Can your gut microbiome predict your lifespan?

Can your gut microbiome predict your lifespan?

The secret to ageing well might not just lie in genetics, diet, or exercise. It could be in your gut. Scientists are increasingly uncovering how the trillions of bacteria residing in your digestive system influence everything from inflammation to brain health, and ultimately, how well you age.¹ Understanding the gut microbiome and its role in ageing could be a gateway for improving longevity and preventing age-related diseases.

The gut microbiome is a lifelong evolution

Your gut is home to a vast community of bacteria, viruses, fungi, and other microbes, collectively known as the gut microbiome. These microorganisms play a crucial role in digestion, immunity, and even mental health. But as we age, our microbiome changes, and not always for the better.

From birth, factors like mode of delivery (vaginal birth vs. C-section), diet, environment, and antibiotic exposure shape our gut bacteria.² Throughout adulthood, the microbiome remains relatively stable, especially in those who maintain a diverse and fibre-rich diet. However, around the age of 65, diversity begins to decline, and by the time we reach our 80s, our gut microbiome may look very different from what it once was.³ This shift can have profound effects on overall health.

Gut health and the ageing process

One of the most striking findings in gut health research is its link to inflammation, which is a key driver of many age-related diseases. Scientists refer to this as ‘inflammaging’, a chronic, low-grade inflammation that accelerates the breakdown of tissues and contributes to conditions like heart disease, arthritis, and cognitive decline.⁴ A well-balanced microbiome helps keep inflammation in check by producing anti-inflammatory compounds called short-chain fatty acids (SCFAs), which nourish gut cells and support the immune system.¹

Studies of centenarians (people who live beyond 100) suggest they maintain a unique microbiome profile that supports longevity.⁵ These ‘super-agers’ often have higher levels of beneficial bacteria which promote gut integrity and regulate immune responses.⁵ In contrast, those with unhealthy ageing patterns tend to have an overgrowth of inflammatory bacteria that can damage gut walls and allow harmful substances to enter the bloodstream, triggering a cascade of negative effects.¹

Protecting against dementia

Ageing isn’t just about physical health, as cognitive decline is a major concern as well. Recent research suggests the gut microbiome plays a role in brain ageing, with links to neurodegenerative diseases like Alzheimer’s.⁶ Certain bacteria produce neurotransmitters like serotonin and dopamine, which affect mood and cognition, while others generate harmful metabolites that may contribute to brain inflammation and cognitive decline.¹

In fact, some studies have found that people with Alzheimer’s disease have distinct gut microbiome profiles, with fewer beneficial bacteria and more inflammatory microbes.⁷ The gut-brain axis (a two-way communication system between the gut and brain) may be a critical factor in maintaining mental sharpness as we age.⁶

Can we slow ageing through gut health?

Your microbiome is adaptable, and making simple lifestyle changes can help slow the ageing process. Here’s how:

1. Eat a fibre-rich diet: Fibre feeds beneficial bacteria and helps produce SCFAs, which reduce inflammation. Aim for a variety of fruits, vegetables, whole grains, and legumes to support a diverse microbiome.⁸

2. Reduce processed foods and sugar: Highly processed foods and excess sugar can disrupt gut balance by encouraging the growth of harmful bacteria. Instead, focus on whole foods that nourish the gut.⁸

3. Incorporate fermented foods: Yoghurt, kefir, kimchi, sauerkraut, and miso introduce beneficial probiotics into your gut, enhancing microbiome diversity and promoting healthy digestion.⁸

4. Stay active: Exercise has been shown to positively influence the gut microbiome, promoting beneficial bacteria that help regulate metabolism and reduce inflammation.⁹

5. Prioritise sleep and stress management: Chronic stress and poor sleep can disrupt gut health, weakening the gut barrier and increasing inflammation. Practicing mindfulness, maintaining a regular sleep schedule, and engaging in relaxing activities can help maintain a balanced gut environment.

The numan take

Researchers are now exploring microbiome-based therapies, including probiotics, prebiotics, and even faecal microbiota transplants, to support healthy ageing. Some promising interventions aim to replenish beneficial bacteria in older adults to restore gut balance and improve resilience against disease. Understanding how the microbiome influences ageing is still a work in progress, but it’s clear that a healthy gut is a key pillar of longevity. By taking care of your gut microbiome today, you may be setting yourself up for a healthier future.

References

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2. Dominguez-Bello MG, Costello EK, Contreras M, Magris M, Hidalgo G, Fierer N, et al. Delivery mode shapes the acquisition and structure of the initial microbiota across multiple body habitats in newborns. Proc Natl Acad Sci U S A [Internet]. 2010;107(26):11971–5. Available from: http://dx.doi.org/10.1073/pnas.100260110

3. Odamaki T, Kato K, Sugahara H, Hashikura N, Takahashi S, Xiao J-Z, et al. Age-related changes in gut microbiota composition from newborn to centenarian: a cross-sectional study. BMC Microbiol [Internet]. 2016;16(1):90. Available from: http://dx.doi.org/10.1186/s12866-016-0708-5 

4. Franceschi C, Garagnani P, Morsiani C, Conte M, Santoro A, Grignolio A, et al. The continuum of aging and age-related diseases: Common mechanisms but different rates. Front Med (Lausanne) [Internet]. 2018;5:61. Available from: http://dx.doi.org/10.3389/fmed.2018.00061

5. Mancabelli L, Milani C, De Biase R, Bocchio F, Fontana F, Lugli GA, et al. Taxonomic and metabolic development of the human gut microbiome across life stages: a worldwide metagenomic investigation. mSystems [Internet]. 2024;9(4):e0129423. Available from: http://dx.doi.org/10.1128/msystems.01294-23

6. Loh JS, Mak WQ, Tan LKS, Ng CX, Chan HH, Yeow SH, et al. Microbiota-gut-brain axis and its therapeutic applications in neurodegenerative diseases. Signal Transduct Target Ther [Internet]. 2024;9(1):37. Available from: http://dx.doi.org/10.1038/s41392-024-01743-1

7. Chandra S, Sisodia SS, Vassar RJ. The gut microbiome in Alzheimer’s disease: what we know and what remains to be explored. Mol Neurodegener [Internet]. 2023;18(1):9. Available from: http://dx.doi.org/10.1186/s13024-023-00595-7

8. Aziz T, Hussain N, Hameed Z, Lin L. Elucidating the role of diet in maintaining gut health to reduce the risk of obesity, cardiovascular and other age-related inflammatory diseases: recent challenges and future recommendations. Gut Microbes [Internet]. 2024;16(1):2297864. Available from: http://dx.doi.org/10.1080/19490976.2023.2297864 

9. Varghese S, Rao S, Khattak A, Zamir F, Chaari A. Physical exercise and the gut microbiome: A bidirectional relationship influencing health and performance. Nutrients [Internet]. 2024;16(21). Available from: http://dx.doi.org/10.3390/nu16213663