skin ageing: why gut health comes before collagen.

Skin Ageing: Why Gut Health Comes Before Collagen

Collagen is everywhere right now, especially if you’re into skincare. And there’s a good reason for it. But what often gets overlooked is how much your gut health plays a part in how collagen works in your body, and how your gut might even influence how much of it you produce.

Collagen vs. Collagen Peptides: What’s the Difference?

Collagen is the most abundant protein in your body. It forms the structure for your skin, bones, muscles and gut lining. You can think of it like scaffolding that holds everything together. As we age, our natural collagen levels begin to decline, and things like stress, sun exposure, and diet can speed that process up. When people talk about taking collagen for skin or gut health, they’re often referring to collagen peptides. But what exactly does that mean, and how does it differ from regular collagen?

• Collagen is the protein that naturally occurs in your body, providing structural support to your skin, bones, muscles, and gut lining. It's a large, complex molecule that is difficult for the body to absorb in its whole form.
  
  

• Collagen peptides, on the other hand, are collagen that has been broken down into smaller, more digestible pieces. This process called hydrolysis makes it much easier for the body to absorb and use. These smaller molecules are absorbed quickly and efficiently, which is why collagen peptides are commonly found in supplements. 

Collagen and Ageing: What Happens to Skin Over Time

As we get older, our skin naturally changes - it gets dehydrated, loses its elasticity, and fine lines or wrinkles start to appear. A big reason for that is collagen as it makes up about 80% of the dry weight of your skin and keeps it firm and smooth. But as we age, our body slows down its collagen production. The cells that make it (called fibroblasts) become fewer, and the blood supply to the skin can also decline which means less support for your skin. You can get collagen from food (like bone broth or oily fish) but people tend to take collagen in supplement form as it’s easier but that’s only part of the story.

Gut First: Why Digestion Matters

If you’re focusing on getting more collagen in your body, either through diet or supplements, your body needs to be able to absorb and use it. That means supporting digestion and the gut lining is essential. When your gut is functioning well, you’re more likely to absorb the amino acids, vitamins and minerals that help your body build its own collagen.

But if your gut lining is compromised - a condition sometimes called “leaky gut”- nutrient absorption may be reduced. That could mean you’re not getting the full benefit of collagen, or the ingredients that help you make more of it naturally like vitamin C or zinc.

Can Collagen Help Your Gut?

Yes, and it goes both ways. While your gut helps you absorb and use collagen, some early studies suggest that collagen peptides might also support gut health. In particular, they may help with:

• Supporting gut lining integrity which means helping to keep the barrier strong and resilient

• Reducing digestive discomfort such as occasional bloating or changes in bowel habits

• Encouraging microbial diversity which means a healthy mix of gut bacteria, which supports both digestion and immunity
  
  

That said, collagen isn’t a magic fix - your gut still needs fibre, hydration, and a balanced diet to function its best.

Conclusion

Collagen may be trending, but your gut is the true foundation for skin health by supporting nutrient absorption. By looking after your gut microbiome, you give your body the best chance to make and use collagen where it matters, whether that’s for plump, glowing skin or better digestive comfort. As always, it starts from within and your gut is a good place to begin.

References

Larder, C. E., Iskandar, M. M., & Kubow, S. (2021). Gastrointestinal digestion model assessment of peptide diversity and microbial fermentation products of collagen hydrolysates. Nutrients, 13(8), 2720. https://doi.org/10.3390/nu13082720

Pu, S.-Y., Huang, Y.-L., Pu, C.-M., Kang, Y.-N., Hoang, K. D., Chen, K.-H., Chen, C. (2023). Effects of oral collagen for skin anti-aging: A systematic review and meta-analysis. Nutrients, 15(9), 2080. https://doi.org/10.3390/nu15092080

Ren, B., Yue, K., Zhang, Y., & Fu, Y. (2024). Collagen-derived peptides as prebiotics to improve gut health. Current Opinion in Food Science, 55, 101123. https://doi.org/10.1016/j.cofs.2024.101123
Zhang, H., Yao, Z., Song, Y., Hua, Q., Geng, X., Zhou, F., Li, Q., Li, Z., Luo, Z., Sun, J., Qi, C., & Li, D. (2025). Collagen peptides promote skin collagen synthesis by modulating the gut microbiota and activating the TGF-β pathway. Food & Function, Issue 13.