The Monogastric Secret: Why Donkey Biology Sets a New Standard for Skincare

When we discuss the benefits of milk in skincare, we often treat all sources—cow, goat, sheep, and donkey—as if they are on a level playing field. However, from a biological standpoint, this is a profound misconception. The true secret to the superior efficacy of donkey milk lies not just in its ingredients, but in the animal’s digestive architecture.

Donkeys are monogastric animals, possessing a single-chambered stomach, much like humans. This fundamental biological trait creates a "purity filter" that sets donkey milk apart from the milk of ruminants like cows or goats.

1. The Ruminant Filter vs. The Monogastric Direct Path

Ruminants (cows, goats, and sheep) have complex, four-chambered stomachs designed for intense microbial fermentation. While this is efficient for digesting grass, the rumen is a harsh environment filled with enzymes and microbes that can modify or degrade delicate bioactive molecules before they are ever secreted into the milk.

In contrast, the monogastric system of the donkey allows for a more direct and gentle enzymatic digestion. This means that sensitive regulatory molecules—most notably miRNAs and bioactive peptides—are preserved in their original, potent state as they move through the system and into the mammary glands.

2. The 7.74% Benchmark: A Masterpiece of miRNA Preservation

The biological advantage of being monogastric is most clearly visible in the milk's molecular profile. A groundbreaking 2024 study comparing four livestock species revealed a startling disparity in the concentration of microRNAs (miRNAs):

• Donkey Milk: miRNAs account for 7.74% of the total annotated RNA.
• Goat Milk: Only 1.57%.
• Sheep Milk: Only 1.12%.
• Buffalo Milk: Only 0.87%.

This massive concentration of miRNAs in donkey milk is a direct result of the donkey’s streamlined biological processing. These miRNAs act as the "instructional software" for the skin, regulating gene expression to repair the barrier and modulate immune responses. When sourcing donkey milk, retailers are acquiring a high-fidelity biological message that hasn't been altered by a ruminant’s fermentation process.

3. Bioactive Integrity: Why "Pure" Matters for 2026

As we look toward the future of skincare, "bioactive integrity" is becoming the gold standard. A monogastric origin ensures that milk proteins, such as lysozyme and lactoferrin, maintain a higher degree of their native structure.

This similarity to human milk—both in digestive origin and molecular composition—explains why donkey milk is so uniquely biocompatible. It does not simply sit on the surface; it speaks the same biological language as human skin, facilitating deeper cellular communication and more effective results.

References & DOI

Topic: miRNA Abundance and Species Comparison

• Cendron, F., et al. (2024). Analysis of miRNAs in milk of four livestock species. BMC Genomics, 25:859. DOI: 10.1186/s12864-024-10783-4

Topic: Nutritional Composition and Biological Integrity

• Xu, Q., et al. (2025). Nutritional Composition and Biological Activities of Donkey Milk: A Narrative Review. Foods, 14(13), 2337. DOI: 10.3390/foods14132337

Topic: Bioactive Components and Functionality

• Naydenova, N. (2022). Bioactive components of donkey milk. Food Science and Applied Biotechnology, 5(2), 219-231. DOI: 10.30721/fsab2022.v5.i2.189