Can Probiotics Contribute to Healthy Aging?

Anti-Aging Benefits of Probiotics – Are Gut Bacteria the Key to Healthy Aging?

Can Probiotics Contribute to Healthy Aging?

Are Gut Bacteria the Key to Healthy Aging?

An increasing number of recent studies are asking an important question: Do gut bacteria hold the key to healthy aging? New research, recently presented at the London Microbiome Meeting, brings us closer to the answer.

In the ancient myth of Tithonus, the eponymous protagonist asks the gods to live forever but forgets to demand eternal youth.

Although he gained immortality, the diseases of old age eventually defeat Tithonus, and he bitterly regrets his immortality.

While achieving longevity is a goal worth pursuing and an ambition that humankind has harbored since the times of Ancient Greece, the myth of Tithonus reminds us that a long life has little value if riddled with disease…


Anti-Aging Benefits of Probiotics

A balanced gut microbiome teeming with probiotics is essential for healthy aging. Here’s how the good guy microbes can keep you feeling in your prime:

1. Protect brain cell health. Research shows that probiotics can promote the growth of new brain cells, especially after antibiotic use. In one trial, mice given antibiotics that indiscriminately wiped out all of their beneficial bacteria showed reduced brain cell growth, but treatment with probiotics was able to reverse the effects 1.

2. Enhance memory and cognitive function. Many people notice a decline in memory retention as they get older, but probiotics can boost your memory at any age.

In a research study, volunteers who took probiotics for one month scored higher on memory tests than when they took a placebo 2.

And, studies show that subjects who consume probiotics may have an improved connection between the brainstem and the cognition-centered part of the brain

3. Regulate immune health. Aging can have a negative effect on immune function, due to the decreased microbial diversity common in the later years.

You see, 80% of your immune system resides in your gut, and your beneficial bacteria help to balance your immune function.

Without enough good microbes, your immune system may be suppressed or overstimulated, affecting your overall health…


The Composition of Gut Bacteria Almost Recovers After Antibiotics

The trillions of bacteria in the human gut affect our health in multiple ways, including effects on immune functions and metabolism.

A rich and diverse gut microbiota is considered to promote health, providing the human host with many competences to prevent chronic diseases.

In contrast, poor diversity of the gut ecosystem is a characteristic feature of chronic diseases, including obesity, diabetes, asthma, and gut inflammatory disorders…


Can Borrowing Younger Gut Microbes Reverse Aging?

Can the gut microbes of young people make older people feel younger and live longer? Researchers found that the profile of your microbiome (the ecosystem of microorganisms in your gut) changes as you age. Read on to find out why reversing aging and restoring vitality in fish might matter for humans…


How will Microbiome Research Revolutionize Public Health?

New technologies have revolutionized the way we see and understand the human microbiome: the approximately 100 trillion bacteria and other microbes that live in and on the human body.

Most of these microbes do not cause disease—indeed, humans rely on these organisms to perform vital functions. In the coming decades, clarifying the many roles of the microbiome will dramatically reshape medicine and public health.

Curtis Huttenhower, associate professor of computational biology and bioinformatics, describes the changes ahead.

The biggest advance in studying the microbiome is that genetic sequencing has become cheap. And there are now other molecular technologies that complement DNA sequencing, looking at microbial small molecules or having easy, high-throughput ways to get a variety of different microbial community samples, to grow or isolate microbes. Everybody’s strain of every bug is a little different…



Can Probiotics Contribute to Healthy Aging?

Can Probiotics Contribute to Healthy Aging?

Probiotic supplementation may help support the immune systems of elderly adults, while animal studies hint at more intriguing potential benefits in aging. Where is the research headed next? Find out here.

Probiotics & Healthy Aging: Insufficient Evidence

When we age, the composition of our gut flora shifts, and our immune response declines. Are these connected? Some researchers think they might be. This post will explore the relationship between probiotics and immune function in elderly people.

Because immune function is less robust in older adults than in young people, it’s especially important to consult your doctor before taking probiotics to stave off the effects of aging.

Note that probiotics’ benefits to aging are only supported by limited, low-quality clinical studies. There is insufficient evidence to support the use of probiotics for this purpose. Remember to speak with a doctor before taking probiotic supplements, and never use it in place of something your doctor recommends or prescribes.

Human Studies

Levels of Bifidobacteria decrease as we age [1].

B. animalis spp. lactis beneficially modifiedgut microbiota in the elderly, increasing Bifidobacteria, Lactobacilli, and Enterococci and reducing Enterobacteria [2].

B. animalis spp. lactisenhanced natural immunity in healthy elderly subjects [3]. B. animalis spp. lactis increased leukocyte phagocytic and NK cell tumor-cell-killing activity in the elderly and increases the proportions of total, helper (CD4(+)), and activated (CD25(+)) T lymphocytes and natural killer cells [4, 5, 6].

B. longumstimulated the immune functions in the elderly [7].

B. bifidum and L. acidophilus positively modulated the immunological and inflammatory responses in elderly subjects [8].

Some researchers believe that L. delbrueckii ssp. bulgaricus may favor the maintenance of an adequate immune response in the elderly, possibly by slowing the aging of the T-cell subpopulations and increasing the number of immature T cells which are potential responders to new antigens [9].

L. acidophilus increased Bifidobacteria levels and beneficially changedmicrobiota in elderly subjects [10].

Heat-killed L. gasserienhanced immunity in the elderly. This probiotic increased the number of CD8(+) T cells and reduced CD28 expression loss in CD8(+) T cells [11].

Animal Studies

Feeding of probiotic bacteria (L. reuteri) to aged mice induced integumentary changes mimicking peak health and reproductive fitness characteristic of much younger animals [12].

A probiotic fermented milk drink called Dahi with L. lactis, L. acidophilus and B. bifidum reversed age-related decline in expression of biomarkers of aging, PPAR-α, SMP-30, and Klotho in hepatic and kidney tissues in mice [13].

L. lactis along with L. acidophilus or combined with L. acidophilus and B. bifidum reversed age-related decline in immune functions and improve lymphocyte functions in aging mice [14].

Heat-killed L. gasseri increased natural killer cell (NK cell) activities and enhanced cell-mediated immunity in aged host animals, thereby altering age-related immunosenescence [15].

Dahi containing L. acidophilus was effective in reversing age-related immune function decline in mice [16], where this probiotic also combatedoxidative stress and molecular alterations associated with aging [17].

L. fermentum alleviated immunosenescence, possibly by enhancing antioxidant enzyme activities and was shown to reduce E. coli infection in aging mice [18].

L. johnsonii helped recover nutritional status and systemic immune responses in aged mice [19].

Long-term oral intake of L. lactissuppressed the reduction of bone density and body weight in senescence-accelerated mice [20].

B. bifidumdelayed immunosenescence in mice by enhancing the anti-oxidation activity in thymus and spleen and by improving immune function [21].

Intake of heat-killed L. lactis altered the intestinal flora, affected plasma metabolite levels, including fatty acid levels, and slowed down age-related hearing loss in mice. Researchers have suggested that this probiotic may have inhibited the loss of neurons and hair cells in mouse inner ear [22].

In mice, L. reuteri increased thyroid size and activity (increasing T4 levels), lessening fatigue and weight gain associated with aging and resulting in a more youthful physical appearance [23].

Antioxidant Action

L. casei, L. helveticus, L. fermentum, B. bifidum and B. subtilisexhibit antioxidant properties [24, 25, 26, 27, 28, 29].

Similarly, B. animalis and L. lactiseffectively scavenge free radicals and significantly enhance the activity of antioxidative enzymes in mice [30, 31].

A B. subtilis signal molecule induces the heat shock protein Hsp27 in mammalian cells; this protein protects intestinal cells against oxidant-mediated tissue damage [32].

Further Reading

We’ve compiled deep dives into each potential benefit of probiotics. Check them out here:


Healthy Aging: A handy digest to understanding probiotic products

Can Probiotics Contribute to Healthy Aging?

There’s lots of talk about probiotics these days – probiotics in your yogurt, probiotics in your bread, even probiotics in your skin care products or household cleaners! But what are probiotics, and why would we need them in the first place?

A widely accepted description of probiotics defines them as “live micro-organisms that, when administered in adequate amounts, confer a health benefit on the host.” In plain language, probiotics are “good bugs” or “good microbes” that are meant to help the person taking them.

These friendly microbes help us digest food, maintain health and fight disease. Many Canadians are hearing about how great probiotics are, and are looking to take them as supplements, or to add them to their diet or take them as needed to improve health. Seems a pretty logical idea, right?

It’s important to note that if you are generally a healthy person (physically active, eat well, aren’t under a lot of stress) you ly do not need to add probiotics to your regimen.

Not everyone needs a probiotic to stay healthy. An important role for probiotics has been identified as being a treatment for specific conditions, offering symptom relief or resolving the issue entirely.

I suggest that you talk with your pharmacist, physician or dietitian before taking probiotics to ensure you have a proper diagnosis, or know why you are taking it.

Together, you can select an appropriate probiotic that is the most suitable for you.

With so many products available, and so much chatter around this hot topic, it’s no wonder that people are having trouble choosing the right probiotic.

What often happens is that people will take something labelled “probiotic,” or that purports to have “live bacterial cultures,” but as these products often aren’t right for their diagnosis, they might not see any health difference and assume that probiotics just don’t work. But how wrong that is!


Research and patient experience support the great benefits of probiotics, but only if they are chosen appropriately. “One size fits all” does not apply to probiotics. You will need to know which one to take, for how long to take it and when you can expect benefits. Your health-care provider can help you select the correct probiotic strain and product.

We never walk into a pharmacy and say, “I would to take some drugs.” Your pharmacist will need to know about your symptoms, past experiences, allergies and other factors before making any recommendations. The same applies to probiotics. Different strains of probiotics have very different effects.

This issue of selecting the appropriate probiotic strain has been addressed, and a solution provided, in the Clinical Guide to Probiotic Products, whose publishing and distribution is co-ordinated by the Alliance for Education on Probiotics (AEProbio).

The guide is evidence-based, independently prepared and updated every year.

It has been recognized as the only reliable resource providing health-care professionals and consumers with a list of probiotic formulations that have been specifically clinically tested – so you can select the appropriate product, dose and formulation for a specific indication.

Within the clinical guide, recommendations are tied to brand names, making it easier for consumer to select the recommended product when purchasing at a pharmacy. Probiotic strain names and doses are also listed. Favourable published clinical evidence for the particular strain(s) presented in each product are given and include numerous conditions.

To quote author Dragana Skokovic-Sunjic, “You need to use the right probiotic, for the right person, for the right reason.”

The clinical guide is available in English and French at, and on the App Store or Google Play by searching “Probiotic Guide.”


Dead probiotic strain shown to reduce harmful, aging-related inflammation

Can Probiotics Contribute to Healthy Aging?

Scientists at Wake Forest School of Medicine have identified a dead probiotic that reduces age-related leaky gut in older mice. The study is published in the journal GeroScience.

But what exactly is leaky gut and what does a probiotic — dead or alive — have to do with it?

Some research has indicated that leaky gut, in which microbes and bacteria in the gut leak into the blood stream through holes or cracks in the intestinal lining, causes an increase in low-grade inflammation, and these conditions are common in older people. This resulting inflammation is thought to play a role in the development of many age-related diseases, such as diabetes, obesity, cancer, cardiovascular disease and decline in physical and cognitive functions.

“We know that probiotics are instrumental in maintaining a healthy gut and preventing leakage, but there isn't much data available to pinpoint which ones work and which ones don't,” said Hariom Yadav, Ph.D., assistant professor of molecular biology at Wake Forest School of Medicine and principal investigator of the study.

“Determining the strain that is most effective at reducing leaky gut and inflammation would help us target more effective strategies to address the problem, and help explain why probiotics work for some people but not others.”

In the study, Yadav's team first screened eight strains of human-origin probiotics in roundworms, a commonly used model with a short lifespan of 11 to 20 days. They discovered that a strain of Lactobacillus paracasei (D3-5), even in the non-viable or heat-killed form, extended the roundworms' life span.

They then tested their initial findings in mice. The results showed that feeding heat-killed D3-5 to older mice prevented high fat diet-induced metabolic dysfunctions, decreased leaky gut and inflammation, and improved physical and cognitive functions.

“Not only did we determine which probiotic strain was the most effective in preventing leaky gut and inflammation, we also showed that the dead version of that probiotic had the same benefits,” Yadav said.

“This is the first-of-its kind study to show that a component (lipoteichoic acid) from the cell wall of a dead probiotic induced changes in the gut microbiome and mucin production, thereby reducing leaky gut and inflammation in elderly mice.

“We think our findings could be very useful to the food and supplement industries because dead probiotics have the potential to be more stable and have a longer shelf life than live probiotics.”

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Story Source:

Materials provided by Wake Forest Baptist Medical Center. Note: Content may be edited for style and length.

Journal Reference:

  1. Shaohua Wang, Shokouh Ahmadi, Ravinder Nagpal, Shalini Jain, Sidharth P. Mishra, Kylie Kavanagh, Xuewei Zhu, Zhan Wang, Donald A. McClain, Stephen B. Kritchevsky, Dalane W. Kitzman, Hariom Yadav. Lipoteichoic acid from the cell wall of a heat killed Lactobacillus paracasei D3-5 ameliorates aging-related leaky gut, inflammation and improves physical and cognitive functions: from C. elegans to mice. GeroScience, 2019; DOI: 10.1007/s11357-019-00137-4


The role of probiotics in ageing and longevity

Can Probiotics Contribute to Healthy Aging?

Over the last decade, the proportion of the developed world’s population over the age of 65 years has inc
reased by more than 10%. Furthermore, it is projected to increase over 20% by 2030.

Life expectancy continues to increase globally and is expected to reach the mid-70s by 2050.

Maintaining health in older age depends on the appropriate function of the homeostatic systems (nervous, endocrine and immune) and correct interactions between these systems and gut microbiota.

However, these systems undergo modifications in elderly persons, thus accounting for a reduction in the functional capacity of all the organs in the body, which, in turn, may evolve toward “inflammaging”, a phenomenon characterized by a low-grade inflammatory state, involved in the aetiology of several age-related chronic pathological conditions. Physiological declines in immune function are termed “immunosenescence”, which may lead to the impairment in both cellular and adaptive immunity, together with age-related oxidative stress, a low-grade inflammatory state, and intestinal dysbiosis. Overall, immunosenescence may be linked to a perturbed gut microbiota and frailty in the elderly.

Gut immune response and microbiota composition are impaired in elderly.

In older adults there seems to be a decline in microbiota diversity, with lower numbers of Firmicutes and bifidobacteria and an increase in Bacteroidetes and certain Proteobacteria (which are thought to play a role in bowel disease).

However, it is not yet clear how these changes are a result of the senescence of the immune system or altered dietary intake or physical activity.

  Despite the fact that ageing has a significant effect on the microbiota, its alterations can be consequent to conditions that occur frequently in the elderly, such as the decline of the general state of health with malnutrition and with increased need for medication. Thus, a causal relationship cannot yet be assumed between aging and gut microbiota changes.

There is therefore a growing awareness about the role of probiotics in modulating the gut microbiota to maintain health in the elderly.

Clinical trials that have assessed their effectiveness in ageing populations are scarce, but may show that health benefits can be achieved through: 1) Their effect on the composition of the microbiota in elderly populations; and 2) Their effect on the symptoms of major gastrointestinal diseases. Probiotics with Bifidobacterium and Lactobacillus genera are among the most studied in clinical trials with elderly populations. They may restore a healthy microbiota and control oxidation and inflammatory processes, which can be beneficial in ameliorating immunosenescence, the risk of infections, and nervous system impairments in older adults.

In conclusion, probiotics may have a particular application in elderly populations, especially in terms of protection against infections and perhaps also in the prevention of several age-related diseases. Further studies with a double-blind, placebo-controlled design should be performed for a better assessment of probiotics’ potential to maintain a beneficial microbial balance to promote health in the elderly.

These findings were reviewed in a talk by Dr. Mónica de la Fuente, a researcher from the Faculty of Biology at Complutense University of Madrid during the 7th edition of the latest Spanish Society of Probiotics and Prebiotics (SEPyP)’s annual workshop, which was held on Seville (Spain) on January, 28-29th under the theme: “Probiotics, Prebiotics and Health: Scientific Evidence”.


Bischoff SC. Microbiota and aging. Curr Opin Clin Nutr Metab Care. 2016;19(1):26-30.

Brüssow H. Microbiota and healthy ageing: observational and nutritional intervention studies. Microb Biotechnol. 2013;6(4):326-34.

Duncan SH, Flint HJ. Probiotics and prebiotics and health in ageing populations. Maturitas. 2013;75(1):44-50.

Rondanelli M, Giacosa A, Faliva MA, Perna S, Allieri F, Castellazzi AM. Review on microbiota and effectiveness of probiotics use in older. World J Clin Cases. 2015;3(2):156-62.

Saraswati S, Sitaraman R. Aging and the human gut microbiota-from correlation to causality. Front Microbiol. 2014;5:764.

9 Mar 2020

by Andreu Prados

2 Mar 2020

by GMFH Editing Team

28 Feb 2020

by GMFH Editing Team


Healthy aging: Gut bacteria may prevent disease

Can Probiotics Contribute to Healthy Aging?

An increasing number of recent studies are asking an important question: Do gut bacteria hold the key to healthy aging? New research, recently presented at the London Microbiome Meeting, brings us closer to the answer.

Share on PinterestResearch presented at the London Microbiome Meeting zoomed in on the role of bacteria for human health and aging.

In the ancient myth of Tithonus, the eponymous protagonist asks the gods to live forever but forgets to demand eternal youth.

Although he gained immortality, the diseases of old age eventually defeat Tithonus, and he bitterly regrets his immortality.

While achieving longevity is a goal worth pursuing and an ambition that humankind has harbored since the times of Ancient Greece, the myth of Tithonus reminds us that a long life has little value if riddled with disease.

As human life expectancy increases, the world population is aging at much higher rates. In fact, the United Nations estimate that the senior population — that is, the number of people aged 60 and above — is increasing at a rate of approximately 3 percent per year.

Currently, there are 962 million people aged 60 and above across the globe, according to the most recent estimates. By the year 2050, this number is projected to more than double, and the number of people aged 80 and above is expected to triple.

A range of chronic diseases accompanies aging. By the year 2060, for example, the Alzheimer’s disease burden in the United States will have doubled, say the Centers for Disease Control and Prevention (CDC).

They predict that almost 14 million people will have Alzheimer’s and other forms of dementia by then, and researchers are hard at work trying to prevent this and other age-related diseases.

So, the question “How can we live longer and healthier lives?” is slowly replacing that of “How can we live longer?” As scientists embark on the quest for a longer healthspan, it is becoming clearer that aging is not just an inevitable process that simply “happens,” but that there are precise molecular mechanisms that regulate it.

Marina Ezcurra, Ph.D. — a lecturer in neuroscience at the School of Biological & Chemical Sciences at Queen Mary University of London in the United Kingdom — dedicates her time to understanding these mechanisms.

Her research focuses on how aging and its related diseases occur in a worm called Caenorhabditis elegans. More recently, Ezcurra and her team have been examining gastrointestinal aging and the role of the microbiome in this process.

On 24 October, 2018, Ezcurra presented her research at the London Microbiome Meeting in the U.K. In this Spotlight feature, we report on the key takeaways from her presentation.

In her presentation — entitled “The worm-bug: a combined model system to study host-microbiome interactions” — Ezcurra introduced C. elegans as a viable model for studying aging. C. elegans has a lifespan of only 2–3 weeks, but as it ages, it develops several pathologies — just the human organism.

Share on PinterestThe C. elegans ‘worm-bug.’

However, in the case of C. elegans, all the pathologies come down to a single one: gastrointestinal aging.

As Ezcurra explained in her talk, all the lifespan-increasing treatments that scientists have applied to C. elegans work by suppressing intestinal aging.

Using C. elegans, researchers can examine a host of age-related processes, such as resistance to stress, growth, fecundity, and lifespan. Experts have also used C. elegans as a model for several human diseases, such as Alzheimer’s.

Ezcurra quotes existing research that saw C. elegans fed with Escherichia coli. As the worm feeds on bacteria, the researchers created about 4,000 mutant strains of E. coli, each with a specific gene deleted. Then, the team fed C. elegans each of these strains and examined the effects.

Senior study author Meng Wang — who is an associate professor of molecular and human genetics at the Baylor College of Medicine in Houston, TX — reported on the findings, saying, “We fed C. elegans each individual mutant bacteria and then looked at the worms’ lifespan.”

“Of the nearly 4,000 bacterial genes we tested, 29, when deleted, increased the worms’ lifespan. Twelve of these bacterial mutants also protected the worms from tumor growth and accumulation of amyloid-beta, a characteristic of Alzheimer’s disease in humans.”

Meng Wang

Also, the researchers found that one bacterial mutant overproduced a substance called colanic acid; this compound increased longevity by stimulating activity in the mitochondria, the so-called powerhouses of the cell, which are responsible for turning nutrients into energy.

In her talk, Ezcurra mentioned another example of successful research into C. elegans that showed the effects of the microbiome on the aging process. This study involved the common diabetes drug metformin.

Metformin is currently the world’s most widely prescribed diabetes drug. Previous research has found that the oral medication does not only reduce blood sugar levels, but that it also reduces the risk of cancer.

Scientists found that the drug can delay aging in mice and C. elegans. Metformin is currently being tested in clinical trials as a potential treatment against aging and aging-related diseases.

As the researcher explained in her talk, this means that metformin could potentially target several age-related chronic diseases at once. Metformin may be able to target not just diabetes, but also cancer and Alzheimer’s pathologies.

The interesting thing about metformin’s effects is that they delay aging through bacteria. Studies in C. elegans that Ezcurra cited have shown that the longevity effects of metformin do not work in the absence of bacteria.

Specifically, metformin affects the folate bacterial metabolism, Ezcurra explained, which, in turn, triggers a chain reaction that ends with the activation of a molecular pathway known to regulate aging.

Ezcurra’s own research seeks to combine two model organisms — E. coli and C. elegans — to study how bacteria mediate the aging process.

Previous studies have teased out the microbiome of C. elegans, and others have colonized the gut of C. elegans with E. coli OP50 and noticed some interesting effects. The bacterial strain had positive effects on reproduction, immunity, and the organism’s response to stress.

So, Ezcurra and her colleagues wondered whether there are any other additional effects that OP50 has on the aging process. Experiments carried out in her laboratory revealed that adding antibiotics to worms colonized with E. coli OP50 improves intestinal aging. Wiping out bacterial growth delayed the atrophy of the intestine that tends to happen with age in C. elegans.

Also, the researchers found two strains of bacteria from the C. elegans microbiome that reduce intestinal aging. Therefore, the research found, anti-aging effects can also be achieved without wiping out bacterial growth, but by doing quite the opposite: colonizing the gut with specific strains of bacteria.

Another experiment carried out in Ezcurra’s laboratory used a previously established human disease model that used C. elegans to recreate age-related muscle paralysis. The researchers analyzed the effects of a “cocktail” of 14 different bacterial strains that make up the experimental microbiome.

They found that this experimental cocktail strongly suppressed age-induced paralysis. Also, the media extracted from the experimental microbiome had the same positive effect.

In the future, Ezcurra’s team aims to see if it can colonize C. elegans with human bacterial strains to study the effects on aging and healthspan.

The researcher recently received funding from the Wellcome Trust to use simple human microbiomes — such as bacteria that have a beneficial effect on health and bacteria that impact health negatively — and study their effects in C. elegans.

Using real-time imaging, the scientists hope to unravel the molecular mechanisms that underpin the interactions between the host and the microbiome, as well as their effects on the aging process.

“The next step for my research,” Ezcurra told Medical News Today, “is to use C. elegans to ask specific questions about the role of the microbiome in human health.”

“There are many, many studies showing that there are links between the microbiome and diseases, such as psychiatric diseases, neurodegenerative diseases, obesity, diabetes etc., but we don’t understand what is cause and [what is] effect.”

“There is a real need to figure out the exact relationship between the microbiome composition and disease,” she went on. “Which microbial strains contribute to health and disease, and more importantly, how do these strains contribute to health?”

“It is becoming clear that microbiome diversity is important for human health,” Ezcurra added. “Many factors contribute to microbiome diversity, such as diet and lifestyle, and as we become old we typically experience a loss in diversity.”


Data supports increased role for probiotics, prebiotics in healthy aging, study finds

Can Probiotics Contribute to Healthy Aging?

Dealing with the implications of aging populations is a worldwide issue. China, Japan, the United States and many European countries are facing demographic bulges that will see an increasing share of gross domestic product going to care for these populations. 

Critical problem of aging

The issue is especially acute in Japan, where a recent census found that almost 27% of Japanese are now 65 or older.

Many of these elderly Japanese live alone, and the number of younger workers available to support them is shrinking. The country’s population fell by more than 1 million in the 2010-2015 time frame to about 127 million.

With a low birth rate, some reports have predicted that Japan’s population may fall below the 100 million mark in coming decades.

So finding cost effective ways to support this population is of critical national importance.  In the recent review, published in the World Journal of Gastroenterology​, researcher Yukihiro Shimizu summarized the microbiome aspects of the afflictions of aging.

Shimizu looked at the microbiome research related to Alzheimer’s Disease, osteoporosis, sarcopenia and atherosclerotic cardiovascular disease and stroke.  (Obesity, which is a plague elsewhere in the developed world, is not yet a serious concern for the elderly populations in Japan.)

The review found a wealth of information on dysbiosis connected to all of these conditions. A recent study on Japanese Alzheimer’s Disease patients isolated four bacterial strains common to all, information with Shimizu said may shed light on the unique gut microbiome features related to this condition. 

 The review also noted that as much as 90% of serotonin was produced in the gut​​, and exogenous serotonin has been shown in a mouse model to reduced deposition in the brain of the amyloid plaque​​s associated with the disease.

  As gut-produced serotonin has yet to be shown to cross the blood-brain barrier, Shimizu noted that, “Thus, the actual role of gut-derived serotonin in brain function remains unclear.

”  But he said that studies have shown that a reduced gut microbial diversity seems associated with the disease.

Probiotics, prebiotics specifically cited in osteoporosis

For osteoporosis, the review noted that most of the microbiome data comes from mouse models.

  A recent study​​ found that gut microbes can “increase serum concentrations of insulin- growth factor-1 (IGF-1), which promotes bone formation and remodeling.

”​ The review found a specific role for probiotics here, noting that, “Probiotics such as ​Lactobacillus strains have been shown to increase bone mass along with changes in gut microbiota.”​

Shimizu also noted that prebiotics have been shown by several studies to increase calcium absorption.

  Taken together, he said recent research shows that, “[S]upplementation with probiotics or prebiotics may be a potential therapeutic intervention for the prevention or treatment of osteoporosis in humans.

However, there is limited evidence showing that prebiotics are effective in patients with postmenopausal or senile osteoporosis.”​

Sarcopenia, CVD evidence

For sarcopenia, the review found that the evidence is less clear cut.  But it did find studies that link probiotics with preventing muscle loss in mice with leukemia, and cited a study linking prebiotics with improved muscle function in humans as measured by grip strength.

For heart disease, the review cited studies linking the gut microbiome with playing both a positive and negative role.

  Some aspects of gut dysbiosis have been linked with increase levels of trimethylamine-N-oxides  in the liver, which is associated with arterial plaque formation.

  But other gut microbial species have been associated with improved lipid metabolism and reduced cholesterol levels.

“Although, adequate exercise and a proper diet are important for the prevention of these diseases, the combination of these lifestyle interventions with methods that manipulate the composition and/or diversity of gut microbiota may be a promising strategy for maintenance of healthy conditions with preserved activities of daily living,”​ the review concluded.

Source: World Journal of Gastroenterology​​
“Gut microbiota in common elderly diseases affecting activities of daily living”​
Published online Nov 14, 2018. doi: 10.3748/wjg.v24.i42.4750​
Shimizu Y