Impact of encapsulating a probiotic (Pediococcus pentosaceus Li05) within gastro-responsive microgels on Clostridium difficile infections

Accelerated infected wound healing by probiotic-based living microneedles with long-acting antibacterial effect

Delays in infected wound healing are usually a result of bacterial infection and local inflammation, which imposes a significant and often underappreciated burden on patients and society. Current therapies for chronic wound infection generally suffer from limited drug permeability and frequent drug administration, owing to the existence of a wound biofilm that acts as a barrier restricting the entry of various antibacterial drugs. Here, we report the design of a biocompatible probiotic-based microneedle (MN) patch that can rapidly deliver beneficial bacteria to wound tissues with improved delivery efficiency. The probiotic is capable of continuously producing antimicrobial substances by metabolizing introduced glycerol, thereby facilitating infected wound healing through long-acting antibacterial and anti-inflammatory effects. Additionally, the beneficial bacteria can remain highly viable (>80 %) inside MNs for as long as 60 days at 4 °C. In a mouse model of Staphylococcus aureus-infected wounds, a single administration of the MN patch exhibited superior antimicrobial efficiency and wound healing performance in comparison with the control groups, indicating great potential for accelerating infected wound closure. Further development of live probiotic-based MN patches may enable patients to better manage chronically infected wounds.

Intestinal Delivery of Probiotics: Materials, Strategies, and Applications

Probiotics with diverse and crucial properties and functions have attracted broad interest from many researchers, who adopt intestinal delivery of probiotics to modulate the gut microbiota. However, the major problems faced for the therapeutic applications of probiotics are the viability and colonization of probiotics during their processing, oral intake, and subsequent delivery to the gut. The challenges of simple oral delivery (stability, controllability, targeting, etc.) have greatly limited the use of probiotics in clinical therapies. Nanotechnology can endow the probiotics to be delivered to the intestine with improved survival rate and increased resistance to the adverse environment. Additionally, the progress in synthetic biology has created new opportunities for efficiently and purposefully designing and manipulating the probiotics. In this article, a brief overview of the types of probiotics for intestinal delivery, the current progress of different probiotic encapsulation strategies, including the chemical, physical, and genetic strategies and their combinations, and the emerging single-cell encapsulation strategies using nanocoating methods, is presented. The action mechanisms of probiotics that are responsible for eliciting beneficial effects are also briefly discussed. Finally, the therapeutic applications of engineered probiotics are discussed, and the future trends toward developing engineered probiotics with advanced features and improved health benefits are proposed.

Advances in polysaccharides for probiotic delivery: Properties, methods, and applications

Probiotics are essential to improve the health of the host, whereas maintaining the viability of probiotics in harsh environments remains a challenge. Polysaccharides have non-toxicity, excellent biocompatibility, and outstanding biodegradability, which can protect probiotics by forming a physical barrier and show a promising prospect for probiotic delivery. In this review, we summarize polysaccharides commonly used for probiotic microencapsulation and introduce the microencapsulation technologies, including extrusion, emulsion, spray drying, freeze drying, and electrohydrodynamics. We discuss strategies for better protection of probiotics and introduce the applications of polysaccharides-encapsulated probiotics in functional food, oral formulation, and animal feed. Finally, we propose the challenges of polysaccharides-based delivery systems in industrial production and application. This review will help provide insight into the advances and challenges of polysaccharides in probiotic delivery.

Reinforcing alginate matrixes by tea polysaccharide conjugates or their stabilized nanoemulsion for probiotics encapsulation: Characterization, survival after gastrointestinal digestion and ambient storage

Tea polysaccharide conjugates (TPC) were used as fillers in the form of biopolymer or colloidal particles (TPC stabilized nanoemulsion, NE) for reinforcing alginate (ALG) beads to improve the probiotic viability. Results demonstrated that adding TPC or NE to ALG beads significantly enhanced the gastrointestinal viability of encapsulated probiotics when compared to free cells. Moreover, the survivability of free and ALG encapsulated probiotics markedly decreased to 2.03 ± 0.05 and 2.26 ± 0.24 log CFU/g, respectively, after 2 weeks ambient storage, indicating pure ALG encapsulation had no effective storage protective capability. However, adding TPC or NE could greatly enhance the ambient storage viability of probiotics, with ALG + NE beads possessing the best protection (8.93 ± 0.06 log CFU/g) due to their lower water activity and reduced porosity. These results suggest that TPC and NE reinforced ALG beads have the potential to encapsulate, protect and colonic delivery of probiotics.

Pediococcus pentosaceus PR-1 modulates high-fat-died-induced alterations in gut microbiota, inflammation, and lipid metabolism in zebrafish

Introduction

Obesity is a health issue worldwide. This study aimed to evaluate the beneficial effects of Pediococcus pentococcus PR-1 on the modulating of gut microbiota, inflammation and lipid metabolism in high-fat-diet (HFD)-fed zebrafish.

Methods

Adult zebrafish were fed a commercial (C), high fat (H, 25% fat), probiotic (P, 10⁶ CFU/g), or high fat with probiotic (HP) diets twice daily for 5 weeks. Gut microbiota were analysed using 16S rRNA gene sequencing. Gene expressions of intestinal cytokine, intestinal TJ protein, and liver lipid metabolism were analysed by quantitative real-time polymerase chain reaction. Biochemical and histological analysis were also performed.

Results and discussion

P. pentosaceus PR-1 reduced body weight and BMI, indicating its anti-obesity effect. The 16S rRNA sequencing results showed HFD induced a distinct gut microbiota structure from C group, which was restored by probiotic. P. pentosaceus PR-1 improved gut health by decreasing the abundance of Ralstonia and Aeromonas which were increased induced by HFD. Moreover, probiotic restored abundance of Fusobacteria, Cetobacterium and Plesiomonas, which were decreased in HFD-fed zebrafish. The results of quantitative real-time polymerase chain reaction showed probiotic suppressed HFD-induced inflammation by decreasing the expressions of IL-1b and IL-6. Levels of hepatic TNF-α, IL-1ß, and IL-6 were reduced by probiotic in HFD-fed zebrafish. Probiotic also ameliorated gut barrier function by increasing the expressions of occludin, Claudin-1, and ZO-1. Probiotic exerted anti-adipogenic activity through regulating the expressions of SREBP1, FAS and LEPTIN. Levels of hepatic triglyceride, total cholesterol, low density lipoprotein were also reduced by probiotic. Histological analysis showed probiotic alleviated liver steatosis and injury induced by HFD. P. pentosaceus PR-1 might be useful as a dietary health supplement, especially for reducing obesity.

Recent advances in cellulose microgels: Preparations and functionalized applications

Microgels are soft, deformable, permeable, and stimuli-responsive microscopic polymeric particles that are now emerging as prospective multifunctional soft materials for delivery systems, interface stabilization, cell cultures and tissue engineering. Cellulose microgels are emerging biopolymeric microgels with unique characteristics such as abound hydroxyl structure, admirable designability, multiscale pore network and excellent biocompatibility. This review summarizes the fabrication strategies for microgel, then highlights the fabrication routes for cellulose microgels, and finally elaborates cellulose microgels' bright application prospects with unique characteristics in the fields of controlled release, interface stabilization, coating, purification, nutrition/drug delivery, and bio-fabrication. The challenges to be addressed for further applications and considerable scope for development in future of cellulose microgels are also discussed.

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.

Functional food: complementary to fight against COVID-19

Background

The novel coronavirus has embarked on a global pandemic and severe mortality with limited access for its treatments and medications. For the lack of time, research, and enough efficacy, most vaccines are underdeveloped or unreachable to society. However, many recent studies suggest various alternative, complementary remedies for COVID-19, which are functional foods. This review provides an overview of how functional foods can play a great role through modulating the host immune system, generating antiviral activities, and synthesizing biologically active agents effective against the coronavirus.

Main body

This review article summarizes the natural defense mechanisms in tackling SARS-CoV-2 alongside conventional therapeutic options and their corresponding harmful side effects. By analyzing bioactive components of functional foods, we have outlined its different contributions to human health and its potential immunomodulatory and antiviral properties that can enhance resistivity to viral infection. Moreover, we have provided a myriad of accessible and cost-effective functional foods that could be further investigated to target specific key symptoms of COVID-19 infections. Finally, we have found various functional foods with potent bioactive compounds that can inhibit or prevent COVID-19 infections and disease progression.

Short conclusion

Numerous functional foods can help the body fight COVID-19 through several mechanisms such as the reduced release of pro-inflammatory cytokines, reduced expression of ACE2 receptors in cells, and inhibiting essential enzymes in SARS-CoV-2.

Modulation of Intestinal Barrier, Inflammatory Response, and Gut Microbiota by Pediococcus pentosaceus zy-B Alleviates Vibrio parahaemolyticus Infection in C57BL/6J Mice

Modulation of the intestinal barrier, inflammation, and gut microbiota by Pediococcus pentosaceus zy-B (zy-B) in Vibrio parahaemolyticus (Vp)-infected C57BL/6J mice was studied. Mice intragastrically pretreated with 10⁸ colony-forming units (CFU) zy-B significantly alleviated Vp infection as evidenced by maintaining body weight and reduced disease activity index score and intestine ratio. In addition, zy-B reduced the Vp load in the ileum and cecum, significantly reduced the load in the colon, prevented colonic atrophy, and strengthened mucosal integrity. Mechanistically, zy-B ameliorated intestinal barrier dysfunction by upregulating tight junction protein expression, which in turn reduced the lipopolysaccharide, d-lactic acid (d-LA), and diamine oxidase concentrations and downregulated the cannabinoid receptor 1 (CB1) and CB2 mRNA expressions. Moreover, zy-B systemically reduced inflammation by decreasing interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α levels, and increased interleukin-10 (IL-10), immunoglobulin M (IgM), and immunoglobulin G (IgG) levels in the colon and serum. Furthermore, zy-B markedly altered the gut microbiota composition by enriching Bifidobacterium, Akkermansia, and Lactobacillus in the colon. Overall, zy-B appears to act as a probiotic to alleviate Vp infection by protecting the intestinal barrier, reducing inflammation, and promoting the growth of "beneficial" gut microbiota.

Latest developments in food-grade delivery systems for probiotics: A systematic review

Tremendous progress in the inseparable relationships between probiotics and human health has enabled advances in probiotic functional foods. To ensure the vitality of sensitive probiotics against multiple harsh conditions, rising food-grade delivery systems for probiotics have been developed. This review gives a summary of recently reported delivery vehicles for probiotics, analyzes their respective merits and drawbacks and makes comparisons among them. Subsequently, the applications and future prospects are discussed. According to the types of encapsulating probiotics, food-grade delivery systems for probiotics can be classified into "silkworm cocoons" and "spider webs", which are put forward in this paper. The former, which surrounds the inner probiotics with the outer protective layers, includes particles, emulsions, beads, hybrid electrospun nanofibers and microcapsules. While hydrogels and bigels belong to the latter, which protects probiotics with the aid of network structures. The future prospects include preferable viability and stability of probiotics, co-delivery systems, targeted gut release of probiotics, delivery of multiple strains, more scientific experimental verification and more diversified food products, which will enlighten further studies on delivering probiotics for human health. Taken together, delivery vehicles for probiotics are-or will soon be-in the field of food science, with further applications under development.

Effects of Pediococcus pentosaceus LI05 on immunity and metabolism in germ-free rats

Many Pediococcus spp. have health-promoting benefits, and Pediococcus pentosaceus LI05 is one such species that was proved to be beneficial in previous studies. Our research aimed to determine the immune and metabolic effects of P. pentosaceus LI05 on germ-free rats. Germ-free rats were gavaged with P. pentosaceus LI05 suspensions (1 × 10⁹ CFU) for 2 weeks, and 3 weeks later, blood, spleen, intestine and liver samples were gathered for metabolome, intestine morphology, immunity, and transcriptomics analyses. Oral gavage of P. pentosaceus LI05 reduced the bodyweight of rats, which manifested as increased fecal carbohydrate concentrations, decreased intestinal fat intake and the hepatic fat synthesis gene expression, and accelerated fat-to-glycogen conversion. In addition, P. pentosaceus LI05 exhibited an anti-inflammatory ability, reducing serum proinflammatory cytokine levels and increasing intestinal subepidermal CD4⁺ cell levels. Furthermore, administration of P. pentosaceus LI05 increased the antimicrobial ability and enhanced the liver detoxification function. These results indicate that as a probiotic, P. pentosaceus LI05 ameliorates the hampered immune response of GF animals and improves the metabolism of fat and toxic substances.