Activities of free and encapsulated Lactobacillus acidophilus LA5 or Lactobacillus casei 01 in processed longan juices on exposure to simulated gastrointestinal tract

Effects of Bifidobacterium animalis subsp. lactis IU100 on Immunomodulation and Gut Microbiota in Immunosuppressed Mice

Probiotics are live microorganisms with immunomodulatory effects in a strain-specific and dose-dependent manner. Bifidobacterium animalis subsp. lactis IU100 is a new probiotic strain isolated from healthy adults. This study aimed to evaluate the effects of IU100 on cyclophosphamide (CTX)-induced immunosuppression in mice. The results showed that IU100 significantly ameliorated CTX-induced decreases in body weight and immune organ indices. The promoted delayed-type hypersensitivity, serum hemolysins and immunoglobulin (IgA, IgG and IgM) levels after IU100 treatment indicated its enhancing role in cellular and humoral immunity. In addition, oral administration of IU100 increased serum cytokine (IL-1β, IL-2, IL-4, IL-6, IFN-γ, TNF-α) levels dose-dependently, which are associated with CTX-induced shifts in the Th1/Th2 balance. The probiotic IU100 also modulated the composition of gut microbiota by reducing the Firmicutes/Bacteroidetes ratio; increasing beneficial Muribaculaceae and the Lachnospiraceae NK4A136 group; and inhibiting harmful Clostridium sensu stricto 1, Faecalibaculum and Staphylococcus at the genus level. The above genera were found to be correlated with serum cytokines and antibody levels. These findings suggest that IU100 effectively enhances the immune function of immunosuppressed mice, induced by CTX, by regulating gut microbiota.

Effects of Bifidobacterium animalis subsp. lactis IU100 on Immunomodulation and Gut Microbiota in Immunosuppressed Mice

Probiotics are live microorganisms with immunomodulatory effects in a strain-specific and dose-dependent manner. Bifidobacterium animalis subsp. lactis IU100 is a new probiotic strain isolated from healthy adults. This study aimed to evaluate the effects of IU100 on cyclophosphamide (CTX)-induced immunosuppression in mice. The results showed that IU100 significantly ameliorated CTX-induced decreases in body weight and immune organ indices. The promoted delayed-type hypersensitivity, serum hemolysins and immunoglobulin (IgA, IgG and IgM) levels after IU100 treatment indicated its enhancing role in cellular and humoral immunity. In addition, oral administration of IU100 increased serum cytokine (IL-1β, IL-2, IL-4, IL-6, IFN-γ, TNF-α) levels dose-dependently, which are associated with CTX-induced shifts in the Th1/Th2 balance. The probiotic IU100 also modulated the composition of gut microbiota by reducing the Firmicutes/Bacteroidetes ratio; increasing beneficial Muribaculaceae and the Lachnospiraceae NK4A136 group; and inhibiting harmful Clostridium sensu stricto 1, Faecalibaculum and Staphylococcus at the genus level. The above genera were found to be correlated with serum cytokines and antibody levels. These findings suggest that IU100 effectively enhances the immune function of immunosuppressed mice, induced by CTX, by regulating gut microbiota.

Gum Arabic/Chitosan Coacervates for Encapsulation and Protection of Lacticaseibacillus rhamnosus in Storage and Gastrointestinal Environments

Probiotics, such as Lacticaseibacillus rhamnosus, are essential to the food industry for their health benefits to the host. The Lcb. rhamnosus strain is susceptible to processing, gastrointestinal, and storage conditions. In this study, Lcb. rhamnosus strains were encapsulated by complex coacervation in a gum arabic/chitosan or gum arabic/trehalose/chitosan and cross-linked with sodium tripolyphosphate. The physicochemical properties (zeta potential, water activity, water content, and hygroscopicity), encapsulation efficiency, and probiotic survival under storage conditions and simulated gastrointestinal fluids were evaluated. The results showed that crosslinking improves the encapsulation efficiency after drying; however, this result was remarkable when trehalose was used as a cryoprotectant. Furthermore, the encapsulation matrix preserved the viability of probiotics during 12 weeks with probiotic counts between 8.7-9.5, 7.5-9.0, and 5.2-7.4 log10 CFU g-1 at -20, 4, and 20 °C, respectively. After 12 days of digestion in an ex vivo simulator, acetic, butyric, propionic, and lactic acid production changed significantly, compared to free probiotic samples. This work shows that encapsulation by complex coacervation can promote the stability of probiotic bacteria in storage conditions and improve the viability of Lcb. rhamnosus HN001 during consumption so that they can exert their beneficial action in the organism.

Fortification of orange juice with microencapsulated Kocuria flava Y4 towards a novel functional beverage: Biological and quality aspects

To commercialize functional foods, probiotics must exhibit high resistance and acceptable stability under various unfavorable conditions to maintain the quality of fruit juices. This study will provide an insight into fortification of orange juice with a plant probiotic Kocuria flava Y4 by microencapsulation. Therefore, this study investigated the colony release, physicochemical and phytochemical parameters, and antioxidant activity of the orange juice exposed to microencapsulated probiotics and the one without probiotics (control). Evaluation of orange juice on the growth of probiotic bacteria showed that the fortification with alginate and psyllium micro-particles showed highest encapsulation efficiency (99.01%) and acceptable viability of probiotic cells (8.12 ± 0.077 CFU/mL) during five weeks storage at 4 °C. The morphology and functional properties of beads was studied by SEM, Zeta-potential and FTIR analysis. The sucrose and organic acids concentrations decreased significantly during fortification period (0-72 h) except ascorbic acid. Furthermore, glucose, pH, acidity, TSS were maintained. The results affirm the suitability and feasibility of developing a plant probiotic beverage using orange juice by encapsulation method.

In vitro models of gut digestion across childhood: current developments, challenges and future trends

The human digestion is a multi-step and multi-compartment process essential for human health, at the heart of many issues raised by academics, the medical world and industrials from the food, nutrition and pharma fields. In the first years of life, major dietary changes occur and are concomitant with an evolution of the whole child digestive tract anatomy and physiology, including colonization of gut microbiota. All these phenomena are influenced by child exposure to environmental compounds, such as drugs (especially antibiotics) and food pollutants, but also childhood infections. Due to obvious ethical, regulatory and technical limitations, in vivo approaches in animal and human are more and more restricted to favor complementary in vitro approaches. This review summarizes current knowledge on the evolution of child gut physiology from birth to 3 years old regarding physicochemical, mechanical and microbial parameters. Then, all the available in vitro models of the child digestive tract are described, ranging from the simplest static mono-compartmental systems to the most sophisticated dynamic and multi-compartmental models, and mimicking from the oral phase to the colon compartment. Lastly, we detail the main applications of child gut models in nutritional, pharmaceutical and microbiological studies and discuss the limitations and challenges facing this field of research.

Improved Viability of Microencapsulated Probiotics in a Freeze-Dried Banana Powder During Storage and Under Simulated Gastrointestinal Tract

Freeze-dried banana powder represents an ideal source of nutrients and has not yet been used for probiotic incorporation. In this study, microencapsulation by freeze drying of probiotics Lactobacillus acidophilus and Lactobacillus casei was made using whey protein isolate (WPI), fructooligosaccharides (FOS), and their combination (WPI + FOS) at ratio (1:1). Higher encapsulation yield was found for (WPI + FOS) microspheres (98%). Further, microcapsules of (WPI + FOS) were used to produce a freeze-dried banana powder which was analyzed for bacterial viability under simulated gastrointestinal fluid (SGIF), stability during storage at 4 °C and 25 °C, and chemical and sensory properties. Results revealed that (WPI + FOS) microcapsules significantly increased bacteria stability in the product over 30 days of storage at 4 °C averaging (≥ 8.57 log CFU/g) for L. acidophilus and (≥ 7.61 log CFU/g) for L. Casei as compared to free cells. Bacteria encapsulated in microspheres (WPI + FOS) were not significantly affected by the SGIF, remaining stable up to 7.05 ± 0.1 log CFU/g for L.acidophilus and 5.48 ± 0.1 log CFU/g for L.casei after 90 min of incubation at pH 2 compared to free cells which showed minimal survival. Overall, encapsulated probiotics enriched freeze-dried banana powders received good sensory scores; they can therefore serve as safe probiotics food carriers.

The Inoculation of Probiotics In Vivo Is a Challenge: Strategies to Improve Their Survival, to Avoid Unpleasant Changes, or to Enhance Their Performances in Beverages

The inoculation of probiotics in beverages (probiotication) requires special technologies, as probiotic microorganisms can experience stress during food processing (acid, cold, drying, starvation, oxidative, and osmotic stresses) and gastrointestinal transit. Survival to harsh conditions is an essential prerequisite for probiotic bacteria before reaching the target site where they can exert their health promoting effects, but several probiotics show a poor resistance to technological processes, limiting their use to a restricted number of food products. Therefore, this paper offers a short overview of the ways to improve bacterial resistance: by inducing a phenotypic modification (adaptation) or by surrounding bacteria through a physical protection (microencapsulation). A second topic briefly addressed is genetic manipulation, while the last section addresses the control of metabolism by attenuation through physical treatments to design new kinds of food.

Effects of Frozen Storage on Viability of Probiotics and Antioxidant Capacities of Synbiotic Riceberry and Sesame-Riceberry Milk Ice Creams

According to many recent studies, ice cream was found to be an effective carrier of probiotics along the human gastrointestinal tract. While probiotics have long been known to improve gut health, prebiotic-supplemented ice creams have demonstrated properties that could be linked to various health benefits and improvement of the gut microbiota. In this study, riceberry and sesame-riceberry milk ice creams were supplemented with inulin, Lactobacillus casei 01 and Lactobacillus acidophilus LA5 to examine the changes of probiotic populations in different formulations of ice cream. The survivability of probiotics after 60 days of frozen storage and the level of viable cell tolerance towards the simulated gastrointestinal environment were also assessed, followed by sensory evaluation with 100 untrained panelists and determination of chemical qualities of ice cream samples. Findings revealed L. casei 01 to be more resistant to frozen storage compared to L acidophilus LA5, whereas addition of sesame milk and inulin were shown to minimize levels of viable cell loss following environmental and mechanical stress, suggesting enhanced probiotic activity. Significant reductions in probiotic viability were observed for all ice cream samples, however higher survival rates were observed in prebiotic-supplemented samples prior to and after 60 days of frozen storage. Probiotic cell counts in all samples exceeded the minimum recommended value (6 log CFU/g). In simulated gastric and bile fluid, all samples illustrated a significant change in probiotic levels, which significantly decreased with increase time of exposure to acidic and basic conditions. Probiotic strains in samples containing riceberry, sesame and inulin demonstrated greatest survivability as observed by reduction in pH and increased total acidity, with increased antioxidant and phenolic contents. On the other hand, changes in physicochemical properties of ice cream lowered overall sensory scores in terms of color and flavor. This study contributes to future development and applications of riceberry and sesame for inducement of synbiotic effects in novel probiotic products.

Microencapsulation of endophytic LAB (KCC-41) and its probiotic and fermentative potential for cabbage kimchi

The aim of the present study was to isolate novel lactic acid bacteria (LAB) from hairy vetch forage crop and characterize their probiotic and fermentative potential for preparing Korean cabbage kimchi. First, functional characterization of isolated strains such as antagonistic property, auto-aggregation, antibiotic susceptibility, and extracellular enzyme production was performed. The isolated Lactobacillus plantarum KCC-41 strain was able to inhibit pathogenic fungal spore formation. It showed susceptibility to common commercial antibiotics drugs. The selected LAB strain was then subjected to microencapsulation with alginate biopolymer. Its ability to survive in in vitro simulated gastro-intestinal fluid was evaluated. It was also used in the fermentation of cabbage kimchi samples. The encapsulated KCC-41 strain could effectively lead to kimchi fermentation in terms of reducing its pH and dominating bacterial count. It also significantly increased organic acid production than non-encapsulated LAB (KCC-41) for cabbage kimchi samples.

In situ fabrication of radiopaque microcapsules for oral delivery and real-time gastrointestinal tracking of Bifidobacterium

INTRODUCTION

Although oral administration of Bifidobacterium is a promising approach for diseases, lack of resistance to harsh conditions and real-time tracking in gastrointestinal system in vivo are still major challenges in basic research and clinical applications.

MATERIALS AND METHODS

In this study, we fabricated a chitosan-coated alginate microcapsule loaded with in situ synthesized barium sulfate (CA/BaSO4 microcapsule) for oral Bifidobacterium delivery and real-time X-ray computed tomography (CT) imaging. CA/BaSO4 microcapsules containing the Bifidobacterium were prepared in situ by one-step electrostatic spraying method, and then coated with chitosan.

RESULTS

The results indicated that CA/BaSO4 microcapsules with an average diameter of approximately 200 μm possessed favorable mechanical stability and X-ray attenuation capacity. Encapsulation of Bifidobacteria in the CA/BaSO4 microcapsules exhibited superior resistance to cryopreservation and gastric acid environment in vitro. After oral administration in mice, these CA/BaSO4 microcapsules could be real-time visualized by CT imaging and readily reached the intestine to release Bifidobacteria.

CONCLUSION

The radiopaque CA/BaSO4 microcapsules provide a novel platform for efficient protection, non-invasive real-time monitoring and intestinal-targeted Bifidobacterium delivery.

Effect of Non-Dairy Food Matrices on the Survival of Probiotic Bacteria during Storage

The viability of probiotics in non-dairy food products during storage is required to meet content criteria for probiotic products. This study investigated whether non-dairy foods could be matrices for probiotics. Selected probiotic bacteria were coated on non-dairy foods under two storage conditions, and viabilities were assessed. The non-dairy foods were coated with 5-7 log cfu g-1 of Lactobacillus acidophilus ATCC4356T, Lactobacillus plantarum RC30, and Bifidobacterium longum ATCC15707T. The coated non-dairy foods were stored at 20 °C and 20% relative humidity (RH) or 30 °C and 50% RH. Viability of probiotic bacteria was determined after 0, 2, and 4 weeks of storage. B. longum showed the highest survival at week 4 of 6.5-6.7 log cfu g-1 on wheat bran and oat, compared with 3.7-3.9 log cfu g-1 of L. acidophilus and 4.2-4.8 log cfu g-1 of L. plantarum at 20 °C 20% RH. Under the storage conditions of 30 °C 50% RH, survival of 4.5 log cfu g-1 of B. longum was also found on oat and peanut. This was two and four times higher than the population of L. acidophilus and L. plantarum, respectively. The results suggest that probiotics can survive on non-dairy foods under ambient storage conditions. However, the storage conditions, food matrices, and probiotic strains should be carefully chosen to maximize probiotic bacteria survival.

Novel intestinal-targeted Ca-alginate-based carrier for pH-responsive protection and release of lactic acid bacteria

A novel intestinal-targeted carrier for pH-responsive protection of lactic acid bacteria in stomach and rapid release of lactic acid bacteria in small intestine is successfully developed. The proposed carrier is composed of a Ca-alginate/protamine (CAP) composite shell and a Lactobacillus-casei-encapsulated Ca-alginate (CA) core. The carriers are prepared simply by a coextrusion minifluidic and subsequent adsorption method. The CAP composite shell offers not only improved protection for Lactobacillus casei to guarantee the endurance and survival in the stomach but also satisfactory intestinal-targeted characteristics to guarantee the rapid release of Lactobacillus casei in the small intestine. In the stomach, where there is an acidic environment, the diffusion channels delineated by the CA networks in the CAP composite shell of the carriers are choked with protamine molecules; as a result, it is hard for the gastric acid to diffuse across the CAP composite shell and thus the encapsulated Lactobacillus casei inside carriers can be efficiently protected. However, when they come to the small intestine, where there is a neutral environment, the carriers dissolve rapidly because of the cooperation between protamine and trypsin; consequently, the encapsulated Lactobacillus casei can be quickly released. The proposed CAP composite carrier provides a novel mode for developing efficient protection systems, responsive controlled-release systems, and intestinal-targeted drug delivery systems.