Bioactive natural products in donkey and camel milk: a perspective review

Single-cell RNA sequencing unveils dynamic transcriptional profiles during the process of donkey spermatogenesis and maturation

INTRODUCTION

With the increasing demand for donkey production, there has been a growing focus on the breeding of donkeys. However, our current understanding of the mechanisms underlying spermatogenesis and maturation in donkeys during reproduction remains limited.

OBJECTIVES

This study is to provide a comprehensive single-cell landscape analysis of spermatogenesis and maturation in donkeys.

METHODS

In this study, we employed single-cell RNA sequencing to investigate cell composition, gene expression patterns, and regulatory roles during spermatogenesis and maturation in donkeys.

RESULTS

The expression patterns of CDK1, CETN3, and UBE2J1 were found to be indicative of specific germ cells during donkey spermatogenesis. Additionally, the DEFB121, ELSPBP1, and NPC2 genes were specifically identified in the principal cells of the donkey epididymis.

CONCLUSIONS

We performed single-cell RNA sequencing to analyze the cellular composition and spatial distribution of donkey testis and epididymis, thereby generating comprehensive transcriptional atlases at the single-cell resolution.

Chemical contaminants in donkey milk: A review of literature on sources, routes and pathways of contamination, regulatory framework, health risks, and preventive measures

Donkey milk has garnered increasing attention due to its potential health benefits and nutritional properties, positioning it as a valuable alternative to cow's milk for specific consumer groups, such as individuals with allergies, young children, elderly populations, and those with compromised immune systems. However, the presence of chemical contaminants in donkey milk presents a significant concern for food safety and public health. This review aims to provide an assessment of the types and sources of chemical contaminants in donkey milk, including heavy metals, mycotoxins, pesticides, polychlorinated biphenyls, and antimicrobial and antiparasitic veterinary drugs. Through a comprehensive analysis of available literature, we examine the routes and pathways through which these contaminants enter the milk, their prevalence, and the associated health risks. The review also briefly discusses analytical methods for detecting these contaminants and the existing legislative framework that regulates these contaminants, underscoring its critical role in safeguarding public health and promoting safe consumption of donkey milk products. By identifying gaps in existing research and suggesting areas for further study, this review seeks to contribute to the development of more effective strategies for monitoring and mitigating chemical contamination in donkey milk, ultimately safeguarding consumer health and supporting the sustainable production of this niche dairy product.

Benefits of Camel Milk over Cow and Goat Milk for Infant and Adult Health in Fighting Chronic Diseases: A Review

The nutritional composition, antimicrobial properties, and health benefits of camel milk (CAM), cow milk (COM), and goat milk (GOM) have been extensively studied for their roles in managing diabetes and cardiovascular diseases (CVD). This review compares these milk types' nutritional and therapeutic properties, emphasizing their applications in chronic disease management. CAM is rich in insulin-like proteins, vitamins, minerals, and bioactive compounds that benefit glycemic control and cardiovascular health. It also exhibits potent antioxidants, anti-inflammatory, and lipid-lowering effects, which are crucial for managing diabetes and reducing CVD risk factors. While COM and GOM provide essential nutrients, their impact on metabolic health differs. GOM is known for its digestibility and antihypertensive properties, whereas COM's higher lactose content may be less suitable for diabetic patients. CAM's unique nutritional profile offers distinct therapeutic benefits, particularly for diabetes and CVD management. Further research is needed to clarify its mechanisms of action and optimize its clinical application for chronic disease prevention and management.

Is there sufficient evidence to support the health benefits of including donkey milk in the diet?

Donkey milk has attracted attention due to its distinctive nutritional composition and potential health advantages, particularly because of its whey protein content, which includes lysozyme, α-lactalbumin, lactoferrin, and β-lactoglobulin and vitamin C, among other components. These elements contribute to immunoregulatory, antimicrobial, antioxidant, and anti-inflammatory properties, positioning donkey milk as a possible therapeutic option. In addition, due to the low levels of caseins, the casein-to-whey protein ratio, and the β-lactoglobulin content in donkey milk, it presents an optimal alternative for infant formula for individuals with cow's milk allergies. Moreover, research into donkey milk's potential for cancer prevention, diabetes management, and as a treatment for various diseases is ongoing, thanks to its bioactive peptides and components. Nevertheless, challenges such as its low production yield and the not fully understood mechanisms behind its potential therapeutic role necessitate more thorough investigation. This review consolidates the existing knowledge on the therapeutic possibilities of donkey milk, emphasizing its importance for human health and the need for more detailed studies to confirm its health benefits.

Is it possible to obtain substitutes for human milk oligosaccharides from bovine milk, goat milk, or other mammal milks?

Considering the current level of chemical and biological synthesis technology, it was a sensible selection to obtain milk oligosaccharides (MOs) from other mammals as the potential substitute for human MOs (HMOs) that possessed various structural features in the infant formula. Through a comprehensive analysis of the content, structure, and function of MOs in six distinct varieties of mammal milk, it has been shown that goat milk was the most suitable material for the preparation as a human milk substitute. Goat MOs (GMOs) had a relatively high content and diverse structural features compared to those found in other mammalian milks. The concentration of GMOs in colostrum ranged from 60 to 350 mg/L, whereas in mature milk, it ranged from 200 to 24,00 mg/L. The acidic oligosaccharides in goat milk have attracted considerable attention due to their closeness in acidic content and structural diversity with HMOs. Simultaneously, it was discovered that some structures, like N-glycolylneuraminic acid, were found to have a certain content in GMOs and served essential functional properties. Moreover, studies focused on the extraction of MOs from goat milk indicated that the production of GMOs on an industrial scale was viable. Furthermore, it is imperative to do further study on GMOs to enhance the preparation process, discover of new MOs structures and bioactivity evaluation, which will contribute to the development of both the commercial production of MOs and the goat milk industry.

Invited review: Camel milk and gut health-Understanding digestibility and the effect on gut microbiota

Camel milk (CM), known for its immune-regulatory, anti-inflammatory, antiapoptotic, and antidiabetic properties, is a natural healthy food. It is easily digestible due to the high levels of β-casein and diverse secreted antibodies, exhibiting superior antibacterial and antiviral activities compared with bovine milk. β-casein is less allergic and more digestible because it is more susceptible to digestive hydrolysis in the gut; therefore, higher levels of β-casein make CM advantageous for human health. Furthermore, antibodies help the digestive system by destroying the antigens, which are then overwhelmed and digested by macrophages. The connection between the gut microbiota and human health has gained substantial research attention, as it offers potential benefits and supports disease treatment. The gut microbiota has a vital role in regulating the host's health because it helps in several biological functions, such as protection against pathogens, immune function regulation, energy harvesting from digested foods, and reinforcement of digestive tract biochemical barriers. These functions could be affected by the changes in the gut microbiota profile, and gut microbiota differences are associated with several diseases, such as inflammatory bowel disease, colon cancer, irritable bowel disorder, mental illness, allergy, and obesity. This review focuses on the digestibility of CM components, particularly protein and fat, and their influence on gut microbiota modulation. Notably, the hypoallergenic properties and small fat globules of CM contribute to its enhanced digestibility. Considering the rapid digestion of its proteins under conditions simulating infant gastrointestinal digestion, CM exhibits promise as a potential alternative for infant formula preparation due to the high β-/αs-casein ratio and protective proteins, in addition to the absence of β-lactoglobulin.

Donkey Colostrum and Milk: How Dietary Probiotics Can Affect Metabolomic Profile, Alkaline Sphingomyelinase and Alkaline Phosphatase Activity

Positive results on animal health, feed efficiency, and milk's nutritional content have been obtained after oral administration of probiotics. The aim of the present study was therefore to evaluate the effect of dietary supplementation with high numbers of multispecies probiotic formulations on the milk metabolomic profiles of alkaline sphingomyelinase (alk-SMase) and alkaline phosphatase (ALP) in donkeys. Twenty animals were randomly allocated to receive either a normal diet (group B) or a supplemented diet (group A). Colostrum and milk samples were obtained within 48 h, at 15 days (supplementation start), and at 45 days after parturition. Different metabolomic profiles were observed between colostrum and milk, as were the concentrations of 12 metabolites that changed following 30 days of probiotic supplementation. Alk-SMase activity was found to be higher in donkey colostrum (vs. milk at 15 days); this enzyme, together with ALP, increased in milk after 30 days of probiotic supplementation. The results of the present study provide new insight into the complex changes in donkey colostrum and milk composition in the first 45 days of lactation and how the milk metabolome can be modulated by probiotic supplementation.