Student essay 

How a Plant-Based Diet Modulates the Gut Microbiome and Skin Ageing

Oct 27 / Anjalia Tiscia

The Gut Microbiome: Your Inner Ecosystem and Its Impact on Ageing

The gut microbiome refers to a dynamic population of microorganisms which exert a marked influence on the health and wellbeing of the host (Thursby & Juge 2017). When the composition of microorganisms is out of balance, this is referred to as dysbiosis.

Gut dysbiosis is a significant pathophysiology that contributes to overall cellular ageing and is implicated in a number of human diseases, including neurodegenerative, cardiovascular, metabolic and gastrointestinal diseases (Chen et al. 2021).

What Influences the Gut Microbiome?

Many factors significantly impact the microbiome composition, either promoting or preventing gut dysbiosis, and thus, by extension, cellular ageing.

One of the primary factors is diet (Vijay & Valdes 2022).

The Western Diet and Gut Dysbiosis

A Western-style diet high in animal protein, saturated fats and refined carbohydrates is associated with gut dysbiosis (Singh et al. 2017).

This dietary pattern causes an increase in opportunistic microorganisms that trigger inflammation, a key factor in cellular ageing. Moreover, these pathogenic microorganisms that arise from high intakes of dairy, eggs and meat cause an increase in the compound Trimethylamine N-Oxide (TMAO), which is a powerful pro-inflammatory and pro-atherogenic agent.

This same dietary pattern also elevates the inflammatory marker C-reactive protein (Singh et al. 2017).

The Power of Plant-Based Eating

Conversely, a dietary pattern centred upon plants with high quantities of 'microbiota accessible carbohydrates' (MACs), such as oligosaccharides, resistant starches and pectins, promotes a healthy microbiome and thus downregulates this dysbiosis-ageing pathway (Singh et al. 2017).

When beneficial gut microorganisms ferment these MACs, they produce Short-Chain Fatty Acids (SCFAs), like butyrate and propionate, as a by-product.

SCFAs are a major energy source for intestinal epithelial cells and strengthen the mucosal barrier (Singh et al. 2017). These SCFAs also reduce inflammation and cellular ageing (Vijay & Valdes 2022).

Gut Health and Skin Ageing

Beneficial metabolites produced by gut microorganisms can protect against soft tissue changes and signs of ageing, like decreased collagen production, epidermal thinning and loss of subcutaneous fat. These changes often lead to fine lines, wrinkles and skin dryness.

This occurs, for example, through the downregulation of Matrix Metalloproteinases (MMPs) (Ratanapokasatit et al. 2022).

The skin itself has its own population of microorganisms that help maintain skin barrier integrity when balanced, providing protection against conditions such as eczema, psoriasis and rosacea.

Polyphenols: Plant Power Meets Microbiome Health

Adopting a plant-based diet rich in fruits and vegetables also increases other beneficial plant components besides MACs, such as polyphenols (including anthocyanins, quercetin and catechins).

A reciprocal relationship exists between these polyphenols and the gut microbiome: beneficial microorganisms increase the bioavailability of polyphenols, and these polyphenols in turn reduce pro-inflammatory markers like C-reactive protein and plasma triacylglycerol.

The Takeaway

Through the presence of microbiota accessible carbohydrates and various polyphenols, a plant-based diet rich in fruits and vegetables helps to promote a healthy gut microbiome and mitigate gut dysbiosis.

In doing so, it causes a marked decrease in inflammation, toxin production and premature cellular ageing.

REFERENCES

  1. Chen, Y, Zhou, J & Wang, L 2021, ‘Role and mechanism of gut microbiota in human disease’, Frontiers in Cellular and Infection Microbiology, vol. 11, pp. 1–12.
  2. Ratanapokasatit, Y, Laisuan, W, Rattananukrom, T, Petchlorlian, A, Thaipisuttikul, I & Sompornrattanaphan, M 2022, ‘How microbiomes affect skin aging: the updated evidence and current perspectives’, Life (Basel), vol. 12, pp. 936–953.
  3. Singh, R. K, Chang, H. W, Yan, D, Lee K. M, Ucmak, D, Wong, K, et al. 2017, ‘Influence of diet on the gut microbiome and implications for human health’, Journal of Translational Medicine, vol. 15, pp. 73.
  4. Thursby, E & Juge, N 2017, ‘Introduction to the human gut microbiota’, Biochemical Journal, vol. 474, pp. 1823–1836.
  5. Vijay, A & Valdes A. M 2022, ‘Role of the gut microbiome in chronic diseases: a narrative review’, European Journal of Clinical Nutrition, vol. 76, pp. 489–501.
I am an Accredited Practising Dietitian with over five years of clinical experience, specialising in gut health and skin-related conditions. My background includes extensive work with individuals managing Irritable Bowel Syndrome (IBS), Coeliac Disease, and a wide range of food intolerances. I am passionate about helping clients restore their gut health through personalised, evidence-based nutrition strategies that support long-term wellbeing. Expanding on my clinical expertise, I have completed a Diploma in Integrative Nutridermatology, allowing me to specialise further in the management of skin conditions from a dietary perspective. I work closely with individuals experiencing acne, eczema, psoriasis, rosacea, and other inflammatory skin concerns, recognising the critical link between gut health, nutrition, and skin integrity. My approach combines the latest scientific research with practical, personalised care.
Anjalia Tiscia | SKIN NUTRITION INSTITUTE GRADUATE

Frequently Asked Questions

What is the gut microbiome?

The gut microbiome refers to the community of microorganisms living in your digestive tract, including bacteria, fungi and viruses. These microbes play essential roles in digestion, immunity, mood regulation and ageing.

What is gut dysbiosis?

Gut dysbiosis occurs when the balance of “good” and “bad” bacteria in your gut is disrupted. This imbalance can lead to inflammation, poor digestion, skin issues, and faster cellular ageing.

How does gut health affect ageing?

An unhealthy gut can trigger chronic inflammation, one of the main drivers of cellular and skin ageing. Over time, inflammation damages tissues, reduces collagen production and contributes to wrinkles, dryness and fatigue.

What foods cause gut dysbiosis?

A Western-style diet high in red meat, processed foods, saturated fats and refined carbohydrates promotes gut dysbiosis. These foods can increase inflammatory compounds like TMAO and C-reactive protein, accelerating ageing.
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