When it comes to aging, your gut might not be top of your list of organs that can help you grow old healthily, but emerging research suggests it should be. Fuelling your intestinal ecosystem with prebiotics and fiber-rich foods could be the key to healthy aging and fending off chronic disease.
Content Outline
Who knew that deep in your colon lies an ecosystem that could hold the secret to growing old gracefully? Research published in 2024 and supported by the National Institute of Aging, found that older adults with a more diverse gut microbiome were more likely to live longer than those whose microbiome was unchanged or not unique. So, what is it about the gut that makes it more than just a digestive organ? We look at some of the recent supporting evidence to find out why the gut may be the organ you should be taking care of if you want to live a long and healthy life.
What is Gut Health All About?
Gut health is a collective term for a myriad of components within the digestive system that contribute to the normal digestion of food, the extraction and absorption of nutrients, the maintenance of gut lining integrity, the regulation of the immune response, and the control of inflammation.
Gut health incorporates the gut microbiome, a community of microbes, predominantly bacteria, that contribute to the normal functioning of the gastrointestinal system and your overall health, but also metabolite production, including short-chain fatty acids (SCFAs), like butyrate, and immune and nerve cell signalling.
What Does a Healthy Gut “Look” Like?
Some of the obvious signs that your gut is healthy and functioning as it should include:
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regular, daily bowel movements
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consistent energy levels
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minimal pain, discomfort, and bloating
Yet, it’s not just your gut that benefits when your gut health is in tip-top condition; the rest of your body does too. For example, some other subtle signs that you have a healthy gut are:
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minimal illness or a well-functioning immune system (cuts heal quickly etc)
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efficient metabolism
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good mood
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pain-free muscle and joints
What’s The Link Between The Gut and Aging?
Huge amounts of research demonstrate that one of the key things healthy older people have in common is the types of bacteria residing in their guts. Centenarians, those people who have reached the amazing age of 100 and beyond, are good subjects to analyse because their guts could hold the secret to living longer, healthier lives.
A 2023 study involving almost 1600 people, including 297 centenarians, revealed that those who had reached 100 had gut microbiomes that were more commonly associated with younger people. Their microbiomes were dominated by Bacteroides, with a more balanced set of microbes, increased abundance of beneficial Bacteroidetes, and reduced potential pathogenic community. The same researchers also showed that people over 80 who had Bacteroides dominating their gut were more likely to die over a 4-year follow-up period than those who did not.
Similarly, a study by Wu and colleagues found that compared to young people, the gut microbiota of centenarians was more diverse, and included several probiotic species:
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Lactobacillus – a common type of lactic acid bacteria that are involved in modulating key anti-aging pathways, and one strain, L.paracasei HIIO1, could prevent age-related diseases and promote healthy aging
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Akkermansia – a mucin-loving species which is integral to strengthening the gut barrier and lowering the prevalence of age-related issues
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Methanobrevibacter – common methane producers that are important for the proper digestion of polysaccharides
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Roseburia – a crucial butyrate producer that contributes to the overall health of the gut and strengthens the gut lining
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Clostridiales and Ruminococcaceae – support gut health, produce SCFAs, and help to make neurotransmitters that can regulate mood
When the gut is in balance, microbes can help regulate your immune system and produce beneficial metabolites. SCFAs, like acetate, butyrate, and propionate, are produced when intestinal bacteria ferment prebiotic fiber. These important compounds can lower inflammation, maintain your gut barrier integrity, and protect against chronic disease.
▶ Find out more about the 12 Hallmarks of Aging.
How Does The Gut Microbiome Contribute to Aging?
On the flip side, dysbiosis – an imbalanced gut microbiome – can dampen your health, increase inflammation, and the risk of diseases, such as Alzheimer’s, Parkinson’s, inflammatory bowel disease (IBD), and even some cancers.
Leaky Gut
With ageing comes the potential for a leaky gut, in which your gut barrier weakens, allowing bacteria and bacterial toxins, such as lipopolysaccharide (LPS), to enter the bloodstream and cause inflammation. This chronic low-grade inflammation drives many age-related illnesses, including dementia, heart disease, and increased frailty.
Aging can mean that you lose some beneficial microbial members of your gut who produce SCFAs, which can bolster the integrity of the gut barrier. When healthy and strong, microbes and molecules are kept separate from the gut lining and circulation, but if the integrity is compromised, bacteria, toxins, and undigested food particles can cross into circulation and initiate an inflammatory response, which can directly impact organs throughout the body.
Inflammaging
As you get older, your gut microbiome becomes less diverse and more inflammatory, contributing to a process scientists call “inflammaging”. There are several risk factors for inflammaging, such as:
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genetics
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obesity
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changes in the composition of the gut microbiota
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increased gut permeability
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oxidative stress
High levels of pro-inflammatory signalling molecules and markers are more common in older people and are linked to an increased chance of cardiovascular disease, frailty, and cognitive and physical decline. Inflammaging results from an overactive innate immune system, driven by cellular damage and changes in the gut microbiota, which trigger pro-inflammatory signals throughout the body.
Research in mice has shown that transferring the gut microbiota of old mice into young mice can promote inflammaging. This suggests that the gut microbiota plays a direct role in the process. On the other hand, transferring the gut microbiota of young mice into old mice can have a positive effect, by slowing down or even reversing some of the metabolic and immunological effects of aging.
However, older adults, such as centenarians, tend to have healthier microbiomes and lower inflammation. This means that strategies like healthy eating, regular physical activity, and leading a relatively healthy lifestyle can help to keep inflammaging and its consequences at bay.
Harnessing Your Gut Microbiota to Promote Healthy Aging
Supporting your gut microbiome throughout your lifetime by eating a balanced diet is the most important way you can help promote healthy aging. Although it may not provide eternal youth, it can go a long way to help you live a long and healthy life.
Diet
Diet is likely the most important way you can support your gut microbiome with very little effort. Many of the changes in gut microbiome composition that are associated with poorer health outcomes and increased aging stem from the diet. For example:
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poor dietary choices
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reduced fiber intake
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increased processed food consumption
A healthy, balanced diet has proven benefits, particularly for aging. One study found that people aged 65 to 79 who ate a Mediterranean Diet for one year had reduced frailty markers, improved cognitive function, and an increased number of microbes that produced beneficial SCFAs.
Natural, fibrous foods help to nourish the good gut microbes in your gut. So, boosting your consumption of fiber, fermented foods, like Kefir, kimchi, and yoghurt are a simple yet effective way to improve the composition of your gut microbiome and your general health.
Supplements
Probiotic and prebiotic supplements can offer an effective way to bolster your gut. Akkermansia muciniphila supplementation in mice for 10 weeks halted the age-related decline in intestinal mucosal thickness, thereby reducing inflammation and immune processes that are common with increasing age.
Further research by Yadav and Co. found that supplementing the diet of old mice with a probiotic bacterial strain commonly used in infants, L. paracasei D3-5, improved physical and cognitive function and reduced leaky gut and inflammation.
Prebiotic supplements are also emerging for their potential in healthy aging. Recent research has found that the human milk oligosaccharide (HMO), 2’-fucosyllactose (2’-FL), increases the abundance of Bifidobacteria in the guts of older adults. This improved some metabolic markers, and these individuals also performed better on cognitive tests involving visual memory. Therefore, 2’-FL could have potential for healthy aging.
Summary
The gut is not just a digestive organ involved in breaking down food, extracting nutrients, and getting rid of waste. It also has vital roles in immunity, cognitive function, and the aging processes. Although there’s still plenty of research needed to fully understand the link between the gut and aging, it’s clear that a diverse gut microbiome is a common denominator in people who live longer, healthier lives.
Looking after your gut doesn’t need to be complicated or expensive. Simple approaches like eating more fiber, incorporating some fermented foods, adding some exercise to your routine and prioritizing sleep are easy ways to nourish and diversify your gut. While probiotics and prebiotic supplements, like HMOs, are an excellent way to bolster the health-promoting communities that could hold the secret to aging well.
Written by: Leanne 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.
