Highly active probiotic hydrogels matrixed on bacterial EPS accelerate wound healing via maintaining stable skin microbiota and reducing inflammation

Skin microbiota plays an important role in wound healing, but skin injuries are highly susceptible to wound infections, leading to disruption of the skin microbiota. However, conventional antibacterial hydrogels eliminate both probiotics and pathogenic bacteria, disrupting the balance of the skin microbiota. Therefore, it is important to develop a wound dressing that can fend off foreign pathogenic bacteria while preserving skin microbiota stability. Inspired by live bacteria therapy, we designed a probiotic hydrogel (HAEPS@L.sei gel) with high viability for promoting wound healing. Lactobacillus paracasei TYM202 encapsulated in the hydrogel has the activity of promoting wound healing, and the hydrogel matrix EPS-M76 has the prebiotic activity that promotes the proliferation and metabolism of Lactobacillus paracasei TYM202. During the wound healing process, HAEPS@L.sei gel releases lactic acid and acetic acid to resist the growth of pathogenic bacteria while maintaining Firmicutes and Proteobacteria balance at the phylum level, thus preserving skin microbiota stability. Our results showed that live probiotic hydrogels reduce the incidence of inflammation during wound healing while promoting angiogenesis and increasing collagen deposition. This study provides new ideas for developing wound dressings predicated on live bacterial hydrogels.

Lactobacillus paracasei-derived extracellular vesicles alleviate neutrophilic asthma by inhibiting the JNK pathway in airway epithelium

BACKGROUND

Lactobacillus paracasei has been known to reduce airway resistance and inflammation in asthma. However, the therapeutic effect of its extracellular vesicles (EVs) in patients with asthma remains unclear.

METHODS

To validate the clinical relevance of L. paracasei-derived EVs (LpEV) in asthma, the composition of gut microbial EVs was verified by metagenomics in LPS-induced C57BL/6 mice. The components of proteins and metabolites in LpEV were identified by peptide mass fingerprinting and metabolomic analysis. The serum levels of specific IgG1 or IgG4 antibodies to LpEV were compared by ELISA between patients with eosinophilic asthma (EA, n = 10) and those with neutrophilic asthma (NA, n = 10) as well as with healthy controls (HCs, n = 10). Finally, therapeutic effects of LpEV and their metabolites in asthma were validated in vivo/in vitro.

RESULTS

Significantly lower proportions of EVs derived from Lactobacillus at the genus level were noted in mice with NA than in control mice. Moreover, the serum levels of LpEV-specific IgG4, but not IgG1, were lower in patients with NA than in those with EA or in HCs and positively correlated with FEV1 (%) values. In addition, oral administration of LpEV reduced airway resistance and inflammation in mice with NA. Finally, LpEV and their 3 metabolites (dodecanoic acid, palmitoleic acid, and D-(-)-tagatose) significantly inhibited JNK phosphorylation/IL-8 production in airway epithelium in vitro.

CONCLUSIONS

These findings suggest that LpEV may have a therapeutic potential targeting NA by suppressing the JNK pathway and proinflammatory cytokine production in airway epithelium.

Regulation and mechanism of organic selenium on quorum sensing, biofilm, and antioxidant effects of Lactobacillus paracasei

Different organic compounds can have varying degrees of impact on the activity of Lactobacillus paracasei. The study focused on the impact and action mechanism of different organic selenium products on the bioactivity of two strains of L. paracasei. The growth, antioxidant activity, extracellular polysaccharide secretion, quorum sensing (QS), and biofilm formation of the strains before and after the addition of organic selenium crude products and three organic selenium standard were evaluated. The results showed that the addition of crude organic selenium promoted the various activities of the strain. l-selenocysteine had the strongest regulatory effect, with maximum GIM1.80 biofilm formation when it reached a critical concentration of 0.4 μg/mL; l-selenomethionine resulted in the highest activity of the signal molecule Auto inducer-2 of GDMCC1.155, when it reached a critical concentration of 0.4 μg/mL. The results of scanning electron microscopy demonstrated that the addition of organic selenium effectively improved the morphological structure of the two bacterial cells. Molecular docking revealed that the mechanism by which organic selenium regulates QS in Lactobacillus was achieved by binding two crucial receptor proteins (histidine protein kinase HKP and periplasmic binding protein LuxP) from specific sites. Furthermore, organic selenium products have a beneficial regulatory effect on the biological activity of L. paracasei. Overall, these findings provide a new alternative (organic selenium) for regulating the viability and beneficial activity of L. paracasei.

Regulation of Hepatocellular Cholesterol Metabolism By Lactobacillus Paracasei BY2 and Its Embedding Delivery

In this study, five strains of lactic acid bacteria (LAB) with excellent cholesterol-lowering ability were screened from fermented foods. The gastrointestinal stress resistance, intestinal adhesion, and bacteriostasis abilities were evaluated to obtain the best LAB. And then, high-cholesterol HepG2 cell model was further prepared to explore the cholesterol-lowering mechanism of the LAB. Finally, pH-sensitive hydrogel prepared by Millettia speciosa Champ. carboxymethyl cellulose and Millettia speciosa Champ. cellulose was first applied to the microencapsulation of LAB. As a result, Lactobacillus paracasei BY2 (LP-BY2) exhibited higher cholesterol-lowering activity, intestinal adhesion, and bacteriostasis abilities compared with other LAB. Furthermore, it was found that LP-BY2 could reduce the cholesterol level by regulating the expression of key genes that involved in cholesterol synthesis (HMGCR and SREBP-2), uptake (LDLR), and outflow (LXR-α, ABCA1, ABCG5, ABCG8, and CYP7A1) in liver. At the same time, microencapsulation significantly enhanced the survival rate and cholesterol-lowering ability of LP-BY2 after gastrointestinal digestion. This study will provide an available reference for the application of Lactobacillus in prevention and treatment of hypercholesterolemia.

Analysis of the Fecal Metabolomic Profile in Breast vs. Different Formula Milk Feeding in Late Preterm Infants

Human milk is the gold standard for infant nutrition, but when it is not available or insufficient to satisfy the needs of the infant, formula milk is proposed as an effective substitute. A prospective observational cohort study was conducted on late preterm infants fed with breast and two different formula milks. On this basis, they were divided into three groups: group FMPB (fed with formula + postbiotic), group FM (fed with standard formula), and group BM (breastfed). Stool samples for a metabolomic study were collected at T0 (5-7 days after birth), T1 (30 days of life), and T2 (90 days of life), giving rise to 74 samples analyzed via liquid chromatography coupled with high-resolution mass spectrometry. The T0, T1, and T2 LC-MS raw data were processed for Partial Least Square Discriminant Analysis (PLS-DA), followed by a statistical analysis. This preliminary study highlighted a good overlapping between the fecal metabolome of breast and substitute feeding systems, confirming the efficacy of the formula preparations as breast milk substitutes. Moreover, several similarities were also detected between the FMPB and BM metabolome, highlighting that the addition of a postbiotic to standard formula milk could be more effective and considered a better alternative to breast milk.

Molecular insights into the anti-inflammatory activity of fermented pineapple juice using multimodal computational studies

Pineapple has been recognized for its potential to enhance health and well-being. This study aimed to gain molecular insights into the anti-inflammatory properties of fermented pineapple juice using multimodal computational studies. In this study, pineapple juice was fermented using Lactobacillus paracasei, and the solution underwent liquid chromatography-mass spectrometry analysis. Network pharmacology was applied to investigate compound interactions and targets. In silico methods assessed compound bioactivities. Protein-protein interactions, network topology, and enrichment analysis identified key compounds. Molecular docking explored compound-receptor interactions in inflammation regulation. Molecular dynamics simulations were conducted to confirm the stability of interactions between the identified crucial compounds and their respective receptors. The study revealed several compounds including short-chain fatty acids, peptides, dihydroxyeicosatrienoic acids, and glycerides that exhibited promising anti-inflammatory properties. Leucyl-leucyl-norleucine and Leu-Leu-Tyr exhibited robust and stable interactions with mitogen-activated protein kinase 14 and IκB kinase β, respectively, indicating their potential as promising therapeutic agents for inflammation modulation. This proposition is grounded in the pivotal involvement of these two proteins in inflammatory signaling pathways. These findings provide valuable insights into the anti-inflammatory potential of these compounds, serving as a foundation for further experimental validation and exploration. Future studies can build upon these results to advance the development of these compounds as effective anti-inflammatory agents.

Human Probiotic Lactobacillus paracasei-Derived Extracellular Vesicles Improve Tumor Necrosis Factor-α-Induced Inflammatory Phenotypes in Human Skin

Lactic acid bacteria (LAB), a probiotic, provide various health benefits. We recently isolated a new Lactobacillus paracasei strain with strong anti-inflammatory effects under lipopolysaccharide-induced conditions and proposed a new mode of action-augmenting the endoplasmic reticulum stress pathway for anti-inflammatory functions in host cells. The beneficial effects of the L. paracasei strains on the skin have been described; however, the effects of L. paracasei-derived extracellular vesicles (LpEVs) on the skin are poorly understood. Herein, we investigated whether LpEVs can improve inflammation-mediated skin phenotypes by determining their effects on primary human skin cells and a three-dimensional (3D) full-thickness human skin equivalent under tumor necrosis factor (TNF)-α-challenged inflammatory conditions. LpEVs were efficiently taken up by the human skin cells and were much less cytotoxic to host cells than bacterial lysates. Furthermore, low LpEV concentrations efficiently restored TNF-α-induced cellular phenotypes, resulting in increased cell proliferation and collagen synthesis, but decreased inflammatory factor levels (matrix metalloproteinase 1, interleukin 6, and interleukin 8) in the human dermal fibroblasts, which was comparable to that of retinoic acid, a representative antiaging compound. The beneficial effects of LpEVs were validated in a 3D full-thickness human skin equivalent model. LpEV treatment remarkably restored the TNF-α-induced epidermal malformation, abnormal proliferation of keratinocytes in the basal layer, and reduction in dermal collagen synthesis. Additionally, LpEVs penetrated and reached the deepest dermal layer within 24 h when overlaid on top of a 3D full-thickness human skin equivalent. Furthermore, they possessed superior antioxidant capacity compared with the human cell-derived EVs. Taken together, the anti-inflammatory probiotic LpEVs can be attractive antiaging and antioxidant substances for improving inflammation-induced skin phenotypes and disorders.

Newly isolated Lactobacillus paracasei strain modulates lung immunity and improves the capacity to cope with influenza virus infection

BACKGROUND

The modulation of immune responses by probiotics is crucial for local and systemic immunity. Recent studies have suggested a correlation between gut microbiota and lung immunity, known as the gut-lung axis. However, the evidence and mechanisms underlying this axis remain elusive.

RESULTS

In this study, we screened various Lactobacillus (L.) strains for their ability to augment type I interferon (IFN-I) signaling using an IFN-α/β reporter cell line. We identified L. paracasei (MI29) from the feces of healthy volunteers, which showed enhanced IFN-I signaling in vitro. Oral administration of the MI29 strain to wild-type B6 mice for 2 weeks resulted in increased expression of IFN-stimulated genes and pro-inflammatory cytokines in the lungs. We found that MI29-treated mice had significantly increased numbers of CD11c+PDCA-1+ plasmacytoid dendritic cells and Ly6Chi monocytes in the lungs compared with control groups. Pre-treatment with MI29 for 2 weeks resulted in less weight loss and lower viral loads in the lung after a sub-lethal dose of influenza virus infection. Interestingly, IFNAR1-/- mice did not show enhanced viral resistance in response to oral MI29 administration. Furthermore, metabolic profiles of MI29-treated mice revealed changes in fatty acid metabolism, with MI29-derived fatty acids contributing to host defense in a Gpr40/120-dependent manner.

CONCLUSIONS

These findings suggest that the newly isolated MI29 strain can activate host defense immunity and prevent infections caused by the influenza virus through the gut-lung axis. Video Abstract.

Bifidobacterium bifidum and Lactobacillus paracasei alleviate sarcopenia and cognitive impairment in aged mice by regulating gut microbiota-mediated AKT, NF-κB, and FOXO3a signaling pathways

Sarcopenia is closely associated with gut dysbiosis. Probiotics alleviate gut dysbiosis. Therefore, we selected probiotics Lactobacillus paracasei P62 (Lp) and Bifidobacterium bifidum P61 (Bb), which suppressed muscle RING-finger protein-1 (MuRF1) expression and NF-κB activation in C2C12 cells, and examined their effects on muscle mass loss and dysfunction in aged mice. Oral administration of Lp, Bb, or their mix (LB) increased grip strength and treadmill running distance and time. They significantly increased muscle weight in aged mice. They also increased AKT activation, PGC1α, SIRT1, and myosin heavy chain (MyHC) expression, MyHC-positive cell population, and cell size in the gastrocnemius (GA) muscle, while FOXO3a and NF-κB activation, MuRF1, muscle atrophy F-box, and p16 expression, and NF-κB+CD11c+ cell population decreased. Furthermore, they reduced cognitive impairment-like behavior, IL-6 expression, FOXO3a activation, and NF-κB-positive cell population in the hippocampus, GA, and colon, while hippocampal brain-derived neurotropic factor expression increased. They shifted gut microbiota composition in aged mice: they increased Akkermansiaceae and Bacteroidaceae populations, which were positively correlated with total muscle weight and MyHC expression, and decreased Odoribacteraceae and Deferribacteriaceae populations, which were positively correlated with MuRF1 and IL-6 expression. LB alleviated sarcopenia- and cognitive impairment-like symptoms more potently than Lp or Bb alone. Based on these findings, probiotics, particularly Lp, Bb, and LB, can alleviate aging-dependent sarcopenia and cognitive impairment by regulating gut microbiota-mediated AKT, NF-κB, and/or FOXO3a signaling pathways.

Transcriptomics of Lactobacillus paracasei: metabolism patterns and cellular responses under high-density culture conditions

Lactobacillus paracasei has significant potential for development and application in the environmental field, particularly in addressing malodor pollution. This study aims to investigate the cellular response of L. paracasei B1 under high-density culture conditions. The selected strain has previously shown effective deodorizing and bacteriostatic abilities. Transcriptomics techniques are employed to dissect the nutrient metabolism pattern of L. paracasei B1 and its response mechanism under environmental stress. The study characterizes the functions of key differentially expressed genes during growth before and after optimizing the culture conditions. The optimization of fermentation culture conditions provides a suitable growth environment for L. paracasei B1, inducing an enhancement of its phosphotransferase system for sugar source uptake and maintaining high levels of glycolysis and pyruvate metabolism. Consequently, the strain is able to grow and multiply rapidly. Under acid stress conditions, glycolysis and pyruvate metabolism are inhibited, and L. paracasei B1 generates additional energy through aerobic respiration to meet the energy demand. The two-component system and quorum sensing play roles in the response and regulation of L. paracasei B1 to adverse environments. The strain mitigates oxygen stress damage through glutathione metabolism, cysteine and methionine metabolism, base excision repair, and purine and pyrimidine metabolism. Additionally, the strain enhances lysine synthesis, the alanine, aspartate, and glutamate metabolic pathways, and relies on the ABC transport system to accumulate amino acid-compatible solutes to counteract acid stress and osmotic stress during pH regulation. These findings establish a theoretical basis for the further development and application of L. paracasei B1 for its productive properties.

Genetically engineered Lactobacillus paracasei rescues colonic angiotensin converting enzyme 2 (ACE2) and attenuates hypertension in female Ace2 knock out rats

Engineered gut microbiota represents a new frontier in medicine, in part serving as a vehicle for the delivery of therapeutic biologics to treat a range of host conditions. The gut microbiota plays a significant role in blood pressure regulation; thus, manipulation of gut microbiota is a promising avenue for hypertension treatment. In this study, we tested the potential of Lactobacillus paracasei, genetically engineered to produce and deliver human angiotensin converting enzyme 2 (Lacto-hACE2), to regulate blood pressure in a rat model of hypertension with genetic ablation of endogenous Ace2 (Ace2-/- and Ace2-/y). Our findings reveal a sex-specific reduction in blood pressure in female (Ace2-/-) but not male (Ace2-/y) rats following colonization with the Lacto-hACE2. This beneficial effect of lowering blood pressure was aligned with a specific reduction in colonic angiotensin II, but not renal angiotensin II, suggesting the importance of colonic Ace2 in the regulation of blood pressure. We conclude that this approach of targeting the colon with engineered bacteria for delivery of ACE2 represents a promising new paradigm in the development of antihypertensive therapeutics.

Intestinal Microbiomics and Metabolomics Insights into the Hepatoprotective Effects of Lactobacillus paracasei CCFM1222 Against the Acute Liver Injury in Mice

In recent years, acute liver injury (ALI) has received wide-range attention in the world due to its relatively high morbidity and mortality. This study aimed to explore the hepatoprotective effect of Lactobacillus paracasei CCFM1222 against lipopolysaccharide (LPS)-induced ALI mice and further elaborate its mechanism of action from the perspective of intestinal microbiomics and metabolomics. The results displayed that L. paracasei CCFM1222 pretreatment significantly decreased the serum ALT, and AST levels, inhibited the releases of hepatic TNF-α, IL-1β, and IL-6 levels, and activated the SOD, CAT, and GSH-Px activities in LPS-treated mice. The cecal short-chain fatty acid (SCFAs) levels were increased in LPS-treated mice with L. paracasei CCFM1222 pretreatment. In addition, L. paracasei CCFM1222 pretreatment remarkably shifted the intestinal microbiota composition, including the higher abundance of Faecalibaculum, Bifidobacterium, and lower abundance of the Prevotellaceae NK3B31 group, which is positively associated with the cecal propionic, butyric, valeric, isobutyric, and isovaleric acids. The metabolomics based on UPLC-QTOF/MS revealed that L. paracasei CCFM1222 pretreatment significantly regulated the composition of feces metabolites in LPS-treated mice, especially the potential biomarker-related butanoate metabolism, vitamin B6 metabolism, D-glutamine and D-glutamate metabolism, tryptophan metabolism, caffeine metabolism, arginine biosynthesis, arginine, and proline metabolism. Moreover, L. paracasei CCFM1222 pretreatment remarkably regulated the expression of gene-associated ALI (including Tlr4, Myd88, Nf-kβ, iNOS, Cox2, Iκ-Bα, Nrf2, and Sirt-1). In conclusion, these results suggest the possibility that L. paracasei CCFM1222 supplementation has beneficial effects on preventing the occurrence and development of ALI by inhibiting the inflammatory responses and altering intestinal microbiota composition and their metabolites.

Comparative Case Study of Efficacy of Oral Bilastine Monotherapy to Concomittant Administration of Oral Bilastine with Probiotic in Patients with Allergic Rhinitis

Introduction

Allergic rhinitis continues to pose a global burden in both adult and paediatric population and requires adequate medical therapy to avoid long term complications making it a challenging concern. This prompts the need to find a suitable and appropriate treatment regimen for this condition.

Aim

To study the clinical efficacy of Oral Bilastine and Probiotics in patients with allergic rhinitis. To compare the effectiveness of Bilastine monotherapy to Oral Bilastine combined with Probiotics in patients with allergic rhinitis.

Materials and Methods

Total of 100 patients were selected and randomized into two groups- Group 1 and Group 2 and were treated with Oral Bilastine 20 mg OD and Oral Bilastine 20 mg with Oral Probiotics OD (Lactobacillus fermentum & L. paracasei - 4 billion cells) respectively to maintain uniformity. Baseline scoring and follow up scoring after 6 weeks was done using the Total symptom score, Absolute eosinophil count and Nasal smear eosinophil count and were evaluated and documented as per their response to treatment.

Results

A significant reduction was observed in the severity of symptoms especially nasal obstruction, sneezing in patients of both groups along with extra nasal symptoms, with average mean score in Group 1 being 7.72 before treatment that reduced to 3.66 and that of Group 2 from 9.32 to 5.02. The mean score of Group 2 was greater in both before and after treatment which is highly significant. (p < 0.001).

Conclusion

Monotherapy with Oral Bilastine has proven in relieving allergic symptoms. Addition of Oral Probiotics along with Bilastine has shown to have synergistic effect in further improving overall symptoms in allergic rhinitis.

Supplementation of microencapsulated probiotics modulates gut health and intestinal microbiota

The beneficial effect of probiotics on host health is impaired due to the substantial loss of survivability during gastric transit caused by small intestinal enzymes and bile acids. Encapsulation helps to preserve the probiotics species from severe environmental factors. Lactobacillus paracasei, highly sensitive probiotic species to gastric acid, was encapsulated with polyacrylate resin. C57BL/6 male mice were equally divided into three groups; control group was fed with basal diet without any additives, the un-encapsulated group was fed with 0.1% of a mixture of encapsulating material and L. paracasei, and encapsulated group was fed with 0.1% encapsulated L. paracasei (microcapsule) for 4 weeks. The result showed elevated fecal moisture percentage in the encapsulated group, but not in the un-encapsulated group. Further study showed that the ratio of villus height to crypt depth in the small intestine was significantly higher compared to un-encapsulated and the control group. Microencapsulated probiotics also remarkably increased intestinal mucin and secretory immunoglobulin A (sIgA) concentration, intestinal MUC-2, and tight junction protein mRNA expression levels improving the intestinal barrier function of mice. In addition, microcapsules also reduced proinflammatory factor mRNA expression, while considerably increasing anti-inflammatory factor mRNA expression. Microbiota metabolites, fecal LPS (Lipopolysaccharide) were downregulated, and acetate and lactate were upraised compared to control. Furthermore, glutathione peroxidase (GSH-Px) and TAOC levels were increased and Malondialdehyde (MDA) was decreased improving antioxidant capacity. Microflora and bioinformatic predictive analysis of feces showed that encapsulated probiotics remarkably increased Lactobacillus proportions. Mice's intestinal health can thus be improved by using microencapsulated probiotics.

Exopolysaccharide-mediated silver nanoparticles synthesized from Lactobacillus paracasei with antimicrobial, antibiofilm and antioxidant activities

Biofilm formation and resistance to antibiotics in pathogenic bacteria are important concerns in the treatment of infectious diseases. A new rapid, eco-friendly and cost-effective strategy to overcome these problems is the use of microbial exopolysaccharides (EPS) for green synthesis of various metal nanoparticles (NPs). This study used EPS from a native probiotic Lactobacillus isolate to synthesize silver nanoparticles (AgNPs) with effective antimicrobial, antibiofilm and antioxidant properties. AgNPs were synthesized by 10 mg of EPS of Lactobacillus paracasei (L. paracasei MN₈₀₉₅₂₈) isolated from a local yogurt. The characteristics of EPS AgNPs were confirmed using UV-VIS, FT-IR, DLS, XRD, EDX, FE-SEM, and zeta potential. Antimicrobial, antibiofilm and antioxidant activities of EPS AgNPs were evaluated by the agar well diffusion, microtiter dilution, SEM electron microscopy, and DPPH radical absorption methods, respectively. Spectroscopy data indicated the presence of a 466-nm peak as a feature of AgNPs. FT-IR confirmed the presence of biological agents in the synthesis of AgNPs. FE-SEM results showed that the synthesized AgNPs had a spherical shape with the size of 33-38 nm. Synthesized AgNPs at a concentration of 100 mg/ml demonstrated a significant inhibitory activity compared to chemically synthesized AgNPs. These NPs, exhibited the greatest effect of inhibiting the Escherichia coli and Pseudomonas aeruginosa biofilm formation at sub-MIC concentration, and the best effect of DPPH radical as antioxidant activity was determined at 50-μg/ml concentration. Our findings reveal that EPS AgNPs synthesized by the native isolate of L. paracasei (MN₈₀₉₅₂₈) is an inexpensive and environment-friendly candidate for application in pharmaceuticals fields.

Corrected and Republished from: "Understanding Lactobacillus paracasei and Streptococcus oralis Biofilm Interactions through Agent-Based Modeling"

As common commensals residing on mucosal tissues, Lactobacillus species are known to promote health, while some Streptococcus species act to enhance the pathogenicity of other organisms in those environments. In this study we used a combination of in vitro imaging of live biofilms and computational modeling to explore biofilm interactions between Streptococcus oralis, an accessory pathogen in oral candidiasis, and Lactobacillus paracasei, an organism with known probiotic properties. A computational agent-based model was created where the two species interact only by competing for space, oxygen, and glucose. Quantification of bacterial growth in live biofilms indicated that S. oralis biomass and cell numbers were much lower than predicted by the model. Two subsequent models were then created to examine more complex interactions between these species, one where L. paracasei secretes a surfactant and another where L. paracasei secretes an inhibitor of S. oralis growth. We observed that the growth of S. oralis could be affected by both mechanisms. Further biofilm experiments support the hypothesis that L. paracasei may secrete an inhibitor of S. oralis growth, although they do not exclude that a surfactant could also be involved. This contribution shows how agent-based modeling and experiments can be used in synergy to address multiple-species biofilm interactions, with important roles in mucosal health and disease. IMPORTANCE We previously discovered a role of the oral commensal Streptococcus oralis as an accessory pathogen. S. oralis increases the virulence of Candida albicans infections in murine oral candidiasis and epithelial cell models through mechanisms which promote the formation of tissue-damaging biofilms. Lactobacillus species have known inhibitory effects on biofilm formation of many microbes, including Streptococcus species. Agent-based modeling has great advantages as a means of exploring multifaceted relationships between organisms in complex environments such as biofilms. Here, we used an iterative collaborative process between experimentation and modeling to reveal aspects of the mostly unexplored relationship between S. oralis and L. paracasei in biofilm growth. The inhibitory nature of L. paracasei on S. oralis in biofilms may be exploited as a means of preventing or alleviating mucosal fungal infections.

Protective effects of CCL01 against Aβ-induced neurotoxicity in 5xFAD transgenic mouse model of Alzheimer's disease

Alzheimer's disease (AD) is the most common dementia characterized by the excessive accumulation of amyloid-beta (Aβ) and tau aggregates, as well as neuronal damage and neuroinflammation. Metabolic disruption in AD has been noticed because metabolite alterations closely correlate with Aβ neuropathology and behavioral phenotypes. Accordingly, controlling various neuropathological processes and metabolic disruption is an efficient therapeutic strategy for AD treatment. In this study, we evaluated the effects of a combination of Cuscuta seeds and Lactobacillus paracasei NK112 (CCL01) on AD neuropathology and altered metabolism in five familial AD (5xFAD) transgenic mice and neuronal cell cultures. First, we observed that CCL01 exerted neuroprotective effects in HT22 hippocampal neurons and primary cultured neurons. CCL01 ameliorated memory decline and protected synapses and neuronal survival in 5xFAD mice. These effects were related to the inhibition of tau phosphorylation. CCL01 also inhibited the activation of mitogen-activated protein kinase (MAPK) signaling and neuroinflammatory processes. Moreover, the metabolite profile-particularly characterized by altered phospholipid metabolism-was significantly changed in the 5xFAD group, while CCL01 partly restored the alteration. Lysophosphatidylcholine (lysoPC), the levels of which were higher in the brains of 5xFAD mice, exerted neurotoxicity in vitro, whereas CCL01 protected neurons from lysoPC-induced toxicity by regulating MAPK signaling. Additionally, CCL01 administration reduced gut inflammation in the 5xFAD mice. In summary, we demonstrated that CCL01 improved the memory function of 5xFAD mice by protecting neurons against Aβ- and lysoPC-induced toxicity through the regulation of MAPK signaling, neuroinflammation, tau phosphorylation, and gut inflammation, suggesting the potential of CCL01 as treatment for AD.

Safety and Effects of Lactobacillus paracasei TISTR 2593 Supplementation on Improving Cholesterol Metabolism and Atherosclerosis-Related Parameters in Subjects with Hypercholesterolemia: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Probiotics have the potential as a multi-target approach to modulate hypercholesterolemia associated with premature atherosclerosis. Various strains of Lactobacillus paracasei have been reported to affect hypercholesterolemia positively. This study aimed to investigate the effects of L. paracasei TISTR 2593 on lipid profile, cholesterol metabolism, and atherosclerosis according to the registration of Thai Clinical Trial Registry as identification number TCTR 20220917002. A total of 50 participants with hypercholesterolemia were randomly and equally assigned to consume L. paracasei TISTR 2593 or a placebo in maltodextrin capsules daily. Biomarkers of lipid profiles, oxidative stress state, inflammatory state, and other biological indicators were examined on days 0, 45, and 90. The results showed that subjects taking the L. paracasei TISTR 2593 could significantly reduce the level of serum low-density lipoprotein-cholesterol (p < 0.05), malondialdehyde (p < 0.001), and tumor necrosis factor-α (p < 0.01). Moreover, L. paracasei TISTR 2593 increased the level of serum apolipoprotein E (p < 0.01) and adiponectin (p < 0.001) significantly. No changes in serum total cholesterol, high-density lipoprotein-cholesterol, triglyceride, total bile acids, and monocyte chemoattractant protein-1 were observed during L. paracasei TISTR 2593 supplementation. Therefore, L. paracasei TISTR 2593 could be an adjuvant probiotic supplement to ameliorate hypercholesterolemia and prevent or delay the development of atherosclerosis.

Lactobacillus paracasei ATG-E1 improves particulate matter 10 plus diesel exhaust particles (PM10D)-induced airway inflammation by regulating immune responses

Particulate matter (PM) exposure can adversely affect respiratory function. Probiotics can alleviate the inflammatory responses in respiratory diseases. We examined the protective effects of Lactobacillus paracasei ATG-E1 isolated from the feces of a newborn baby against airway inflammation in a PM₁₀ plus diesel exhaust particle (DEP) (PM₁₀D)-induced airway inflammation model. BALB/c mice were exposed to PM₁₀D by intranasal injection three times at 3-day intervals for 12 days, and L. paracasei ATG-E1 was administered orally for 12 days. Analysis of immune cell population and expression of various inflammatory mediators and gut barrier-related genes were determined in bronchoalveolar lavage fluid (BALF), lung, peyer's patch, and small intestine. A histological analysis of the lungs was performed. In addition, the in vitro safety and their safety in genomic analyses were examined. L. paracasei ATG-E1 was found to be safe in vitro and by genomic analysis. L. paracasei ATG-E1 suppressed neutrophil infiltration and the number of CD4⁺, CD4⁺CD69⁺, CD62L^-CD44^+high, CD21/35⁺B220⁺, and Gr-1⁺CD11b⁺ cells, as well as the expression of inflammatory mediators, including chemokine (C-X-C motif) ligand (CXCL)-1, macrophage inflammatory protein (MIP)-2, interleukin (IL)-17a, tumor necrosis factor (TNF)-α, and IL-6 in BALF and lungs in PM₁₀D-induced airway inflammation. It protected against histopathological damage in the lungs of mice with PM₁₀D-induced airway inflammation. L. paracasei ATG-E1 concomitantly increased the expression levels of the gut barrier function-related genes occludin, claudin-1, and IL-10 in the small intestine, with an increased number of CD4⁺ and CD4⁺CD25⁺ immune cells in the peyer's patch. L. paracasei ATG-E1 suppressed immune activation and airway inflammatory responses in the airways and lungs by restoring the lung damage by PM₁₀D. It also regulated intestinal immunity and ameliorated the gut barrier function in the ileum. These results indicate the potential of L. paracasei ATG-E1 as an protective and therapeutic agent against airway inflammation and respiratory diseases.

Dietary Lactobacillus fermentum and Lactobacillus paracasei improve the intestinal health of broilers challenged with coccidia and Clostridium perfringens

Necrotic enteritis (NE) is a great threat to the intestinal health of broilers, resulting in decreased growth performance and significant economic losses. Lactobacillus fermentum (LF) and Lactobacillus paracasei (LP) exert beneficial effects on intestinal health. The aim of the present study was to investigate the effects of dietary LF and LP on the intestinal health and growth performance of broilers challenged with coccidia and Clostridium perfringens (CCP). The animal trial was carried out using 336 broilers (Ross 308) for 35 days with a completely randomized design. The broilers were divided into 4 groups based on treatment as follows: the control (CTR) group was fed the basal diet and without CCP challenge and the CCP group was fed the basal diet and with CCP challenge. The broilers in the CCP+LF and CCP+LP groups were challenged by CCP, and meanwhile, LF (1 × 10⁹ CFU/g) and LP (1 × 10⁹ CFU/g) were supplemented into the basal diets, respectively. The results showed that the growth performance and the intestinal morphology were negatively affected by the CCP challenge. In addition, the number of coccidia in the intestinal digesta and the relative abundance of Escherichia coli in the cecal digesta were increased. Besides, the mRNA level of IgA in the jejunum was downregulated, and the transcript level of IL-8 was upregulated by the CCP challenge. Dietary LF and LP failed to improve the growth performance of broilers with the CCP challenge. However, they were beneficial for intestinal barrier function. In addition, dietary LF was able to alleviate the downregulation of TGF-β mRNA level in the spleen with CCP challenge and decreased the lesion scores compared with the CCP group. Furthermore, dietary LP alleviated the upregulation of the IL-8 mRNA level in the jejunum with CCP challenge and reduced the number of coccidia in the ileal digesta. In conclusion, dietary LF and LP failed to mitigate the negative effects of CCP infection on growth performance; however, they were able to improve the intestinal health of broilers challenged with CCP by strengthening the intestinal barrier and alleviating inflammation.

Extract Promotes Human Dermal Papilla Cell Cytoprotective Effect and Hair Regrowth Rate in C57BL/6 Mice

Hair loss is a disease that requires accurate diagnosis and type-specific medical treatment. Many hair loss treatments have some side effects, such as hormone-related effects, so there is a need for safe and effective hair loss treatment. In this study, we investigated the effects of Lactobacillus paracasei HY7015 (HY7015) and Lycopus lucidus Turcz. (LT) extract on hair regrowth and protection. In vitro experiments were conducted to assess the effects of HY7015 and/or LT extract on human follicle dermal papilla cells (HFDPC) of cytoprotective functions such as proliferations, antioxidants, anti-inflammatory, and growth factor expressions. In animal experiments, we investigated hair regrowth rate, hair follicle formation and secretion of growth factors in telogenic C57BL/6 mice. We confirmed the cytoprotective effects of HY7015 and LT through regulations of proliferation, SOD and IL-1β in HFDPC. In mouse experiments, oral administration of HY7015 and LT promoted hair regrowth as well as hair follicle maturation in the dermal skin of C57BL/6 mice, and upregulated VEGF and IGF-1 growth factor levels in mouse serum. In summary, our data demonstrate that ingestions of HY7015 and LT can promote hair regrowth by enhancing cytoprotective effects and expressions of growth factors.

Plant-Derived Lactobacillus paracasei IJH-SONE68 Improves the Gut Microbiota Associated with Hepatic Disorders: A Randomized, Double-Blind, and Placebo-Controlled Clinical Trial

Our previous clinical study has shown that the exopolysaccharide (EPS) produced by a plant-derived lactic acid bacterium, Lactobacillus paracasei IJH-SONE68, improves chronic allergy status in humans. In addition, an inhibition of visceral fat accumulation was observed following the intake of EPS during animal experimentation. In the present study, we have further evaluated the health-promoting effects of a spray-dried powder of pineapple juice that is fermented with the IJH-SONE68 strain. This was conducted in a double-blind, randomized, placebo-controlled, parallel-group clinical trial at Hiroshima University from May 2019 to July 2021. Eighty healthy volunteers at range of ages 23-70, with a body mass index between 25 and 29.99, were enrolled. After the 12 weeks of the experimental period were complete, although the average visceral fat area in both groups similarly decreased, there was no significant difference in the content of visceral fat area or in the obesity-related physical parameters in both groups. Further, we found that the serum liver function indices (AST and ALT) in the test group decreased within a statistically determined trend (p = 0.054). The fecal microflora analysis revealed, in the test group, a statistically significant increase in the relative abundance changes within Anaerostipes, which has been reported to help suppress hepatic inflammation.

A Nanocomposite with Extracellular Vesicles from Lactobacillus paracasei as a Bioinspired Nanoantibiotic Targeting Staphylococcus aureus

The utilization of biomimetic materials that merge functional nanoparticles (NPs) with a cell-derived nanosized membrane is a state-of-the-art approach to harnessing cellular properties for biomedical applications. However, the development of biocompatible and species-selective biomimetic agents against hazardous pathogens threatening human health is still in its early stages. Herein, we report the synthesis and functional analysis of a novel nanoplatform in which a PEGylated MoS2-ZnO (MZ) nanocomposite was cloaked with a generally regarded as safe (GRAS)-grade Lactobacillus paracasei-derived extracellular vesicle (LPEV) for MZ-LPEV nanocomposite and evaluated its activity against Staphylococcus aureus. The MZ nanocomposite was characterized via X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The coating of MZ with LPEV was confirmed through nanoparticle tracking analysis and zeta potential measurements. MZ-LPEV exhibited 5- to 20-fold higher antibacterial activity than that of ZO NPs and MZ nanocomposite against S. aureus. Reactive oxygen species (ROS) production and bacterial membrane disruption were confirmed as antibacterial mechanisms of MZ-LPEV. Finally, MZ-LPEV exhibited enhanced biocompatibility and selectivity for S. aureus. All our results showed that LPEV could be utilized for developing synergistic nanoantibiotics against S. aureus.

Dietary of Lactobacillus paracasei and Bifidobacterium longum improve nonspecific immune responses, growth performance, and resistance against Vibrio parahaemolyticus in Penaeus vannamei

This study investigated the effects of two probiotics, namely Lactobacillus paracasei and Bifidobacterium longum, as feed additives on growth performance, nonspecific immunity, immune-related gene expression, and disease resistance against Vibrio parahaemolyticus in Penaeus vannamei. The experimental diets were prepared using L. paracasei and B. longum at concentrations of 10⁵ and 10⁷ CFU/g; these diets were referred to as P5, P7, B5, and B7. After 8 weeks of the diets, regarding growth performance, the B7 group showed the highest weight gain rate (890.34 ± 103.65%), special growth rate (4.08 ± 0.19%), and feed conversion rate (1.52 ± 0.19%) compared with the other groups. Moreover, the total hemocyte counts were significantly increased (p < 0.05) in the P7 groups on day 14 during the 28-day feeding trial. The phagocytosis rate in all experimental groups was increased on day 14 and was persistently significantly activated to day 21, especially in the P7 and B5 group. The phagocytic index of the P7 group showed a significant increase on day 14 and persistent activation to day 21. In the analysis of respiratory burst activity and phenoloxidase activity, the P7 and B5 groups showed a significant increase on day 7 and persistent activation to day 21. The expression level of the immune-related genes of superoxide dismutase, clotting protein, Penaeidin2, Penaeidin3, Penaeidin4, anti-LPS factor, crustin, and lysozyme was significantly increased in the experimental groups, especially in the P7 group. Furthermore, the optimum conditions of feed additives were determined in challenge trials conducted using P7 and B5. Shrimps fed P7 and B5 showed an increased survival rate (72.73% and 66.67%) after the V. parahaemolyticus challenge. In sum, the results revealed that B. longum, as a feed additive at 10⁷ CFU/g, enhanced growth performance. L. paracasei at 10⁷ CFU/g and B. longum at 10⁵ CFU/g can enhance nonspecific immune responses and immune-related gene expression, and 10⁷ CFU/g L. paracasei has the highest resistance ability for V. parahaemolyticus. Thus, dietary supplementation with L. paracasei and B. longum may be a valuable approach in white shrimp aquaculture.

Lactobacillus paracasei M11-4 isolated from fermented rice demonstrates good antioxidant properties in vitro and in vivo

BACKGROUND

Probiotics are defined as microorganisms that can exert health benefits for the host. Among the recognized probiotics, Lactobacillus paracasei are one of the most frequently used probiotics in humans. The L. paracasei strain M11-4, isolated from fermented rice (which could ferment soymilk within a short curd time) and fermented soymilk presented high viability, acceptable flavor, and antioxidant activity, which revealed that the strain maybe have a potential antioxidant value. Therefore, it is necessary to further explore the antioxidant activity of L. paracasei strain M11-4.

RESULTS

The radical scavenging activities, lipid peroxidation inhibition, and reducing power of L. paracasei M11-4 were the highest in the fermentation culture without cells, whereas the activities of other antioxidant enzymes of L. paracasei M11-4 were high in the cell-free extract and bacterial suspension. Moreover, L. paracasei M11-4 exerted its antioxidant effect by upregulating the gene expression of its antioxidant enzymes - the thioredoxin and glutathione systems - when hydrogen peroxide existed. Supplementation of rats with L. paracasei M11-4 effectively alleviated d-galactose-induced oxidative damage in the liver and serum and prevented d-galactose-induced changes to intestinal microbiota. Supplementation with L. paracasei M11-4 also reduced the elevated expression of thioredoxin and glutathione system genes induced by d-galactose.

CONCLUSION

L. paracasei M11-4 has good antioxidant properties both in vitro and in vivo, and its antioxidant mechanism was studied at the molecular level. © 2021 Society of Chemical Industry.

Metagenomic Analysis Reveals a Mitigating Role for Lactobacillus paracasei and Bifidobacterium animalis in Experimental Periodontitis

Probiotics have aroused increasing concern as an intervention strategy for periodontitis (PD), but their underlying mechanism of action remains poorly characterized. Regarding the significance of oral microbiota dysbiosis related to PD, we predicted that the preventive activity of probiotics may be influenced by suppressing the bacterial pathogenicity. Herein, we investigated the effects of Lactobacillus paracasei L9 (L9) and Bifidobacterium animalis A6 (A6) on PD using a rat model, and demonstrated a regulatory effect of probiotics on oral flora from a metagenomics perspective. Oral administration of A6 or L9 effectively relieved gingival bleeding, periodontal inflammatory infiltration, and alveolar bone resorption. In addition, A6 or L9 treatment reduced the inflammatory response and increased the expression of anti-inflammatory cytokines, which we expected to ameliorate alveolar bone resorption as mediated by the receptor activator of the nuclear factor-κB ligand/OPG signaling pathway. More importantly, using metagenomic sequencing, we showed that probiotics significantly altered the taxonomic composition of the subgingival microbiome, and reduced the relative proportions of pathogenic bacterial genera such as Streptococcus, Fusobacterium, Veillonella, and Escherichia. Both probiotics significantly inhibited levels of bacterial virulence factors related to adherence, invasion, exoenzyme, and complement protease functions that are strongly correlated with the pathogenesis of PD. Our overall results suggest that A6 and L9 may constitute promising prophylactic agents for PD, and should thus be further explored in the future.

Metagenomic Analysis Reveals a Mitigating Role for Lactobacillus paracasei and Bifidobacterium animalis in Experimental Periodontitis

Probiotics have aroused increasing concern as an intervention strategy for periodontitis (PD), but their underlying mechanism of action remains poorly characterized. Regarding the significance of oral microbiota dysbiosis related to PD, we predicted that the preventive activity of probiotics may be influenced by suppressing the bacterial pathogenicity. Herein, we investigated the effects of Lactobacillus paracasei L9 (L9) and Bifidobacterium animalis A6 (A6) on PD using a rat model, and demonstrated a regulatory effect of probiotics on oral flora from a metagenomics perspective. Oral administration of A6 or L9 effectively relieved gingival bleeding, periodontal inflammatory infiltration, and alveolar bone resorption. In addition, A6 or L9 treatment reduced the inflammatory response and increased the expression of anti-inflammatory cytokines, which we expected to ameliorate alveolar bone resorption as mediated by the receptor activator of the nuclear factor-κB ligand/OPG signaling pathway. More importantly, using metagenomic sequencing, we showed that probiotics significantly altered the taxonomic composition of the subgingival microbiome, and reduced the relative proportions of pathogenic bacterial genera such as Streptococcus, Fusobacterium, Veillonella, and Escherichia. Both probiotics significantly inhibited levels of bacterial virulence factors related to adherence, invasion, exoenzyme, and complement protease functions that are strongly correlated with the pathogenesis of PD. Our overall results suggest that A6 and L9 may constitute promising prophylactic agents for PD, and should thus be further explored in the future.

The Evaluation of the Effects of Two Probiotic Strains on the Oral Ecosystem: A Randomized Clinical Trial

Introduction

In the current study, we evaluated the effectiveness of two well-defined probiotic strains, Lactobacillus paracasei LPc-G110 (CCTCC M 2013691) and Lactobacillus plantarum GOS42 (DSM 32131), during an experimental gingivitis challenge. The primary objective was to evaluate clinically the effectiveness of lozenges containing one of the two oral probiotic strains, compared with placebo lozenges, on the gingival bleeding (bleeding on marginal probing; BOMP change) after a two-week experimental gingivitis period. The secondary objectives were to assess the effects of the test products on gingival health (Modified Gingival Index; MGI), dental plaque accumulation and fluorescence, and the dynamics of immunological and microbiological aspects after the wash-in phase, followed by a two-week period refraining from oral hygiene and a two-week wash-out phase.

Methods

This single-center challenge intervention study was a triple-blind randomized placebo-controlled clinical trial with three parallel groups. The full study population consisted of 117 healthy 18-55 years old human volunteers. Subjects were instructed to use one lozenge, 3 times daily after each meal, containing either L. plantarum, L. paracasei, or lozenges without probiotics (placebo group). After a 2-week wash-in period, the subjects were requested to refrain from any form of oral hygiene for 2 weeks.

Results

There were no differences in the primary outcome (BOMP change) among the groups. However, gingival health (MGI) in individuals from the groups exposed to the test products recovered better from experimental gingivitis than the individuals in the placebo group (p = 0.021, one-way ANOVA). The two test products inhibited pro-inflammatory cytokine IL-1ß production, measured in saliva, during the experimental gingivitis period. Both test strains significantly reduced bacterial DNA in tongue samples and L. paracasei strain showed stronger microbiome-modulating potential than the L. plantarum strain.

Conclusions

The two tested lozenges with the L. paracasei or L. plantarum strains did show potential for beneficial effects for the oral health of the host during experimental gingivitis to the oral ecosystem.

Effect of Fluidized Bed Drying, Matrix Constituents and Structure on the Viability of Probiotic Lactobacillus paracasei ATCC 55544 during Storage at 4 °C, 25 °C and 37 °C

The stabilization of probiotics for application in non-refrigerated food products is a challenging task. In the present study, probiotic Lactobacillus paracasei (Lacticaseibacillus paracasei) ATCC 55544 cells were immobilized in a dairy matrix comprising of whole milk powder, skim milk powder, or milk protein isolate using fluidized bed drying technology. The samples were taken out at different drying stages, with an apparent water activity (a_w) of a_w 0.5, a_w 0.4, and a_w 0.3, respectively, and vacuum-packed to maintain the a_w and stored at three different temperatures of 4 °C, 25 °C, and 37 °C. The study evaluated the impact of matrix constituents, milk fat, protein, and carbohydrate on the viability of encapsulated probiotic L . paracasei ATCC 55544 during storage for 1 month. The whole milk powder matrix provided superior protection to the bacteria. Confocal Laser Scanning Microscopy (CLSM) was used to investigate the structure of the immobilizing matrix and the location of the probiotic L. paracasei cells embedded within the matrix. The CLSM study revealed that the probiotic bacterial cells are mostly embedded as clusters beneath the top layer. We hypothesize that the biofilm-like structure, together with the protective whole milk powder matrix, helps to retain the superior viability of probiotic cells during storage at non-refrigerated storage conditions of 25 °C and 37 °C.

Understanding Lactobacillus paracasei and Streptococcus oralis Biofilm Interactions through Agent-Based Modeling

As common commensals residing on mucosal tissues, Lactobacillus species are known to promote health, while some Streptococcus species act to enhance the pathogenicity of other organisms in those environments. In this study, we used a combination of in vitro imaging of live biofilms and computational modeling to explore biofilm interactions between Streptococcus oralis, an accessory pathogen in oral candidiasis, and Lactobacillus paracasei, an organism with known probiotic properties. A computational agent-based model was created where the two species interact only by competing for space, oxygen and glucose. Quantification of bacterial growth in live biofilms indicated that S. oralis biomass and cell numbers were much lower than predicted by the model. Two subsequent models were then created to examine more complex interactions between these species, one where L. paracasei secretes a surfactant, and another where L. paracasei secretes an inhibitor of S. oralis growth. We observed that the growth of S. oralis could be affected by both mechanisms. Further biofilm experiments support the hypothesis that L. paracasei may secrete an inhibitor of S. oralis growth, although they do not exclude that a surfactant could also be involved. This contribution shows how agent-based modeling and experiments can be used in synergy to address multiple species biofilm interactions, with important roles in mucosal health and disease. IMPORTANCE We previously discovered a role of the oral commensal Streptococcus oralis as an accessory pathogen. S. oralis increases the virulence of Candida albicans infections in murine oral candidiasis and epithelial cell models through mechanisms which promote the formation of tissue-damaging biofilms. Lactobacillus species have known inhibitory effects on biofilm formation of many microbes, including Streptococcus species. Agent-based modeling has great advantages as a means of exploring multifaceted relationships between organisms in complex environments such as biofilms. Here, we used an iterative collaborative process between experimentation and modeling to reveal aspects of the mostly unexplored relationship between S. oralis and L. paracasei in biofilm growth. The inhibitory nature of L. paracasei on S. oralis in biofilms may be exploited as a means of preventing or alleviating mucosal fungal infections.

Selenium nanoparticles from Lactobacillus paracasei HM1 capable of antagonizing animal pathogenic fungi as a new source from human breast milk

The current study was performed to develop a simple, safe, and cost-effective technique for the biosynthesis of selenium nanoparticles (SeNPs) from lactic acid bacteria (LAB) isolated from human breast milk with antifungal activity against animal pathogenic fungi. The LAB was selected based on their speed of transforming sodium selenite (Na2SeO3) to SeNPs. Out of the four identified LAB isolates, only one strain produced dark red color within 32 h of incubation, indicating that this isolate was the fastest in transforming Na2SeO3 to SeNPs; and was chosen for the biosynthesis of LAB-SeNPs. The superior isolate was further identified as Lactobacillus paracasei HM1 (MW390875) based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and phylogenetic tree analysis of 16S rRNA sequence alignments. The optimum experimental conditions for the biosynthesis of SeNPs by L. paracasei HM1 were found to be pH (6.0), temperature (35˚C), Na2SeO3 (4.0 mM), reaction time (32 h), and agitation speed (160 rpm). The ultraviolet absorbance of L. paracasei-SeNPs was detected at 300 nm, and the transmission electron microscopy (TEM) captured a diameter range between 3.0 and 50.0 nm. The energy-dispersive X-ray spectroscopy (EDX) and the Fourier-transform infrared spectroscopy (FTIR) provided a clear image of the active groups associated with the stability of L. paracasei-SeNPs. The size of L. paracasei-SeNPs using dynamic light scattering technique was 56.91 ± 1.8 nm, and zeta potential value was -20.1 ± 0.6 mV in one peak. The data also revealed that L. paracasei-SeNPs effectively inhibited the growth of Candida and Fusarium species, and this was further confirmed by scanning electron microscopy (SEM). The current study concluded that the SeNPs obtained from L. paracasei HM1 could be used to prepare biological antifungal formulations effective against major animal pathogenic fungi. The antifungal activity of the biologically synthesized SeNPs using L. paracasei HM1 outperforms the chemically produced SeNPs. In vivo studies showing the antagonistic effect of SeNPs on pathogenic fungi are underway to demonstrate the potential of a therapeutic agent to treat animals against major infectious fungal diseases.

Screening of immune-enhancing Lactobacillus in mice by using a cell-line

In this study, we found that it is possible to screen Lactobacillus strains that enhance the immune function of mice using HCT-8 cells. Lactobacillus were co-incubated with intestinal epithelial HCT-8 cells to detect and screen the strains that induced more interleukin-6 (IL-6) in the culture supernatant. Simultaneously, a mouse model of low immunity was established to administer the screened lactobacilli by gavage. After 4 weeks of continuous gavage, related cytokines in blood and immune cell indexes in organs were detected to comprehensively evaluate the feasibility of in vitro cell culture model for screening immune-enhancing strains. The content of IL-6 in the culture supernatant of HCT-8 cells induced by the three tested strains increased approximately 5, 8 and 15 fold compared with that of the control group. IL-6 content in serum of mice was significantly higher than that of the control group provided with cyclophosphamide (CTX). Lactobacillus paracasei ZLPC01 presented a higher ability to protect against the immune damage of CTX by decreasing the serum IgG level, increasing the transformation of mouse splenocytes, and the activity of NK cells. Furthermore, L. paracasei ZLPC01 increased cytokine content in serum (IL-6, IL-2, TNF-α and IFN-γ) and colon (IL-6 and TNF-α) in CTX-treated mice. Screening strains that enhance immunity via an in vitro cell-line is simple in operation, and the results are well correlated with those of animal experiments, which is feasible and effective in practice. In addition, L. paracasei ZLPC01 could have the potential to enhance the immunity of mice effectively through inducing intestinal cells to produce IL-6, TNF-α and other cytokines.

Plant-Derived Lactobacillus paracasei IJH-SONE68 Improves Chronic Allergy Status: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

We have recently demonstrated that the exopolysaccharides (EPSs) produced by a plant-derived lactic acid bacterium, Lactobacillus paracasei IJH-SONE68, prevent and ameliorate allergic reaction on contact in dermatitis model mice. In the present study, we conducted a clinical trial using a capsule containing spray-dried powder from pineapple juice broth fermented with the LAB strain as an experimental diet. The clinical trial was conducted as a double-blind and placebo-controlled randomized comparative study from May 2019 to July 2021. Males and females between the ages of 21 and 70 who experience chronic allergies participated in the study. Sixty subjects were instructed to orally take a capsule containing the IJH-SONE68 powder or placebo, every day for 12 weeks. After the clinical trial was over, the scores based on subjects' self-assessment of allergic status were significantly improved in the intervention group, as compared with the placebo group. Some serum biochemicals associated with inflammation response were also significantly improved by intake of the experimental diet. In conclusion, the IJH-SONE68-derived EPS improves chronic allergy status in humans and is expected to decrease their inconvenience.

The Exopolysaccharide Produced by Lactobacillus paracasei IJH-SONE68 Prevents and Ameliorates Inflammatory Responses in DSS-Induced Ulcerative Colitis

Inflammatory bowel disease (IBD) is an autoimmune disease characterized by chronic inflammation of the gastrointestinal tract. IBD includes Crohn’s disease (CD) and ulcerative colitis (UC). CD can occur in any part of the gastrointestinal tract, whereas UC mainly occurs in the colon and rectum. We previously demonstrated that a novel exopolysaccharide (EPS) produced by a plant-derived bacterium, Lactobacillus paracasei IJH-SONE68, prevents and improves the inflammation in contact dermatitis model mice via oral administration. To evaluate the preventive effect of the EPS against other inflammatory diseases, in the present study, we employed dextran sulfate sodium (DSS)-induced UC model mice. The stool consistency, hematochezia, and colonic atrophy of the mice were improved by the orally administered EPS. We also evaluated the cytokine transcription. Overexpression of the mouse macrophage inflammatory protein 2 mRNA in the colon as a functional homolog of human interleukin-8 was decreased by the orally administered EPS. However, the expression of interleukin-10, which is known as an anti-inflammatory cytokine, was stimulated in the EPS-administrated group. Based on these results, we conclude that the IJH-SONE68-derived EPS is a promising lead material for the development of drugs useful in treating inflammatory diseases such as UC.

Influence of Diet on the Effect of the Probiotic Lactobacillus paracasei in Rats Suffering From Allergic Asthma

Mounting evidence suggests that probiotics can be used to treat allergic asthma by modulating the gut microbiota, and that the effects of probiotics may be influenced by environmental factors such as diet. We conducted a rat model with allergic asthma (AA) modulated by Lactobacillus paracasei, feeding up with high-fat or high-fiber diets based on collecting data from 85 questionnaires. The systemic proinflammatory cytokines were detected by ELISA and the overall structure of fecal microbiota was analyzed via 16S rRNA gene sequencing. The results showed consumption of a high-fiber diet alleviated the allergic symptoms and airway inflammation, and led to improving the imbalance of T-helper type 1 (Th1)/Th2 cells with increased expression of interferon-γ and decreased expression of interleukin-4. Whereas, the high-fat diet had deteriorating implications and skewed the inflammatory perturbation. Furthermore, abundances of phylum Bacteroidetes, families Muribaculaceae, Tannerellaceae, Prevotellaceae, Enterococcaceae, genera Allobaculum, Parabacteroides, and Enterococcus were enriched in L. paracasei-modulating rats fed with high-fiber diet. Firmicutes and Proteobacteria, families Lachnospiraceae, Ruminococcaceae and Desulfovibrionaceae, genera Blautia, unidentified_Ruminococcaceae, unidentified_Clostridiales and Oscillibacter were in relatively high abundance in the rats administered high-fat diet. Association between changed microbiota and inflammatory cytokines was also conferred. These data indicated that the efficacy of L. paracasei in allergic asthma was influenced by different dietary patterns. Hence, diet is important for probiotic therapy when managing allergic asthma.

Production of fermented spicy rabbit meat using Lactobacillus paracasei

Lactobacillus paracasei was used to produce fermented spicy rabbit meat. A series of indexes were determined, including pH value, free amino acid content, true protein content, texture, microstructure and the volatile compounds of fermented spicy rabbit meat and unfermented spicy rabbit meat. The results showed that Lactobacillus paracasei could reduce the pH value of spicy rabbit meat (from 6.85 to 4.65), could degrade the proteins of spicy rabbit meat, could increase the content of free amino acids (from 205.1 mg/100 g to 505.6 mg/100 g), and could improve its textural properties and organoleptic quality of the spicy rabbit meat. The microstructure of the fermented spicy rabbit meat and unfermented spicy rabbit meat was observed by scanning electron microscope. The results showed that the microstructure of the fermented spicy rabbit meat changed obviously, the arrangement of muscle fibers was loose or even seriously broken, and many small pieces were formed, which indicated that the fermentation could improve the tenderness of the rabbit meat. The kinds of volatile flavor compounds after fermentation were increased from 14 to 40 as estimated by solid phase microextraction and GC-MS. Therefore, utilization of microbial fermentation technology can improve the quality, texture, tenderness and flavor of spicy rabbit meat, and enhance the digestion and absorption capacity.

Assessment of resistance and biosorption ability of Lactobacillus paracasei to remove lead and cadmium from aqueous solution

Since heavy metals have been regarded as ubiquitous environmental pollutants, the exploitation of bacterial biosorption has been suggested as an applicable method for being employed for heavy metal depletion. The present study aimed to characterize the function of Lactobacillus paracasei in the presence of Pb (II) and Cd (II). The simultaneous effect of pH, initial metal concentration, and inoculum size demonstrated the Pb (II) removal of 85.77% at the lowest pH, while the inoculum size was enhanced to 45 CFU/100 ml. The maximum Cd (II) removal was obtained at a high level of pH and inoculum size, while the metal concentration was reduced to 30 ppb. The addition of Cd (II) concentration in access led to the 10% drop in Cd (II) removal efficiency attributed to the metal toxicity and pH. Additionally, the slight variation in the amount of inoculum size caused the decreasing trend in the Cd (II) removal. According to the obtained results, the benefit of L. paracasei in the biosorption of heavy metals was well-recognized, which could be suggested as an alternative candidate. PRACTITIONER POINTS: Strain of Lactobacillus paracasei as potential probiotics was tested for biosorption. A successful response surface method was proposed. L. paracasei showed a good efficiency for the lead and cadmium biosorption. Biosorption process was effective in removing low metal level from drinking water. The maximum biosorption was found to be 85.77% for Pb (II) obtained from the experiment.

Lactobacillus paracasei S16 Alleviates Lumbar Disc Herniation by Modulating Inflammation Response and Gut Microbiota

Lumbar disc herniation (LDH) is a common cause for low back pain. In this study, we aimed to explore the effects of a specific Lactobacillus paracasei (L. paracasei), L. paracasei S16, on the symptoms of LDH using a mouse model of LDH. The results showed that L. paracasei S16 treatment improved the behavior, increased the cell proliferation, and decreased the apoptosis in LDH mice. Moreover, L. paracasei S16 treatment alleviated the aberrant inflammation response in the LDH mice, which is characterized by the decreased anti-inflammatory cytokines, increased pro-inflammatory cytokines, and decreased percentage of Th1 and Th2 cells and Th17/Treg ratio. 16S rRNA sequencing results showed that the LDH mice treated with L. paracasei S16 have higher relative abundance of Lachnospiraceae and Ruminococcaceae and lower abundance of Lactobacillaceae than mice in the LDH group. Additionally, the serum metabolites involved in the linoleic acid metabolism, alanine. aspartate, and glutamate, glycerophospholipid, and TCA cycle were significantly decreased and the metabolite involved in purine metabolism was significantly increased after the L. paracasei S16 treatment in the LDH mice. These results showed that administration of L. paracasei S16 can improve inflammation response, alter gut microbiota, and modulate serum metabolomics in a mouse model of LDH.

Manganese accumulation in probiotic Lactobacillus paracasei ATCC 55544 analyzed by synchrotron X-ray fluorescence microscopy and impact of accumulation on the bacterial viability following encapsulation

Lactobacillus spp. are known to accumulate large amounts of inorganic manganese, which protects against oxidative damage by scavenging free radicals. The ability of probiotic L. paracasei ATCC 55544 to maintain viability during long-term ambient storage may be enhanced by this microorganism's ability to accumulate manganese, which may act as a free radical scavenger. To investigate this hypothesis, X-ray fluorescence microscopy (XFM) was employed to determine the changes in the elemental composition of L. paracasei during growth in the MRS medium with or without added manganese. Moreover, manganese uptake by cells as a function of physiological growth state, early log vs. stationary phase was evaluated. The semiquantitative X-ray fluorescence microscopy results revealed that lower levels of manganese accumulation occurred during the early log phase of bacterial growth of L. paracasei cells (0.0064 µg/cm²) compared with the stationary phase cells (0.1355 µg/cm²). L. paracasei cells grown in manganese deficient MRS medium resulted in lower manganese uptake by cells (0.0027 µg/cm²). The L. paracasei cells were further embedded in milk powder matrix using a fluidized-bed drying technique and stored at a water activity (a_w) of 0.33 at 25 °C for 15 days. The viability counts of L. paracasei cells grown in MRS medium harvested after 18 h growth and embedded in milk powder matrix retained viability of (9.19 ± 0.12 log CFU/g). No viable L. paracasei cells were observed in the case of embedded L. paracasei cells grown in manganese-deficient MRS medium harvested after 18 h growth or in the case of L. paracasei cells harvested after 4 h when grown in MRS medium. The lower level of manganese accumulation was found to be related to the loss of bacterial viability during storage.

Lactobacillus paracasei R3 protects against dextran sulfate sodium (DSS)-induced colitis in mice via regulating Th17/Treg cell balance

Inflammatory bowel diseases (IBD), mainly comprising ulcerative colitis (UC) and Crohn's Disease, are most often a polygenic disorder with contributions from the intestinal microbiome, defects in barrier function, and dysregulated host responses to microbial stimulation. Strategies that target the microbiota have emerged as potential therapies and, of these, probiotics have gained the greatest attention. Herein, we isolated a strain of Lactobacillus paracasei R3 (L.p R3) with strong biofilm formation ability from infant feces. Interestingly, we also found L.p R3 strain can ameliorate the general symptoms of murine colitis, alleviate inflammatory cell infiltration and inhibit Th17 while promote Treg function in murine dextran sulfate sodium (DSS)-induced colitis. Overall, this study suggested that L.p R3 strain significantly improves the symptoms and the pathological damage of mice with colitis and influences the immune function by regulating Th17/Treg cell balance in DSS-induced colitis in mice.

Lactobacillus paracasei R3 protects against dextran sulfate sodium (DSS)-induced colitis in mice via regulating Th17/Treg cell balance

Inflammatory bowel diseases (IBD), mainly comprising ulcerative colitis (UC) and Crohn's Disease, are most often a polygenic disorder with contributions from the intestinal microbiome, defects in barrier function, and dysregulated host responses to microbial stimulation. Strategies that target the microbiota have emerged as potential therapies and, of these, probiotics have gained the greatest attention. Herein, we isolated a strain of Lactobacillus paracasei R3 (L.p R3) with strong biofilm formation ability from infant feces. Interestingly, we also found L.p R3 strain can ameliorate the general symptoms of murine colitis, alleviate inflammatory cell infiltration and inhibit Th17 while promote Treg function in murine dextran sulfate sodium (DSS)-induced colitis. Overall, this study suggested that L.p R3 strain significantly improves the symptoms and the pathological damage of mice with colitis and influences the immune function by regulating Th17/Treg cell balance in DSS-induced colitis in mice.

Lactobacillus paracasei R3 protects against dextran sulfate sodium (DSS)-induced colitis in mice via regulating Th17/Treg cell balance

Inflammatory bowel diseases (IBD), mainly comprising ulcerative colitis (UC) and Crohn's Disease, are most often a polygenic disorder with contributions from the intestinal microbiome, defects in barrier function, and dysregulated host responses to microbial stimulation. Strategies that target the microbiota have emerged as potential therapies and, of these, probiotics have gained the greatest attention. Herein, we isolated a strain of Lactobacillus paracasei R3 (L.p R3) with strong biofilm formation ability from infant feces. Interestingly, we also found L.p R3 strain can ameliorate the general symptoms of murine colitis, alleviate inflammatory cell infiltration and inhibit Th17 while promote Treg function in murine dextran sulfate sodium (DSS)-induced colitis. Overall, this study suggested that L.p R3 strain significantly improves the symptoms and the pathological damage of mice with colitis and influences the immune function by regulating Th17/Treg cell balance in DSS-induced colitis in mice.

paracasei KNI9 Inhibiting Adherence of Yersinia enterocolitica on Caco-2 Cells In Vitro

The study was aimed to characterize the probiotic properties of Lactobacillus paracasei subsp. paracasei strain KNI9 and its antagonistic activity against Yersinia enterocolitica subsp. enterocolitica. The strain KNI9 was susceptible to antibiotics such as chloramphenicol, tetracycline, erythromycin, and streptomycin recommended by European food safety authority (EFSA). Strain KNI9 exhibited tolerance to simulated oro-gastrointestinal (OGT) condition, adherence to Caco-2 cells, and antimicrobial activity against intestinal enteric pathogens such as Yersinia enterocolitica subsp. enterocolitica, Shigella boydii, and Listeria monocytogenes. Furthermore, the strain KNI9 inhibited the adherence and invasiveness of Y. enterocolitica subsp. enterocolitica to Caco-2 cell line. These results indicate that the L. paracasei subsp. paracasei KNI9 could be further developed into a potential probiotic strain after appropriate in vivo studies.

Safety and Stability of Two Potentially Probiotic Lactobacillus Strains After In Vitro Gastrointestinal Transit

According to FAO and WHO, probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Most probiotic bacteria used today belong to the genera Lactobacillus and Bifidobacterium and are of animal or human origin. The fundamental characteristic routinely evaluated in potential probiotics strains is their limited viability loss during gastrointestinal transit (GIT), but to date, no studies reported whether probiotics, besides viability, still also maintain their beneficial properties intact. To study this aspect, we considered two strains, Lactobacillus rhamnosus DTA 79 and L. paracasei DTA 83, previously characterised for the presence of some probiotic properties, isolated from faeces of 7- to 21-day-old babies. Here, we examined some additional properties, namely antibiotic resistance, resistance to lysozyme, presence of haemolytic activity and inhibition of pathogen biofilm formation. We then tested the effect of in vitro GIT on all these features and our results show evidence that this procedure had in some cases limited and in others no significant effects on them. Additionally, we examined the gastrointestinal resistance of the strains after skim milk fermentation and successive storage of the product for 20 and 40 days at refrigeration temperature, to see whether prolonged storage could weaken cell resistance to GIT. Our results demonstrate that a protracted refrigeration period before in vitro GIT did not affect or influenced very weakly this essential probiotic property.

Influence of Lactobacillus paracasei HII01 Supplementation on Glycemia and Inflammatory Biomarkers in Type 2 Diabetes: A Randomized Clinical Trial

It has been shown that gut dysbiosis can be associated with the development of type 2 diabetes mellitus (T2DM). Consequently, intervention with probiotics may be a useful approach to improve metabolic variables in diabetes. The present study aimed to evaluate the efficacy of L. paracasei HII01 on glycemia in T2DM patients. In a randomized, double-blind, placebo-controlled study, 50 participants were allocated to receive L. paracasei HII01 (50 × 10⁹ CFU/day) or a placebo (corn starch 10 mg/day). Blood and fecal samples were assessed at baseline and at the end of the trial. After 12 weeks of intervention, fasting blood glucose level had significantly decreased in the probiotic group compared with the placebo group. Importantly, probiotic supplementation significantly decreased the plasma levels of LPS, TNF-α, IL-6 and hsCRP compared the placebo group. Additionally, an increase in beneficial bacteria and a decrease in pathogenic bacteria, which related to the improvement of SCFAs, was found following L. paracasei HII01 supplementation. These findings demonstrated that L. paracasei HII01 improved hyperglycemia and inflammatory markers by favorably modifying gut microbiota and subsequently ameliorating the leaky gut and endotoxemia, thereby suggesting a potential role as an adjuvant treatment in type 2 diabetes.

Hepatoprotective Effect of Probiotic Lactic Acid Bacteria on Thioacetamide-Induced Liver Fibrosis in Rats

Hepatic fibrosis is a reversible wound-healing response characterized by the accumulation of extracellular matrix. Probiotics have been used to prevent and treat various disorders. The aim of the present study was to investigate the hepatoprotective effects of probiotic lactic acid bacteria (mixture of Lactobacillus paracasei, Lactobacillus casei, and Weissella confusa) on thioacetamide (TAA)-induced liver fibrosis in rats. Thirty-five male Wistar rats were randomly divided into five groups: (1) control, (2) TAA, (3) TAA+probiotics, (4) TAA+silymarin, and (5) probiotics. Group 1 rats received a standard diet. In groups 2-4, fibrosis was induced by intraperitoneal injection of TAA (200 mg/kg BW) 3 times weekly for 8 consecutive weeks. Group 4 received TAA plus 100 mg/kg BW of silymarin 2 times weekly. Groups 3 and 5 were fed 10⁹ CFU/mL viable microbial cells daily by gavage. The rats were sacrificed after 8 weeks of treatment. Liver tissues were collected immediately and processed for histopathological, lipid peroxidation, and Western blot analyses of TNF-α, TGF-β1, and α-SMA. Blood serum was collected to measure liver enzymes. Rats in the TAA groups suffered from hepatic injury (increased serum enzyme levels, liver inflammation, and increased concentration of TNF-α, TGF-β1, and α-SMA proteins) and extensive liver fibrosis. In contrast, TAA-treated rats receiving probiotics or silymarin had significantly lower serum enzyme levels, less inflammation, and less fibrosis. Liver damage was lower in the TAA+probiotics-treated group. Consumption of a mixture of probiotic lactic acid bacteria attenuates the development of liver fibrosis.

Differences in the expression of cell envelope proteinases (CEP) in two Lactobacillus paracasei probiotic strains

Proteinase PrtP (EC:3.4.21.96) is a cell envelope proteinase (CEP) highly expressed in the probiotic strain Lactobacillus paracasei BL312(VSL#3) that accounts for its anti-inflammatory properties. The main aim of this work is to understand differences in CEP expression between this strain and L. paracasei BL23. Hence, differences in the regulation by amino acid sources of four proteinase related genes (prtP, prsA, prtR1 and prtR2) were determined by RT-qPCR in BL312(VSL#3) and BL23 using as a reference BL368, a BL23 derepressed mutant lacking the response regulator (RR) PrcR. BL312(VSL#3) showed greater expression of prtP (2- to 3-fold) than BL23, and prtP was highly repressed by peptone in both strains. Two other putative CEP genes, prtR1 and prtR2, showed a low expression profile. Interestingly, when the prsA-prtP promoter region from both strains, and deleted mutants, were cloned in vector pT1GR, expression of the gfp and mrfp fluorescent reporters was always repressed in BL23 (high or low peptone) and derepressed in BL368, revealing an interesting mechanism of regulation affecting specifically to this promoter. In conclusion, BL312(VSL#3) has higher expression of prtP and other CEP related genes than BL23, that could respond to a natural deregulation in this strain, possibly independent from the RR PrcR.

FTIR microspectroscopic investigation of Lactobacillus paracasei apoptosis induced by cisplatin

Recent studies have shown that bacteria can also undergo apoptosis, which has gradually attracted researchers' attention. Cisplatin is a first-line drug to treat several cancers, but it can damage beneficial bacteria. Hence it is very important to explore the damage mechanism of cisplatin on beneficial bacteria. In this study, Lactobacillus paracasei, one kind of beneficial bacteria, was used as the model to investigate cisplatin damage. Conventional detection showed that cisplatin induced the apoptosis of Lactobacillus paracasei. Then Fourier transform infrared (FTIR) microspectroscopy was used to detect biomacromolecular changes in Lactobacillus paracasei apoptosis, and the following results were obtained: ① Second derivative IR spectra showed the changes of DNA, proteins, polysaccharides and lipids; ② Peak-area ratios suggested the changes of the protein and lipid structure and the decrease of DNA content; ③ Principal component analysis (PCA) further revealed significant changes in the DNA and protein content/structure. This study may have a new insight into the adverse reaction mechanism of cisplatin on Lactobacillus, moreover, it suggests that FTIR microspectroscopy may be a useful supplementary tool for investigating bacterial apoptosis.

Biomedical and therapeutic potential of exopolysaccharides by Lactobacillus paracasei isolated from sauerkraut: Screening and characterization

The intention of the study was evaluated for purification and characterization of exopolysaccharides from Lactobacillus paracasei; was isolated from homemade Sauerkraut sample collected from Sivakasi, Tamil Nadu, India, confirmed by biochemical and gene sequencing (16S rRNA). The purification and characterization of exopolysaccharides from candidate bacterium were studied on appearance, solubility of the EPS, carbohydrate estimation, emulsifying activity, sulphate, protein, uronic acid content, FTIR, HPLC and GC-MS analysis. The percentage of elemental carbon, (54.36%) hydrogen (21.74%), nitrogen (9.63%) and sulphur content (18.03%) were recorded in exopolysaccharides. The emulsification index (E24) of EPS was higher in toluene (79.20) and benzene (78.867) supplemented medium. FTIR spectrum of the candidate bacterial EPS confirmed presence of sulphate compounds, carboxyl group, and hydrogen bonded compounds etc. EPS exhibited 76.34% of Total Antioxidant Capacity (TAC), 71.15% of reducing power, 68.65% of Hydrogen Peroxide scavenging activity and also 60.31% DPPH radical scavenging activity. The potential antioxidant properties observed in exopolysaccharides from Lactobacillus paracasei is considered as valuable drugs.

A Palmitoylethanolamide Producing Lactobacillus paracasei Improves Clostridium difficile Toxin A-Induced Colitis

Genetically engineered probiotics, able to in situ deliver therapeutically active compounds while restoring gut eubiosis, could represent an attractive therapeutic alternative in Clostridium difficile infection (CDI). Palmitoylethanolamide is an endogenous lipid able to exert immunomodulatory activities and restore epithelial barrier integrity in human models of colitis, by binding the peroxisome proliferator–activated receptor-α (PPARα). The aim of this study was to explore the efficacy of a newly designed PEA-producing probiotic (pNAPE-LP) in a mice model of C. difficile toxin A (TcdA)-induced colitis. The human N-acyl-phosphatidylethanolamine-specific phospholipase D (NAPE-PLD), a key enzyme involved in the synthesis of PEA, was cloned and expressed in a Lactobacillus paracasei that was intragastrically administered to mice 7 days prior the induction of the colitis. Bacteria carrying the empty vector served as negative controls (pLP).In the presence of palmitate, pNAPE-LP was able to significantly increase PEA production by 27,900%, in a time- and concentration-dependent fashion. Mice treated with pNAPE-LP showed a significant improvement of colitis in terms of histological damage score, macrophage count, and myeloperoxidase levels (−53, −82, and −70.4%, respectively). This was paralleled by a significant decrease both in the expression of toll-like receptor-4 (−71%), phospho-p38 mitogen-activated protein kinase (−72%), hypoxia-inducible factor-1-alpha (−53%), p50 (−74%), and p65 (−60%) and in the plasmatic levels of interleukin-6 (−86%), nitric oxide (−59%), and vascular endothelial growth factor (−71%). Finally, tight junction protein expression was significantly improved by pNAPE-LP treatment as witnessed by the rescue of zonula occludens-1 (+304%), Ras homolog family member A-GTP (+649%), and occludin expression (+160%). These protective effects were mediated by the specific release of PEA by the engineered probiotic as they were abolished in PPARα knockout mice and in wild-type mice treated with pLP. Herein, we demonstrated that pNAPE-LP has therapeutic potential in CDI by inhibiting colonic inflammation and restoring tight junction protein expression in mice, paving the way to next generation probiotics as a promising strategy in CDI prevention.