How Can the Gut Microbiome Help Reverse Aging?

June 09, 2024 8 min read

How Can the Gut Microbiome Help Reverse Aging

Aging is the one thing we all have in common. We will inevitably all progress with age, but how it affects us will depend on several factors, including genetics, the environment, and our lifestyle.

There’s another factor that can drive or maybe even slow the aging process, the gut microbiome. Here, we’ll explore what aging is, some of the metabolic and biological processes that underpin getting old, and the impact of the gut microbiome.

The biology of aging

In scientific terms, aging is the time-related decline in physiological processes necessary for survival and fertility[i], ultimately contributing to death. On the face of it, most of us associate aging with physical features, such as:

  • Graying hair
  • Aching joints and muscles
  • Wrinkling skin
  • Memory issues
  • Increased incidence of disease

However, these physical manifestations arise because of aging at both a cellular and systemic level. Although aging may be noticeable, it is a complex phenomenon underpinned by many cellular processes.

How long can humans live?

Scientists believe the human lifespan is fixed at a limit of around 122 years[ii]. However, that’s not the same thing as life expectancy which is on the rise. In the US, average life expectancy at birth is 73.5 years for men and 79.3 years for women[iii].

Yet, there are several ‘blue zones’ across the world, a place where there is an unusually high number of people who live to at least 100 years old[iv]. Japan has the highest percentage of centenarians in the world, suggesting that with a healthy lifestyle, aging can be slowed down.

Tell-tale signs of aging

In recent years, scientists have begun to identify the cellular and molecular signs of aging.

1. DNA damage

DNA or deoxyribonucleic acid is the genetic information we inherit from our parents and is critical for our development and functioning[v]. However, DNA is relatively sensitive and is consistently being damaged by both internal and external factors. A prime example is the damage too much ultraviolet (UV) light from the sun can do to your skin.

It's estimated that up to 1000000 DNA lesions happen in a cell each day, many of them are efficiently removed but some pass through undetected, cannot be repaired, are repaired wrong, or are not fixed early enough. In time, these injuries to your DNA, also known as genome instability, continue to build up, contributing to aging.

DNA damage leads to cell death and senescence contributing to loss of function in your cells and organs, inflammation, and cancer development[vi].

2. Telomere shortening

A telomere is a region of repeated DNA sequences at the end of a chromosome. Telomeres protect the end of the chromosome from becoming frayed or tangled, like an aglet at the end of your shoelace.

Every time a cell divides, a piece of the telomere is lost, meaning telomeres shorten as you age. When a critical telomere length limit is reached, the cell undergoes senescence or cell death, also known as apoptosis[vii]. This increases the risk of loss of cells and tumor growth[viii].

Interestingly, telomere length can be preserved which helps to slow down aging and lower the risk of developing cancer by eating a diet that’s high in antioxidants, such as:

Tuna

Flax seeds

Tomatoes

Salmon

Green tea

Olives

Herring

Broccoli

Chia seeds

Mackerel

Red grapes

Kiwi

 

You can also support your telomere length further by limiting your exposure to:

  • Smoking
  • External pollutants
  • Obesity
  • Stressiv

A study by Jaskelioff et al., (2011) demonstrated that reactivating telomerase, the enzyme responsible for maintaining telomere length, in mice with severe telomere dysfunction reversed neurodegeneration, reduced DNA damage signaling, and extended telomere length[ix].

3. Increased ‘inflammaging’

‘Inflammaging’ is the age-related increase in inflammation, characterized by an increase in circulating pro-inflammatory biomarkers in the blood and tissues. This type of chronic inflammation is strongly associated with many diseases that are common in the elderly population[x].

When you’re younger, inflammation is generally a result of an injury or infection which clears once the injury has healed, or the infection has stopped. But chronic, low-grade inflammation is a contributory factor to aging tissue and illnesses, including:

Lavin and colleagues (2020) investigated the ability of regular exercise to delay or lower the onset of inflammaging. The researchers discovered that regular and lifelong aerobic exercise reduces the level of proinflammatory factors in the blood and generally promotes an overall anti-inflammatory profile. This suggests that exercise can serve as a good anti-inflammatory activity and has the potential to protect against age-dependent inflammation[xii].  

4. The gut microbiome

The gut microbiome is integral to human health. It’s so powerful that it is often called the body’s ‘second brain’. The gut-derived ecosystem is colonized by bacteria, fungi, protozoa, and viruses, collectively making up the microbiome. However, the world within your gut is more than just a colonic zoo of microorganisms, it has several important functions for your body and wider health.

Gut microbes:

  • Digest food, particularly fiber
  • Support immunity
  • Produce essential metabolites, including short-chain fatty acids (SCFAs) and vitamins
  • Defend against pathogens[xiii]

The gut microbiome is also key to healthy aging through its influence on the immune system, inflammation, and as a general biomarker for health.

Interactions between the gut microbiome and aging

The development of the human gut microbiome is strongly believed to begin from birth. For babies born naturally, the gut is rapidly colonized by microbes from the birth canal, like  Lactobacilli.

Microbiome diversity increases in the first year of life. From around 2.5 years of age, it resembles an adult microbiota in terms of diversity, composition and function, having been influenced by the infant's diet and environment[xiv].

The gut microbiome isn’t static and can be altered by various lifestyle and environmental factors, and age is no exception.

As you age, the gut microbiome becomes less diverse, with commensal genera such as  Bacteroides,  Bifidobacteria,  and  Lactobacilli  declining in numbers and opportunist pathogens, like  C. difficile increasing.

It’s not just the diversity and composition that’s affected. As you age, the metabolic capacity of the microbiome reduces, too, including the production of metabolites like SCFAs which could influence:

  • Irregular bowel function
  • Reduced appetite
  • Weight loss
  • Cognitive decline
  • Nutrient deficiencies
  • The onset of chronic disease

Dysbiosis and aging

As aging occurs, the gut microbiome becomes less diverse, and the shift towards an unhealthier dominance within the gut can lead to dysbiosis[xv]. This imbalance in the gut microbial community is linked to the development of disease.

In the elderly, an altered bacterial composition and a ‘leaky gut; contribute to the escape of microbes and their by-products through the intestinal barrier, instigating an inflammatory response. Therefore, this increases the risk of both gut and systemic illnesses because of changes in the gut-brain axis, blood-brain barrier, and gut-liver axis[xvi], accelerating the rate of aging.

The gut microbiome and neurological health

The gut has a direct communication pathway with the brain, they effectively have each other on speed dial, called the gut-brain axis. Numerous studies have shown that microbial imbalances in the gut microbiome and changes in the production of specific bacterial metabolites can influence brain health and function, raising the risk of mood changes, cognitive decline, and neurodegenerative diseases, like Alzheimer’s and Parkinson’s Disease[xvii].

Can aging be reversed?

Aging cannot be reversed. Once the damage has occurred in the cells there is very little you can do to undo it. However, it is possible to slow down subsequent aging by making healthier changes to your lifestyle.

Following a healthy diet and staying as active as possible are critical to slow down the physical signs of aging and keeping the body’s cells functioning optimally for as long as possible.

Keeping the gut microbiome in balance is also crucial because issues such as dysbiosis and a compromised gut barrier can contribute to inflammaging and the development of disease, but it also produces some key ‘anti-aging metabolites’:

  • Short-chain fatty acids:SCFA production is critical for most of the health benefits associated with the microbiome. As you age, your production of one SCFA reduces, butyrate. A 2019 study, transplanted gut microbes from old mice into germ-free young mice and found that after 8 weeks the younger mice had an improved intestinal growth and a greater production of brain neurons. This was because of an enrichment in butyrate-producing bacteria. Therefore, suggesting that butyrate could have a neuroprotective benefit, and could slow down aging and cognitive decline[xviii].
  • Urolithin A:A postbiotic produced by the gut microbiome from ellagitannin breakdown. Ellagitannins are bioactive compounds found in plant foods, such as pomegranates and berries, which have several health benefits[xix]. Urolithin A has shown strong promise for its anti-aging effects in osteoporosis development[xx] and several other age-related conditions related to the brain, muscles and other organs[xxi].

Summary

Aging is just a fact of life. Even though it cannot be undone, there are things we can do to slow down its progress or make it easier to deal with. Emerging research is showing that the gut microbiome could play a pivotal role in slowing or advancing aging. By better understanding the connection between aging and the intestinal community, we can gain better knowledge of how the gut microbiome can be manipulated to promote health and longevity.

Written byLeanne Edermaniger, M.Sc. Leanne is a professional science writer who specializes in human health and enjoys writing about all things related to the gut microbiome. 

Sources 

[i] Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. Aging: The Biology of Senescence. Available from: https://www.ncbi.nlm.nih.gov/books/NBK10041/

[ii] Blagosklonny MV. No limit to maximal lifespan in humans: how to beat a 122-year-old record. Oncoscience. 2021 Dec 1;8:110-119. doi: 10.18632/oncoscience.547. PMID: 34869788; PMCID: PMC8636159.

[iii] FastStats - life expectancy [Internet]. Centers for Disease Control and Prevention; 2023 [cited 2024 Apr 27]. Available from: https://www.cdc.gov/nchs/fastats/life-expectancy.htm

[iv] Home - live better, longer [Internet]. 2024 [cited 2024 Apr 27]. Available from: https://www.bluezones.com/

[v] Deoxyribonucleic acid (DNA) [Internet]. [cited 2024 Apr 27]. Available from: https://www.genome.gov/genetics-glossary/Deoxyribonucleic-Acid

[vi] Schumacher B, Pothof J, Vijg J, Hoeijmakers JHJ. The central role of DNA damage in the ageing process. Nature. 2021 Apr;592(7856):695-703. doi: 10.1038/s41586-021-03307-7. Epub 2021 Apr 28. PMID: 33911272; PMCID: PMC9844150.

[vii] Shammas MA. Telomeres, lifestyle, cancer, and aging. Curr Opin Clin Nutr Metab Care. 2011 Jan;14(1):28-34. doi: 10.1097/MCO.0b013e32834121b1. PMID: 21102320; PMCID: PMC3370421.

[viii] Aubert G, Lansdorp PM. Telomeres and aging. Physiol Rev. 2008 Apr;88(2):557-79. doi: 10.1152/physrev.00026.2007. PMID: 18391173.

[ix] Jaskelioff M, Muller FL, Paik JH, Thomas E, Jiang S, Adams AC, Sahin E, Kost-Alimova M, Protopopov A, Cadiñanos J, Horner JW, Maratos-Flier E, Depinho RA. Telomerase reactivation reverses tissue degeneration in aged telomerase-deficient mice. Nature. 2011 Jan 6;469(7328):102-6. doi: 10.1038/nature09603. Epub 2010 Nov 28. PMID: 21113150; PMCID: PMC3057569.

[x] Ferrucci L, Fabbri E. Inflammageing: chronic inflammation in ageing, cardiovascular disease, and frailty. Nat Rev Cardiol. 2018 Sep;15(9):505-522. doi: 10.1038/s41569-018-0064-2. PMID: 30065258; PMCID: PMC6146930.

[xi] Head T, Daunert S, Goldschmidt-Clermont PJ. The Aging Risk and Atherosclerosis: A Fresh Look at Arterial Homeostasis. Front Genet. 2017 Dec 14;8:216. doi: 10.3389/fgene.2017.00216. PMID: 29312440; PMCID: PMC5735066.

[xii] Lavin KM, Perkins RK, Jemiolo B, Raue U, Trappe SW, Trappe TA. Effects of aging and lifelong aerobic exercise on basal and exercise-induced inflammation. Journal of Applied Physiology. 2020 Jan 1;128(1):87–99. doi:10.1152/japplphysiol.00495.2019

[xiii] Jandhyala SM, Talukdar R, Subramanyam C, Vuyyuru H, Sasikala M, Nageshwar Reddy D. Role of the normal gut microbiota. World J Gastroenterol. 2015 Aug 7;21(29):8787-803. doi: 10.3748/wjg.v21.i29.8787. PMID: 26269668; PMCID: PMC4528021.

[xiv] Thursby E, Juge N. Introduction to the human gut microbiota. Biochem J. 2017 May 16;474(11):1823-1836. doi: 10.1042/BCJ20160510. PMID: 28512250; PMCID: PMC5433529.

[xv] Holmes A, Finger C, Morales-Scheihing D, Lee J, McCullough LD. Gut dysbiosis and age-related neurological diseases; an innovative approach for therapeutic interventions. Transl Res. 2020 Dec;226:39-56. doi: 10.1016/j.trsl.2020.07.012. Epub 2020 Aug 2. PMID: 32755639; PMCID: PMC7590960.

[xvi] Nagpal R, Mainali R, Ahmadi S, Wang S, Singh R, Kavanagh K, Kitzman DW, Kushugulova A, Marotta F, Yadav H. Gut microbiome and aging: Physiological and mechanistic insights. Nutr Healthy Aging. 2018 Jun 15;4(4):267-285. doi: 10.3233/NHA-170030. PMID: 29951588; PMCID: PMC6004897.

[xvii] Hofer U. Gut–Brain Axis in ageing. Nature Reviews Microbiology. 2022 Jun 14;20(8):446–446. doi:10.1038/s41579-022-00762-5

[xviii] Kundu P, Lee HU, Garcia-Perez I, Tay EX, Kim H, Faylon LE, et al. Neurogenesis and prolongevity signaling in young germ-free mice transplanted with the gut microbiota of old mice. Science Translational Medicine. 2019 Nov 13;11(518). doi:10.1126/scitranslmed.aau4760

[xix] Banc R, Rusu ME, Filip L, Popa D-S. The impact of ellagitannins and their metabolites through gut microbiome on the gut health and brain wellness within the gut–brain axis. Foods. 2023 Jan 6;12(2):270. doi:10.3390/foods12020270

[xx] Kothe B, Klein S, Petrosky SN. Urolithin A as a Potential Agent for Prevention of Age-Related Disease: A Scoping Review. Cureus. 2023 Jul 27;15(7):e42550. doi: 10.7759/cureus.42550. PMID: 37637627; PMCID: PMC10460156.

[xxi] D'Amico D, Andreux PA, Valdés P, Singh A, Rinsch C, Auwerx J. Impact of the Natural Compound Urolithin A on Health, Disease, and Aging. Trends Mol Med. 2021 Jul;27(7):687-699. doi: 10.1016/j.molmed.2021.04.009. Epub 2021 May 21. PMID: 34030963.


Leave a comment


Also in GUT HEALTH KNOWLEDGE CENTER

New Study Links Gut Microbiome Composition With Your Social Decision-Making
New Study Links Gut Microbiome Composition With Your Social Decision-Making

June 01, 2024 7 min read

Read More
Layer Orignin - The Health Benefits of Urolithin A - A Postbiotic Produced In Your Gut - for Bone, Muscle, Brain Health, and Aging
The Health Benefits of Urolithin A - A Postbiotic Produced In Your Gut - for Bone, Muscle, Brain Health, and Aging

May 19, 2024 7 min read

The human gut microbiome is a myriad of microbes working together in harmony, but it's also the hub of numerous biological transactions. The conversion of the polyphenols, ellagic acid and ellagitannins, into urolithin A is an interesting and hot topic. Urolithin A has been earmarked for its anti-aging potential, and in this article, we explore its benefits for bone, muscle, and brain health.
Read More
Gut microbiome test results: How PureHMO® prebiotic impacted bacteria strains for a consumer
How PureHMO® prebiotic impacted bacteria strains for a consumer - from gut microbiome test (Updated Analysis)

May 12, 2024 7 min read

Take a look at a consumer's gut microbiome data before and after taking PureHMO, and see what beneficial bacteria have been boosted by PureHMO.
Read More