Intestinal Fluid Research Articles

Effect of four different cooking methods on the fat digestion characteristics of yellow-feathered chicken

The aim of this study was to investigate the effects of four cooking methods (boiling, microwaving, air frying and roasting) on the fat characteristics of chicken. The results showed that cooking significantly exacerbated fat oxidation, with boiling showing significantly lower level of malondialdehyde (MDA) at 0.25 ug/g. Microwaving, air frying and roasting significantly increased the levels of saturated fatty acids (SFA), while boiling decreased the levels to 1137.24 µg/g. In terms of digestive characteristics, in the gastric digestive fluid, the roast group had the largest particles while the boil group had the smallest particles. In the intestinal digestive fluid, boiled and microwaved chicken exhibited significantly smaller particle sizes, which was consistent with the trends in lipid droplet size and number observed by laser confocal. Boiling and microwaving significantly increased digestibility, reaching 51.51% and 54.25%, respectively. In conclusion, boiling could slow fat oxidation and reduce particle size, and promote lipid digestion.

Polycaprolactone-Vitamin E TPGS Micellar Formulation for Oral Delivery of Paclitaxel.

This study aimed to investigate the potential of polycaprolactone-vitamin E TPGS (PCL-TPGS) micelles as a delivery system for oral administration of paclitaxel (PTX). The PCL-TPGS copolymer was synthesized using ring opening polymerization, and PTX-loaded PCL-TPGS micelles (PTX micelles) were prepared via a co-solvent evaporation method. Characterization of these micelles included measurements of size, polydispersity, and encapsulation efficiency. The cellular uptake of PTX micelles was evaluated in Caco-2 cells using rhodamine 123 (Rh123) as a fluorescent probe. Moreover, an everted rat sac study was conducted to evaluate the ex vivo permeability of PTX micelles. Additionally, a comparative pharmacokinetic study of PTX micelles versus the marketed formulation, Ebetaxel® (a Taxol generic), was performed after a single oral administration to rats. The results demonstrated that the micellar formulation significantly improved PTX solubility (nearly 1 mg/mL). The in vitro stability and release of PTX micelles in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) demonstrated that PTX micelles remained stable for up to 24 h and significantly slowed the release of PTX in both media compared to Ebetaxel®. The in vitro cellular uptake, ex vivo intestinal permeability, and in vivo pharmacokinetic profile demonstrated that PTX micelles enhanced the permeability and facilitated a rapid absorption of the drug. Conclusively, the PCL7000-TPGS3500 micelles exhibit potential as an effective oral delivery system for PTX.

An investigation of nano- and micron-sized carriers based on calcium carbonate and polylactic acid for oral administration of siRNA

ABSTRACT Background Oral delivery of small interfering RNAs (siRNAs) draws significant attention, but the gastrointestinal tract (GIT) has many biological barriers that limit the drugs’ bioavailability. The aim of this work was to investigate the potential of micro- and nano-sized CaCO3 and PLA carriers for oral delivery of siRNA and reveal a relationship between the physicochemical features of these carriers and their biodistribution. Research design and methods In vitro stability of carriers was investigated in simulated gastric and intestinal fluids. Toxicity and cellular uptake were investigated on Caco-2 cells. The biodistribution profiles of the developed CaCO3 and PLA carriers were examined using different visualization methods, including SPECT, fluorescence imaging, radiometry, and histological analysis. The delivery efficiency of siRNA loaded carriers was investigated both in vitro and in vivo. Results Micro-sized carriers were accumulated in the stomach and later localized in the colon tissues. The nanoscale particles (100–250 nm) were distributed in the colon tissues. nPLA was also detected in small intestine. The developed carriers can prevent siRNA from premature degradation in GIT media. Conclusion Our results reveal how the physicochemical properties of the particles, including their size and material type can affect their biodistribution profile and oral delivery of siRNA.

Preparation, characterization, in vitro and in vivo studies of liposomal berberine using novel natural Fiber Interlaced Liposomal technology

Berberine hydrochloride (BBR), used in various traditional medicinal practices, has a variety of pharmacological effects. It is a plant-derived quaternary isoquinoline alkaloid with a low water solubility and can be used in the treatment of various conditions. However, the therapeutic use of BBR has been compromised because of its hydrophobic characteristics, in addition to its low stability and poor bioavailability. To overcome these drawbacks of BBR’s oral bioavailability, technologies like liposomal delivery systems have been developed to ensure enhanced absorption. But conventional liposomes have low physical and chemical stability due to delicate liposomal membranes, peroxidation and rapid clearance from the bloodstream. Surface modification of liposomes could be a solution and creating a liposome with plant-based fibers as surface material will provide enhanced stability, aqueous solubility and protection against degradation. Consequently, the aim of this study is to create and describe a Fiber Interlaced Liposome™ (FIL) as a vehicle for an enhanced bioavailability platform for BBR and other biomolecules. This optimised FIL-BBR formulation was analysed for its structural and surface morphological characteristics by using FTIR, SEM, TEM, XRD, zeta potential and DSC. Encapsulation efficiency, stability, and sustained release studies using an in vitro digestion model with simulated gastric and intestinal fluids were also examined. FIL formulation showed a sustained release of BBR at 59.03 % as compared to the unformulated control (46.73 %) after 8 h of dialysis. Furthermore, the FIL-BBR demonstrated enhanced stability in the simulated gastric fluid (SGF) in addition to a more sustained release in the simulated intestinal fluid (SIF). The efficacy of FIL-BBR were further anlaysed by an in vivo bioavailability study using male Wistar rats and it demonstrated a 3.37−fold higher relative oral bioavailability compared to the unformulated BBR. The AUC 0-t for BBR in FIL-BBR was 1.38 ng.h/mL, significantly greater than the unformulated BBR (0.41 ng.h/mL). Similarly, the Cmax for BBR in FIL-BBR (50.98 ng/mL) was discovered to be far greater than unformulated BBR (15.54 ng/mL) after the oral administration. These findings imply that fruit fiber based liposomal encapsulation improves the stability and slows down BBR release, which could be advantageous for applications requiring a higher bioavailability and a more sustained release.

Preparation of starch-based green nanofiber mats for probiotic encapsulation by electrospinning.

In this study, starch-based nanofiber mats were successfully prepared from aqueous solution by electrospinning and used for probiotic encapsulation for the first time. The physicochemical properties of the octenylsuccinated (OS) starch/poly(vinyl alcohol) (PVA) blend solutions were systematically investigated. Through Fourier transform infrared spectroscopy and X-ray diffraction spectra analysis, it was found that miscibility and hydrogen bonding interactions exist between OS starch and PVA molecules. Thermogravimetric analysis and derivative thermogravimetric analysis revealed that the produced nanofibers possess satisfactory thermal stability. Scanning electron microscopy images and diameter distribution histograms showed that continuous and defect-free nanofibers were obtained and along with the increase in the weight ratio of OS starch, the average diameter gradually decreased. In addition, it was confirmed that the probiotics were successfully encapsulated in nanofiber mats. The survival rates of Lactobacillus plantarum AB-1 and Lactobacillus rhamnosus GG encapsulated in nanofibers were as high as 94.63% and 92.42%, respectively, significantly higher than those of traditional freeze-drying. Moreover, compared to free cells, probiotics encapsulated in nanofiber mats retained better viability after 21 days of storage at 4 and 25°C, and showed remarkably higher survival rates after exposure to simulated gastric and intestinal fluid. This study showed that the developed nanofibers can be a promising encapsulation system for the protection of probiotics.

Enhancing therapeutic effects alginate microencapsulation of thyme and calendula oils using ionic gelation for controlled drug delivery

This study focuses on encapsulating and characterizing essential oils such as thyme and calendula oils, which are known for their therapeutic properties but are limited in pharmaceutical formulations due to their low water solubility and instability, with alginate microspheres. Alginate presents an excellent option for microencapsulation due to its biocompatibility and biological degradability. The ionic gelation (IG) technique, based on the ionic binding between alginate and divalent cations, allows the formation of hydrogel materials with high water content, mechanical strength, and biocompatibility. The microspheres were characterized using FT-IR, SEM, and swelling analyses. After determining the encapsulation efficiency and drug loading capacity, the microspheres were subjected to dissolution studies under simulated digestion conditions. It was observed that the swelling percentage of the microspheres in simulated gastric fluid (SGF) ranged from ∼15% to 100%, while in simulated intestinal fluid (SIF) it ranged from ∼150% to 325%. Thyme oil, with low viscosity, exhibited higher encapsulation efficiency than marigold oil. The highest encapsulation efficiency was observed in A-TO-2 microspheres, while the highest drug loading capacity was observed in A-TO-5 microspheres. During the examination of the dissolution profiles of the microspheres, dissolution rates ranging from 10.98% to 23.56% in SGF and from 52.44% to 63.20% in SIF were observed.

Alginate Beads with Encapsulated Bioactive Substances from Mangifera indica Peels as Promising Peroral Delivery Systems.

Since various bioactive substances are unstable and can degrade in the gastrointestinal tract, their stabilization is crucial. This study aimed to encapsulate mango peel extract (MPE) into edible alginate beads using the ionotropic gelation method for the potential oral delivery of bioactive substances. Mango peels, generally discarded and environmentally harmful, are rich in health-promoting bioactive substances. The alginate beads were examined for entrapment efficiency, particle size, morphology, thermal stability, physiochemical interactions, release profile under gastrointestinal conditions, and antibacterial efficacy. The study demonstrated the successful encapsulation of MPE with an efficiency of 63.1%. The in vitro release study showed the stability of the alginate beads in simulated gastric fluid with a maximum release of 45.0%, and sustained, almost complete release (99.4%) in simulated intestinal fluid, indicating successful absorption into the human body. In both fluids, the MPE release followed first-order kinetics. Encapsulation successfully maintained the antibacterial properties of MPE, with significant inhibitory activity against pathogenic intestinal bacteria. This is the first study on MPE encapsulation in alginate beads, presenting a promising oral delivery system for high-added-value applications in the food industry for dietary supplements, functional foods, or food additives. Their production is sustainable and economical, utilizing waste material and reducing environmental pollution.

Spray-drying microencapsulation of plum peel bioactives using Arabic gum and maltodextrin as coating matrix

The goal of the current study is to develop a microencapsulation formulation of plum peel bioactives in Arabic gum and/or maltodextrin through spray-drying. A mixture design of experiments was used with 2 coating materials (Arabic gum and maltodextrin) and 1 process factor (inlet temperature) to find the optimum conditions for maximizing the encapsulation efficiency (EE) in terms of total phenolic content (TPC), encapsulation yield (EY), antioxidant activity and total anthocyanin content (TAC). The systems for the selected 4 responses were modeled satisfactorily (p < 0.0001) with non-significant lack of fit (p > 0.05). The optimum conditions (5% maltodextrin and 5% Arabic gum at 160 °C) to obtain the maximum yields (85% EE, 81.50% EY, 5.78 mg trolox equivalents of antioxidant activity per g dried microcapsule and 0.65 TAC as mg cyaniding-3-glucoside per g dried microcapsule) were tested to confirm the proposed method. The difference between the actual and the predicted values were less than 2%. Moreover, morphological and physicochemical properties of the microparticles were also performed. Release behaviour of the TPC was also investigated based on the in vitro digestion test. TPC release in the gastric fluid was higher than in the intestinal fluid (78.92% versus 69.37%).

Water-soluble biodegradable polyesters with pH and ionic responsivity

The synthesis of novel water-soluble polymers with biodegradability is an effective way to mitigate their negative environmental impacts. In this study, semi-aromatic copolyester poly(butylene succinate-co-butylene terephthalate) (PBST) with exceptional biodegradability is used as the resin matrix. Anionic sodium 1–3-isophthalate-5-sulfonate (SIPA) is introduced as a fourth monomer to prepare random poly(butylene succinate-co-butylene terephthalate-co-butylene 5-sodiosulfoisophthalate) (PBSTS) copolyesters by melt copolymerization. The incorporation of ionic groups enhances the hydrophilicity and water absorption of the copolyesters, resulting in water-soluble materials that exhibit ionic and temperature responsivity. Furthermore, the ionized biodegradable copolyesters demonstrate distinct pH-dependent degradation, which is accelerated at pH = 5.5 and 8.5 but inhibited at pH = 7.2. Degradation assessments in simulated body fluids reveal that the PBSTS copolyesters exhibit significant degradation in gastric fluids at pH = 1.5 with minimal degradation in intestinal fluids at pH = 6.8 and in body fluids at pH = 7.0. This unique degradation performance highlights the potential of these materials for addressing the challenges associated with selective drug delivery and localized controlled release in the human body.

Enterococcus avium from a traditional Chinese liquor fermentation system with the potential for the de novo synthesis of GABA

γ-Aminobutyric acid (GABA) is a prevalent nonprotein amino acid with diverse physiological functions, attracting considerable interest in the food industry. However, current GABA-producing strains require glutamate as a substrate for synthesis. Probiotics capable of de novo GABA synthesis using sugars without glutamate are crucial for developing novel foods. This study employed a pH indicator method to selectively screen for GABA-producing bacteria. Nineteen strains with fermentation liquid pH greater than 5 were obtained, all demonstrated the ability to synthesize GABA from Daqu. Among these strains, Enterococcus (E.) avium GL1 stood out for its high GABA production capacity, reaching 9.8 g/L when utilizing glucose for de novo GABA synthesis without monosodium glutamate (MSG). E. avium GL1 exhibited robust viability in challenging environments, maintaining stability in simulated gastric and intestinal fluids. As a potentially probiotic strain, E. avium GL1 achieved remarkable GABA production of 206.84 g/L with a production efficiency of 2.87 g/L/h, facilitated by automatic pH control during fermentation through continuous addition of glucose and MSG addition. This exceptional result represents the highest GABA production reported for E. avium, highlighting its significant potential for the development of innovative functional foods.

Safety assessment of probiotic Lactiplantibacillus plantarum MCC5231 and its persistence in gastrointestinal tract

Probiotics are the health beneficial microorganisms and suitable for food industry if found fit for human consumption. In the present study, Lactiplantibacillus plantarum MCC5231, a probiotic bacterium included in vegetable-based beverages, was evaluated for its safety characteristics and gastrointestinal survival using a combined in silico and in vitro approach. The strain was found to be devoid of hemolytic, lecithinase and gelatinase activities. Additionally, it does not consist any transferable antibiotic resistance genes. Further, whole genome sequence analysis revealed the presence of three intact prophages and 14 virulence-associated genes, however, none of them posed a pathogenic threat. Importantly, MCC5231 do not possess any gene associated with toxin production. The strain harbored a CRISPR system, enhancing defense against prophages. Survival assays under simulated gastric and intestinal fluid conditions demonstrated viability rates of 71.4 % and 83.3 %, respectively. Genetic analysis of the mucin binding protein indicated possession of a type II mucin binding domain, suggesting moderate adhesion to intestinal cells. Furthermore, L. plantarum MCC5231 exhibited the ability to produce exopolysaccharides and form biofilms, which may confer additional protection in the gastrointestinal tract. Based on these findings, L. plantarum MCC5231 appears to be a safe probiotic candidate suitable for commercial use in the food industry.

Synthesis of C3'-Foused Aryl/Penta-1,4-Dien-3-One/Amine Hybrids as HSP90C-Terminal Inhibitors.

24 C3'-focused hybrids of aryl/penta-1,4-dien-3-one/amine (APDA) were designed and synthesized. Of these hybrids, 2 n demonstrated improved antiproliferative effects on HER2-positive breast cancer cells (SKBr3 and BT474) and triple-negative breast cancer (TNBC) cells (MDA-MB-231 and MDA-MB-468) with IC50 values ranging from 7.45 to 10.75 μM, but less toxicity to normal breast cells MCF-10A than the first generation of hybrid 1. Additionally, 2 n retained its ability to inhibit HSP90C-terminus, leading to the degradation of HSP90 client proteins HER2, EGFR, pAKT, AKT, and CDK4, without inducing a heat-shock response. Notably, 2 n also demonstrated improved thermostability compared to 1 and maintained in vitro metabolic stability in simulated intestinal fluid. These findings will provide a scientific basis for developing HSP90C-terminal inhibitors in the future.

Integration of metagenomics and metaproteomics in the intestinal lavage fluids benefits construction of discriminative model and discovery of biomarkers for HBV liver diseases.

Intestinal lavage fluid (IVF) containing the mucosa-associated microbiota instead of fecal samples was used to study the gut microbiota using different omics approaches. Focusing on the 63 IVF samples collected from healthy and hepatitis B virus-liver disease (HBV-LD), a question is prompted whether omics features could be extracted to distinguish these samples. The IVF-related microbiota derived from the omics data was classified into two enterotype sets, whereas the genomics-based enterotypes were poorly overlapped with the proteomics-based one in either distribution of microbiota or of IVFs. There is lack of molecular features in these enterotypes to specifically recognize healthy or HBV-LD. Running machine learning against the omics data sought the appropriate models to discriminate the healthy and HBV-LD IVFs based on selected genes or proteins. Although a single omics dataset is basically workable in such discrimination, integration of the two datasets enhances discrimination efficiency. The protein features with higher frequencies in the models are further compared between healthy and HBV-LD based on their abundance, bringing about three potential protein biomarkers. This study highlights that integration of metaomics data is beneficial for a molecular discriminator of healthy and HBV-LD, and reveals the IVF samples are valuable for microbiome in a small cohort.

Inactivation of listerial biofilm on the food-contact surface using thymol and bio-modulated yeast microcarriers

Decontamination of bacterial biofilms formed on food-contact surfaces is a serious challenge in the food industry. In this study, a food-grade antimicrobial system was developed using yeast-based microcarriers and essential oil (EOs; thymol) to inactivate bacterial biofilms on food-contact surfaces. A bio-inspired method that involves pre-treatment of yeast microcarriers with simulated intestinal fluid (SIF) was employed to modulate the release of the encapsulated EOs. The effectiveness of the developed antimicrobial delivery system was evaluated based on physicochemical characterization, antimicrobial activities against planktonic bacterial cells in the presence of organic matter, affinity to bind bacterial biofilms, and co-incubation and residual antimicrobial activities against bacterial biofilms. The results illustrate that pre-treatment of yeast-based microcarriers with SIF significantly (p < 0.05) enhanced the release of the encapsulated EOs without influencing the encapsulation yield and binding of yeast-based microcarriers with bacterial biofilms. Strong antibiofilm activities were exhibited by the thymol encapsulated in the pre-digested yeast cells (pdYC@Thymol) compared to free thymol or thymol encapsulated in the undigested yeast microcarriers. Populations of Listeria innocua in biofilms (ca. 7.54 log CFU/cm2) decreased to ca. 2.63 log CFU/cm2 after 1 h of co-incubation with the pdYC@Thymol suspensions and further decreased to ca. 0.85 log CFU/cm2 after removal of the loosely bound pdYC@Thymol particles. Overall, this study suggests that the combined effects of the targeted delivery of the EOs via encapsulation in yeast-based microcarriers and facilitated release of the encapsulated EOs upon binding with bacterial biofilms can effectively inactivate the bacterial biofilms formed on food-contact surfaces, thereby enhancing the microbiological safety of the food-related environments.

In Vitro Evaluation of Probiotic Properties and Anti-Pathogenic Effects of Lactobacillus and Bifidobacterium Strains as Potential Probiotics.

Probiotics restore gut microbial balance, thereby providing health-promoting effects to the host. They have long been suggested for managing intestinal disorders caused by pathogens and for improving gut health. This study evaluated the probiotic properties and anti-pathogenic effects of specific probiotic strains against the intestinal pathogens Staphylococcus aureus and Escherichia coli. The tested strains-Lactiplantibacillus plantarum LC27, Limosilactobacillus reuteri NK33, Lacticaseibacillus rhamnosus NK210, Bifidobacterium longum NK46, and Bifidobacterium bifidum NK175-were able to survive harsh conditions simulating gastric and intestinal fluids. These strains exhibited good auto-aggregation abilities (41.8-92.3%) and ideal hydrophobicity (30.9-85.6% and 38.3-96.1% for xylene and chloroform, respectively), along with the ability to co-aggregate with S. aureus (40.6-68.2%) and E. coli (38.6-75.2%), indicating significant adhesion levels to Caco-2 cells. Furthermore, these strains' cell-free supernatants (CFSs) demonstrated antimicrobial and antibiofilm activity against S. aureus and E. coli. Additionally, these strains inhibited gas production by E. coli through fermentative activity. These findings suggest that the strains tested in this study have potential as novel probiotics to enhance gut health.

Anti-obesity effects of Lactiplantibacillus plantarum BHP03 on high-fat diet mice and its regulatory function on intestinal microbiota

Obesity is defined as abnormal or excessive accumulation of body fat, which always causes serious harm to body health. In this work, an anti-obesity strain, Lactiplantibacillus plantarum BHP03 (L. plantarum), was explored. This strain showed good reproductive and acid production abilities. And its simulated intestinal fluid tolerance was better than that of Lacticaseibacillus rhamnosus GG（LGG). The in vitro lipid-lowering indicators (inhibition rate of pancreatic lipase, bile-acid salt binding capacity) of L. plantarum BHP03 were at the same level as LGG, but L. plantarum BHP03 exhibited better ability to clear cholesterol. Further, L. plantarum BHP03 was used to intervene high-fat diet mice by oral administration. The results showed that high (109 CFU/day) and low (108 CFU/day) doses of L. plantarum BHP03 could alleviate excessive weight gain caused by high-fat diet and improve the symptoms of hepatorenal enlargement and liver fatty lesions. In addition, high dose L. plantarum BHP03 significantly reduced the content of the serum total cholesterol and low-density lipoprotein cholesterol in mice. Moreover, high dose L. plantarum BHP03 enhanced the species richness of intestinal flora in mice fed with high-fat diet, decreasing the abundance of harmful bacteria such as Staphylococcus and increasing the abundance of beneficial bacteria such as Dubosiella, Akkermansia, Bifidobacterium and Lactobacillus. Therefore, it could be concluded that high dose L. plantarum BHP03 was more effective in preventing obesity and balancing gut microbiota. These findings may provide a theoretical basis for the application of lactobacilli to develop functional foods related to anti-obesity.

Safety evaluation of Bifidobacterium animalis subsp. lactis BLa80 under in vitro, and in vivo conditions

Bifidobacterium animalis subsp. lactis BLa80 is a new probiotic strain with extensive applications in food products both domestically and internationally. Given the rising consumption of this probiotic, its safety assessment is increasingly crucial in the food industry. This study evaluates the safety of strain BLa80 using a combination of in vitro and in vivo assays along with genomic analysis. Methods included exposing the strain to artificial gastric and intestinal fluids, as well as a medium containing bile salts, to stimulate human digestive conditions. The strain showed high tolerance to gastric fluid at pH of 2.5 and to 0.3 % bile salts. It maintained a 99.92 % survival rate in intestinal fluid. Additional tests assessed hemolytic activity, antibiotic susceptibility (revealing sensitivity to 7 antibiotics), and biogenic amine production using HPLC-ELSD, confirming the absence of histamine, and other harmful amines. Bile salt hydrolase activity was demonstrated qualitatively, and metabolic byproducts were quantitatively analyzed using a D-/l-lactic acid assay kit, showing that BLa80 produces 1.48 mg/mL of l-lactic acid and no harmful d-lactic acid. Genomic analysis confirmed the absence of virulence or pathogenicity genes, and a 90-day oral toxicity study in rats confirmed no toxic effects at various doses. Overall, these findings support the safety classification of the strain BLa80.

Structural characterization of oligosaccharide from Dendrobium officinale and its properties in vitro digestion and fecal fermentation

Oligosaccharides from Dendrobium officinale (DOO) is a kind of new potential prebiotic for health. In this study, structural characteristics, digestion properties and regulatory function on intestinal flora of DOO were investigated. An oligosaccharide, DOO 1–1, was purified by DEAE-Sepharose Fast Flow and Sephadex G-25, and its physicochemical properties were characterized as a glucomannan oligosaccharide with a molecular weight of 1560 Da (DP = 9). In vitro simulated digestion, it proved that the structure of DOO 1–1 was degraded hardly in the simulated gastric and small intestinal fluid. By evaluating the gas, short-chain fatty acids and intestinal microbiota in vitro fermentation, DOO has an excellent regulatory effect on intestinal microbiota, especially promoting the proliferation of Bacteroidetes and Actinobacteria. Therefore, DOO can be used as a potential prebiotic in functional foods.

Enhanced oral bioavailability of cannabidiol by flexible zein nanoparticles: in vitro and pharmacokinetic studies.

Cannabidiol (CBD) has a variety of pharmacological effects including antiepileptic, antispasmodic, anxiolytic and anti-inflammatory among other pharmacological effects. However, since CBD is a terpene-phenolic compound, its clinical application is limited by its poor water solubility, low stability, and low bioavailability. In this study, we used several strategies to address the above problems. Hydrochloric acid was used to modify zein to improve the molecular flexibility. Flexible zein nanoparticles (FZP-CBD) loaded with CBD was prepared to improve the stability and bioavailability of CBD. The parameters were evaluated in terms of morphology, particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE%), loading capacity (LC%), and storage stability. Simulated gastrointestinal fluid release experiment and bioavailability assay were applied in the evaluation. The simulated gastrointestinal fluid experiment showed that the release rates of FZP-CBD and natural zein nanoparticles (NZP-CBD) loaded with CBD were 3.57% and 89.88%, respectively, after digestion with gastric fluid for 2 h, 92.12% and 92.56%, respectively, after intestinal fluid digestion for 2 h. Compared with NZP-CBD, the C max of FZP-CBD at 3 different doses of CBD was increased by 1.7, 1.3 and 1.5 times respectively, and AUC0-t was increased by 1.4, 1.1 and 1.7 times respectively, bioavailability (F) was increased by 135.9%, 114.9%, 169.6% respectively. The experimental results showed that FZP-CBD could protect most of the CBD from being released in the stomach, and then control its release in the intestines, promote the absorption of CBD in the small intestine, and increase the bioavailability of CBD. Therefore, FZP-CBD could improve the utilization value of CBD and provide a new idea for the application of CBD in medicine and pharmacy.

Discovery and Characterization of a Novel Bacteriocin That Strongly Inhibits Staphylococcus aureus

Drug resistance in Staphylococcus aureus is a serious problem, and the development of new antimicrobial drugs to circumvent drug resistance has become a trend. In this study, we isolated a strain of Bacillus subtilis with high tolerance to alcohol, pH, NaCl, bile salt, surfactants, temperature, and simulated intestinal fluids. We optimized culture parameters to obtain the best fermentation conditions for the production of inhibitory compounds in cell-free culture media. The crude extract showed excellent stability when exposed to temperature, pH, and ultraviolet radiation, with almost no loss of bacteriostatic activity after treatment. After isolation and purification, the peptide sequences were identified using ultraperformance liquid chromatography–mass spectrometry (UPLC–MS), and the antibacterial sequences were analyzed using bioinformatics. The results of the identification showed that there was one novel bacteriocin (NSGGSYGSGGGGGGGNSHGY) with a molecular weight of 1513.58 Da. The minimum inhibitory concentration (MIC) of the B5 bacteriocin was 31.25 μg/mL against S. aureus, and it is noteworthy that bacteriocin B5 also showed weak antibacterial activity against Vibrio parahaemolyticus. In conclusion, this study developed a novel bacteriocin that has the potential to be used as an alternative to S. aureus antibiotics.