal stability of the intestinal microbiota of the elderly
Claesson, M. J., Cusack, S., O'Sullivan, O., Greene-Diniz, R., de Weerd, H., Flannery, E., Marchesi, J. R., Falush, D., Dinan, T., Fitzgerald, G., et al. (2011) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1000097107 · Cited by 1,754 · see citing works
Structural segregation of gut microbiota between colorectal cancer patients and healthy volunteers
Wang, T., Cai, G., Qiu, Y., Fei, N., Zhang, M., Pang, X., Jia, W., Cai, S., & Zhao, L. (2012) · The ISME Journal · doi:10.1038/ismej.2011.109 · Cited by 1,287 · see citing works
Human oral, gut, and plaque microbiota in patients with atherosclerosis
Koren, O., Spor, A., Felin, J., Fåk, F., Stombaugh, J., Tremaroli, V., Behre, C. J., Knight, R., Fagerberg, B., Ley, R. E., et al. (2011) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1011383107 · Cited by 1,196 · see citing works
Age-dependent dysregulation of innate immunity
Shaw, A. C., Goldstein, D. R., & Montgomery, R. R. (2013) · Nature Reviews Immunology · doi:10.1038/nri3547 · Cited by 1,061 · see citing works
Gough, E., Shaikh, H., & Manges, A. R. (2011) · Clinical Infectious Diseases · doi:10.1093/cid/cir632 · Cited by 1,003 · see citing works
Sequence-based identification of microbial pathogens: a reconsideration of Koch's postulates
Fredericks, D., & Relman, D. (1996) · Clinical Microbiology Reviews · doi:10.1128/cmr.9.1.18 · Cited by 969 · see citing works
Commensal bacteria at the interface of host metabolism and the immune system
Brestoff, J. R., & Artis, D. (2013) · Nature Immunology · doi:10.1038/ni.2640 · Cited by 945 · see citing works
Microbes, Microbiota, and Colon Cancer
Sears, C. L., & Garrett, W. S. (2014) · Cell Host & Microbe · doi:10.1016/j.chom.2014.02.007 · Cited by 820 · see citing works
Immune Effector Mechanisms Implicated in Atherosclerosis: From Mice to Humans
Libby, P., Lichtman, A. H., & Hansson, G. K. (2013) · Immunity · doi:10.1016/j.immuni.2013.06.009 · Cited by 667 · see citing works
Innate immune recognition of the microbiota promotes host-microbial symbiosis
Chu, H., & Mazmanian, S. K. (2013) · Nature Immunology · doi:10.1038/ni.2635 · Cited by 630 · see citing works
Lawley, T. D., Clare, S., Walker, A. W., Stares, M. D., Connor, T. R., Raisen, C., Goulding, D., Rad, R., Schreiber, F., Brandt, C., et al. (2012) · PLoS Pathogens · doi:10.1371/journal.ppat.1002995 · Cited by 540 · see citing works
Metagenomic Pyrosequencing and Microbial Identification
Petrosino, J. F., Highlander, S. K., Luna, R. A., Gibbs, R. A., & Versalovic, J. A. (2009) · Clinical Chemistry · doi:10.1373/clinchem.2008.107565 · Cited by 536 · see citing works
Periodontal Microbiota and Carotid Intima-Media Thickness
Desvarieux, M., Demmer, R. T., Rundek, T., Boden-Albala, B. M., Jacobs, D. R., Sacco, R. L., & Papapanou, P. N. (2005) · Circulation · doi:10.1161/01.cir.0000154582.37101.15 · Cited by 489 · see citing works
Association between the vaginal microbiota, menopause status, and signs of vulvovaginal atrophy
Brotman, R. M., Shardell, M. D., Gajer, P., Fadrosh, D., Chang, K., Silver, M. I., Viscidi, R. P., Burke, A. E., Ravel, J., & Gravitt, P. E. (2013) · Menopause The Journal of The North American Menopause Society · doi:10.1097/gme.0b013e3182a4690b · Cited by 393 · see citing works
Epidemiology and Unique Aspects of Aging and Infectious Diseases
Yoshikawa, T. T. (2000) · Clinical Infectious Diseases · doi:10.1086/313792 · Cited by 392 · see citing works
Ageing of the human metaorganism: the microbial counterpart
Biagi, E., Candela, M., Fairweather‐Tait, S. J., Franceschi, C., & Brigidi, P. (2011) · AGE · doi:10.1007/s11357-011-9217-5 · Cited by 365 · see citing works
Review: Systemic inflammation and<scp>A</scp>lzheimer's disease
Holmes, C. (2013) · Neuropathology and Applied Neurobiology · doi:10.1111/j.1365-2990.2012.01307.x · Cited by 356 · see citing works
Recycling Metchnikoff: Probiotics, the Intestinal Microbiome and the Quest for Long Life
Mackowiak, P. A. (2013) · Frontiers in Public Health · doi:10.3389/fpubh.2013.00052 · Cited by 294 · see citing works
Introduction to intestinal microecology
Luckey, T. D. (1972) · American Journal of Clinical Nutrition · doi:10.1093/ajcn/25.12.1292 · Cited by 288 · see citing works
Poulain, M., Pes, G. M., Grasland, C., Carru, C., Ferrucci, L., Baggio, G., Franceschi, C., & Deiana, L. (2004) · Experimental Gerontology · doi:10.1016/j.exger.2004.06.016 · Cited by 286 · see citing works
Collino, S., Montoliu, I., Martin, F.-P. J., Scherer, M., Mari, D., Salvioli, S., Bucci, L., Ostan, R., Monti, D., Biagi, E., et al. (2013) · PLoS ONE · doi:10.1371/journal.pone.0056564 · Cited by 270 · see citing works
You Are What You Host: Microbiome Modulation of the Aging Process
Heintz, C., & Mair, W. (2014) · Cell · doi:10.1016/j.cell.2014.01.025 · Cited by 222 · see citing works
Desvarieux, M., Demmer, R. T., Jacobs, D. R., Jr, Rundek, T., Boden-Albala, B., Sacco, R. L., & Papapanou, P. N. (2010) · Journal of Hypertension · doi:10.1097/hjh.0b013e328338cd36 · Cited by 206 · see citing works
Hummelen, R., Macklaim, J. M., Bisanz, J. E., Hammond, J.-A., McMillan, A., Vongsa, R., Koenig, D. W., Gloor, G. B., & Reid, G. (2011) · PLoS ONE · doi:10.1371/journal.pone.0026602 · Cited by 190 · see citing works
Comorbidity in Older Adults: Nosology of Impairment, Diseases, and Conditions
Karlamangla, A. S., Tinetti, M. E., Guralnik, J. M., Studenski, S. A., Wetle, T. T., & Reuben, D. B. (2007) · The Journals of Gerontology Series A · doi:10.1093/gerona/62.3.296 · Cited by 157 · see citing works
de Kruif, P. (1926) · Transactions of the American Microscopical Society · doi:10.2307/3221690 · Cited by 148 · see citing works
Stehle, J. R., Leng, X., Kitzman, D. W., Nicklas, B. J., Kritchevsky, S. B., & High, K. P. (2012) · The Journals of Gerontology Series A · doi:10.1093/gerona/gls178 · Cited by 133 · see citing works
Santoro, A., Pini, E., Scurti, M., Palmas, M. G., Berendsen, A. A. M., Brzozowska, A., Pietruszka, B., Szczecińska, A., Cano, N., Meunier, N., et al. (2013) · Mechanisms of Ageing and Development · doi:10.1016/j.mad.2013.12.001 · Cited by 129 · see citing works
Petričević, L., Unger, F. M., Viernstein, H., & Kiss, H. (2008) · European Journal of Obstetrics & Gynecology and Reproductive Biology · doi:10.1016/j.ejogrb.2008.06.003 · Cited by 121 · see citing works
The human superorganism – Of microbes and men
Sleator, R. D. (2009) · Medical Hypotheses · doi:10.1016/j.mehy.2009.08.047 · Cited by 118 · see citing works
Fecal microbiota transplantation: effectiveness, complexities, and lingering concerns
Pamer, E. G. (2014) · Mucosal Immunology · doi:10.1038/mi.2013.117 · Cited by 109 · see citing works
Metagenomics: the role of the microbiome in cardiovascular diseases
Ordovás, J. M., & Mooser, V. (2006) · Current Opinion in Lipidology · doi:10.1097/01.mol.0000217897.75068.ba · Cited by 85 · see citing works
Clostridium difficile Infection in the Elderly
Keller, J. M., & Surawicz, C. M. (2013) · Clinics in Geriatric Medicine · doi:10.1016/j.cger.2013.10.008 · Cited by 82 · see citing works
Report from the second cytomegalovirus and immunosenescence workshop
Wills, M. R., Akbar, A. N., Beswick, M., Bosch, J. A., Caruso, C., Colonna‐Romano, G., Dutta, A., Franceschi, C., Fülöp, T., Gkrania‐Klotsas, E., et al. (2011) · Immunity & Ageing · doi:10.1186/1742-4933-8-10 · Cited by 40 · see citing works
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Gut instincts: microbiota as a key regulator of brain development, ageing and neurodegeneration
Dinan, T. G., & Cryan, J. F. (2017) · The Journal of Physiology · doi:10.1113/jp273106 · Cited by 813 · see citing works
Gut microbiome and aging: physiological and mechanistic insights
Nagpal, R., Mainali, R., Ahmadi, S., Wang, S., Singh, R., Kavanagh, K., Kitzman, D. W., Kushugulova, A., Marotta, F., & Yadav, H. (2018) · Nutrition and Healthy Aging · doi:10.3233/nha-170030 · Cited by 670 · see citing works
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The impact of skin care products on skin chemistry and microbiome dynamics
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- Authors
- Zapata, H. J., & Quagliarello, V. J.
- Affiliations
- Yale University (US)
- Corresponding author
- Zapata, Heidi J.
- ORCID
- Zapata, Heidi J.
- Venue
- Journal of the American Geriatrics Society
- Publisher
- Wiley
- Published
- 2015-04
- Volume
- 63
- Issue
- 4
- Pages
- 776-781
- ISSN
- 0002-8614 (ISSN-L)
- 1532-5415
- PMC
- PMC4406803
- OpenAlex
- W2025399737
- Cited by
- 279
- References
- 50
- Citations by year
- 2026: 13 · 2025: 11 · 2024: 26 · 2023: 24 · 2022: 31 · 2021: 31 · 2020: 36 · 2019: 29 · 2018: 18 · 2017: 25 · 2016: 27 · 2015: 7
- FWCI
- 11.14
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Journal of the American Geriatrics Society (publishedVersion)
- PubMed (publishedVersion)
- Europe PMC (PubMed Central) (acceptedVersion)
- PubMed Central (acceptedVersion)
- Funders
- National Institutes of Health (T32 AI007517, K07AG030093)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gut microbiota and health
- Health Sciences › Dentistry › Periodontics › Oral microbiology and periodontitis research
- Life Sciences › Agricultural and Biological Sciences › Food Science › Probiotics and Fermented Foods
- Keywords
- gut microbiota, microbiome, aging, inflammaging, older adults, frailty, Clostridium difficile colitis, vaginal atrophy, colorectal cancer, atherosclerosis, comorbidities, diet, long-term care, skin microbiome, oral microbiota, vaginal microbiota
- MeSH terms
- Aged, Aging, Colitis, Disease Susceptibility, Humans, Inflammation, Residence Characteristics, Frail Elderly, Clostridioides difficile, Gastrointestinal Tract, Microbiota
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