Polysaccharide of Lactobacillus casei SB27 reduced colon cancer cell prognosis through mitochondrial damage by upregulation of HINT2

AIMS

Colorectal cancer (CRC) is one of the most common malignant tumors worldwide. This study aimed to explore the effects of Polysaccharide of Lactobacillus casei SB27 in colon cancer and its possible mechanisms.

METHODS

Colon cancer was induced by giving dextran sulfate sodium and Azoxymethane. Uman Colon Cancer Cell Line (HCT)-116 cells were used to vitro model in this experiment.

RESULTS

Polysaccharide of L. casei SB27 reduced colon cancer in azoxymethane-dextran sulfate sodium (AOM+DSS)-induced mice. Polysaccharide of L. casei SB27 reduced colon cancer prognosis in vitro model. Polysaccharide of L. casei SB27 reduced short chain fatty acids by Bacillus coli. Polysaccharide of L. casei promoted mitochondrial damage by Calcium ion entry. Polysaccharide of L. casei induced histidine nucleotide binding protein 2/mitochondrial calcium uniporter (HINT2/MCU) signaling pathway. Immunocoprecipitation (IP) showed that HINT2 protein interlinked MCU protein. Polysaccharide of L. casei suppressed HINT2 ubiquitination. The regulation of HINT2 affected the effects of L. casei polysaccharide on colon cancer prognosis and mitochondrial damage by Calcium ion entry in vitro model.

CONCLUSION

In conclusion, the present report demonstrated that polysaccharide of L. casei SB27 reduced colon cancer cell prognosis through mitochondrial damage by upregulation of HINT2. Polysaccharide of L. casei SB27 might be used for colon cancer treatment and could be helpful for personalized treatment.

The performance of tongue swabs for detection of pulmonary tuberculosis

Introduction

Oral and/or tongue swabs have demonstrated ability to detect Mycobacterium tuberculosis (Mtb) in adults with pulmonary tuberculosis (TB). Swabs provide useful alternative specimens for diagnosis of TB using molecular assays however, the diagnostic pickup by culture requires further improvement and development. Several studies identified the presence of differentially culturable tubercle bacilli (DCTB) populations in a variety of clinical specimens. These organisms do not grow in routine laboratory media and require growth factors in the form of culture filtrate (CF) from logarithmic phase cultures of Mtb H37Rv.

Methods

Herein, we compared the diagnostic performance of sputum and tongue swabs using Mycobacterial Growth Indicator Tube (MGIT) assays, Auramine smear, GeneXpert and DCTB assays supplemented with or without CF.

Results

From 89 eligible participants, 83 (93%), 66 (74%) and 79 (89%) were sputum positive by MGIT, smear and GeneXpert, respectively. The corresponding tongue swabs displayed a lower sensitivity with 39 (44%), 2 (2.0%) and 18 (20%) participants respectively for the same tests. We aimed to improve the diagnostic yield by utilizing DCTB assays. Sputum samples were associated with a higher positivity rate for CF-augmented DCTB at 82/89 (92%) relative to tongue swabs at 36/89 (40%). Similarly, sputum samples had a higher positivity rate for DCTB populations that were CF-independent at 64/89 (72%) relative to tongue swabs at 26/89 (29%). DCTB positivity increased significantly, relative to MGIT culture, for tongue swabs taken from HIV-positive participants. We next tested whether the use of an alternative smear stain, DMN-Trehalose, would improve diagnostic yield but noted no substantial increase.

Discussion

Collectively, our data show that while tongue swabs yield lower bacterial numbers for diagnostic testing, the use of growth supplementation may improve detection of TB particularly in HIV-positive people but this requires further interrogation in larger studies.

Lactobacillus casei ATCC 393 combined with vasoactive intestinal peptide alleviates dextran sodium sulfate-induced ulcerative colitis in C57BL/6 mice via NF-κB and Nrf2 signaling pathways

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) which is related to an immunological imbalance of the intestinal mucosa. Many clinical evidences indicate probiotics supplementation appears to be effective and safe in patients with UC. Vasoactive intestinal peptide (VIP) is an endogenous neuropeptide with multiple physiological and pathological effects. In this study, we investigated the protective effect of the combination of Lactobacillus casei ATCC 393 (L. casei ATCC 393) with VIP on dextran sodium sulfate (DSS)-induced UC in mice and the potential mechanism. The results showed that, compared with the control group, DSS treatment significantly shortened the colon length, caused inflammation and oxidative stress, and further resulted in the intestinal barrier dysfunction and gut microbiota dysbiosis. In addition, intervention with L. casei ATCC 393, VIP or L. casei ATCC 393 combined with VIP significantly reduced UC disease activity index. However, compared with L. casei ATCC 393 or VIP, L. casei ATCC 393 combined with VIP effectively relieved symptoms of UC by regulating immune response, enhancing antioxidant capacity, and regulating nuclear factor kappa-B (NF-κB) and nuclear factor erythroid-derived-2-like 2 (Nrf2) signaling pathways. In conclusion, this study suggests that L. casei ATCC 393 combined with VIP can effectively relieve DSS-induced UC, which is a promising treatment strategy for UC.

Lc-pPG-612-OmpU-CTB: A promising oral vaccine for protecting Carassius auratus against Vibrio mimicus infection

Vibrio mimicus (V. mimicus) is known to cause severe bacterial diseases with high mortality rates in fish, resulting in significant economic losses in the global aquaculture industry. Therefore, the objective of this study was to develop a safe and effective vaccine for protecting Carassius auratus (C. auratus) against V. mimicus infection. Recombinant Lactobacillus casei (L. casei) strains, Lc-pPG-612-OmpU and Lc-pPG-612-OmpU-CTB (surface-displayed), were constructed using a L. casei strain (ATCC 393) as an antigen delivery carrier and the cholera toxin B subunit (CTB) as an adjuvant. The two recombinant strains of L. casei were administered to C. auratus via oral immunization, and the protective efficacy of the oral vaccines was assessed. The results demonstrated that oral immunization with the two strains significantly increased the levels of nonspecific immune indicators in C. auratus, including alkaline phosphatase (AKP), lysozyme (LYS), acid phosphatase (ACP), complement 3 (C3), complement 4 (C4), lectin, and superoxide dismutase (SOD). Moreover, the experiment groups exhibited significant increases in specific immunoglobulin M (IgM) antibodies against OmpU, as well as the transcription of immune-related genes (ie., IL-1β, TNF-α, IL-10, and TGF-β), when compared to the control groups. Following infection of C. auratus with V. mimicus, the mortality rate of the recombinant L. casei-treated fish was observed to be lower compared to the control group. This finding suggests that recombinant L. casei demonstrates effective protection against V. mimicus infection in C. auratus. Furthermore, the addition of the immune adjuvant CTB was found to induce a more robust adaptive and innate immune response in C. auratus, resulting in reduced mortality after infection with V. mimicus.

The activation of CaN/NFAT signaling pathway in macrophages aggravated Lactobacillus casei cell wall extract-induced Kawasaki disease vasculitis

OBJECTIVES

By using GWAS(genome-wide association studies) and linkage disequilibrium analysis to investigate the susceptibility genes of KD(Kawasaki disease), previous studies have identified that the CaN(calcineurin)-NFAT(the nuclear factor of activated T cell) signal pathway were significantly associated with susceptibility to KD. However, little is known about the molecular basis of the CaN/NFAT pathway involved in KD. Therefore, in our study we investigate the role of Ca2+/CaN/NFAT signaling pathway in macrophages in vitro and in vivo on coronary artery lesions induced by LCWE (Lactobacillus casei cell wall extract).

METHODS AND RESULTS

We observed that LCWE could increase the expression of NFAT1 and NFAT2 in macrophages in vitro, and also enhance the transcriptional activity of NFAT by promoting the nucleus translocation. Similarly, in LCWE-induced mice model, the expression of NFAT1 and NFAT2 and associated proinflammatory factors were increased significantly. In addition, by knocking down or overexpressing NFAT1 or NFAT2 in macrophages, the results indicated that NFAT signaling pathway mediated LCWE-induced immune responses in macrophages and regulated the synthesis of IL(interleukin)-6, IL-1β and TNF(tumor necrosis factor)-α in LCWE-induced macrophage activation. As well, we found that this process could be suppressed by CaN inhibitor CsA(cyclosporinA).

CONCLUSIONS

Therefore, the CaN/NFAT signaling pathway mediated LCWE-induced immune responses in macrophages, and also participated in the LCWE-induced CALs(coronary artery lesions). And also the inhibitory effect of CsA in LCWE-induced cell model towards a strategy to modulate the CaN/NFAT pathway during the acute course of KD might be helpful in alleviate KD-induced CALs.

Lactobacillus casei-derived postbiotics inhibited digestion of triglycerides, glycerol phospholipids and sterol lipids via allosteric regulation of BSSL, PTL and PLA2 to prevent obesity: perspectives on deep learning integrated multi-omics

The anti-obesity potential of probiotics has been widely reported, however their utilization in high-risk patients and potential adverse reactions have led researchers to focus their attention on postbiotics. Herein, pseudo-targeted lipidomics linked with deep learning-based metabolomics was utilized to dynamically characterize the postbiotic potential of heat-inactivated Lactobacillus casei JCM1134 supplementation after a high-fat diet in treating obesity. MG (ranged from 423.0 ± 1.4 mg L-1 to 331.45 ± 2.3 mg L-1), LPC (ranged from 13.1 ± 0.08 mg L-1 to 10.2 ± 0.1 mg L-1) and Cho (ranged from 9.0 ± 0.3 mg L-1 to 5.7 ± 0.2 mg L-1) in intestinal digestive products were significantly decreased, indicating that the digestion of lipid was inhibited. 8-C-glucosylorobol, from Lactobacillus casei, was confirmed from quantitative results and molecular simulation calculations to inhibit the transformation of TG, DG, and ChE through weakening hydrogen bonds between enzymes and substrates and reducing the binding energy. Pristimerin and 2,4-quinolinediol can effectively reduce the hydrogen bonding force between PC and phospholipase A2, which were related to the obstruction of phosphatidylcholine digestion. This research deepened the understanding of the mechanism underlying the inactivated probiotics affecting lipid digestion, establishing the critical groundwork for clinical application of probiotics in inhibiting obesity.

The effect of physical exercise and dairy probiotics (Lactobacillus casei) on gut microbiome in childhood cancer survivors

Gut microbial dysbiosis persists months after intensive cancer treatment in children and adolescents. This prospective study compared the intestinal microbiome of children 1-3 years after completion of Berlin-Frankfurt-Münster protocol (BFM)-based pediatric ALL (PALL) treatment and healthy controls. To induce a favorable shift in the bacterial composition of the intestines in PALL with gut microbiome disruptions, 8 weeks of physical activity and probiotic consumption were used. Blood analyses and 16S rRNA sequencing for the gut microbiome were performed on 16 pediatric cases and 16 healthy controls. Significant differences in bacterial diversity were found between pre- and post-intervention, respectively (Shannon index, 3.22±0.45 vs. 3.47±0.24, p=0.04; Simpson index, 0.10±0.05 vs. 0.06±0.02, p=0.02; and Chao1 index, 693.88±238.58 vs. 794.23±116.34, p=0.04). Furthermore, the increase in the relative abundance of Lactobacillus casei (5.04E-03±1.62E-02 vs. 2.92E-02±5.03E-02, p=0.04) and the increase in some strains of Veillonella, a bacterial genus recently linked to improved physical fitness, were identified. Promisingly, the exercise program combined with dairy probiotics increased bacterial richness and diversity.

Effect of Lacticaseibacillus paracasei strain Shirota supplementation on clinical responses and gut microbiome in Parkinson's disease

Parkinson's disease (PD) is a common neurodegenerative disease characterized by motor issues and a range of non-motor symptoms. Microbial therapy may be a useful approach for the treatment of PD. However, comprehensive analyses of the impact of probiotic supplementation on motor and non-motor symptoms are still lacking and the mechanisms whereby the treatment works remain unclear. This study investigated Lacticaseibacillus paracasei strain Shirota (LcS) supplementation on clinical responses, gut microbiota and faecal metabolites in PD patients. Patients (n = 128) were randomised to receive either probiotics (LcS-fermented milk, containing 1 × 1010 living LcS cells) or placebo for 12 weeks. All participants were examined and the basic clinical features were recorded using questionnaires. Fecal and blood samples were collected at the baseline and after 12 weeks for further omics analysis. We found that LcS intervention significantly alleviated patients' constipation-related symptoms and non-motor symptoms. We found no significant shifts in the composition of gut microbiota or faecal metabolites. Several taxa were differentially abundant between the groups, especially with regard to LcS intake, which increased the abundance of the genus Lacticaseibacillus in the probiotic group compared with those at the baseline and in the placebo group. The faecal concentration of L-tyrosine was significantly decreased and the plasma concentration of L-tyrosine was increased in the probiotic group compared with the placebo group. Our study demonstrated that although supplementation with LcS did not induce major changes in the global gut microbiome, the probiotic had favorable effects in managing constipation and other non-motor symptoms in PD patients. This study was registered at the Chinese Clinical Trial Registry: ChiCTR1800016795.

A Mixture of Multi-Strain Probiotics (Lactobacillus Rhamnosus, Lactobacillus Helveticus, and Lactobacillus Casei) had Anti-Inflammatory, Anti-Apoptotic, and Anti-Oxidative Effects in Oxidative Injuries Induced By Cadmium in Small Intestine and Lung

INTRODUCTION

Cadmium (Cd) produces severe oxidative stress, which can result in serious clinical consequences and tissue injury. The aim of the present survey was to investigate the protective effects of native Iranian probiotics (Lactobacillus rhamnosus, L. helveticus, and L. casei) against cadmium (Cd)-induced toxicity against the small intestine and lung at histopathological and biochemical levels.

MATERIALS AND METHODS

Twenty-one adult male Wistar rats were randomized into three groups of seven rats (control, Cd-treated (3 mg/kg), and concomitant Cd and mix probiotic treatment for 30 days). Histological alterations were appraised via hematoxylin & eosin, Trichrome Masson, and PAS staining. The qRT-PCR technique was applied to assess the expression of pro-apoptotic, anti-apoptotic, and pro-inflammatory genes. Antioxidant enzymes activity was measured via ZellBio kits.

RESULTS

Probiotic-treated rats displayed low production of lipid peroxides, reduced malondialdehyde (MDA) level, and elevated contents of superoxide dismutase (SOD) and catalase (CAT) enzymes compared with Cd-treated rats. The results of qRT-PCR demonstrated the up-regulation of Bax, p53, and caspase 3 and down-regulation of Bcl2, TNF-α, and IL-6 genes in both the intestine and lungs of mix probiotic-treated rats compared with Cd-treated animals. Histopathological findings revealed that the probiotic formulation improved Cd-triggered tissue damage in the intestine and lungs.

CONCLUSION

The strong cytoprotective benefits of Iranian probiotics against Cd-induced tissue injury observed in this study may be due to their anti-inflammatory and antioxidant properties. Therefore, additional clinical and experimental research is required to explain the precise mechanisms of probiotics' beneficial impacts and underline their potential therapeutic use.

Immunization effect of recombinant Lactobacillus casei displaying Aeromonas veronii Aha1 with an LTB adjuvant in carp

Aeromonas veronii is an important aquatic zoonotic, which elicits a range of diseases, such as haemorrhagic septicemia. To develop an effective oral vaccine against Aeromonas veronii infection in carp, the Aeromonas veronii adhesion (Aha1) gene was used as a target molecule to attach to intestinal epithelial cells. Two anchored recombinant. Lactic acid bacteria strains (LC-pPG-Aha1 1038 bp and LC-pPG-Aha1-LTB 1383 bp) were constructed by fusing them with the E. coli intolerant enterotoxin B subunit (LTB) gene and using Lactobacillus casei as antigen delivery vector to evaluate immune effects of these in carp. Western blotting and immunofluorescence were used to confirm that protein expression was successful. Additionally, levels of specific IgM in serum and the activities of ACP, AKP, SOD, LYS, C3, C4, and lectin enzymes-were assessed. Cytokines IL-10, IL-1β, TNF-α, IgZ1, and IgZ2 were measured in the liver, spleen, kidney, intestines, and gills tissue by qRT-PCR, which showed an increasing trend compared with the control group (P < 0.05). A colonization assay showed that the two L. casei recombinants colonized the middle and hind intestines of immunized fish. When immunized carp were experimentally challenged with Aeromonas veronii the relative percentage protection of LC-pPG-Aha1 was 53.57%, and LC-pPG-Aha1-LTB was 60.71%. In conclusion, these results demonstrate that Aha1 is a promising candidate antigen when it is displayed on lactic acid bacteria (Lc-pPG-Aha1 and Lc-pPG-Aha1-LTB) seems promising for a mucosal therapeutic approach. We plan to investigate the molecular mechanism of the L. casei recombinant in regulating the intestinal tissue of carp in future studies.

Dietary Effects of Probiotic Lactobacillus casei on Some Immunity Indices of Common Carp (Cyprinus carpio) Exposed to Cadmium

The present study investigated the effect of feeding common carp with Lactobacillus probiotic supplement on growth, blood indices, and immunity of serum and mucus exposed to cadmium. A total of 250 common carp with an average weight of 15 ± 0.62 were divided into three groups: fish without probiotics, and fish with two levels of probiotic. At the end of a 42-day feeding period, 50% of the lethal concentrations of cadmium were exposed for 14 days and blood and immune indices of serum and mucus were measured. The results showed that growth indices, blood indices, and serum and mucus immunity were significantly different from the control group (P < 0.05). Finally, this study showed probiotics could improve the decreasing effect of cadmium in BWI and PBWI indices and the additive effect of cadmium in FCR and ALT. Probiotic was also able to completely improve the decreasing effect of cadmium on lymphocyte indices and the additive effect of cadmium on ALP and AST and monocyte.

Wahid UNI, Ling LL, Liansim SMS, Oon J, Balakrishnan MN, Ng WL, Cheong AT. Prevalence and associated factors of delayed sputum smear conversion in patients treated for smear positive pulmonary tuberculosis: A retrospective follow up study in Sabah, Malaysia

INTRODUCTION

Tuberculosis remains a major health problem globally and in Malaysia, particularly in the state of Sabah. Delayed sputum conversion is associated with treatment failure, drug-resistant tuberculosis and mortality. We aimed to determine the prevalence of delayed sputum conversion among smear positive pulmonary tuberculosis (PTB) patients and its associated factors in Sabah, Malaysia.

METHODS

A retrospective follow up study on all patients newly diagnosed with smear positive pulmonary tuberculosis from 2017 to 2019 was conducted at three government health clinics in Sabah, utilizing data from a national electronic tuberculosis database and medical records. Descriptive statistics and binary logistic regression were applied for data analysis. The outcome of the study was the sputum conversion status at the end of the two-month intensive treatment phase with either successful conversion to smear negative or non-conversion.

RESULTS

374 patients were included in the analysis. Our patients were generally younger than 60 years old with no medical illness and varying proportions of tuberculosis severity as judged by radiographic appearance and sputum bacillary load upon diagnosis. Foreigners constituted 27.8% of our sample. 8.8% (confidence interval: 6.2-12.2) did not convert to smear negative at the end of the intensive phase. Binary logistic regression showed that older patients ≥60 years old (adjusted odds ratio, AOR = 4.303), foreigners (AOR = 3.184) and patients with higher sputum bacillary load at diagnosis [2+ (AOR = 5.061) and 3+ (AOR = 4.992)] were more likely to have delayed sputum smear conversion.

CONCLUSION

The prevalence of delayed sputum conversion in our study was considerably low at 8.8% with age ≥60 years old, foreigners and higher pre-treatment sputum bacillary load associated with delayed conversion. Healthcare providers should take note of these factors and ensure the patients receive proper follow up treatment.

An Integrated Analytical Approach for the Characterization of Probiotic Strains in Food Supplements

Research surrounding health benefits from probiotics is becoming popular because of the increasing demand for safer products with protective and therapeutic effects. Proven benefits are species- or genus-specific; however, no certified assays are available for their characterization and quantification at the strain level in the food supplement industry. The objective of this study was to develop a strain-specific Real-time quantitative polymerase chain reaction (RT-qPCR)-based method to be implemented in routine tests for the identification and quantification of Bifidobacterium longum, Bifidobacterium animalis spp. lactis, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus casei, Bifidobacterium breve, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus helveticus, starting from a powder mixture of food supplements. The method optimization was carried out in combination with flow cytometry to compare results between the two strategies and implement the analytical workflow with the information also regarding cell viability. These assays were validated in accordance with the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) criteria using the plate count enumeration as the gold standard reference. Briefly, probiotic DNAs were extracted from two powder food supplements. Strain-specific primers targeting unique sequence regions of 16S RNA were identified and amplified by RT-qPCR. Primers were tested for specificity, sensitivity, and efficiency. Both RT-qPCR and flow-cytometry methods described in our work for the quantification and identification of Lactobacillus and Bifidobacterium strains were specific, sensitive, and precise, showing better performances with respect to the morphological colony identification. This work demonstrated that RT-qPCR can be implemented in the quality control workflow of commercial probiotic products giving more standardized and effective results regarding species discrimination.

The beneficial effects of Lacticaseibacillus casei on the small intestine and colon of Swiss mice against the deleterious effects of 5-fluorouracil

BACKGROUND

Intestinal mucositis is one of the most common and important side effects of 5-fluorouracil (5-FU). Currently, there are still no specific and effective protocols for its prevention and treatment. The aim of the present study was to evaluate the effect of oral administration of Lacticaseibacillus casei (L. casei) on the progression of 5-FU-induced intestinal mucositis. Methods: L. casei (1x109 CFU/ml) or saline was orally administered to Swiss mice, beginning 15 days before intestinal mucositis induction by single intraperitoneal 5-FU administration (450 mg/kg). Body weight, number of peripheral leukocytes and fecal lactic acid bacteria were monitored. After euthanasia, on day 18, tissue samples from colon and each small intestine segment were collected for histopathology. Jejunal tissues were collected and evaluated for iNOS and TNF-alpha immunoexpression, IL-1-beta, IL-6 and TNF-alpha levels, malonaldehyde (MDA) accumulation, invertase activity and factor nuclear kappa B (NFkB-P65) gene expression, toll like receptor-4 (TLR-4), mucin-2 (MUC-2), occludin and zonula occludens-1 (ZO-1).

RESULTS

The positive impact of L. casei on 5-FU-induced leukopenia was observed, but not on 5-FU-induced weight loss in mice. L. casei reduced 5-FU-induced inflammation in the colon and small intestine (p<0.05). Decreased TNF-α, IL-1β, IL-6 (p<0.05) and MDA (p<0.05) levels, as well as decreased iNOS and TNF-alpha protein expressions (p<0.05) were found in the jejunum from L casei group. In addition, L-casei down-regulated NFKB-P65 (p<0.05) and TLR-4 (p<0.05) gene expressions and up-regulated MUC-2 and mucosal barrier proteins occludin and ZO-1 gene expressions (p<0.05). Furthermore, greater lactic acid bacteria population (p<0.05) was found in the L. casei group when compared to control groups.

CONCLUSION

Oral L. casei administration can protect the intestine of Swiss mice from 5-FU-induced intestinal mucositis, thus contributing to overall health.

Effect of Dietary Lactobacillus casei on Physiometabolic Responses and Liver Histopathology in Common Carp (Cyprinus carpio) After Exposure to Iron Oxide Nanoparticles

A 60-day feeding trial was performed to assess the dietary effect of Lactobacillus casei as a probiotic supplement on some serum biochemical parameters and liver histopathology in common carp fry after exposure to iron oxide nanoparticles (IoNPs). Six treatments were prepared as follows: control (no IoNP exposure and no dietary probiotic), P6: 10⁶ CFU/g probiotic diet, P7: 10⁷ CFU/g probiotic diet, NPs: 0.15 mg/l IoNPs, NPs + P6: 0.15 mg/l IoNPs with 10⁶ CFU/g probiotic diet, and NPs + P7: 0.15 mg/l IoNPs with 10⁷ CFU/gprobiotic diet. Based on the results, serum aspartate aminotransferase and alanine aminotransferase levels were significantly increased in 0.15 mg/l IoNPs, P7, and NPs + P6 treatments compared to the control group. In addition, the examination of antioxidant enzymes showed a significant increase in the levels of cortisol and glutathione S-transferase as well as malondialdehyde level. IoNPs also caused significant histopathological changes in the fish liver during the experiment such as hyperemia in sinusoidal spaces, hepatocytes vacuolation and necrosis, pyknosis, and disruption of hepatic lobules and atrophy. Results revealed the protective effects of dietary L. casei to mitigate the adverse impacts of IoNPs on the physiological processes of common carp.

Immunological Effects of Recombinant Lactobacillus casei Expressing IHNV G Protein and Rainbow Trout (Oncorhynchus mykiss) Chemokine CK6 as an Oral Vaccine

IHNV is a virus that infects salmonids and causes serious economic damage to the salmonid farming industry. There is no specific treatment for the disease caused by this pathogen and the main preventive measure is vaccination, but this is only possible for small groups of individuals. Therefore, it is important to investigate new oral vaccines to prevent IHNV. In this study, the CK6 chemokine protein of rainbow trout and the truncated G protein of IHNV were used to construct a secretory expression recombinant L.casei vaccine for rainbow trout. The results showed that the levels of IgM and IgT antibodies in rainbow trout reached the highest level on the 15th day after the secondary immunization, and the antibodies exhibited high inhibitory activity against viral infection. Furthermore, the expression of relevant cytokines in different tissues was detected and found to be significantly higher in the oral vaccine group than in the control group. It was also found that pPG-612-CK6-G/L.casei 393 could stimulate splenic lymphocyte proliferation and improve mucosal immunity with significant differences between the immunized and control groups. When infected with IHNV, the protection rate of pPG-612-CK6-G/L.casei 393 was 66.67% higher than that of the control group. We found that pPG-612-CK6-G/L.casei 393 expressed and secreted the rainbow trout chemokine CK6 protein and IHNV truncated G protein, retaining the original immunogenicity of rainbow trout while enhancing their survival rate. This indicates that recombinant L.casei provides a theoretical basis and rationale for the development of an oral vaccine against IHNV and has important practical implications for the protection of rainbow trout from IHNV infection.

Effects of Lactobacillus casei on Iron Metabolism and Intestinal Microflora in Rats Exposed to Alcohol and Iron

BACKGROUND

Higher alcohol consumption was reported in those who consumed more red meat. Both excessive alcohol and iron intake can cause damage to the liver. The purpose of this study is to investigate the effect of Lactobacillus casei strain Shirota (L. casei) on iron metabolism and intestinal microflora in rats after alcohol and iron co-exposure.

METHODS

Sixty male rats were randomly divided into 3 groups for 12 weeks: the control group: treated with normal saline by gavage and normal diet; the model group: treated with alcohol (8-12 mL/kg/day) by gavage and iron (1500 mg/kg) in diet; the model group supple- mented with L. casei (8 × 108 CFU/kg/day) as the L. casei group.

RESULTS

Compared with the control group, the levels of serum ferritin, hepcidin, the protein expressions of ferroportin 1 and divalent metal transporter 1 in the model group were significantly increased, while it was significantly decreased after L. casei supplement (P < .05). Compared with the control group, the amount of Lactobacillus of the model group was significantly decreased, while the amount of Bacteroides and Escherichia coli was significantly increased (P < .05). After the supplementation of L. casei, the amount of Lactobacillus increased significantly, while the amount of Bacteroides and E. coli decreased significantly (P < .05).

CONCLUSION

L. casei could effectively improve iron metabolism and intestinal flora disorder induced by excessive alcohol and iron. The effective treatment of iron metabolism may be related to the changes of intestinal flora.

Lactobacillus casei Ghosts as a Vehicle for the Delivery of DNA Vaccines Mediate Immune Responses

We developed Lactobacillus casei bacterial ghosts (BGs) as vehicles for delivering DNA vaccines and analyzed their effects on immune responses. Uptake of the plasmids encoding the enhanced green fluorescent protein (pCI-EGFP) and BGs loaded with pCI-EGFP by macrophages was investigated using fluorescence microscopy and flow cytometry. The results showed that pCI-EGFP-loaded L. casei BGs were efficiently taken up by macrophages. Lactobacillus casei BGs loaded with plasmids encoding VP6 protein of PoRV (pCI-PoRV-VP6) significantly upregulated the mRNA expression of interleukin (IL)-1β, IL-10, tumor necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), arginase-1 (Arg-1), Mannose receptor (CD206) toll-like receptor (TLR)-2, TLR4, and TLR9 in macrophages. The levels of markers of M1 polarization (IL-10 and TNF-α) and M2 polarization (Arg-1 and CD206) were increased in macrophages incubated with pCI-PoRV-VP6-loaded BGs compared with the control group. The results of the enzyme-linked immunosorbent assay showed that the secretion of IL-1β, IL-10, and TNF-α in macrophages was significantly upregulated compared with the control group. Flow cytometry demonstrated that L. casei BGs loaded with pCI-PoRV-VP6 promoted the maturation of dendritic cells (DCs). Following incubation with pCI-PoRV-VP6-loaded BGs, the mRNA expression levels of IL-1β, IL-6 and interferon (IFN)-γ in DCs were significantly increased. ELISA assay showed the secretion of the IL-1β, IL-6, IFN-γ IL-10 and TNF-α in DCs were upregulated significantly. Thus, L. casei BGs promoted the maturation and activation of DCs. We analyzed the stimulatory capacity of DCs in a mixed lymphocyte reaction with allogeneic T cells. T cell proliferation increased upon incubation with DCs stimulated by BGs. After immunizing mice with BGs loaded with pCI-PoRV-VP6, the specific IgG levels in the serum were higher than those elicited by BGs loaded with pCI-PoRV-VP6. BGs loaded with pCI-PoRV-VP6 on Th1 and Th2 cytokines polarized T cells into the Th1 type and increased the proportion of CD4⁺/CD8⁺ T cells. These results indicate L. casei BGs effectively mediate immune responses and can be used as delivery system for DNA vaccination.

Changes in Gut Microbiota by the Lactobacillus casei Anchoring the K88 Fimbrial Protein Prevented Newborn Piglets From Clinical Diarrhea

In the last 20 years, accumulating evidence indicates that the gut microbiota contribute to the development, maturation, and regulation of the host immune system and mediate host anti-pathogen defenses. Lactobacillus casei (L.casei) is a normal flora of the gastrointestinal tract in mammals and, as a great mucosal delivery vehicle, has wide use in bioengineering. However, the diarrhea prevention role of commensal intestinal microbiota interfered by the recombinant L.casei (rL.casei) in newborn piglets is not well understood. In our study, newborn piglets orally fed with the rL.casei surface displayed the fimbrial protein K88 of enterotoxigenic Escherichia coli (ETEC) and their feces were collected for a period of time after feeding. The next-generation sequencing of these fecal samples showed that the relative abundance of L.casei was significantly increased. The oral administration of rL.casei altered the intestinal microbial community as evidenced by altered microbial diversity and microbial taxonomic composition. Remarkably, the functional enhancing of the intestinal bacterial community by rL.casei was positively correlated with membrane transport, replication, and repair (p < 0.05). The specific antibody detection indicates that high levels of anti-K88 secretory immunoglobulin A (sIgA) were induced in fecal samples and systemic immunoglobulin G was produced in serum. The diarrhea rate in piglets caused by ETEC K88 was decreased by about 24%. Thus, the oral administration of rL.casei not only activated the mucosal and humoral immune responses in vivo but also contributed to shape the intestinal probiotics in newborn piglets and to significantly reduce the diarrhea rates of newborn piglets.

Lactobacillus casei modulates inflammatory cytokines and metabolites during tuberculosis treatment: A post hoc randomized controlled trial

BACKGROUND AND OBJECTIVES

Inflammatory cytokines and metabolic abnormalities are common in patients with tuberculosis. Observational studies have indicated that probiotics modulate inflammatory cytokines and metabolites; however, clinical evidence of the effect of probiotics on patients with tuberculosis is lacking. This study investigated the effects of Lactobacillus casei on inflammatory cytokines and metabolites during tuberculosis treatment.

METHODS AND STUDY DESIGN

A randomized controlled trial was conducted. A total of 47 inpatients were included and randomly assigned to receive standard antituberculosis therapy only (control group) or that treatment together with 1 × 1010 colony-forming units per day of Lactobacillus casei (low-dose group) or 2 × 1010 colony-forming units per day of Lactobacillus casei (high-dose group) for 4 weeks of intensive treatment during hospitalization. Plasma samples were analyzed for inflammatory cytokines and metabolomics with ELISA kits and ultrahigh performance liquid chromatography quadrupole time-of-flight mass spectrometry.

RESULTS

Daily Lactobacillus casei supplementation of up to 2 × 1010 colony-forming units significantly lowered the concentrations of tumor necrosis factor-α, interleukin-6, interleukin-10, and interleukin-12 (p=0.007, p=0.042, p=0.002, p<0.001, respectively) in patients with tuberculosis. Compared with the control and low-dose groups, the plasma metabolites of phosphatidylserine, maresin 1, phosphatidylcholine, L-saccharopine, and pyridoxamine were significantly upregulated, and N-acetylmethionine, L-tryptophan, phosphatidylethanolamine, and phenylalanine were downregulated in the high-dose group. Strong correlations were observed between metabolites and inflammatory cytokines.

CONCLUSIONS

Lactobacillus casei supplementation during the intensive phase of tuberculosis treatment can significantly modulate inflammatory cytokines and metabolites. Decreased inflammatory cytokines may be related to metabolite changes.

Reduction of blood C-reactive protein concentration complements the resolution of sputum bacillary load in patients on anti-tuberculosis therapy

Background

Tuberculosis (TB) is a difficult-to-treat disease requiring the combination of four antibiotics for a minimum of 6 months. Rapid and quantitative biomarkers to monitor treatment response are urgently needed for individual patient management and clinical trials. C-reactive protein (CRP) is often used clinically as a rapid marker of inflammation caused by infection. We assessed the relationship of TB bacillary load and CRP as biomarkers of treatment response.

Methods

Xpert MTB/RIF-confirmed pulmonary TB cases were enrolled for treatment response assessment in Mozambique. Treatment response was measured using the Tuberculosis Molecular Bacterial Load Assay (TB-MBLA) in comparison with standard-of-care Mycobacterium Growth Indicator Tube (MGIT) culture at baseline and at weeks 1, 2, 4, 8, 12, 17, and 26 of treatment. Blood CRP concentration was measured at baseline, week 8, and week 26. Treatment response was defined as increase in MGIT culture time to positivity (TTP), and reduction in TB-MBLA-measured bacillary load and blood CRP concentration.

Results

Out of the 81 screened presumptive TB cases, 69 were enrolled for 6-month treatment follow-up resulting in 94% treatment completion rate. Four participants did not complete TB treatment and 22 participants had missing CRP or TB-MBLA results and were excluded from TB-MBLA-CRP analysis. The remaining 43 participants-median age, 31 years old [interquartile range (IQR): 18-56]; 70% (30/43) male; and 70% (30/43) infected with HIV-were considered for analysis. Culture TTP and bacillary load were inversely correlated, Spearman's r = -0.67, p < 0.0001. Resolution of sputum bacillary load concurred with reduction of blood CRP, r = 0.70, p < 0.0001. At baseline, bacillary load had a median (IQR) of 6.4 (5.5-7.2), which reduced to 2.4 (0.0-2.9) and 0.0 (0.0-0.0) log₁₀ CFU/ml at months 2 and 6 of treatment, respectively. Correspondingly, blood CRP reduced from 1.9 (1.6-2.1) at baseline to 1.3 (0.9-1.7) and 0.4 (0.1-0.8) log₁₀ mg/dl at months 2 and 6 of treatment, respectively. CRP reduction trialed bacteriological resolution at a rate of -0.06 log₁₀ mg/dl compared to a bacillary load of 0.23 log₁₀ CFU/ml per week. Consequently, 14 (33%) and 37 (88%) patients had reduced CRP to normal concentration and bacillary load to zero by the end of treatment, respectively. Pre-treatment CRP concentration and bacillary load, and resolution during treatment were slightly lower in HIV co-infected patients but not significantly different from HIV-uninfected TB patients.

Conclusion

TB-MBLA-measured bacillary load and blood CRP complement each other in response to anti-TB therapy. Slow CRP reduction probably reflects residual TB bacilli in the lung not expectorated in sputum. Combining both measures can improve the accuracy of these biomarkers for monitoring TB treatment response and shorten turnaround time since the results of both assays could be available in 24 h.

Effect of Lactobacillus casei fermented milk on fracture healing in osteoporotic mice

The interaction between the gut microbiota and the host has been described experimentally by germ-free animals or by antibiotic-disturbed gut microbiota. Studies on germ-free mice have shown that gut microbiota is critical for bone growth and development in mice, emphasizing that microbiota dysbiosis may interfere with normal bone development processes. This study aimed to clarify the effect of antibiotic treatment on disturbed gut microbiota on bone development in mice and to investigate the effect of probiotic treatment on fracture healing in mice with dysbiosis. Our results showed that 4 weeks old female Kunming mice showed significantly lower abundance and diversity of the gut microbiota and significantly lower bone mineral density after 12 weeks of antibiotic treatment and significantly increased levels of RANKL and Ang II in serum (p<0.05). Mice with dysbiosis received 5 mL of Lactobacillus casei fermented milk by daily gavage after internal fixation of femoral fractures, and postoperative fracture healing was evaluated by X-ray, micro-CT scan, and HE staining, which showed faster growth of the broken ends of the femur and the presence of more callus. Serological tests showed decreased levels of RANKL and Ang II (p<0.05). Similarly, immunohistochemical results also showed increased expression of α smooth muscle actin in callus tissue. These results suggest that oral antibiotics can lead to dysbiosis of the gut microbiota in mice, which in turn leads to the development of osteoporosis. In contrast, probiotic treatment promoted fracture healing in osteoporotic mice after dysbiosis, and the probiotic effect on fracture healing may be produced by inhibiting the RAS/RANKL/RANK pathway.

Novel Antioxidative Wall Materials for Lactobacillus casei Microencapsulation via the Maillard Reaction between the Soy Protein Isolate and Prebiotic Oligosaccharides

In this study, three kinds of Maillard reaction products (MRPs) have been, for the first time, successfully prepared by conjugating soy protein isolate (SPI) with isomaltooligosaccharide, xylooligosaccharide, or galactooligosaccharide at 80 °C for 30 or 60 min and applied for the construction of Lactobacillus casei (L. casei) microcapsules. The results showed that MRPs exhibited enhanced antioxidative activities compared with their physically mixed counterparts. The digested MRPs displayed excellent resistance to pathogenic bacteria and promoted the growth of L. casei. Moreover, MRP-encapsulated L. casei showed a higher survival rate than free L. casei under tested adverse conditions including heat treatment, storage, and mechanical forces. Under simulated digestion conditions, the viability of L. casei decreased from 8.8 log cfu/mL to 1.6 log cfu/mL, while that of MRP-encapsulated L. casei was maintained at 7.4 log cfu/mL. Thus, MRP-based SPI-oligosaccharide conjugates exhibited great potential for microencapsulation of probiotics.

Supplementation of Lactobacillus casei reduces the mortality of Bombyx mori larvae challenged by Nosema bombycis

OBJECTIVE

Pebrine, caused by the microsporidium Nosema bombycis, is one of the severe diseases in Thai polyvoltine strains of the silkworm Bombyx mori. Studies showing the presence of Lactobacillus species in the silkworm gut, where the Nosema parasites enter, suggests that these bacteria may have a protective effect. The aim of this study was to investigate the effect of supplementation of Lactobacillus casei on the survival ratio of silkworm larvae challenged with N. bombycis.

RESULTS

A group of silkworm larvae of the commercial Thai polyvoltine hybrid strain DokBua was supplemented with L. casei on the second day of the 2nd, 3rd, 4th, and 5th instar. When a control group of silkworm larvae were challenged with N. bombycis on the second day of the 4th instar, the survival rate was 68%, but it was 91% for larvae supplemented with L. casei. For those larvae that survived the treatments until pupation, we determined the growth characters larval weight, cocooning ratio, and pupation ratio, and the economic characters cocoon weight and cocoon shell weight. When infected with N. Bombycis, growth characters were significantly higher in larvae also receiving L. casei.

Lactobacillus casei reduces the extracellular matrix components of fluconazole-susceptible Candida albicans biofilms

Fluconazole-sensitive (CaS) and -resistant (CaR) C. albicans were grown as single-species and dual-species biofilms with Lactobacillus casei (Lc) and Lactobacillus rhamnosus (Lr). Single-species Lc and Lr were also evaluated. Biofilm analysis included viable plate counts, the extracellular matrix components, biomass, and structural organization. Lc reduced the viability of CaS, water-soluble polysaccharides, and eDNA in CaS + Lc biofilm. Lc biofilm presented more eDNA than CaS. The total biomass of CaS + Lc biofilm was higher than the single-species biofilms. The viability of Lc and Lr was reduced by CaR dual-species biofilms. The total and insoluble biomass in CaS + Lr was higher than in single-species CaS biofilms. Lc hindered the growth of CaS, and their association hampered matrix components linked to the structural integrity of the biofilm. These findings allow understanding of how the implementation of probiotics influences the growth of C. albicans biofilms and thereby helps with the development of novel approaches to control these biofilms.