Efeito prebiótico do mel sobre o crescimento e viabilidade de Bifidobacterium spp. e Lactobacillus spp. em leite

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.

Role of milk and honey in the tolerance of lactobacilli to oxidative stress

In the development of functional probiotic food, the carrier matrices should be carefully selected and optimized to ensure the highest levels of probiotic survival in the symbiotic food along storage. Because milk and honey food matrices are rich in antioxidant substances, the aim of the research was to evaluate their effect in protecting lactobacilli from reactive oxygen species (ROS) generated by the addition of hydrogen peroxide. Viability assays were performed with and without the addition of H₂O₂, in three different matrices: 0.9% peptone saline, 5% honey, or 12% reconstituted skim milk. The milk matrix provided protection for the Lacticaseibacillus paracasei DTA83 and Lacticaseibacillus rhamnosus DTA76. However, this protective effect was not observed in the survival of Lactobacillus acidophilus La 5. Honey solution did not maintain the viability of probiotic microorganisms exposed to hydrogen peroxide and, on the contrary, caused a significant reduction in the population of L. rhamnosus DTA76 (p < 0.001). Lower membrane lipid peroxidation due to H₂O₂ exposure was observed in L. acidophilus La 5 and L. rhamnosus DTA76, but this marker showed no relation with viability. It was concluded: (i) lactobacilli from the Lacticaseibacillus genus were the ones that benefited most from the lactic environment; (ii) the absence of the protective effect of honey was possibly due to the presence of Fe²⁺ which reacts with H₂O₂ to produce hydroxyl radicals; and (iii) cell viability did not correlate with membrane lipid peroxidation, and it is not a good marker to evaluate this type of damage in cells of different microorganisms.

Sensory, Microbiological and Physicochemical Characterisation of Functional Manuka Honey Yogurts Containing Probiotic Lactobacillus reuteri DPC16

Consumer acceptance of synbiotics, which are synergistic combinations of probiotics and their prebiotic substrates, continues to expand in the functional food category. This research aimed at evaluating the effect of antibacterial manuka honey on the probiotic growth and sensory characteristics of potentially synbiotic yogurts manufactured with Lactobacillus reuteri DPC16. Probiotic viable count in yogurts with 5% w/v Manuka honey (Blend, UMF^TM 18⁺, AMF^TM 15⁺ and AMF^TM 20⁺) was evaluated by the spread plate method over the refrigerated storage period of three weeks. A panel of 102 consumers preferred the yogurt made with invert syrup over the manuka honey variants, and the unsweetened control was least liked overall. Invert syrup yogurt was also the most effective in promoting the growth of the probiotic lactobacilli. However, the honey-sweetened yogurts had a more favourable fermentation metabolite profile, especially the lactic and propionic acids, as estimated by nuclear magnetic resonance (NMR) analyses. The probiotic counts in AMF^TM 15⁺ manuka honey yogurt (7 log cfu/mL) were significantly higher than the other honey yogurt types (Manuka Blend and UMF^TM 18⁺) and above the recommended threshold levels. The combination thus can be developed as a synbiotic functional food by further improving the sensory and physicochemical properties such as texture, apparent viscosity and water holding capacity.

The resistance of Bacillus, Bifidobacterium, and Lactobacillus strains with claimed probiotic properties in different food matrices exposed to simulated gastrointestinal tract conditions

The resistance of Bifidobacterium, Lactobacillus, and Bacillus strains with claimed probiotic properties in different food matrices was evaluated. Lactobacillus paracasei PXN 37, Lactobacillus acidophilus La-5, Bifidobacterium animalis subsp. lactis Bb-12, Bifidobacterium breve PXN 25, Bacillus subtilis PXN 21, Bacillus coagulans GBI30 6086 and Bacillus coagulans MTCC 5856 strains were inoculated in "requeijão cremoso" cheese, pasteurized orange juice, and bread. Further, the counts of the strains with claimed probiotic properties were determined throughout the products' shelf-life. Additionally, the survival (%), at the beginning and at the end of their shelf-life, of each strain with claimed probiotic properties inoculated in the three foods was estimated by using a static in vitro system simulating the gastric (pH 2), enteric I (pH 5) and enteric II (pH 7) phases of gastrointestinal tract (GIT). Overall, it has been found that the Bacillus strains with claimed probiotic properties showed greater viability than probiotic Bifidobacterium and Lactobacillus strains no matter the food studied. The percentage of survival of the Bacillus strains with claimed probiotic properties were always above 83%. The Bacillus strains with claimed probiotic properties were able to survive well in all the food matrices tested. Therefore, this study shows that these strains of Bacillus may comprise a feasible strategy for expanding the range of "probiotic food" choices given their high resistance to the composition of foods, manufacturing steps, and resistance to simulated GIT conditions.

Honey as a Complementary Medicine

The beneficial effects of honey on human health have long been recognized. Today, many of those positive effects have been studied to elucidate its mode of action. This review briefly summarizes the best studied features of honey, highlighting it as an appealing alternative medicine. In these reports, the health benefits of honey range from antioxidant, immunomodulatory, and anti-inflammatory activity to anticancer action, metabolic and cardiovascular benefits, prebiotic properties, human pathogen control, and antiviral activity. These studies also support that the honey's biological activity is mainly dependent on its floral or geographic origin. In addition, some promising synergies between honey and antibiotics have been found, as well as some antiviral properties that require further investigation. Altogether, these studies show that honey is effectively a nutraceutical foodstuff.

Survival of free and microencapsulated Bifidobacterium: effect of honey addition

This study evaluated the effect of honey addition on the viability of free and emulsion encapsulated cells of two strains of Bifidobacterium that underwent simulation of human upper gastrointestinal transit. In the control condition, without honey, free cells were drastically reduced after exposure to gastrointestinal conditions. The reduction was more pronounced with Bifidobacterium J7 of human origin. On the other hand, when cells were encapsulated, the viability reduction was higher for strain Bifidobacterium Bb12. The microencapsulation improved the viability maintenance of both Bifidobacterium strains, in recommended amounts for probiotic activity, after exposure to simulated gastrointestinal conditions. Moreover, suspending free cells of both Bifidobacterium strains in honey solutions resulted in a protective effect, equivalent to the plain microencapsulation with sodium alginate 3%. It is concluded that microencapsulation and the addition of honey improved the ability of Bifidobacterium to tolerate gastrointestinal conditions in vitro.

Short communication: Viability of culture organisms in honey-enriched acidophilus-bifidus-thermophilus (ABT)-type fermented camel milk

The aim of this research was to monitor the survival during refrigerated storage of Lactobacillus acidophilus LA-5 (A), Bifidobacterium animalis ssp. lactis BB-12 (B), and Streptococcus thermophilus CHCC 742/2130 (T) in cultured dairy foods made from camel and, for comparison, cow milks supplemented with black locust (Robinia pseudoacacia L.) honey and fermented by an acidophilus-bifidus-thermophilus (ABT)-type culture. Two liters of dromedary camel milk and 2 L of cow milk were heated to 90 °C and held for 10 min, then cooled to 40 °C. One half of both types of milk was fortified with black locust honey at the rate of 5.0% (wt/vol), whereas the other half was devoid of honey and served as a control. The camel and cow milks with and without honey were subsequently inoculated with ABT-5 culture and were fermented at 37 °C until a pH value of 4.6 was reached. Thereafter, the probiotic fermented milks were cooled to 15 °C in ice water and were each separated into 18 fractions that were transferred in sterile, tightly capped centrifuge tubes. After 24 h of cooling at 8 °C (d 0), the samples were stored at refrigeration temperature (4 °C). Three tubes of all 4 products (i.e., fermented camel and cow milks with and without honey) were taken at each sampling time (i.e., following 0, 7, 14, 21, 28, and 35 d of storage), and the counts of characteristic microorganisms and those of certain spoilage microbes (yeasts, molds, coliforms, Escherichia coli) were enumerated. The entire experimental program was repeated twice. The results showed that addition of black locust honey at 5% to heat-treated camel and cow milks did not influence the growth and survival of starter streptococci during production and subsequent refrigerated storage of fermented ABT milks. In contrast, honey improved retention of viability of B. animalis ssp. lactis BB-12 in the camel milk-based product during storage at 4 °C up to 5 wk. No spoilage organisms were detected in any of the samples tested in this study. In conclusion, supplementation of cultured dairy foods, especially those made from camel milk, with honey is recommended because honey is a healthy natural sweetener with a variety of beneficial microbiological, nutritional, and sensory properties.