Why fermentation increases bioavailability

In modern natural cosmetics, one topic is becoming increasingly important: bioavailability. After all, it is not just the content of valuable ingredients that determines the effectiveness of a formulation - the decisive factor is how well the skin can absorb and utilize these substances.

This is where fermentation comes in. Numerous studies show that microbial processes convert complex plant substances into smaller, more easily bioavailable molecules. In mallow(Malva sylvestris), for example, a threefold increase in phenol content and significantly higher antioxidant activity was measured after lactic acid fermentation (Wiktor et al., 2025). Researchers have reported similar effects in fermented New Zealand spinach(Tetragonia tetragonioides), where both phenol and flavonoid content increased significantly (Jung et al., 2025).

Fermentation also led to a measurable increase in antioxidant capacity in quinoa and amaranth (Arriola et al., 2024). And in the case of peppermint(Mentha arvensis), it was shown that fermentation not only increases the amount of bioactive metabolites, but also enhances their anti-inflammatory effect (Kim et al., 2023).

These findings are impressive proof that fermentation is not just a traditional process, but an innovative tool for making plant substances more effective for cosmetic applications - and thus setting new standards in terms of effectiveness and naturalness.

Sources:

• Arriola, N.D.A.; Chavira, G.; Velázquez, J. & Paredes-López, O. (2024): Effect of germination and fermentation on the phenolic compounds and antioxidant activity of quinoa and amaranth seeds. International Journal of Molecular Sciences, 25(20), 10972. DOI: https://doi.org/10.3390/ijms252010972
• Calhelha, R.C.; Abreu, R.M.V.; Pinela, J.; Prieto, M.A.; Pereira, C.; Barreiro, M.F. et al. (2022): Fermentation as a tool for bioavailability enhancement of plant-based compounds in cosmetics. Fermentation, 8(5), 463. DOI: https://doi.org/10.3390/fermentation8050463
• Jung, E.J.; Jang, J.H.; Choi, J.H. & Lee, H.Y. (2025): Fermentation of Tetragonia tetragonioides enhances antioxidant activity and bioactive compound content. Fermentation, 11(1), 25. DOI: https://doi.org/10.3390/fermentation11010025
• Kim, H.J.; Takahashi, H. & Fukuda, S. (2023): Biotransformation of phenolic acids by Lactobacillus plantarum enhances antioxidant and anti-inflammatory activity in Mentha arvensis. Probiotics and Antimicrobial Proteins, 15, 10103. DOI: https://doi.org/10.1007/s12602-023-10103-4
• Wiktor, A. et al. (2025): Lactic acid fermentation of Malva sylvestris extracts increases phenolic content and antioxidant capacity. Food Production, Processing and Nutrition, 7(1), 315. DOI: https://doi.org/10.1186/s43014-025-00315-2