Efficacy of microencapsulated lactic acid bacteria in Helicobater pylori eradication therapy

Delivery of Probiotic-Loaded Microcapsules in the Gastrointestinal Tract: A Review

Probiotics are live microorganisms that inhabit the gastrointestinal tract and confer health benefits to consumers. However, a sufficient number of viable probiotic cells must be delivered to the specific site of interest in the gastrointestinal tract to exert these benefits. Enhanced viability and tolerance to sublethal gastrointestinal stress can be achieved using appropriate coating materials and food matrices for orally consumed probiotics. The release mechanism and interaction of probiotic microcapsules with the gastrointestinal tract have been minimally explored in the literature to date. To the authors' knowledge, no review has been published to discuss the nature of release and the challenges in the targeted delivery of probiotics. This review addresses gastrointestinal-related complications in the formulation of targeted delivery and controlled release of probiotic strains. It investigates the impacts of environmental stresses during the transition stage and delivery to the target region in the gastrointestinal tract. The influence of factors such as pH levels, enzymatic degradation, and redox conditions on the release mechanisms of probiotics is presented. Finally, the available methods to evaluate the efficiency of a probiotic delivery system, including in vitro and in vivo, are reviewed and assessed. The paper concludes with a discussion highlighting the emerging technologies in the field and emphasising key areas in need of future study.

Controlling Intestinal Infections and Digestive Disorders Using Probiotics

After consumption, probiotics provide health benefits to the host. Probiotics and their metabolites have therapeutic and nutritional properties that help to alleviate gastrointestinal, neurological, and cardiovascular problems. Probiotics strengthen host immunity through various mechanisms, including improved gut barrier function, receptor site blocking, competitive exclusion of pathogens, and the production of bioactive molecules. Emerging evidence suggests that intestinal bowel diseases can be fatal, but regular probiotic consumption can alleviate disease symptoms. The use and detailed description of the health benefits of probiotics to consumers in terms of reducing intestinal infection, inflammation, and digestive disorders are discussed in this review. The well-designed and controlled studies that examined the use of probiotics to reduce life-threatening activities caused by intestinal bowel diseases are also covered. This review discussed the active principles and potency of probiotics as evidenced by the known effects on host health, in addition to providing information on the mechanism of action.

Gamma-Aminobutyric Acid-Producing Levilactobacillus brevis Strains as Probiotics in Litchi Juice Fermentation

Levilactobacillus brevis strains can be isolated from traditional Chinese pickles and used as the starter cultures to improve the nutritional profiles of fermented juices. Three L. brevis strains (LBG-29, LBG-24, LBD−14) that produce high levels of gamma-aminobutyric acid (GABA; >300 mg/L) were isolated from traditional Chinese pickles. The strains showed tolerance to low pH and high bile salts and exhibited safety in vitro. Litchi juice was fermented using each strain at 37 °C for 48 h. The litchi juice was determined to be a good substrate for fermentation as the process enhanced its functional profile. Overall, cell vitality increased (above 8.7 log10 CFU/mL), the antioxidant activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric ion-reducing antioxidant power (FRAP) were significantly increased, and the antioxidant capacity of the 2,2′-amino-di(3-ethyl-benzothiazoline sulphonic acid-6)ammonium salt (ABTS) was decreased. There was also a significant increase in the GABA and acetic acid content after LBG-29 and LBG-24 fermentation. It was thus determined that the LBG-29 and LBG-24 strains could be used to improve beverage functionality and aid in the development of new products. This is the first report of litchi fermentation using L. brevis as a starter culture. Further research is required to elucidate the functional benefits for the human body and the nutritional and functional properties during its shelf life.

Streptomyces rochei MS-37 as a Novel Marine Actinobacterium for Green Biosynthesis of Silver Nanoparticles and Their Biomedical Applications

Periodontitis, as one of the most common diseases on a global scale, is a public health concern. Microbial resistance to currently available antimicrobial agents is becoming a growing issue in periodontal treatment. As a result, it is critical to develop effective and environmentally friendly biomedical approaches to overcome such challenges. The investigation of Streptomyces rochei MS-37's performance may be the first of its kind as a novel marine actinobacterium for the green biosynthesis of silver nanoparticles (SNPs) and potentials as antibacterial, anti-inflammatory, antibiofilm, and antioxidant candidates suppressing membrane-associated dental infections. Streptomyces rochei MS-37, a new marine actinobacterial strain, was used in this study for the biosynthesis of silver nanoparticles for various biomedical applications. Surface plasmon resonance spectroscopy showed a peak at 429 nm for the SNPs. The SNPs were spherical, tiny (average 23.2 nm by TEM, 59.4 nm by DLS), very stable (-26 mV), and contained capping agents. The minimum inhibitory concentrations of the SNPs that showed potential antibacterial action ranged from 8 to 128 µg/mL. Periodontal pathogens were used to perform qualitative evaluations of microbial adhesion and bacterial penetration through guided tissue regeneration membranes. The findings suggested that the presence of the SNPs could aid in the suppression of membrane-associated infection. Furthermore, when the anti-inflammatory action of the SNPs was tested using nitric oxide radical scavenging capacity and protein denaturation inhibition, it was discovered that the SNPs were extremely efficient at scavenging nitric oxide free radicals and had a strong anti-denaturation impact. The SNPs were found to be more cytotoxic to CAL27 than to human peripheral blood mononuclear cells (PBMCs), with IC50 values of 81.16 µg/mL in PBMCs and 34.03 µg/mL in CAL27. This study's findings open a new avenue for using marine actinobacteria for silver nanoparticle biosynthesis, which holds great promise for a variety of biomedical applications, in particular periodontal treatment.

Streptomyces catenulae as a Novel Marine Actinobacterium Mediated Silver Nanoparticles: Characterization, Biological Activities, and Proposed Mechanism of Antibacterial Action

Biosynthesized silver nanoparticles (Bio-SNPs) were synthesized from the marine actinobacterium strain Streptomyces catenulae M2 and characterized using a variety of techniques, including UV–vis spectrum, fourier transform infrared spectroscopy (FTIR), energy dispersive x-ray (EDX), transmission electron microscopy (TEM), dynamic light scattering (DLS), surface-enhanced Raman spectroscopy (SERS), and zeta potential. The antibacterial activity of Bio-SNPs alone and in combination with antibiotic was evaluated using a microtiter-dilution resazurin assay against multidrug-resistant (MDR) bacteria. Bio-SNPs’ minimum inhibitory concentration (MIC) against bacterial strains was determined. To assess the synergistic effect of Bio-SNPs in combination with antibiotics, the Fractional Inhibitory Concentration Index (FICI) was calculated. While the safety of Bio-SNPs in biomedical applications is dependent on their use, the in vitro cytotoxicity of Bio-SNPs on normal human epithelial colon cells (NCM460) and human colorectal adenocarcinoma cells (CaCo2) were evaluated using the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay and cell lactate dehydrogenase (LDH) release. The presence of Bio-SNPs was revealed by UV–vis spectroscopy, which revealed a peak in the Surface Plasmon Resonance (SPR) spectrum at 439.5 nm. Bio-SNPs were spherical in shape and small in size (average 33 nm by TEM, 58.8 nm by DLS), with good stability (−30 mV) and the presence of capping agents. Bio-SNPs had MIC values ranging from 2 to 64 μg/ml against the bacteria tested. The MIC for P. aeruginosa was the lowest (2 μg/ml). Antibiotics have been shown to have a significant synergistic effect when combined with Bio-SNPs against tested bacteria. Bio-SNPs exhibited dose-dependent cytotoxicity against NCM460 and CaCo2 cancer cells, with the latter exhibiting far greater toxicity than  the  former.  NCM460  and CaCo2  cell   viability   decreased   from  99.3 to 95.7% and 92.3 to 61.8%, respectively, whereas LDH leakage increased from 200 to 215 nmol/ml and 261 to 730 nmol/ml, respectively. The half inhibitory concentrations (IC₅₀) for NCM460 and CaCo2 cancer cells were 79.46 and 10.41 μg/ml and 89.4 and 19.3 μg/ml, respectively. Bio-SNPs were found to be biocompatible and to have anti-inflammatory activity. Bio-SNPs are highly appealing for future nanomedicine applications due to their antibacterial and biocompatible properties and their inherent “green” and simple manufacturing.

Biosynthesis of Silver Nanoparticles by Marine Actinobacterium Nocardiopsis dassonvillei and Exploring Their Therapeutic Potentials

Nanoparticles have recently emerged as a popular research topic. Because of their potential applications in therapeutic applications, biosynthesized silver nanoparticles (Bio-AgNPs) have gained much attention in recent years. Cell-free extracts (CFE) from a marine culture of actinobacteria and silver nitrate were used to reduce Ag+ ions and create Bio-AgNPs. Nocardiopsis dasonvillei KY772427, a new silver-tolerant actinomycete strain, was isolated from marine water and used to synthesize AgNPs. In order to characterize Bio-AgNPs, UV-Vis spectral analysis, Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and dynamic light scattering spectroscopy (DLS) were all utilized. Using UV-Vis spectroscopy, a peak in the surface plasmon resonance (SPR) spectrum at 430 nm revealed the presence of Bio-AgNPs. The TEM revealed spherical AgNPs with a diameter of 29.28 nm. DLS determined that Bio-AgNPs have a diameter of 56.1 nm and a negative surface charge (-1.46 mV). The minimum inhibitory concentration (MIC) of Bio-AgNPs was determined against microbial strains. Using resazurin-based microtiter dilution, the synergistic effect of Bio-AgNPs with antimicrobials was investigated. Pseudomonas aeruginosa had the lowest MIC of Bio-AgNPs (4 μg/ml). Surprisingly, the combination of antimicrobials and Bio-AgNPs had a significant synergistic effect on the tested strains. The insecticidal activity of Bio-AgNPs (200 μg/ml) against Macrosiphum rosae was found to be maximal after 36 h. Additionally, Bio-AgNPs demonstrated significant scavenging activity against 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (OH - ) radicals, with IC 50 values of 4.08 and 8.9 g/ml, respectively. In vitro studies using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay revealed a concentration-dependent decrease in cell viability when CaCo2 cells were exposed to Bio-AgNPs. With the decrease in cell viability, lactate dehydrogenase leakage (LDH) increased. The findings of this study open up a new avenue for the use of marine Nocardiopsis dasonvillei to produce Bio-AgNPs, which have significant antimicrobial, antioxidant, insecticidal, and anticancer potential.

Enhanced Efficacy of Some Antibiotics in Presence of Silver Nanoparticles Against Multidrug Resistant Pseudomonas aeruginosa Recovered From Burn Wound Infections

Burn wound infections with multidrug-resistant (MDR) bacteria are shown in many countries as severe widespread health threats. Consequently, attention has been devoted to new nanoparticle-based materials in the field of antimicrobial chemotherapy for burn wound infections. This study aimed to evaluate both in vitro and in vivo efficacies of nanoparticle–antibiotic combinations as new classes of materials subjected against MDR Pseudomonas aeruginosa. Out of 40 Gram-negative isolates, 23 P. aeruginosa were recovered from patients with burn wound infections attending different hospitals in Tanta, Egypt. The susceptibility test revealed that 95.7% of P. aeruginosa isolates were MDR with a high incidence of resistance against carbenicillin. Antibacterial activities of silver nanoparticles (Ag-NPs) against the isolates examined showed various inhibition zone diameters ranging from 11 to 17 mm. Strong synergistic efficacy of neomycin was reported in combination with Ag-NPs against MDR P. aeruginosa P₈ and P₁₄ isolates. The in vivo effectiveness of various pharmaceutical formulations prepared from a combination of neomycin antibiotic with Ag-NPs in the treatment of induced bacterially infected mice burns showed that maximum healing activity along with faster wound contraction reported with the combination of neomycin-Ag-NPs in the spray formulation. Generally, data indicated that incorporating Ag-NPs in combination with certain antibiotics may be a new, promising application for wound treatments, especially burns infected with MDR P. aeruginosa.

Evaluation of Pediococcus pentosaceus strains as probiotic adjunct cultures for soybean milk post-fermentation

Soybean milk is an economical substitute for dairy products. Pediococcus pentosaceus has been used as a food additive to improve taste, nutrition, and food safety. In this study, four P. pentosaceus strains (CICC 24444, QK-1, MQ-1 and RQ-1) isolated from various food sources and known to exhibit broad-spectrum antibacterial activities were used to ferment soybean milk, and their fermentation characteristics and the properties of the resulting beverages were evaluated. The results revealed that the P. pentosaceus strains can inhibited the growth of five types of pathogenic bacteria (Salmonella enterica subsp. enterica serotype Enteritidis, Yersinia enterocolitica, Shigella dysenteriae, Escherichia coli, and Staphylococcus aureus), and their in vitro survival rates in the simulated stomach and intestinal environments were above 90%, satisfying the probiotic requirements. Isomaltose oligosaccharide was used as a protective agent to resist low-temperature freeze-drying damage and ensure a high survival rate, and P. pentosaceus was directly injected into fermented soymilk. The acidification of fermented soybean milk was the weakest with P. pentosaceus QK-1, and the viable bacterial counts of all strains were stable after 28 days of storage. After fermentation, the antioxidant ability was enhanced. Arginine and β-alanine levels increased after fermentation, and the adjunct culture of P. pentosaceus QK-1 increased proline levels. Our data indicate that P. pentosaceus QK-1 is a suitable strain for the development of functional plant-based beverages.

Biocompatibility analysis of high molecular weight chitosan obtained from Pleoticus muelleri shrimps. Evaluation in prokaryotic and eukaryotic cells

The search for the exploitation and recycling of biomaterials is increasing for reducing the use of non-renewable resources and minimizing environmental pollution caused by synthetic materials. In this context, Chitosan (CS) being a naturally occurring biopolymer becomes relevant. The aim of the present work was to explore the effects of High Molecular Weight CS (H-CS) from Argentinean shrimp's wastes in prokaryotic and eukaryotic in vitro cell cultures. Ultrastructure of H-CS was analysed by SEM and TEM. In vitro studies were performed in prokaryotic (Lactobacillus casei BL23) and eukaryotic (Caco-2, ARPE-19, EA.hy926 and 3T3-L1) culture cells. High performance microscopic techniques were applied to examine culture cells. No changes in morphology were found in any of the cell types. In addition, fluorescent-dyed H-CS revealed that eukaryotic cells could internalize it optimally. Viability was maintained and proliferation rate even increased for Caco-2, ARPE-19 and 3T3-L1 cells under H-CS treatment. Besides, viability was neither altered in L. casei nor in EA.hy926 cells after H-CS exposure. In conclusion, H-CS could be a suitable biopolymer to be exploited for biomedical or food industry applications.

In vitro Prebiotic Effects of Bamboo Shoots and Potato Peel Extracts on the Proliferation of Lactic Acid Bacteria Under Simulated GIT Conditions

The present study explored the possible prebiotic application of potato peel and bamboo shoot extracts for the proliferation of lactic acid bacteria (LAB) from diverse niches and their tolerance ability to simulated gastrointestinal tract (GIT) conditions was also examined. Initially, the complete 16S rDNA sequencing of selected isolates revealed them as Lactobacillus paracasei (6), Staphylococcus simulans (2), and Streptococcus thermophilus (1). Higher cell densities and rapid pH change were obtained from cultured media supplemented with BS (2%) and PP (2%) as a carbon source. Their higher tolerance and the lowest reducing sugar abilities were obtained for BS at pH 2.5 and 9.0, while at pH 3.5 and 8.0 for PP. The isolates were screened for additional functional and technological properties to harvest the most appropriate starter. The selected isolates harbored promising functional properties such as amylase presence, cell surface hydrophobicity, autoaggregation, proteolytic and lipolytic activity, antifungal action, as well as exopolysaccharide production. On the basis of these attributes, microencapsulated strain K3 was found resistant to gastrointestinal conditions after 2 h, resulting in significantly (p ≤ 0.05) improved survival compared to non-capsulated strain. The current approach presents an interesting economical strategy to modulate LAB through supplementation of plant-derived carbon sources as well as to enhance their survival under GIT.

Probiotics in Helicobacter pylori eradication therapy: Systematic review and network meta-analysis

BACKGROUND

Several probiotics were effective in the eradication treatment for Helicobacter pylori (Hp), but their comparative efficacy was unknown.

AIM

To compare the efficacy of different probiotics when supplemented in Hp eradication therapy.

METHODS

A comprehensive search was conducted to identify all relevant studies in multiple databases and previous meta-analyses. Bayesian network meta-analysis was performed to combine direct and indirect evidence and estimate the relative effects.

RESULTS

One hundred and forty studies (44 English and 96 Chinese) were identified with a total of 20,215 patients, and more than 10 probiotic strategies were supplemented in Hp eradication therapy. The rates of eradication and adverse events were 84.1 and 14.4% in probiotic group, while 70.5 and 30.1% in the control group. In general, supplementary probiotics were effective in improving the efficacy of Hp eradication and decreasing the incidence of adverse events, despite of few ineffective subtypes. In triple eradication therapy, there was no significant difference among the effective probiotics, and combined probiotics did not show a better efficacy and tolerance than single use. In triple therapy of 7 days and 14 days, Lactobacillus acidopilus was a slightly better choice, while Saccharomyces boulardii was more applicable for 10-day triple therapy.

CONCLUSIONS

Compared to placebo, most probiotic strategies were effective when supplemented in Hp eradication therapy. In triple eradication therapy, no probiotic showed a superior efficacy to the others. Compared to single use, combined probiotics could not improve the efficacy or tolerance significantly.

Biofilm Forming Lactobacillus: New Challenges for the Development of Probiotics

Probiotics are live bacteria, generally administered in food, conferring beneficial effects to the host because they help to prevent or treat diseases, the majority of which are gastrointestinal. Numerous investigations have verified the beneficial effect of probiotic strains in biofilm form, including increased resistance to temperature, gastric pH and mechanical forces to that of their planktonic counterparts. In addition, the development of new encapsulation technologies, which have exploited the properties of biofilms in the creation of double coated capsules, has given origin to fourth generation probiotics. Up to now, reviews have focused on the detrimental effects of biofilms associated with pathogenic bacteria. Therefore, this work aims to amalgamate information describing the biofilms of Lactobacillus strains which are used as probiotics, particularly L. rhamnosus, L. plantarum, L. reuteri, and L. fermentum. Additionally, we have reviewed the development of probiotics using technology inspired by biofilms.

Elevated amino acids in gastric juice as potential biomarkers for gastric cancer

Early diagnosis plays a vital role in the improvement of the curative rate of gastric cancer. However, the poor specificity and sensitivity of traditional gastric cancer biomarkers, such as carcino-embryonic antigen and carbohydrate antigen 199, make it difficult to screen early gastric cancer. Gastric juice amino acid profile may be an alternative tumor marker, since abnormal elevation of amino acids in gastric juice has been reported in precancerous patients. Normal concentration of amino acids is extremely low in gastric juice, and special techniques are required to detect amino acids in gastric juice. The change of amino acids in gastric juice is more significant than in blood and tumor tissue. The amino acid profile in gastric juice may work as efficient biomarkers for gastric cancer with the development of amino acid detection technique.