Lactobacillus acidophilus attenuates Aeromonas hydrophila induced cytotoxicity in catla thymus macrophages by modulating oxidative stress and inflammation

The effects of synbiotic supplementation on blood pressure and other maternal outcomes in pregnant mothers with mild preeclampsia: a triple-blinded randomized controlled trial

INTRODUCTION

Preeclampsia affects a significant percentage of pregnancies which is a leading cause of premature birth. Probiotics have the potential to affect inflammatory factors, and oxidative stress, which are linked to the development of preeclampsia. The study aimed to compare the effect of synbiotic and placebo on blood pressure and pregnancy duration as primary outcomes, and other pregnancy outcomes.

METHODS

This study comprised 128 pregnant women with mild preeclampsia and gestational ages exceeding 24 weeks who were referred to the high-risk pregnancy clinic. It was a randomized, controlled, phase III, triple-blinded clinical experiment. The intervention and control groups were distributed to the participants at random. Intervention group received one oral synbiotic capsule, and control group received placebo daily until delivery. Based on gestational age at the time of diagnosis, preeclampsia was stratificated as early (< 34 weeks) or late (≥ 34 weeks). Data obtained from questionnaires, and biochemical serum factors were analyzed using SPSS software version 23 software.

RESULTS

With the exception of the history of taking vitamin D3, there were no statistically significant variations in socio-demographic variables between the research groups. After the intervention, the means of systolic blood pressure (adjusted mean difference: -13.54, 95% CI: -5.01 to -22.07), and diastolic blood pressure (adjusted mean difference: -10.30, 95% CI: -4.70 to -15.90) were significantly lower in the synbiotic-supplemented group than in the placebo group. Compared to the placebo group, the incidence of severe PE (p < 0.001), proteinuria (p = 0.044), and mean serum creatinine level (p = 0.005) significantly declined in the synbiotic-supplemented group after the intervention. However, our analysis found no significant association for other outcomes.

CONCLUSION

Based on our results, synbiotic had beneficial effects on some pregnancy outcomes. Further studies with larger samples are needed to verify the advantages of synbiotic supplementation for high-risk pregnancies, particularly with regards to higher doses, and longer intervention periods.

TRIAL REGISTRATION

IRCT20110606006709N20.

The Possible Role of Probiotic Supplementation in Inflammation: A Narrative Review

The fine balance between symbiotic and potentially opportunistic and/or pathogenic microorganisms can undergo quantitative alterations, which, when associated with low intestinal biodiversity, could be responsible for the development of gut inflammation and the so-called "intestinal dysbiosis". This condition is characterized by the disbalance of a fine synergistic mechanism involving the mucosal barrier, the intestinal neuroendocrine system, and the immune system that results in an acute inflammatory response induced by different causes, including viral or bacterial infections of the digestive tract. More frequently, however, dysbiosis is induced slowly and subtly by subliminal causal factors, resulting in a chronic condition related to different diseases affecting the digestive tract and other organs and apparatuses. Studies on animal models, together with studies on humans, highlight the significant role of the gut microbiota and microbiome in the occurrence of inflammatory conditions such as metabolic syndrome and cardiovascular diseases (CVDs); neurodegenerative, urologic, skin, liver, and kidney pathologies; and premature aging. The blood translocation of bacterial fragments has been found to be one of the processes linked to gut dysbiosis and responsible for the possible occurrence of "metabolic endotoxemia" and systemic inflammation, associated with an increased risk of oxidative stress and related diseases. In this context, supplementation with different probiotic strains has been shown to restore gut eubiosis, especially if administered in long-term treatments. The aim of this review is to describe the anti-inflammatory effects of specific probiotic strains observed in clinical trials and the respective indications, highlighting the differences in efficacy depending on strain, formulation, time and duration of treatment, and dosage used.

Remarkable impacts of probiotics supplementation in enhancing of the antioxidant status: results of an umbrella meta-analysis

Introduction

Numerous meta-analyses have demonstrated the beneficial effects of probiotics on oxidative stress biomarkers, although some studies have contradictory results. Therefore, the current research was conducted to obtain a precise and definite understanding on the impact of probiotics on oxidative stress biomarkers in adults.

Methods

We conducted a comprehensive systematic search of results on Scopus, PubMed, Embase, Web of Science, and Google Scholar dating up to March 2022. Fifteen meta-analyses were included in this umbrella meta-analysis. The random-effects model was employed to obtain the overall effect size. Subgroup analyses were carried out based on supplementation dosage and duration, mean age, and study population.

Results

Our results indicated that probiotics supplementation meaningfully decreased serum malondialdehyde (MDA) (ESWMD = -0.56, 95% CI: -0.72, -0.39; p < 0.001, and ESSMD = -0.50, 95% CI: -0.66, -0.34; p < 0.001). Moreover, the findings showed that probiotics resulted in a significant increase in total antioxidant capacity (TAC) (ESWMD = 29.18, 95% CI: 16.31, 42.04; p < 0.001, and ESSMD = 0.25, 95% CI: 0.02, 0.47; p = 0.032), total glutathione (GSH) (ESWMD: 30.65; 95% CI: 16.94, 44.35, p < 0.001), and nitric oxide (NO) (ESWMD: 1.48; 95% CI: 0.31, 2.65, p = 0.013; I2 = 51.7%, p = 0.043).

Discussion

Probiotics could be considered a strong agent in the reinforcement of antioxidant status and preventing the incidence of chronic diseases.

Dietary pattern in autism increases the need for probiotic supplementation: A comprehensive narrative and systematic review on oxidative stress hypothesis

Autism spectrum disorders (ASDs) are associated with specific dietary habits, including limited food selection and gastrointestinal problems, resulting in an altered gut microbiota. Autistic patients have an elevated abundance of certain gut bacteria associated with increased oxidative stress in the gastrointestinal tract. Probiotic supplementation has been shown to decrease oxidative stress in a simulated gut model, but the antioxidant effects of probiotics on the oxidative stress of the gut in autistic patients have not been directly studied. However, it is speculated that probiotic supplementation may help decrease oxidative stress in the gastrointestinal tract of autistic patients due to their specific dietary habits altering the microbiota. PubMed, Scopus and Web of Science databases and Google Scholar were searched up to May 2023. This systematic-narrative review aims to present the latest evidence regarding the changes in eating habits of autistic children which may further increase the gut microbiota induced oxidative stress. Additionally, this review will assess the available literature on the effects of probiotic supplementation on oxidative stress parameters.

Transcriptome, intestinal microbiome and histomorphology profiling of differences in the response of Chinese sea bass (Lateolabrax maculatus) to Aeromonas hydrophila infection

The Chinese sea bass (Lateolabrax maculatus) is an important aquaculture fish, but diseases caused by Aeromonas hydrophila have led to severe economic losses to the aquaculture industry in recent years. To date, only a few studies have focused on the relationship between the intestinal immune response and changes in intestinal microbes by A. hydrophila infection. Here, we report the transcriptome and intestinal changes in infected sea bass. Histopathological results showed that severe steatosis and vacuolation occurred in the liver and that the intestinal villi and mesentery were seriously affected after infection. By extracting total RNA from intestinal tissue and studying the transcriptome profile, 1,678 genes (1,013 upregulated and 665 downregulated) were identified as significantly differentially expressed genes (DEGs). These genes are involved in many immune-related signalling pathways, such as the NOD-like receptor, C-type lectin receptor, and Toll-like receptor signalling pathways. Moreover, the intestinal microbes of sea bass changed significantly after infection. Interestingly, at the genus level, there was an increase in Serratia, Candida arthromitus and Faecalibacterium as well as a decrease in Akkermansia and Parabacteroides after infection. The results also indicated that some of the DEGs involved in the immune response were related to the genus level of intestinal microbiota. Finally, there was a relationship between gene expression patterns and the bacterial structure in the host intestine. Our study provides a reference for the study of the immune response and particular functions of intestinal microbes of sea bass after pathogen infection.

Metabolite features of serum and intestinal microbiota response of largemouth bass (Micropterus salmoides) after Aeromonas hydrophila challenge

The enteric morphology, enteric microbiota structure and serum metabolomics of M. salmoides before and after infected by A. hydrophila were analysed to explore the pathogenic mechanism of A. hydrophila infection in M. salmoides. The results revealed that, after the infection of A. hydrophila, the villus boundary of largemouth bass became less obvious; the relative abundance of Proteobacteria and decreasing relative abundance of Tenericutes were increasing; genera relative abundance of putatively beneficial bacteria (Mycoplasma) were decreasing, whereas the genus Aeromonas increased after infection; serum metabolomic analysis showed that infection with A. hydrophila caused disorder to the metabolic processes of largemouth bass, particularly amino acid metabolism, and caused inflammation; several potential pathogen infection-related and significantly differential intestinal microbiota-related metabolite markers were identified, such as 6-hydroxy-5-methoxyindole glucuronide, zalcitabine, bilirubin, aciclovir. This study may provide new insights into the potential association between enteric microbiota and serum metabolism and the pathogenic mechanism of M. salmoides infected by A. hydrophila, providing a scientific basis for disease control in largemouth bass breeding.

Effects of probiotics on Zebrafish model infected with Aeromonas hydrophila: spatial distribution, antimicrobial, and histopathological investigation

Usage of “probiotics” for treatment of food-borne pathogens associated diseases, makes a significant reduction in transmission of resistant bacteria, and antimicrobial resistance genes from aquaculture environments to humans. In this research, the authors aim to evaluate the immunomodulatory, and histological effects of two probiotic strains on the Zebrafish model. Fish models were treated with Lactobacillus delbrueckii (G2), Lactobacillus acidophilus (G3) and both probiotics (G4) and compared with the control group (G1) (only infected by pathogen and receiving no probiotic). Biometric tests, height, weight, and mortality rate of the fishes were assessed. Afterward, RT-PCR was conducted for bacterial existence of probiotic strains, and quantitative assessment of alterations in targeted immune genes. Subsequently, histological sampling was done for investigation of spatial distribution, and villus length in proximal, middle, and distal sections of intestinal tissues. Based on the results, G4 showed the highest gene expression for Lactobacillus acidophilus after 28 days (P < 0.05). G4 also showed an increase in the number of goblet cells and villus length in the middle and distal sections of intestinal tissue after 56 days. Furthermore, after 56 days, the highest number of intraepithelial cells was observed in the proximal sections of intestinal tissue in G4. G2 and G3 showed significant differences in comparison with G1 (P < 0.05). After 60 days, the highest gene expression for Lactobacillus bulgaricus was found in group treated with only this probiotic bacteria. The highest expression level of IL-1β and TNF-α were found in G1. The highest survival rate was in the case of groups only treated with Lactobacillus bulgaricus (G2). To sum up, it seems that usage of probiotics for the improvement of public health and fisheries industries can be helpful.

Balancing reactive oxygen species generation by rebooting gut microbiota

Reactive oxygen species (ROS; free radical form O₂ ^•‾ , superoxide radical; OH^• , hydroxyl radical; ROO^• , peroxyl; RO^• , alkoxyl and non-radical form ¹ O₂ , singlet oxygen; H₂ O₂ , hydrogen peroxide) are inevitable companions of aerobic life with crucial role in gut health. But, overwhelming production of ROS can cause serious damage to biomolecules. In this review, we have discussed several sources of ROS production that can be beneficial or dangerous to the human gut. Microorganisms, organelles and enzymes play crucial role in ROS generation, where, NOX1 is the main intestinal enzyme, which produce ROS in the intestine epithelial cells. Previous studies have reported that probiotics play significant role in gut homeostasis by checking the ROS generation, maintaining the antioxidant level, immune system and barrier protection. With current knowledge, we have critically analyzed the available literature and presented the outcome in the form of bubble maps to suggest the probiotics that help in controlling the ROS-specific intestinal diseases, such as inflammatory bowel disease (IBD) and colon cancer. Finally, it has been concluded that rebooting of the gut microbiota with probiotics, postbiotics or fecal microbiota transplantation (FMT) can have crucial implications in the structuring of gut communities for the personalized management of the gastrointestinal (GI) diseases.

Hematobiochemical and Immunological Responses of Rats Treated with Multi-strain Probiotics and Infected with Trypanosoma brucei

The effects of treatment with probiotics on the immunological and hematobiochemical changes in Trypanosoma brucei infection were investigated. Probiotic strains used are Bifidobacterium BB-12, Lactobacillus acidophilus LA-5, Lactobacillus delbrueckii LBY-27, Lactobacillus paracasei LC-01, and Streptococcus thermophilus STY-31. Thirty rats randomly assigned to five groups were used in the experiment. Groups A to C received 1 × 10⁹ CFU, 5 × 10⁹ CFU, and 10 × 10⁹ CFU of the multi-strain probiotics daily and respectively from day 0 post-supplementation (PS) to termination. Group D and E were the infected and uninfected controls respectively. On day seven PS, groups A to D were challenged intraperitoneally with approximately 1 × 10⁶ trypanosomes. Parasitemia, nitric oxide level, hematobiochemical parameters, and antibody titer to heterologous antigen stimulation were monitored post-infection. By days 7 and 16 PS, probiotics-treated groups had significantly lower (p < 0.05) mean creatinine concentration than the controls; however, on day 7 PS, there were no significant variations in the leukocyte counts (LC), total erythrocyte counts (TEC), and the packed cell volume (PCV) in all experimental groups. Following infection, by day 16 PS, the pre-patent period, parasitemia levels, and antibody titer were similar in all infected groups. Furthermore, the probiotics-treated groups and the infected control had significantly lower PCV, TEC, and LC values when compared to the uninfected control, and probiotics treated groups (A and C) had only marginally lower nitric oxide levels than the infected control. Treatment with the probiotic strains gave a creatinine-lowering effect, was innocuous to the hematopoietic system, but was not sufficiently immunostimulatory in trypanosomosis.

Role of Gut Microbiota, Probiotics and Prebiotics in the Cardiovascular Diseases

In recent years, there has been a growing interest in identifying and applying new, naturally occurring molecules that promote health. Probiotics are defined as “live microorganisms which, when administered in adequate amounts, confer health benefits on the host”. Quite a few fermented products serve as the source of probiotic strains, with many factors influencing the effectiveness of probiotics, including interactions of probiotic bacteria with the host’s microbiome. Prebiotics contain no microorganisms, only substances which stimulate their growth. Prebiotics can be obtained from various sources, including breast milk, soybeans, and raw oats, however, the most popular prebiotics are the oligosaccharides contained in plants. Recent research increasingly claims that probiotics and prebiotics alleviate many disorders related to the immune system, cancer metastasis, type 2 diabetes, and obesity. However, little is known about the role of these supplements as important dietary components in preventing or treating cardiovascular disease. Still, some reports and clinical studies were conducted, offering new ways of treatment. Therefore, the aim of this review is to discuss the roles of gut microbiota, probiotics, and prebiotics interventions in the prevention and treatment of cardiovascular disease.

Systemic RNA oxidation can be used as a biomarker of infection in challenged with Vibrio parahaemolyticus

More and more evidence support the concept that RNA oxidation plays a substantial role in the progress of multiple diseases; however, only a few studies have reported RNA oxidation caused by microbial pathogens. Urinary 8-oxo-7,8-dihydroguanosine (8-oxo-Gsn) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGsn), which are broadly used as indicators of oxidative damage of RNA and DNA, were analyzed in this study to determine which can be used as a biomarker of infection in challenged with Vibrio parahaemolyticus (V. parahaemolyticus). In this work, 24 specific-pathogen-free (SPF) male SD rats were randomly divided into two groups: an infection group and a phosphate-buffered saline (PBS) control group. Our results proved that 8-oxo-Gsn rather than 8-oxo-dGsn was significantly increased after challenged with V. parahaemolyticus in urine and tissue samples of SD rats compared with the PBS control group. Simultaneously, white blood cells (WBCs) counts, intestinal inflammation and inflammatory factors (including CRP, IL-6, IL-1β, TNF-α, IL-10, and IL-17A) were also increased sharply. Which has more clinical value is that the trend of urinary 8-oxo-Gsn was consistent with WBCs, intestinal inflammation and all kinds of inflammatory factors. More importantly is that urinary 8-oxo-Gsn of infection group was positively correlated with WBCs and various inflammatory cytokines. In a word, our results demonstrated that as a systemic RNA oxidation biomarker, we hope 8-oxo-Gsn can be used as a biomarker of the severity of microbial pathogens infection, rather than a specific biomarker of microbial pathogens infection.

Fish infections associated with the genus Aeromonas: a review of the effects on oxidative status

The aim of this review was to summarize the current knowledge regarding the effects of aeromonosis on fish oxidative status. The bibliographic survey was carried out on the research platforms: Scopus and Science Direct. The keywords 'Aeromonas', 'fish' and 'oxidative status' (or 'oxidative stress', 'oxidative damage' and similar terms) were used. Scientific papers and short communications were considered. Studies involving fish aeromonosis and enzymatic or non-enzymatic markers of oxidative status were selected. The results of antioxidant enzymes activities/expressions after infection lack consistency, suggesting that these findings should be interpreted with caution. Most of the analysed studies pointed to an increase in reactive oxygen species, malondialdehyde and protein carbonylation levels, indicating possible oxidative damage caused by the infection. Thus, these three biomarkers are excellent indicators of oxidative stress during infection. Regarding respiratory burst activity, several studies have indicated increased activity, but other studies have indicated unchanged activity after infection. Nitric oxide levels also increased after infection in most studies. Therefore, it is suggested that the fish's immune system tries to fight a bacterial infection by releasing reactive oxygen and nitrogen species.

Oxidative stress tolerance and antioxidant capacity of lactic acid bacteria as probiotic: a systematic review

Lactic acid bacteria (LAB) are the most frequently used probiotics in fermented foods and beverages and as food supplements for humans or animals, owing to their multiple beneficial features, which appear to be partially associated with their antioxidant properties. LAB can help improve food quality and flavor and prevent numerous disorders caused by oxidation in the host. In this review, we discuss the oxidative stress tolerance, the antioxidant capacity related herewith, and the underlying mechanisms and signaling pathways in probiotic LAB. In addition, we discuss appropriate methods used to evaluate the antioxidant capacity of probiotic LAB. The aim of the present review is to provide an overview of the current state of the research associated with the oxidative stress tolerance and antioxidant capacity of LAB.

Probiotic and Antioxidant Potential of Lactobacillus reuteriLR12 and Lactobacillus lactisLL10 Isolated from Pineapple Puree and Quality Analysis of Pineapple-Flavored Goat Milk Yoghurt during Storage

In recent years, studies have focused on the therapeutic properties of probiotics to eliminate pathogenic microorganisms associated with various diseases. Lactobacilli are important probiotics groups that have been found to possess many health-promoting activities. This study was carried out to isolate LactobacillusreuteriLR12 and L. lactisLL10 from pineapple puree. The invitro analysis to evaluate probiotic characteristics of the isolated bacteria included survival in bile and acid tolerance. The cell-free supernatant of L. reuteri LR12 was effective against various pathogenic bacteria and fungi compared with L. lactisLL10. These two bacterial strains have strong anti-biofilm activity (100%) against Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus. The bacterial strains exhibited adhesion properties to HT-29 cells (human colorectal adenocarcinoma). These bacteria showed DPPH- (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical scavenging activity, scavenging of hydroxyl radical activity, superoxide radical scavenging activity, and reducing power activity in the range of 72% ± 3%to 89.3% ± 1.7%, 64% ± 2.7%to 66.8% ± 1.5%, 59.8% ± 4.1% to 63.8% ± 2.1%, and 60.4% ± 1.8%to 66.1% ± 3.3%, respectively. Pineapple puree was used as the starter culture with milk for 2 days for yogurt preparation. Pineapple puree increased flavor and showed the physicochemical properties of yogurt. The finding of the sensory evaluation revealed no significant change compared with the control, except the appearance of yogurt. These findings show that Lactobacilli and pineapple puree have potential use in various probiotic preparations for the fermentation industry.

Lactic acid bacteria exhibit similar antioxidant capacities in Caenorhabditis elegans- and Campylobacter jejuni-infected mice

Caenorhabditis elegans (C. elegans) is increasingly used as a model organism to screen probiotics for ageing research. In this study, a C. elegans lifespan analysis model exposed to H2O2 and juglone (for chronic and acute assays) was used to preselect lactic acid bacteria (LAB) with resistance to oxidative stress. The mechanism of oxidative stress protection was analyzed. Seven out of ten LAB strains screened for namely 427, X13, 9-5, 422, Z5, G14 and H29M-8M demonstrated higher levels of protection to C. elegans, ranging from 70% to 85% survival rate, in comparison to the inactive strains 408, 13-7 and 430 (35% to 45% survival rate). The survival rates of the seven oxidative stress tolerant strains were correlated to increase in catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) levels and decrease in reactive oxygen species (ROS) expression in C. elegans during H2O2 and juglone exposure. In addition, the transcription of mitogen-activated protein kinase (MAPK) and Nrf2-Keap1-ARE pathway related genes was elevated in the oxidative stress protection of LAB isolates. Finally, a significant correlation was found between the ability of these LAB strains to protect C. elegans from H2O2 or juglone exposure and their antioxidative ability in Campylobacter jejuni-infected mice. Thus the results indicated that the oxidative stress-based lifespan model of C. elegans is useful for screening of LAB with antioxidant efficacy in pathogen-infected mammals.

Effects of Lactococcus lactis from Cyprinus carpio L. as probiotics on growth performance, innate immune response and disease resistance against Aeromonas hydrophila

In the present study, we reported 18 LAB strains isolated from the intestinal contents of Cyprinus carpio, and their probiotic properties both in vitro and in vivo. The results showed that 9 of them had higher in vitro immunomodulatory properties, effectively survived under acidic (pH 2.5) and bile salt (ranging from 0.1% to 0.5%) conditions, and inhibited the growth of 4 pathogens. Among them, Lactococcus lactis Q-8, Lactococcus lactis Q-9, and Lactococcus lactis Z-2 showed the strongest adhesion abilities and inhibition of pathogen adhesion to mucin. When the fish consumed diets containing these 3 strains (5 × 10⁸ CFU/g) for 8 weeks, the weight gain (WG) and specific growth rate (SGR) had significantly (P < 0.05) increased, especially with L. lactis Q-8, which had a WG of 231.45%, and SGR of 2.22%. Survival rate in each LAB supplementation group was also significantly higher than that in control group during the feeding period (P < 0.05). For the cytokines expression levels in serum, different expression patterns were also observed. Before the infection with Aeromonas hydrophila, L. lactis supplementation significant up-regulated protein levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-12) compared with negative (CK1) group, while these cytokines were significantly lower than those in positive (CK2) group after infection. However, whether infected or not, the expression of anti-inflammatory cytokines (IL-10, TGF-β) were significantly increased in L. lactis Q-8, L. lactis Q-9, and L. lactis Z-2 treatment groups. In conclusion, these 3 L. lactis strains screened from common carp were effective in improving growth, innate immunity and disease resistance. Based on the physiological characteristics in our study, they might be used as potential probiotics in aquaculture.

Antibacterial synergy between rutin and florfenicol enhances therapeutic spectrum against drug resistant Aeromonas hydrophila

Emergence of antibiotic resistant bacteria has necessitated the drive to explore competent antimicrobial agents or to develop novel formulations to treat infections including Aeromonas hydrophila. The present study investigates the synergistic antibacterial effects of citrus flavonoid rutin and florfenicol (FF) against A. hydrophila in vitro and in vivo. Rutin is extracted and purified from Citrus sinensis peel through preparative HPLC and characterized through TLC, GC-MS and ¹H and ¹³C NMR analyses. Though rutin did not display significant antibacterial activity, it modulated FF activity resulting in four-fold reduction in the MIC value for FF. The anti-biofilm potential of synergistic association of rutin and FF was validated by protein analysis, quantification of exopolysaccharide (EPS) and microscopy studies using sub-MIC doses. Besides antibacterial action, in vivo studies showed that Rutin/FF combination enhanced host immunity by improving blood cell count, anti-protease, and lysozyme activities as well as decreased the oxidative stress and the pathological changes of tilapia Oreochromis niloticus against A. hydrophila infection. No significant DNA damages or clastogenic effects were detected in tilapia challenged with A. hydrophila under Rutin/FF treatment. It is shown that an acute-phase Lipopolysaccharide binding protein (LBP) enhances the innate host defence against bacterial challenge. Semi quantitative RT-PCR and western blot results revealed the significant increase of LBP in the supernatant of tilapia monocytes/macrophages challenged with A. hydrophila upon treatment. The study findings substantiate that the combination of natural molecules with antibiotics may open up possibilities to treat MDR strains.

Selenium-enriched Bacillus paralicheniformis SR14 attenuates H2O2-induced oxidative damage in porcine jejunum epithelial cells via the MAPK pathway

Oxidative stress plays a detrimental role in gastrointestinal disorders. Although selenium-enriched probiotics have been shown to strengthen oxidation resistance and innate immunity, the potential mechanism remains unclear. Here, we focused on the biological function of our material, selenium-enriched Bacillus paralicheniformis SR14 (Se-BP), and investigated the antioxidative effects of Se-BP and its underlying molecular mechanism in porcine jejunum epithelial cells. First, we prepared Se-BP and quantified for its selenium and bacterial contents. Then, in vitro free radical scavenging activity was measured to evaluate the potential antioxidant effect of Se-BP. Third, to induce an appropriate oxidative stress model, we adopted different concentrations of H₂O₂ and determined the most suitable concentration by a methyl thiazolyl tetrazolium (MTT) assay. Regarding treatment with Se-BP and H₂O₂, we found that Se-BP increased cell viability and prevented lactate dehydrogenase release when administered prior to H₂O₂ exposure. Additionally, Se-BP markedly suppressed reactive oxygen species and malondialdehyde production in cells and effectively attenuated apoptosis. Compared with incubation with H₂O₂ alone, treatment with Se-BP significantly promoted phosphorylation of ERK and p38 MAPK signaling molecules. When administered with ERK and p38 MAPK inhibitors, Se-BP did not alleviate the decrease in cell viability. Our results suggest that Se-BP prevents H₂O₂-induced cell damage by activating the ERK/p38 MAPK signaling pathways.

Immunostimulation of Cyprinus carpio using phage lysate of Aeromonas hydrophila

Over the last 50 years, various approaches have been established for the development of antigens for immunostimulation. We used phage lysate (PL), composed of inactivated antigens by the lytic bacteriophage pAh 6-c for Aeromonas hydrophila JUNAH strain to develop a vaccine for the prevention of A. hydrophila infection in Cyprinus carpio (common carp). We also assessed the poly _D,L lactide-co-glycolic acid (PLGA) microparticles encapsulation method to increase the efficiency of the vaccine. Six groups of vaccines involving encapsulated by PLGA, formalin killed cells, or phage lysate at low or high concentration were prepared for intraperitoneal injection in C. carpio. Blood specimens and head kidney samples were collected at various time points for bacterial agglutination assay and to assess relative expression of immune-related genes interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), lysozyme C, and serum amyloid A (SAA). The vaccine groups using high dose phage lysate antigen showed significantly higher agglutination titers than all other groups at 4- and 6-weeks post vaccination (wpv), with the titer of the PLGA encapsulated vaccine group being highest from 10 wpv to the end of the experiment. The survival rate of fish immunized with the phage lysate vaccines were higher than that of fish immunized with the formailin killed cells vaccine in the challenge experiment conducted 6 wpv. Additionally, the PLGA-encapsulated high dose phage lysate antigen vaccinated groups showed the best protective efficacy in the challenge experiment 12 wpv. Vaccines using the phage lysate antigen also showed higher IL-1β and lysozyme C gene expression at 7 days post vaccination (dpv) and 2 wpv, and higher TNF-α gene expression was seen at 7 dpv. Higher SAA gene expression was seen in these groups at 1 dpv. These results suggest that phage lysate antigen has the potential to induce robust immune responses than formalin killed cells-based vaccines, and could be more effective as a novel inactivated antigen in preventing A. hydrophila infection in C. carpio.

The comparisons in protective mechanisms and efficiencies among dietary α-lipoic acid, β-glucan and l-carnitine on Nile tilapia infected by Aeromonas hydrophila

Dietary α-lipoic acid (LA), β-glucan (Gluc) and l-carnitine (L-Ca) are commonly used additives to promote fish growth and stress resistance in aquaculture production. However their mechanisms and efficiencies in helping fish to resist diseases have not been compared before. In this study, we fed Nile tilapia (Oreochromis niloticus) with diets containing appropriate doses of LA, Gluc and L-Ca for five weeks and further intraperitoneally injected the fish with Aeromonas hydrophila. After dietary treatment, none of the additives affected the fish growth, but dietary Gluc and L-Ca reduced protein and lipid body contents in fish, respectively. After A. hydrophila challenge, all fish treated with the three dietary additives showed higher survival rate, but those fed on dietary L-Ca had lower survival than those fed on LA and Gluc diets, indicating high protection efficiency of LA and Gluc. The protective mechanisms of the three feed additives were quite different under A. hydrophila infection. Dietary LA induced higher total antioxidant capacity and higher mRNA expression of anti-oxidative genes than other additives in liver and also activated partly the immune function in serum and spleen. Gluc largely increased the immune function by activating the immunity enzymes in serum, inducing inflammation in liver and increasing the expression of immune genes in spleen and head kidney. Gluc also increased partly the antioxidant capacity in serum and liver and lipid catabolism in liver. L-Ca largely increased lipid catabolism in liver while it increased partly the antioxidant capacities in serum and liver. Taken together, these results indicate that, dietary LA, Gluc and L-Ca have various protective mechanisms and differ in their efficiencies on resisting A. hydrophila infection in Nile tilapia.

Fecal microbiota transplantation reverses antibiotic and chemotherapy-induced gut dysbiosis in mice

Fecal microbiota transplantation (FMT) is now widely used to treat recurrent Clostridium difficile infection, but has been less studied as a means to restore microbiome diversity and composition following antibiotic or chemotherapy treatments. The purpose of our study was to assess the efficacy of FMT to reverse antibiotic- and chemotherapy-induced gut dysbiosis in a mouse model. C57BL/6J mice were treated with ampicillin for 1 week and/or received a single intraperitoneal injection of 5-Fluorouracil. Fresh stool was collected and analyzed using shotgun metagenomics and the Illumina sequencing platform. Ampicillin caused a significant and immediate decrease in bacterial species richness and diversity that persisted for one week. In mice that received FMT, disruption of the intestinal microbiota was reversed immediately. Antibiotic and chemotherapy administration caused significant alteration in species distribution, including a decrease in the relative proportions of Clostridium scindens and Faecalibacterium prausnitzii, and an increase in known pathogenic species. In mice receiving FMT, we observed a significant increase in species known to exhibit anti-inflammatory properties. Moreover, chemotherapy led to a critical decrease in key ‘health-promoting’ species and to an altered functional profile, especially when chemotherapy was administered in tandem with antibiotics, and that FMT can ameliorate these effects.

Marine yeast Yarrowia lipolytica improves the immune responses in Pacific red snapper (Lutjanus peru) leukocytes

The climatic conditions in saltern saline environments allows the growth of microorganisms adapted to these peculiar ambient and could represent a promising source of new bioactive compounds that could have applications on as animal food supplements, including aquaculture. In this study, we evaluated the role of Yarrowia lipolytica N-6 isolate, from a hypersaline natural environment (Guerrero Negro, Baja California Sur, Mexico), as immunostimulant of the non-specific immune response of head-kidney and spleen Pacific red snapper (Lutjanus peru) leukocytes after challenge with Vibrio parahaemolyticus. In this study, the presence of Y. lipolytica reduced considerably the V. parahaemolyticus load in spleen leukocytes. In vitro assays using head-kidney and spleen leukocytes showed that the response to V. parahaemolyticus infection reveled that leukocyte pre-incubated with Y. lipolytica N-6 significantly increased the non-specific immune response such as respiratory burst, phagocytic activity, NO and MPO activities follow by an increase in SOD and CAT activities, and at the same time inhibited leukocyte apoptosis caused by V. parahaemolyticus. Moreover, Y. lipolytica N-6 incubation also regulated the transcription of genes related to immunity (IL-1β) or oxidative stress (MnSOD, icCu/ZnSOD or CAT) in leukocytes. These results strongly support the idea that the extreme yeast Y. lipolytica N-6 isolate can stimulate the non-specific immune parameters and the antioxidant immune mechanism in head-kidney and spleen Pacific red snapper leukocytes and could be used as potential immunostimulant.

Disruption of the quorum sensing regulated pathogenic traits of the biofilm-forming fish pathogen Aeromonas hydrophila by tannic acid, a potent quorum quencher

The quorum sensing (QS) phenomenon regulates a myriad of pathogenic traits in the biofilm forming fish pathogen, Aeromonas hydrophila. Blocking the QS mechanism of A. hydrophila is a novel strategy to prevent disease in fish. This study evaluated the effect of tannic acid, a QS inhibitor, on A. hydrophila-associated QS regulated phenomena. A streaking assay with Chromobacterium violaceum (CVO26) reported the presence of N-acyl homoserine lactone (AHL) in A. hydrophila, which was confirmed by HPLC and GC-MS analysis. Tannic acid-treated A. hydrophila showed a considerable reduction in violacein production, blood haemolysis activity and the pattern of swarming motility. Biofilm formation was significantly reduced (p < 0.001) (up to 95%), after tannic acid treatment for 48 h. Analysis by qRT-PCR revealed significant downregulation (p < 0.001) of AhyI and AhyR transcripts in A. hydrophila after tannic acid treatment. Co-stimulation of Catla catla with A. hydrophila and tannic acid attenuated pathogen-induced skin haemorrhages and increased the relative survival rate up to 86.6%. The study provides a mechanistic basis of tannic acid as a QS blocker and indicates its therapeutic potential against A. hydrophila-induced pathogenesis.

Screening for proteolytically active lactic acid bacteria and bioactivity of peptide hydrolysates obtained with selected strains

In a screening for proteolytically active lactic acid bacteria, three strains, Lactobacillus delbrueckii ssp. lactis 92202, Lactobacillus helveticus 92201, and Lactobacillus delbrueckii ssp. bulgaricus 92059, showed the highest activities following growth in milk. All three strains degraded α- and β-casein, but did not hydrolyse κ-casein. HPLC analysis of skim milk fermentation revealed increasing amounts of peptides after 5 and 10 h with Lb. d. ssp. bulgaricus 92059. Hydrolysates obtained with Lb. d. ssp. lactis 92202 and Lb. d. ssp. bulgaricus 92059 revealed the highest angiotensin-converting enzyme-inhibitory effect. The effect was dose dependent. Almost no effect (<10%) was seen for Lb. helveticus 92201. For Lb. d. ssp. bulgaricus 92059, maximal inhibition of approx. 65% was reached after 25 h of fermentation. In an in vitro assay measuring potential immunomodulation, hydrolysates of the three strains yielded anti-inflammatory activities in the presence of TNF-α. However, the effects were more pronounced at lower hydrolysate concentrations. In the absence of TNF-α, slight pro-inflammatory effects were observed. The hydrolysate of Lb. d. ssp. bulgaricus 92059, when purified by means of solid-phase extraction, exhibited pro-inflammatory activity. Sour whey containing Lb. d. ssp. bulgaricus 92059 cells showed pro-inflammatory activity while cell-free sour whey was clearly anti-inflammatory. In the purified hydrolysate, 20 different α- and β-casein (CN)-derived peptides could be identified by LC-MS. Most peptides originated from the central and C-terminal regions of β-casein. Peptide length was between 9 (β-CN(f 59-67)) and 22 amino acids (β-CN(f 117-138)).

Debaryomyces hansenii up regulates superoxide dismutase gene expression and enhances the immune response and survival in Pacific red snapper (Lutjanus peru) leukocytes after Vibrio parahaemolyticus infection

Application of yeast is increasing to improve welfare and promotes growth in aquaculture. The halotolerant yeast Debaryomyces hansenii is normally a non-pathogenic yeast with probiotic properties and potential source of antioxidant enzymes as superoxide dismutase. Here, first, we characterized the sequence features of MnSOD and icCu/ZnSOD from Pacific red snapper, and second, we evaluated the potential antioxidant immune responses of the marine yeast Debaryomyces hansenii strain CBS004 in leukocytes which were then subjected to Vibrio parahaemolyticus infection. In silico analysis revealed that LpMnSOD consisted of 1186 bp, with an ORF of 678 bp encoding a 225 amino acid protein and LpicCu/ZnSOD consisted of 1090 bp in length with an ORF of 465 bp encoding a 154 amino acid protein. Multiple alignment analyzes revealed many conserved regions and active sites among its orthologs. In vitro assays using head-kidney and spleen leukocytes immunostimulated with D. hansenii and zymosan in response to V. parahaemolyticus infection reveled that D. hansenii strain CBS004 significantly increased transcriptions of MnSOD and icCu/ZnSOD genes. Flow cytometry assay showed that D. hansenii was able to inhibit apoptosis caused by V. parahaemolyticus in the Pacific red snapper leukocytes and enhanced the phagocytic capacity in head-kidney leukocytes. Immunological assays reveled an increased in superoxide dismutase and peroxidase activities, as well as, in nitric oxide production and reactive oxygen species production (respiratory burst) in fish stimulated with D. hansenii. Finally, our results. These results strongly support the idea that marine yeast Debaryomyces hansenii strain CBS004 can stimulate the antioxidant immune mechanism in head-kidney and spleen leukocytes.

Antioxidant Properties of Probiotic Bacteria

Oxidative stress defines a condition in which the prooxidant-antioxidant balance in the cell is disturbed, resulting in DNA hydroxylation, protein denaturation, lipid peroxidation, and apoptosis, ultimately compromising cells' viability. Probiotics have been known for many beneficial health effects, and the consumption of probiotics alone or in food shows that strain-specific probiotics can present antioxidant activity and reduce damages caused by oxidation. However, the oxidation-resistant ability of probiotics, especially the underling mechanisms, is not properly understood. In this view, there is interest to figure out the antioxidant property of probiotics and summarize the mode of action of probiotic bacteria in antioxidation. Therefore, in the present paper, the antioxidant mechanisms of probiotics have been reviewed in terms of their ability to improve the antioxidant system and their ability to decrease radical generation. Since in recent years, oxidative stress has been associated with an altered gut microbiota, the effects of probiotics on intestinal flora composition are also elaborated.

Clinical drugs for reflux esophagitis

Reflux esophagitis (RE) is a common clinical disease with complex etiology and high incidence which is increasing year by year. Although conventional treatments can ease patients' symptoms, the long-term prognosis is unsatisfactory with many adverse reactions and recurrent symptoms. This article discusses the physiological functions, therapeutic effects and combined application of clinical drugs for reflux esophagitis, with an aim to provide guidance for the treatment of this disease.