Research on donkey milk · Study 20

Donkey milk exosomes & microRNA

An experimental study published in 2026 examined exosomes isolated from donkey milk and their microRNA cargo in a mouse model of chemically induced colitis. The focus was on inflammation, the intestinal barrier, molecular pathways and the gut microbiome.

Crucial distinction: This study used isolated or enriched exosomes from donkey milk. This is not the same as simply drinking a certain amount of donkey milk.
Understanding exosomes View results
DON DONKEY’S® donkey milk
Study 20
Publication Zhong et al.
2026
Model DSS colitis
in mice
Examined Isolated
donkey milk exosomes
Focus microRNA · inflammation
barrier · microbiome

A new line of research

Not just proteins: milk also contains tiny biological transport vesicles.

Exosomes are very small, membrane-enclosed extracellular vesicles. They can transport various molecular components – including proteins, lipids and RNA molecules.

Of particular interest are so-called microRNAs, or miRNAs for short. These small RNA molecules can be involved in regulating gene expression and thus in cellular signalling pathways.

Distinction from lysozyme Lysozyme is a single antimicrobial enzyme. An exosome, by contrast, is a membrane-enclosed transport vesicle with complex molecular cargo. Study 20 therefore examines a biologically different research area from the previous lysozyme studies.

Study logic

From donkey milk to the experimental colitis model

Step 01

Donkey milk

The starting point was donkey milk as a natural source of extracellular vesicles.

Step 02

Exosomes

The vesicles were isolated or enriched from the milk and characterised.

Step 03

DSS colitis

The vesicles were then examined in an experimental colitis mouse model.

Step 04

Analysis

Inflammation, the intestinal barrier, signalling pathways and changes in the gut microbiome were examined.

What does an exosome transport?

A tiny membrane – with molecular cargo.

In simple terms, an exosome can be understood as a very small transport vesicle. Its membrane encloses a complex molecular cargo.

In the study, numerous microRNAs in the donkey milk exosomes were characterised. let-7g and miR-148a were particularly highlighted.

The researchers then examined how these regulatory RNA molecules might be related to inflammation-relevant signalling pathways.

Exosome & target cell · schematic representation Animation
let-7g
miR-148a
RNA
microRNA
SIGNAL
PATHWAY
Schematic biological illustration. It shows the research principle of a vesicle- and microRNA-mediated signalling pathway. It is not a microscope image and not a direct representation of a single observed process.

Understanding exosomes

Vesicles, cargo and regulatory information

EV
01 · Vesicle

Membrane envelope

Exosomes are membrane-enclosed extracellular vesicles. The envelope fundamentally distinguishes them from a single free protein.

miR
02 · RNA cargo

microRNAs

microRNAs are short RNA molecules that can be involved in regulatory processes of gene expression.

→
03 · Regulation

Target molecules

The study examined how selected microRNAs are related to inflammation-relevant molecular signalling pathways.

Mechanistic analysis

Two microRNAs were the particular focus.

The study links let-7g and miR-148a to two different inflammation-relevant signalling axes. These mechanistic investigations go beyond merely observing tissue changes.

microRNA 01

let-7g

let-7g
TLR4
NF-κB
inflammation-relevant signals

The study links let-7g to the regulation of the TLR4/NF-κB pathway, which is involved in inflammatory responses.

microRNA 02

miR-148a

miR-148a
NLRP3
Caspase-1
IL-18 system

miR-148a was associated with the NLRP3/caspase-1/IL-18 system, another inflammation-relevant signalling axis.

Gut barrier

Inflammation and barrier are closely linked.

In the experimental colitis model, the donkey milk exosomes were associated with attenuated inflammatory changes and a better preserved intestinal structure or barrier.

It is important to note: the study shows associations within a controlled mouse model with isolated vesicles. It does not show a corresponding effect from ordinary drinking of donkey milk in humans.

Intestinal barrier · illustration
Schematic representation of an epithelial barrier. The graphic illustrates the field of research and is not a histological image from the study.

Key observations

What the researchers examined in the mouse model

01 · Inflammation

Inflammatory changes

In the experimental DSS colitis model, administration of the isolated donkey milk exosomes was associated with attenuated inflammatory changes.

02 · Intestinal barrier

Preserved intestinal structure

At the same time, findings were described that were consistent with a better preserved intestinal structure or barrier.

03 · microRNA

Regulatory RNA cargo

The vesicles contained numerous microRNAs. The mechanistic investigations focused, among others, on let-7g and miR-148a.

04 · Signalling pathways

Molecular regulation

The study examined specific relationships to TLR4/NF-κB and to the NLRP3/caspase-1/IL-18 system.

05 · Microbiome

Bacterial composition

DSS colitis changed the gut microbiome. After exosome treatment, a changed bacterial composition was also observed.

06 · Causality

More than two molecules

Even mechanistic findings do not mean that let-7g and miR-148a alone explain all observed effects of the complex vesicles.

Gut microbiome

The bacterial composition also changed.

Changes in the gut microbiome were observed in the DSS colitis model. After treatment with donkey milk exosomes, a changed bacterial composition was also seen.

However, the direction of causality must be interpreted with caution. The vesicles could, for example, influence the microbiome indirectly by changing inflammation, the immune response or the intestinal barrier, thereby creating a different microbial environment.

This also distinguishes this research approach from lysozyme: an antimicrobial enzyme and a regulatory vesicle system are biologically different mechanisms.

Microbiome
schematic
illustration

Critical assessment

What Study 20 shows – and what it does not

What was examined

✓ Extracellular vesicles isolated or enriched from donkey milk were examined experimentally.
✓ Inflammation and the intestinal barrier were examined in the DSS colitis mouse model.
✓ The microRNAs let-7g and miR-148a were linked to specific regulatory signalling pathways.
✓ Changes in the gut microbiome were also part of the study.

What was not proven

× No clinical efficacy of donkey milk in humans.
× Isolated exosomes are not the same as ordinary consumption of donkey milk.
× The study does not answer how many intact vesicles actually reach the gut with ordinary consumption.
× It does not show that exosomes and microRNAs are preserved in the same form in the DON DONKEY’S® product after processing.

Research question for DON DONKEY’S®

Do natural vesicles survive freeze-drying?

For DON DONKEY’S®, this raises a clearly testable research question: are natural extracellular vesicles and their RNA cargo detectable in our own fresh milk – and are they preserved after freeze-drying and reconstitution?

Stage 01 · Fresh milk Detect vesicles Isolate extracellular vesicles from a defined batch and characterise their number, size distribution and typical vesicle markers. The RNA cargo could then be examined.
Stage 02 · Powder Compare freeze-drying Freeze-dry the same starting batch, reconstitute the powder and repeat the analysis. What matters is not only whether RNA remains measurable but whether the vesicles remain structurally intact.
Stage 03 · Function Test biologically Only once vesicles and relevant RNA cargo are detectable after processing would a further functional study in a suitable experimental model make sense.
DON DONKEY’S® donkey milk

DON DONKEY’S®

DON DONKEY’S® donkey milk

100 % pure donkey milk

Donkey milk contains a large number of biological structures and components that are the subject of scientific research. With extracellular vesicles and their RNA cargo, Study 20 opens up a particularly young field of research.

Transparency: The DON DONKEY’S® product was not examined in this study. The study worked with isolated or enriched exosomes in a mouse model. Neither a corresponding effect of drinking our donkey milk nor a health effect in humans can be derived from it.
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Original publication

Donkey milk exosomes protect against dextran sulfate sodium-induced colitis by delivering anti-inflammatory miRNAs and reshaping gut microbiota

Zhong Q., Huang G., Liu G., Ren Z., Wang Z.
Journal of Food Science · 2026

DOI: 10.1111/1750-3841.71192

The publication describes experimental preclinical research with extracellular vesicles isolated or enriched from donkey milk in a mouse model. The results do not constitute clinical proof of efficacy for the consumption of donkey milk in humans.