Gut Check: Why Your Microbiome Matters as You Age

Guest blog by Inaya Karmali, Undergraduate Student University of Toronto 

Inside your gut lives a busy community of tiny organisms that do much more than help you digest food. These microbes play a big role in keeping your immune system strong, managing inflammation, and even supporting healthy aging. New research suggests that having a mix of gut microorganisms, also known as a diverse gut microbiome, is linked to improved overall health and a longer lifespan. The catch? As we go through life, that diversity can shrink, often without us even realizing it. So, what exactly is the gut microbiome? How does it change over time, and what can you do to keep it thriving? 

To help explore the gut microbiome and its role in healthy aging, this blog draws on an interview with Dr. Haley Zubyk, who holds a PhD in Biochemistry and Biomedical Sciences from McMaster University, where she focused on antibiotic discovery and antibiotic resistance. Her insights helped shape the discussion below, highlighting why gut diversity matters, how it changes over time, and what can be done to support a healthy microbial balance. 

How the Gut Changes with Age 

With age, noticeable shifts occur in the gut microbiome. One of the most significant changes is a decline in the variety of beneficial bacteria.¹ These helpful microbes are responsible for producing substances that strengthen the gut lining, reduce inflammation, and support immune function.² As their numbers fall, they are replaced by less beneficial bacteria, leading to an overall decline in microbial balance.¹ 

According to Dr. Zubyk, several aging-related factors drive this change. A natural slowdown in digestion and immunity creates a more favourable environment for harmful microbes. Simultaneously, lifestyle changes such as reduced fibre intake, decreased physical activity, and changes in eating patterns all make it harder for beneficial bacteria to thrive.¹ She also emphasized the impact of medication. Older adults typically take more drugs, including antibiotics, which can harm beneficial microbes and contribute to an imbalanced microbiome. ³

A residential setting also plays a role. Differences have been observed in the gut microbiomes of older adults living in community homes compared to those in long-term care facilities.⁴ Factors, such as diet, physical mobility, and environmental exposure all influence the types of microbes present. Disruptions to the gut lining, reduced food movement throughout the digestive tract, and the rise of harmful bacterial species, known as dysbiosis¹³, can result from these combined effects. 

Why Does Gut Diversity Matter? 

A diverse microbiome offers broad protective effects across many systems in the body. The metabolites produced by different microbes contribute to functions that are anti-inflammatory, anti-cancer, anti-infective, and even protective against metabolic diseases.⁵⁻⁶ This web of microbial activity touches many parts of the body, and in the words of Dr. Zubyk, plays a fundamental role in maintaining overall health. 

One striking example comes from the study of centenarians, individuals who live to be at least 100-years-old. Their gut microbiomes tend to have a unique signature incredibly similar to those of younger adults, marked by high diversity and the presence of bacteria associated with better immune regulation and lower inflammation.⁵⁻⁶ These findings suggest that maintaining microbial richness may be one reason some people age more gracefully and stay healthier for longer. 

Diet Tips for Supporting Your Gut Health 

Dr. Zubyk explained how different eating patterns can influence the health of the gut microbiome, particularly in older adults. Diets rich in fibre tend to support beneficial gut bacteria, which can produce molecules linked to lower levels of inflammation.⁷ She noted that prebiotic foods, such as bananas, oats, leeks, and barley, serve as fuel for these microbes. Unlike probiotics, which add new bacteria, prebiotics help nourish the ones already present.⁸ Diets high in fat and processed foods, on the other hand, have been linked to reduced microbial diversity and an imbalanced gut environment. 

Common Misconceptions 

It is important to note that there is no such thing as a “perfect” universal gut microbiome.⁹ As Dr. Zubyk states, everybody’s microbiome is different and is influenced by a variety of factors, including their genetics, living environment, nationality, ethnicity, social behaviour, and more. Your gut microorganisms are a unique representation of who you are, and you should be skeptical of any “quick-fix” diets that claim to transition your gut microbiome into perfection. There is no perfect proportion or list of microbes that determines whether you are healthy or unhealthy. The critical aspect is the overall trends in your food intake, your mobility, and your social behaviour to ensure overall microbial richness. 

Final Takeaways 

According to Dr. Zubyk, as we grow older, the balance and diversity of our gut microbiome naturally decline, which can affect everything from immune strength to inflammation and overall vitality. A diverse microbiome is linked to healthier aging, better resilience to illness, and improved well-being. Fortunately, we can support this inner ecosystem by making simple lifestyle changes, like eating more fiber and prebiotic-rich foods, staying physically active, and being mindful of medications that may disrupt gut health. Dr Zubyk also indicated that while there’s no universal “perfect” microbiome, research shows that maintaining microbial richness is one of the keys to aging well. 

Just like your gut microbiome inside of you, it’s important to have a well-rounded retirement plan and experience. These are the kinds of connections we explore at our seminars, where health, lifestyle, and financial planning come together. You’ll also get a chance to meet Dave, Faisal, and the rest of our team. Register today at morethanmoneyradio.com/seminar-registration

The author is not a medical professional. The above content was accumulated through various sources and is intended for informational purposes only and should not be interpreted as medical recommendations. Readers should consult a physician or their family doctor for professional health and medical advice.

David Popowich and Faisal Karmali are Investment Advisors with CIBC Wood Gundy in Calgary. 

The views of David Popowich, Faisal Karmali, and guest author and referenced material do not necessarily reflect those of CIBC World Markets Inc.

This information, including any opinion, is based on various sources believed to be reliable, but its accuracy cannot be guaranteed and is subject to change.

CIBC Private Wealth consists of services provided by CIBC and certain of its subsidiaries, including CIBC Wood Gundy, a division of CIBC World Markets Inc. 

References 

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6. Zhang D, Jian YP, Zhang YN, et al. Short-chain fatty acids in diseases. Cell Commun Signal. 2023;21:212. doi:10.1186/s12964-023-01219-9https://pubmed.ncbi.nlm.nih.gov/37596634/

7. Kuo SM. The interplay between fiber and the intestinal microbiome in the inflammatory response. Adv Nutr. 2013;4(1):16-28. doi:10.3945/an.112.003046https://pubmed.ncbi.nlm.nih.gov/23319119/

8. Mayo Clinic Staff. Probiotics: What You Need to Know. Mayo Clinic. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/probiotics/faq-20058065 

9. Falony G, Joossens M, Vieira-Silva S, et al. Population-level analysis of gut microbiome variation. Science. 2016. doi:10.1126/science.aad3503https://pubmed.ncbi.nlm.nih.gov/27126039/

10. Uniray Vet. RAYMIN FORTE POWDER | Veterinary Feed Supplements for Improving Fertility & Milk Production. https://www.unirayvet.com/product/raymin-forte-powder

11. Expert Roundtable: getting a gene therapy product to market: pitfalls and how to prevent them. Cell & Gene Therapy Insights. https://www.insights.bio/cell-and-gene-therapy-insights/journal/article/1753/Expert-Roundtable-getting-a-gene-therapy-product-to-market-pitfalls-and-how-to-prevent-them

12. EBOOST Blog. The Protein Puzzle: How Your Choices Impact Your Gut's Happy Dance. https://blog.eboost.com/2023/12/the-protein-puzzle/

13. Dysbiosis. https://my.clevelandclinic.org/health/diseases/dysbiosis