Current Knowledge on Functionality and Potential Therapeutic Uses of Donkey Milk

Abstract

The increase of knowledge on the composition of donkey milk has revealed marked similarities to human milk, which led to a growing number of investigations focused on testing the potential effects of donkey milk in vitro and in vivo. This paper examines the scientific evidence regarding the beneficial effects of donkey milk on human health. Most clinical studies report a tolerability of donkey milk in 82.6–98.5% of infants with cow milk protein allergies. The average protein content of donkey milk is about 18 g/L. Caseins, which are main allergenic components of milk, are less represented compared to cow milk (56% of the total protein in donkey vs. 80% in cow milk). Donkey milk is well accepted by children due to its high concentration of lactose (about 60 g/L). Immunomodulatory properties have been reported in one study in humans and in several animal models. Donkey milk also seems to modulate the intestinal microbiota, enhance antioxidant defense mechanisms and detoxifying enzymes activities, reduce hyperglycemia and normalize dyslipidemia. Donkey milk has lower calorie and fat content compared with other milks used in human nutrition (fat ranges from 0.20% to 1.7%) and a more favourable fatty acid profile, being low in saturated fatty acids (3.02 g/L) and high in alpha-linolenic acid (about 7.25 g/100 g of fat). Until now, the beneficial properties of donkey milk have been mostly related to whey proteins, among which β-lactoglobulin is the most represented (6.06 g/L), followed by α-lactalbumin (about 2 g/L) and lysozyme (1.07 g/L). So far, the health functionality of donkey milk has been tested almost exclusively on animal models. Furthermore, in vitro studies have described inhibitory action against bacteria, viruses, and fungi. From the literature review emerges the need for new randomized clinical trials on humans to provide stronger evidence of the potential beneficial health effects of donkey milk, which could lead to new applications as an adjuvant in the treatment of cardiometabolic diseases, malnutrition, and aging.

Antibacterial activity of donkey’s milk against clinical isolate of Klebsiella pneumoniae

“…Furthermore, other studies have shown that e LF as a minor component in DM can be easily digested by gastric and duodenal juice. Thus, it has been suggested that LF can play its biological role in vivo mainly through its bioactive peptides derived from digestion (Martini et al, 2021). Recent studies also showed that antimicrobial activity of LF was further increased after in vitro simulated gastrointestinal digestion (Martini et al, 2021).…”

“…Thus, it has been suggested that LF can play its biological role in vivo mainly through its bioactive peptides derived from digestion (Martini et al, 2021). Recent studies also showed that antimicrobial activity of LF was further increased after in vitro simulated gastrointestinal digestion (Martini et al, 2021). Similarly, it was suggested that α-lactalbumin possesses bactericidal activity only after its partial digestion by endopeptidases (Vincenzetti et al, 2017).…”

An Integrated Analysis of Lactation-Related miRNA and mRNA Expression Profiles in Donkey Mammary Glands

“…Donkey milk has potential antibacterial and immunoprotective effects that could prove useful for protecting vulnerable newborns or promoting adaptive immunity in infants [ 27 , 28 ]. In this study, we identified several immunoprotection-related genes that were upregulated in the lactating jenny mammary gland but not during the nonlactating period.…”

Mammary gland physiology and farm management of dairy mares and jennies

“…Indeed, the low protein and casein contents of equid milk make these milks suitable for children with cow milk protein allergy (Vincenzetti et al, 2017). Equid milk has nutritional similarities to human milk in terms of protein content and caseins, the most allergenic cow milk components (Martini et al, 2021). Their primary structure is very similar to those of human milk (Cunsolo et al, 2017).…”