A Sweeter Pill to Swallow: A Review of Honey Bees and Honey as a Source of Probiotic and Prebiotic Products

Rosaceae Honey: Antimicrobial Activity and Prebiotic Properties

Background: Flowering members of the globally diffused Rosaceae family include popular plants, such as apple, almond, and cherry, which play a fundamental role as honeybee nectariferous and polleniferous agents. Through the production of honey, these plants can also play an indirect role in the prevention and treatment of many diseases, including infections, fighting the occurrence of resistant microorganisms, and concurrently stimulating the growth of beneficial bacteria. Objectives: This study focused on the effect of some Rosaceae plants' honey, including hawthorn, cherry, raspberry, almond, and apple, against the pathogens Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Pseudomonas aeruginosa, and Staphylococcus aureus. Results: Results demonstrated the honey's ability to impair swimming motility. A crystal violet test indicated that honey could inhibit the formation and stabilization of biofilms, with inhibition rates up to 59.43% for immature biofilms (showed by apple honey against A. baumannii) and 39.95% for sessile bacterial cells in mature biofilms (when we used cherry honey against S. aureus). In the test with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cherry and apple honey were the most effective in inhibiting sessile cell metabolism honey in both immature (56.47% cherry honey vs. K. pneumoniae) and mature biofilms (54.36% apple honey vs. A. baumannii). Honey stimulated the growth of Lactobacillus bulgaricus, Lacticaseibacillus casei Shirota, Lactobacillus gasseri, Lacticaseibacillus plantarum, and Lacticaseibacillus rhamnosus; hawthorn, raspberry, and almond honey significantly increased the in vitro adhesion capacity of L. bulgaricus and L. casei Shirota. Tests with probiotic supernatants demonstrated honey's ability to inhibit the biofilm formation and metabolism of the pathogens. Conclusions: Our results encourage further studies to assess the potential application of Rosaceae honey for food preservation and in the health field, as it could fight the antimicrobial resistance of food and clinical pathogens, and potentially enhance the host's gut wellness. The use of honey for nanotechnological and biotechnological approaches could be suggested too.

Influence of Honey Varieties, Fermentation Techniques, and Production Process on Sensory Properties and Odor-Active Compounds in Meads

This study investigates the impact of key factors on the formation of odorants and sensory properties in mead. The effects of the honey type (acacia, buckwheat, linden), wort heating, and the fermentation method (commercial Saccharomyces cerevisiae yeasts, spontaneous fermentation, Galactomyces geotrichum molds) were examined. Twelve model mead batches were produced, matured for 12 months, and analyzed using gas chromatography-olfactometry (GC-O) and headspace SPME-GC/MS to identify odor-active compounds. Results confirmed that the honey type plays a significant role in sensory profiles, with distinct aroma clusters for buckwheat, acacia, and linden honey. Compounds like phenylacetic acid, 2- and 3-methylbutanal, and butanoic acid were identified as the most important odorants, correlating with sensory attributes such as honey-like, malty, and fermented aromas. Univariate and multivariate analyses, followed by correlation analysis, highlighted how production parameters affect mead aroma, providing insights to optimize sensory quality.

Honey microbiota, methods for determining the microbiological composition and the antimicrobial effect of honey - A review

Honey is a natural product used since ancient times due to its taste, aroma, and therapeutic properties (antibacterial, antiviral, anti-inflammatory, and antioxidant activity). The purpose of this review is to present the species of microorganisms that can survive in honey and the effect they can have on bees and consumers. The techniques for identifying the microorganisms present in honey are also described in this study. Honey contains bacteria, yeasts, molds, and viruses, and some of them may present beneficial properties for humans. The antimicrobial effect of honey is due to its acidity and high viscosity, high sugar concentration, low water content, the presence of hydrogen peroxide and non-peroxidase components, particularly methylglyoxal (MGO), phenolic acids, flavonoids, proteins, peptides, and non-peroxidase glycopeptides. Honey has antibacterial action (it has effectiveness against bacteria, e.g. Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Acinetobacter, etc.), antifungal (effectiveness against Candida spp., Aspergillus spp., Fusarium spp., Rhizopus spp., and Penicillium spp.), antiviral (effectiveness against SARS-CoV-2, Herpes simplex virus type 1, Influenza virus A and B, Varicella zoster virus), and antiparasitic action (effectiveness against Plasmodium berghei, Giardia and Trichomonas, Toxoplasma gondii) demonstrated by numerous studies that are comprised and discussed in this review.

Development of a zebrafish model for toxicity evaluation of adulterated Apis mellifera honey

Since ancient times, honey has been used for medical purposes and the treatment of various disorders. As a high-quality food product, the honey industry is prone to fraud and adulteration. Moreover, limited experimental studies have investigated the impact of adulterated honey consumption using zebrafish as the animal model. The aims of this study were: (1) to calculate the lethal concentration (LC50) of acid-adulterated Apis mellifera honey on embryos, (2) to investigate the effect of pure and acid-adulterated A. mellifera honey on hatching rate (%) and heart rate of zebrafish (embryos and larvae), (3) to elucidate toxicology of selected adulterated honey based on lethal dose (LD50) using adult zebrafish and (4) to screen the metabolites profile of adulterated honey from blood serum of adult zebrafish. The result indicated the LC50 of 31.10 ± 1.63 (mg/ml) for pure A. mellifera honey, while acetic acid demonstrates the lowest LC50 (4.98 ± 0.06 mg/ml) among acid adulterants with the highest mortality rate at 96 hpf. The treatment of zebrafish embryos with adulterated A. mellifera honey significantly (p ≤ 0.05) increased the hatching rate (%) and decreased the heartbeat rate. Acute, prolong-acute, and sub-acute toxicology tests on adult zebrafish were conducted at a concentration of 7% w/w of acid adulterants. Furthermore, the blood serum metabolite profile of adulterated-honey-treated zebrafish was screened by LC-MS/MS analysis and three endogenous metabolites have been revealed: (1) Xanthotoxol or 8-Hydroxypsoralen, (2) 16-Oxoandrostenediol, and (3) 3,5-Dicaffeoyl-4-succinoylquinic acid. These results prove that employed honey adulterants cause mortality that contributes to higher toxicity. Moreover, this study introduces the zebrafish toxicity test as a new promising standard technique for the potential toxicity assessment of acid-adulterated honey in this study and hazardous food adulterants for future studies.

Chemical Characterization and Biological Properties of Leguminous Honey

Honey can beneficially act against different human diseases, helping our body to improve its health. The aim of the present study was first to increase knowledge of some biochemical characteristics (amount and composition of polyphenols and volatile organic compounds, vitamin C content) of five Italian legume honeys (alfalfa, astragalus, carob, indigo, and sainfoin). Furthermore, we evaluated their potential health properties by studying their antioxidant and in vitro anti-inflammatory activities and in vitro inhibitory effects on three enzymes involved in neurodegenerative diseases (acetylcholinesterase, butyrylcholinesterase, and tyrosinase). Alfalfa honey showed the highest total polyphenol content (TPC) (408 μg g-1 of product). Indigo honey showed the lowest TPC (110 μg g-1 of product). The antioxidant activity was noteworthy, especially in the case of sainfoin honey (IC50 = 6.08 mg), which also exhibited excellent inhibitory action against butyrylcholinesterase (74%). Finally, the correlation between the biochemical and functional results allowed us to identify classes of molecules, or even single molecules, present in these five honeys, which are capable of influencing the properties indicated above.

Medical-Grade Honey as a Potential New Therapy for Bacterial Vaginosis

The prevalence of bacterial vaginosis (BV) among women of reproductive age is 29%. BV arises from a vaginal imbalance marked by reduced levels of lactic acid-producing lactobacilli and an overgrowth of pathogenic anaerobes. The multifactorial nature of BV's pathogenesis complicates its treatment. Current antibiotic therapy exhibits a recurrence rate of about 60% within a year. Recurrence can be caused by antibiotic treatment failure (e.g., due to antimicrobial resistance), the persistence of residual infections (e.g., due to biofilm formation), and re-infection. Because of the high recurrence rates, alternative therapies are required. Medical-grade honey (MGH), known for its antimicrobial and wound healing properties in wound care, emerges as a potential novel therapy for BV. MGH exerts broad-spectrum antimicrobial activity, employing multiple mechanisms to eliminate the risk of resistance. For example, the low pH of MGH and the production of hydrogen peroxide benefit the microbiota and helps restore the natural vaginal balance. This is supported by in vitro studies demonstrating that MGH has an antibacterial effect on several pathogenic bacteria involved in the pathophysiology of BV, while lactobacilli and the vaginal microenvironment can be positively affected. In contrast to antibiotics, MGH exerts anti-biofilm activity, affects the microbiome as pre- and probiotic, and modulates the vaginal microenvironment through its anti-inflammatory, anti-oxidative, physicochemical, and immunomodulatory properties. More clinical research is required to confirm the positive effect of MGH on BV and to investigate the long-term cure rate.

Oxymel: A systematic review of preclinical and clinical studies

Background

Oxymel is a functional beverage with a rich historical background of use in multiple societies. Various simple and compound oxymels are prescribed in certain complementary and traditional medical systems, including traditional Persian Medicine. In recent years, numerous clinical and preclinical studies have been conducted in the pharmacy and food industry to investigate the efficacy of various oxymel formulations. This article aims to systematically review and summarize interventional studies on oxymel in both clinical research and animal models.

Methods

Relevant articles were searched in Embase, MEDLINE, Web of Science Core Collection, Scopus, and Google Scholar from inception to July 2023 using the keyword "Oxymel" and its equivalents in other languages. Animal and human interventional studies were selected from the search results for review.

Results

This review includes twenty studies, comprising twelve clinical trials, two case studies, and six animal studies. The most commonly reported actions of oxymel include positive effects on the cardiovascular system, as well as antioxidant and anti-inflammatory properties. Furthermore, compound oxymel formulations have demonstrated additional benefits depending on the inclusion of specific medicinal herbs.

Conclusion

Based on our findings, oxymel appears to be a valuable functional food for healthy individuals and a potentially effective and safe treatment option for managing certain diseases such as asthma, obesity, and type 2 diabetes. However, further clinical trials with larger sample sizes and longer durations are needed to fully elucidate the potential side effects and benefits of both simple and compound oxymels in various disease states.

In Vitro Prebiotic Effects and Antibacterial Activity of Five Leguminous Honeys

Honey is a natural remedy for various health conditions. It exhibits a prebiotic effect on the gut microbiome, including lactobacilli, essential for maintaining gut health and regulating the im-mune system. In addition, monofloral honey can show peculiar therapeutic properties. We in-vestigated some legumes honey's prebiotic properties and potential antimicrobial action against different pathogens. We assessed the prebiotic potentiality of honey by evaluating the antioxidant activity, the growth, and the in vitro adhesion of Lacticaseibacillus casei, Lactobacillus gasseri, Lacticaseibacillus paracasei subsp. paracasei, Lactiplantibacillus plantarum, and Lacticaseibacillus rhamnosus intact cells. We also tested the honey's capacity to inhibit or limit the biofilm produced by five pathogenic strains. Finally, we assessed the anti-biofilm activity of the growth medium of probiotics cultured with honey as an energy source. Most probiotics increased their growth or the in vitro adhesion ability to 84.13% and 48.67%, respectively. Overall, alfalfa honey best influenced the probiotic strains' growth and in vitro adhesion properties. Their radical-scavenging activity arrived at 83.7%. All types of honey increased the antioxidant activity of the probiotic cells, except for the less sensitive L. plantarum. Except for a few cases, we observed a bio-film-inhibitory action of all legumes' honey, with percentages up to 81.71%. Carob honey was the most effective in inhibiting the biofilm of Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, and Staphylococcus aureus; it retained almost entirely the ability to act against the bio-film of E. coli, L. monocytogenes, and S. aureus also when added to the bacterial growth medium instead of glucose. On the other hand, alfalfa and astragalus honey exhibited greater efficacy in acting against the biofilm of Acinetobacter baumannii. Indigo honey, whose biofilm-inhibitory action was fragile per se, was very effective when we added it to the culture broth of L. casei, whose supernatant exhibited an anti-biofilm activity against all the pathogenic strains tested. Conclusions: the five kinds of honey in different ways can improve some prebiotic properties and have an inhibitory biofilm effect when consumed.

The Antioxidant and Prebiotic Activities of Mixtures Honey/Biomimetic NaDES and Polyphenols Show Differences between Honeysuckle and Raspberry Extracts

In our previous research, we demonstrated that honey and its biomimetic natural deep eutectic solvent (NaDES) modulate the antioxidant activity (AOA) of the raspberry extract (RE). In this study, we evaluated the AOA behaviour of the mixture honey/NaDES-honeysuckle (Lonicera caprifolium, LFL) extract and compared it with the mixture honey/NaDES-RE. These two extracts have similar major flavonoids and hydroxycinnamic acid compounds but differ in their total content and the presence of anthocyanins in RE. Therefore, it was of interest to see if the modulation of the LFL polyphenols by honey/NaDES was similar to that of RE. We also evaluated the prebiotic activity of these mixtures and individual components on Limosilactobacillus reuteri DSM 20016. Although honey/NaDES modulated the AOA of both extracts, from synergism to antagonism, the modulation was different between the two extracts for some AOA activities. Honey/NaDES mixtures enriched with LFL and RE did not show significant differences in bacterial growth stimulation. However, at a concentration of 45 mg/mL, the honey -LFL mixture exhibited a higher effect compared to the honey-RE mixture. The antioxidant and prebiotic properties of mixtures between honey and polyphenol-rich extracts are determined by multiple interactions in complex chemical systems.

Study of the activity of sunflower honey against a mixed microbial association isolated from bees with signs of dyspepsia in laboratory conditions

Beekeeping is one of the essential branches of agriculture in Ukraine, the main activity of which is aimed at breeding bees and obtaining honey and other products beneficial for human health. Maintaining the physiological state of bee colonies at the proper level is one of the essential tasks of veterinary medicine doctors and beekeepers. Compliance with veterinary and sanitary requirements at bee farms is the basis of preventing infectious pathologies in bee colonies. Since the body of insects has a fast metabolism, any infectious pathology quickly acquires a massive manifestation. One indicative symptom of infectious damage to the “gut” of bees is dyspepsia. Diarrhea, anorexia, and loss of productivity are observed in bees in this condition. The market of means to prevent such pathological manifestations in beekeeping is relatively narrow. The healing and favorable properties of honey, manifested in pain-relieving, antimicrobial and anti-inflammatory effects, have been known since ancient times. Sunflower honey differs from other types in a wide range of components, particularly phytoncides, which inhibit the growth of pathogenic microorganisms. Therefore, the main goal of the experiment was a laboratory study of the effect of different concentrations of sunflower honey sieve on the mixed microbial association isolated from bees with signs of dyspepsia. The activity of sunflower honey in laboratory conditions was studied by the disco-diffusion method in Petri dishes on MPA medium (meat-peptone agar). To obtain syrup from sunflower honey, sunflower honey was diluted with distilled water in a ratio of 1:1, working solutions were prepared from sunflower honey syrup in dilutions of 1:2, 1:4, 1:10, 1:100. The data analysis indicates the bacteriostatic activity of the syrup from sunflower honey in all studied concentrations concerning the mixed microbial association. Moreover, the largest diameter of the growth inhibition zone of the studied microorganisms was noted when the syrup from sunflower honey was diluted in a ratio of 1:10 (19.2 ± 0.42 mm). In turn, the antagonistic effect of the syrup from sunflower honey was observed in all dilutions concerning the mixed microbial association, where the largest diameter of the antagonism was 19.6 ± 0.27 mm when the disc was impregnated with the native working solution. Thus, it is promising to accumulate and identify a pure culture antagonist concerning a mixed culture of bacteria isolated during bee diarrhea to further create a pharmacological agent for preventing infectious pathologies of bees in unhealthy apiaries.

Synergic Effect of Honey with Other Natural Agents in Developing Efficient Wound Dressings

Honey has been used for therapeutic and nutritional purposes since ancient times. It was considered one of the essential medical assets in wound healing. According to research, honeybees have significant antibacterial, antioxidant, anti-inflammatory, antitumor, and wound-healing properties. Lately, scientific researchers have focused on apitherapy, using bee products to protect and strengthen the immune system. Since honey is the most important natural product rich in minerals, proteins, and vitamins, it has been intensively used in such therapies. Honey has gained significant consideration because of the beneficial role of its antioxidant compounds, such as enzymes, proteins, amino and organic acids, polyphenols, and carotenoids, but mainly due to flavonoids and phenolic acids. It has been proven that phenolic compounds are responsible for honey's biological activity and that its physicochemical properties, antioxidants, and antimicrobial potential are significant for human health. The review also presents some mechanisms of action and the medical applications of honey, such as wound healing dressings, skin grafts, honey-based nanofibers, and cochlear implants, as the most promising wound healing tools. This extensive review has been written to highlight honey's applications in medicine; its composition with the most important bioactive compounds also illustrates its synergistic effect with other natural products having remarkable therapeutic properties in wound healing.

Adhesion and Anti-Adhesion Abilities of Potentially Probiotic Lactic Acid Bacteria and Biofilm Eradication of Honeybee (Apis mellifera L.) Pathogens

Lactic acid bacteria (LAB) naturally inhabits the organisms of honeybees and can exhibit adhesive properties that protect these insects against various pathogenic microorganisms. Thus, cell surface (auto-aggregation, co-aggregation, hydrophobicity) and adhesive properties of LAB to two abiotic (polystyrene and glass) and four biotic (collagen, gelatin, mucus, and intestinal Caco-2 cells) surfaces were investigated. Additionally, anti-adhesion activity and the eradication of honeybee pathogen biofilms by LAB metabolites (culture supernatants) were determined. The highest hydrophobicity was demonstrated by Pediococcus pentosaceus 19/1 (63.16%) and auto-aggregation by Lactiplantibacillus plantarum 18/1 (71.91%). All LAB showed a broad spectrum of adhesion to the tested surfaces. The strongest adhesion was noted for glass. The ability to co-aggregate with pathogens was tested for the three most potently adherent LAB strains. All showed various levels of co-aggregation depending on the pathogen. The eradication of mature pathogen biofilms by LAB metabolites appeared to be weaker than their anti-adhesive properties against pathogens. The most potent anti-adhesion activity was observed for L. plantarum 18/1 (98.80%) against Paenibacillus apiarius DSM 5582, while the strongest biofilm eradication was demonstrated by the same LAB strain against Melissococcus plutonius DSM 29964 (19.87%). The adhesive and anti-adhesive activity demonstrated by LAB can contribute to increasing the viability of honeybee colonies and improving the conditions in apiaries.

The Gut Microbiota at Different Developmental Stages of Apis cerana Reveals Potential Probiotic Bacteria for Improving Honeybee Health

Honeybees play a vital role in the ecological environment and agricultural economy. Increasing evidence shows that the gut microbiome greatly influences the host's health. Therefore, a thorough understanding of gut bacteria composition can lead to the development of probiotics specific for each development stage of honeybees. In this study, the gut microbiota at different developmental stages (larvae, pupae, and adults) of the honeybees Apis cerana in Hanoi, Vietnam, was assessed by sequencing the V3-V4 region in the 16S rRNA gene using the Illumina Miseq platform. The results indicated that the richness and diversity of the gut microbiota varied over the investigated stages of A. cenara. All three bee groups showed relative abundance at both phylum and family levels. In larvae, Firmicutes were the most predominant (81.55%); however, they decreased significantly along with the bee development (33.7% in pupae and 10.3% in adults) in favor of Proteobacteria. In the gut of adult bees, four of five core bacteria were found, including Gilliamella apicola group (34.01%) Bifidobacterium asteroides group (10.3%), Lactobacillus Firm-4 (2%), and Lactobacillus Firm-5 (1%). In contrast, pupae and larvae lacked almost all core bacteria except G. apicola (4.13%) in pupae and Lactobacillus Firm-5 (4.04%) in larvae. This is the first report on the gut microbiota community at different developmental stages of A. cerana in Vietnam and provides potential probiotic species for beekeeping.