Activation of a passive, mesoporous silica nanoparticle layer through attachment of bacterially-derived carbon-quantum-dots for protection and functional enhancement of probiotics

Surface-modified carbon quantum dot for enhanced fluorescent-sensing of hexagonal valent chromium

As one of the most harmful heavy metal pollutants, hexavalent chromium Cr(VI) is becoming a serious threat to human health. Thus pursuing a remarkably sensitive method to monitor the Cr(VI) concentration in natural conditions is favored for the fast response to prevent harm. In the present work, an ethylenediamine (En) and SiO2-modified wool keratin-based carbon quantum dot (CQD)(En@CQDs@SiO2) fluorescent sensor is prepared, and the En is found to improve the discrimination ability by binding the Cr(VI) with the surface carboxyl groups. Based on these designs, the En@CQDs@SiO2 achieves a significant improvement in the Cr(VI) detection ability, with a detection limit of 6.08 × 10-4 mg/L, which succeeded 6 times over CQDs, and is better than conventional UV-Vis and flame atomic absorption (AAS) techniques. Furthermore, the fluorescent sensor has good relative sensitivity, selectivity, good spectral reproducibility, and excellent structural stability. These properties make the sensor suitable for environmental Cr(VI) detection, which undoubtedly improves the economy and environmental friendliness of the fluorescent sensor.

Application of biomass carbon dots in food packaging

Since its discovery, carbon quantum dots (CDs) have been widely applied in cell imaging, drug delivery, biosensing, and photocatalysis due to their excellent water solubility, chemical stability, fluorescence stability biocompatibility, low toxicity, and preparation cost. However, the low fluorescence yield and poor surface structure limit the application of CDs. Heteroatom doping is considered an ideal method to improve CDs' optical and electrical properties. From this perspective, eco-friendly biomass and its derivatives are perfect carbon precursors for CDs because they contain the heteroatoms needed to modify CDs, and their complex chemical composition gives CDs a wide variety of surface functional groups. Besides, converting biomass waste into high-value-added CDs is also an innovation in biomass waste treatment. Therefore, this paper focuses on the carbon precursors of biomass CDs. At the same time, food packaging occupies an essential position in the industry, and fluorescent CDs with good fluorescence properties, high chemical stability, and good photobleaching properties have great application potential in packaging innovation techniques that have emerged in recent years, but relevant reports are scarce and scattered. Considering that the surface morphology, chemical structure, and optical and electrical properties of biomass CDs are primarily affected by the carbon precursors' chemical structure and preparation method, this paper also focuses on the synthesis method of biomass CDs and its application in anti-counterfeiting packaging, intelligent packaging, antioxidant packaging, and antibacterial packaging.

The effects of compound probiotics on production performance, rumen fermentation and microbiota of Hu sheep

Fungal probiotics have the potential as feed additives, but less has been explored in ruminant feed up to date. This study aimed to determine the effect of compound probiotics (CPs) with Aspergillus oryzae 1, Aspergillus oryzae 2 and Candida utilis on Hu sheep's growth performance, rumen fermentation and microbiota. A total of 120 male Hu sheep, aged 2 months and with the body weight of 16.95 ± 0.65 kg were divided into 4 groups. Each group consisted of 5 replicates, with 6 sheep per replicate. Group A was the control group fed with the basal diet. Group B, C and D was supplemented with the basal diet by adding 400, 800 and 1,200 grams per ton (g/t) CPs, respectively. The feeding trial lasted for 60 days after a 10-day adaptation period. The results showed that the average daily gain (ADG) of sheep in the CPs groups were significantly higher, the feed/gain were significantly lower than those in group A in the later stage and the overall period. The addition of CPs increased the economic benefit. The levels of CD4+ and the CD4+/CD8+ ratio in the CPs groups were higher than those in Group A. The levels of GSH, IgG, IL-2, IL-6, and IFN-γ in group C were significantly elevated compared with group A. Group B showed a significant increase in rumen NH3-N and cellulase activity. There was no difference in VFAs content between group A and group B, however, with the increasing addition of CPs, the butyric acid and isobutyric acid content tended to decrease. The rumen microbiota analysis indicated that the CPs addition increased the Firmicutes and Proteobacteria abundances, decreased the Bacteroidetes abundance. The correlation analysis showed that Prevotella was negatively correlated with ADG, and the addition of 400 CPs in group B reduced Prevotella's relative abundance, indicating CPs increased sheep growth by decreasing Prevotella abundance. The CPs addition reduced caspase-3, NF-κB and TNF-α expression in liver, jejunum and rumen tissues. In conclusion, the addition of CPs increased the sheep production performance, reduced inflammation, improved rumen and intestinal health. Considering the above points and economic benefits, the optimal addition of CPs as an additive for Hu sheep is 800 g/t.

Novel Encapsulation Approaches in the Functional Food Industry: With a Focus on Probiotic Cells and Bioactive Compounds

Bioactive substances can enhance host health by modulating biological reactions, but their absorption and utilization by the body are crucial for positive effects. Encapsulation of probiotics is rapidly advancing in food science, with new approaches such as 3D printing, spray-drying, microfluidics, and cryomilling. Co-encapsulation with bioactives presents a cost-effective and successful approach to delivering probiotic components to specific colon areas, improving viability and bioactivity. However, the exact method by which bioactive chemicals enhance probiotic survivability remains uncertain. Co-crystallization as an emerging encapsulation method improves the physical characteristics of active components. It transforms the structure of sucrose into uneven agglomerated crystals, creating a porous network to protect active ingredients. Likewise, electrohydrodynamic techniques are used to generate fibers with diverse properties, protecting bioactive compounds from harsh circumstances at ambient temperature. Electrohydrodynamic procedures are highly adaptable, uncomplicated, and easily expandable, resulting in enhanced product quality and functionality across various food domains. Furthermore, food byproducts offer nutritional benefits and technical potential, aligning with circular economy principles to minimize environmental impact and promote economic growth. Hence, industrialized nations can capitalize on the growing demand for functional foods by incorporating these developments into their traditional cuisine and partnering with businesses to enhance manufacturing and production processes.

Oral delivery of probiotics using single-cell encapsulation

Adequate intake of live probiotics is beneficial to human health and wellbeing because they can help treat or prevent a variety of health conditions. However, the viability of probiotics is reduced by the harsh environments they experience during passage through the human gastrointestinal tract (GIT). Consequently, the oral delivery of viable probiotics is a significant challenge. Probiotic encapsulation provides a potential solution to this problem. However, the production methods used to create conventional encapsulation technologies often damage probiotics. Moreover, the delivery systems produced often do not have the required physicochemical attributes or robustness for food applications. Single-cell encapsulation is based on forming a protective coating around a single probiotic cell. These coatings may be biofilms or biopolymer layers designed to protect the probiotic from the harsh gastrointestinal environment, enhance their colonization, and introduce additional beneficial functions. This article reviews the factors affecting the oral delivery of probiotics, analyses the shortcomings of existing encapsulation technologies, and highlights the potential advantages of single-cell encapsulation. It also reviews the various approaches available for single-cell encapsulation of probiotics, including their implementation and the characteristics of the delivery systems they produce. In addition, the mechanisms by which single-cell encapsulation can improve the oral bioavailability and health benefits of probiotics are described. Moreover, the benefits, limitations, and safety issues of probiotic single-cell encapsulation technology for applications in food and beverages are analyzed. Finally, future directions and potential challenges to the widespread adoption of single-cell encapsulation of probiotics are highlighted.

The single-cell modification strategies for probiotics delivery in inflammatory bowel disease: A review

Oral probiotic therapy has become an increasingly attractive method for treating various diseases, including intestinal barrier dysfunction, inflammatory bowel disease (IBD), and colorectal cancer due to its safety and convenience. However, only a few probiotics after oral gavage can survive the acidic and bile salt conditions of the gastrointestinal tract and colonize the colon to have a nutritional effect on the host. To address these challenges, encapsulation technology has been applied to protect probiotics from harsh gastrointestinal conditions, improve gut adhesion, and reduce immunogenicity. In addition, some of the functional polysaccharides are used to endow probiotics with exogenous functions as prebiotics. In this review, we systematically introduced the advancements of emerging single-cell modification strategies for probiotics in IBD applications. Additionally, we discussed the limitations and perspectives of single-cell modification strategies for probiotics. This review contributed to the development of probiotic delivery systems with higher therapeutic efficacy against colitis.

Delivery Strategies of Probiotics from Nano- and Microparticles: Trends in the Treatment of Inflammatory Bowel Disease-An Overview

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder, most known as ulcerative colitis (UC) and Crohn's disease (CD), that affects the gastrointestinal tract (GIT), causing considerable symptoms to millions of people around the world. Conventional therapeutic strategies have limitations and side effects, prompting the exploration of innovative approaches. Probiotics, known for their potential to restore gut homeostasis, have emerged as promising candidates for IBD management. Probiotics have been shown to minimize disease symptoms, particularly in patients affected by UC, opening important opportunities to better treat this disease. However, they exhibit limitations in terms of stability and targeted delivery. As several studies demonstrate, the encapsulation of the probiotics, as well as the synthetic drug, into micro- and nanoparticles of organic materials offers great potential to solve this problem. They resist the harsh conditions of the upper GIT portions and, thus, protect the probiotic and drug inside, allowing for the delivery of adequate amounts directly into the colon. An overview of UC and CD, the benefits of the use of probiotics, and the potential of micro- and nanoencapsulation technologies to improve IBD treatment are presented. This review sheds light on the remarkable potential of nano- and microparticles loaded with probiotics as a novel and efficient strategy for managing IBD. Nonetheless, further investigations and clinical trials are warranted to validate their long-term safety and efficacy, paving the way for a new era in IBD therapeutics.

Gastrointestinal Microenvironment Responsive Nanoencapsulation of Probiotics and Drugs for Synergistic Therapy of Intestinal Diseases

The gut microbiota are prominent in preserving intestinal environmental homeostasis and managing human health, and their dysbiosis has been directly related to many kinds of intestinal diseases. Probiotics-based therapy appears as a promising approach for the treatment of gut microbiota dysbiosis, while it always suffers from limited bioavailability and therapeutic effect after oral administration. Herein, we presented a facile and safe strategy to treat colitis by nanoencapsulation of probiotics and an anti-inflammatory agent, 5-aminosalicylic acid (5-ASA), within the gastrointestinal microenvironment responsive alginate polysaccharide. Because of acid resistance, the alginate-based coating protected probiotics from the harsh gastric condition. The coating could be disintegrated to release probiotics and 5-ASA upon arriving in the intestinal tract, where the pH is normally higher than 5. In the dextran sulfate sodium-induced colitis mouse model, probiotics recovered their bioactivities and acted together with anti-inflammatory 5-ASA to alleviate colitis by upregulating microbiota richness and diversity, reducing expression of proinflammatory cytokines, and restoring intestinal barriers. This work demonstrated the synergistic therapy of intestinal diseases based on alginate-encapsulated probiotics and a clinical drug, which provided an extensive method to improve the therapeutic effect of oral microecologics.

Prodrug Integrated Envelope on Probiotics to Enhance Target Therapy for Ulcerative Colitis

Ulcerative colitis (UC), affecting millions of patients worldwide, is associated with disorders of the gut microbiota. Probiotics-based therapy positively regulating the community structure of gut microbiota is regarded as an efficient intervention for UC. However, oral probiotics delivery is restricted by limited bioactivity, short retention time, complex pathological condition, and single therapeutic efficacy. Here, a bioengineered probiotic decorated with a multifunctional prodrug coating is constructed to ameliorate the aforementioned shortcomings. The results of UC mice induced by dextran sulfate sodium demonstrate that the intrinsic features of the fabricated coating integrate gut microbes protection, colon-targeted drug release, prolonged drug retention, and inflammation regulation. In parallel, the probiotics Lactobacillus rhamnosus GG (LGG) could regulate the composition of the gut microbiota and improve epithelial barrier function, thereby synergistically ameliorating UC. These results provide ample shreds of evidence of the therapeutic effect on UC, therefore, demonstrate a great promise as the potential therapeutic strategy for UC treatment.

The encapsulation strategy to improve the survival of probiotics for food application: From rough multicellular to single-cell surface engineering and microbial mediation

The application of probiotics is limited by the loss of survival due to food processing, storage, and gastrointestinal tract. Encapsulation is a key technology for overcoming these challenges. The review focuses on the latest progress in probiotic encapsulation since 2020, especially precision engineering on microbial surfaces and microbial-mediated role. Currently, the encapsulation materials include polysaccharides and proteins, followed by lipids, which is a traditional mainstream trend, while novel plant extracts and polyphenols are on the rise. Other natural materials and processing by-products are also involved. The encapsulation types are divided into rough multicellular encapsulation, precise single-cell encapsulation, and microbial-mediated encapsulation. Recent emerging techniques include cryomilling, 3D printing, spray-drying with a three-fluid coaxial nozzle, and microfluidic. Encapsulated probiotics applied in food is an upward trend in which "classic probiotic foods" (yogurt, cheese, butter, chocolate, etc.) are dominated, supplemented by "novel probiotic foods" (tea, peanut butter, and various dry-based foods). Future efforts mainly include the effect of novel encapsulation materials on probiotics in the gut, encapsulation strategy oriented by microbial enthusiasm and precise encapsulation, development of novel techniques that consider both cost and efficiency, and co-encapsulation of multiple strains. In conclusion, encapsulation provides a strong impetus for the food application of probiotics.