Applications and safety considerations of Lactobacillus salivarius as a probiotic in animal and human health

Phenotypic and genomic characterization of bacteriocin-producing lactic acid bacteria with probiotic and biotechnological potential for pathogen control in animal production

The emergence of antibiotic-resistant pathogens has raised significant concerns in the poultry industry, driving the search for alternatives to antibiotics as growth promoters in animal feed. Probiotics, particularly those belonging to the Lactic Acid Bacteria (LAB) group, represent a promising solution by mitigating the risk of infectious disease. However, a uniform concentration of probiotic LAB is not suitable for feed additives due to varying growth kinetics. Additionally, the genomic and physiological profiles of the LAB strains involved must be thoroughly evaluated. In this study, we provide an analytical framework to comprehensively assess LAB as potential antibiotic alternatives in poultry farming. Three LAB strains - Pediococcus pentosaceus (isolated from corn silage), Ligilactobacillus salivarius (from the poultry gut) and Lactococcus lactis (from the gut of rainbow trout) - were sequenced and characterized, with a focus on evaluating their probiotic potential and safety at the genomic level. The analyses included co-culturing LAB with pathogens, assessing viable cells, and determining the minimum inhibitory concentration of bacteriocin-like inhibitory substances (BLIS). In addition to demonstrating effective antimicrobial activity against avian pathogens (Salmonella spp., Clostridium spp. and Campylobacter coli), the results revealed notable probiotic traits in all three LAB strains, such as tolerance to bile salts and acidic environment and adhesion to intestinal cells. In conclusion, our analytical framework and results highlighted the potential of the tested LAB strains as biotechnological tools for developing zootechnical additives. These probiotics show promise as viable alternatives to antibiotics for enhancing poultry health and productivity.

Music exposure enhances resistance to Salmonella infection by promoting healthy gut microbiota

Music intervention is gaining recognition as a cost-effective therapeutic for improving human health. Despite its growing application, the mechanisms through which music exerts beneficial health effects remain largely unexplored. Here, we show that music can exert beneficial effects in mice through modulating gut microbiome composition. Adult mice were exposed to ambient noise, Mozart's Flute Quartet in D Major, K. 285, or white noise over a three-week period. Afterward, we observed treatment-specific changes in the community of gut commensal bacteria in these animals. Upon subsequent challenge with the bacterial pathogen Salmonella typhimurium, control groups exhibited significant weight loss and increased Salmonella colonization, whereas the Mozart-treated group did not. 16S ribosomal RNA gene sequencing revealed that the Mozart group showed a significant increase in Lactobacillus salivarius, a probiotic known for its antibacterial properties. Further experiments confirmed that L. salivarius mitigated Salmonella infection in mice and that L. salivarius acidified local environments in in vitro culture, thus inhibiting Salmonella growth. Additionally, mice exposed to Mozart consumed more food but showed similar body weight compared to the control groups. Behavioral assessments, including open field and object location tests, revealed that Mozart-treated mice were more active, less anxious, and exhibited enhanced spatial memory. Finally, Mozart exposure was shown to significantly boost colonization of administered L. salivarius and alter gut metabolite profiles. These findings suggest that music exposure fosters healthier gut microbiota, enhancing resistance to bacterial infections and highlighting the potential of music therapy as a novel strategy to combat drug-resistant pathogen infections.

IMPORTANCE

Music therapy is increasingly recognized as a low-cost approach to improving health, but how it works remains unclear. Our study demonstrates that music can positively influence health by altering the gut microbiome. In a mouse model, exposure to Mozart's Flute Quartet in D Major enhanced the gut microbiota, specifically increasing levels of the beneficial bacterium Lactobacillus salivarius. This probiotic protected mice from Salmonella infection by creating an acidic environment that inhibited pathogen growth. Mozart-treated mice also showed reduced anxiety, better spatial memory, and higher food intake without weight gain, suggesting the benefits of music exposure. These findings reveal a novel link between music, gut health, and disease resistance, suggesting that music therapy could be a promising strategy for enhancing gut microbiota and combating infections, including those caused by drug-resistant bacteria.

Performance of Pantaneira Breed Cows on Pasture Supplemented with Homeopathic Additives and Yeast

To improve the nutritional efficiency of ruminants and promote well-being in a natural and effective manner, the use of additives such as homeopathic products and yeast has been increasingly incorporated into diets, especially in grazing systems.To evaluate the effects of homeopathic products and yeast on the performance of Pantaneira cows maintained in rotational grazing on Mombaça grass in the Pantanal, Brazil.Sixty cows were assigned to a completely randomized design with four treatments and 15 replicates. The treatments were: CTL: control (without additives); HOM: homeopathic (4 g/kg Entero 100, 4 g/kg Figotonus, and 4 g/kg Convert H); YEA: yeast (24 g/kg Saccharomyces cerevisiae); and HY: homeopathic + yeast (4 g/kg Entero 100, 4 g/kg Figotonus, 4 g/kg Convert H + 24 g/kg S. cerevisiae). The variables measured included forage and supplement intake, diet digestibility, weight gain, and feed conversion. Data were subjected to analysis of variance (ANOVA), followed by Tukey and Duncan tests, with a significance level set at 5%.Cows in the HY treatment group showed higher average daily gains and better feed conversion compared to the CTL treatment (p ≤ 0.05). They exhibited higher digestibility of dry matter, crude protein, neutral detergent fiber, acid detergent fiber, and ether extract, as well as higher levels of total digestible nutrients and digestible energy (p ≤ 0.05).The inclusion of 4 g/kg Entero 100, 4 g/kg Figotonus, 4 g/kg Convert H, and 24 g/kg S. cerevisiae improved nutrient digestibility, body weight gain and feed conversion in Pantaneira cows.

Polystyrene nanoplastics sequester the toxicity mitigating potential of probiotics by altering gut microbiota in grass carp (Ctenopharyngodon idella)

This study evaluated the role of probiotics in enhancing intestinal immunity and mitigating polystyrene nanoplastics (PS-NPs)-induced toxicity in grass carp (Ctenopharyngodon idella). Grass carp were fed probiotics (Bacillus subtilis, Bacillus velezensis, Lactobacillus reuteri, and Lactococcus lactis) for two weeks before being exposed to PS-NPs for five days. Probiotic pretreatment alleviated PS-NPs-induced intestinal damage, with Bacillus velezensis and Lactococcus lactis groups showing milder vacuolation and villus breakage than other groups. Probiotic-treated fish exhibited transient increases in antioxidant enzyme activities (CAT, SOD, MPO) and immune gene expression (IL-6, IL-8, IL-10, IL-1β, TNF-α, and IFN-γ2) shortly after exposure, followed by significant downregulation over time. Higher abundance of the gut dominant phylum Proteobacteria was observed in four probiotic groups exposed to PS-NPs than that in the blank control group. The Clostridium phylum showed a significant decrease in the abundance both in the LRS-PS100 and LLS-PS100 groups, while the abundance of the Thick-walled phylum increased. The Spearman correlation matrix revealed that specific gut microbiota, such as Serratia, Neisseria, and Lactococcus, were significantly associated with enzymatic activities and immune system related genes' expressions. Probiotic pretreatment enhanced the intestinal immune response of grass carp. However, this enhanced immune response was insufficient to counteract the toxic effects of PS-NPs exposure, particularly in terms of oxidative stress levels and gut microbial diversity. This study offers new insights into the potential of probiotics to combat NPs pollution in aquaculture. It emphasizes the need for further research to explore various probiotic combinations. Future studies should also investigate optimal dosages and durations to effectively mitigate the biological toxicity of NPs pollution.

Isolation, genomic characterization and biotechnological evaluation of lactobacilli strains from chicken gastrointestinal tract

During a study investigating possible probiotics from chicken gut microbiota, strains C1-4 and C2-3 were isolated and identified as members of the genus Ligilactobacillus. The strains formed a well-supported cluster with Ligilactobacillus salivarius and Ligilactobacillus hayatikensis in phylogenetic trees. Their genomes, sized 1.8 Mb with G + C content of 32 %, were related to "Candidatus Avacholeplasma faecigallinarum" with a dDDH level of 95.4 %, indicating the strains were the first culturable members of the uncultured taxon. Furthermore, a dDDH value of 78.9 % with L. salivarius DSM 20555T suggested that the strains may represent a novel subspecies of L. salivarius. The functional analysis of the genomes revealed that the strains harbour genes associated with probiotic traits, including lactate utilization, acetoin and butanediol metabolism, pH homeostasis and exopolysaccharide biosynthesis. The genome annotation for the secondary metabolite biosynthesis gene clusters showed that the strains have a type III polyketide gene cluster and a bacteriocin immunity protein gene. The strains exhibited phenotypic features compatible with their potential use as probiotics, such as tolerance to low pH and NaCl, ability to achieve high auto-aggregation, and hydrophobicity properties. In addition, the strains exhibited strong antibacterial activity against pathogenic MRSA (Meticillin-resistant Staphylococcus aureus ATCC 67101), S. aureus ATCC 25923, Listeria monocytogenes MBG16, and VRSA (Vancomycin-resistant Staphylococcus aureus MBG89), while showing moderate activity against Salmonella Typhimurium MBG15, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 13833, and Pseudomonas aeruginosa ATCC 27853. The cell-free supernatant of the strains notably affected Lis. monocytogenes and S. aureus, possibly due to possible bacteriocin production. In conclusion, the strains isolated from chicken gut microbiota have a high potential to be used as probiotics in agriculture and medicine.

Uncovering mercury accumulation and the potential for bacterial bioremediation in response to contamination in the Singalila National Park

Several recent investigations into montane regions have reported on excess mercury accumulation in high-altitude forest ecosystems. This study explored the Singalila National Park, located on the Singalila ridge of the Eastern Himalayas, revealing substantial mercury contamination. Particular focus was on Sandakphu (3636 m), the highest peak in West Bengal, India. It harboured 6.77 ± 0.01 mg/kg of total mercury in its topsoil. Further evidence was provided by accumulation in leaves (0.040 ± 0.01 mg/kg), and roots (0.150 ± 0.008 mg/kg) of local vegetation, litterfall (0.234 ± 0.019 mg/kg), mosses (0.367 ± 0.043 mg/kg), surface water from local lakes and waterbodies (0.010 ± 0.005 mg/l), fresh snow (0.014 ± 0.004 mg/l), and sleet (0.019 ± 0.009 mg/l). Samples from other points of varying elevation in the park also demonstrated contamination. The soil displayed a range of 0.068-5.28 mg/kg, while the mean concentration in leaves was 0.153 ± 0.105 mg/kg, roots was 0.106 ± 0.054 mg/kg, and leaf litter was 0.240 ± 0.112 mg/kg. Additionally, the microbial consortia isolated from the contaminated soil displayed a high tolerance to mercuric chloride, presumably gained through repeated and consistent exposure. Four high tolerance bacterial strains, MTS2C, MTS3A, MTS4B and MTS6A, were further characterized for potential use in bioremediation strategies. Their mercury removal capacities were determined to be 82.35%, 75.21%, 61.95%, and 37.47%, respectively. Overall, the findings presented provide evidence for a highly contaminated environment in the Singalila National Park, that poses significant ecological risk to the flora, fauna and local inhabitants of this biodiversity hotspot. This research also highlights the need for further exploration and monitoring of the Eastern Himalayas for its role as a sink for atmospheric mercury.

Metabolic modelling uncovers the complex interplay between fungal probiotics, poultry microbiomes, and diet

BACKGROUND

The search for alternatives to antibiotic growth promoters in poultry production has increased interest in probiotics. However, the complexity of the interactions between probiotics, gut microbiome, and the host hinders the development of effective probiotic interventions. This study explores metabolic modelling to examine the possibility of designing informed probiotic interventions within poultry production.

RESULTS

Genomic metabolic models of fungi were generated and simulated in the context of poultry gut microbial communities. The modelling approach correlated with short-chain fatty acid production, particularly in the caecum. Introducing fungi to poultry microbiomes resulted in strain-specific and diet-dependent effects on the gut microbiome. The impact of fungal probiotics on microbiome diversity and pathogen inhibition varied depending on the specific strain, resident microbiome composition, and host diet. This context-dependency highlights the need for tailored probiotic interventions that consider the unique characteristics of each poultry production environment.

CONCLUSIONS

This study demonstrates the potential of metabolic modelling to elucidate the complex interactions between probiotics, the gut microbiome, and diet in poultry. While the effects of specific fungal strains were found to be context-dependent, the approach itself provides a valuable tool for designing targeted probiotic interventions. By considering the specific characteristics of the host microbiome and dietary factors, this methodology could guide the deployment of effective probiotics in poultry production. However, the current work relies on computational predictions, and further in vivo validation studies are needed to confirm the efficacy of the identified probiotic candidates. Nonetheless, this study represents a significant step in using metabolic models to inform probiotic interventions in the poultry industry. Video Abstract.

Probiotic Lactobacillus salivarius mediated synthesis of silver nanoparticles (AgNPs-LS): A sustainable approach and multifaceted biomedical application

Biogenic synthesis of silver nanoparticles (AgNPs) has emerged as an eco-friendly and sustainable approach with diverse biological applications. This study presents synthesis of AgNPs-LS using a probiotic strain Lactobacillus salivarius (L. salivarius) and explores their multifaceted biological activities, including antibacterial, antibiofilm, anti-quorum sensing, antifungal, antioxidant, anticancer, anticoagulant and thrombolytic properties. The biosynthesis of AgNPs-LS was successfully achieved using L. salivarius cell free supernatants, resulting in well-characterized nanoparticles as confirmed by UV-Vis spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS) and zeta potential analysis. The AgNPs-LS demonstrated potent antibacterial activity against different pathogenic bacteria (C. violaceum, P. aeruginosa, S. aureus, E. coli and S. marcescens), emphasizing their potential in combating bacterial infections. Moreover, these AgNPs-LS were effective in inhibiting biofilm formation (>60 % at 1/2 MIC), a key mechanism of bacterial virulence, highlighting their utility in preventing biofilm-related infections. AgNPs-LS exhibited anti-quorum sensing activity, disrupting bacterial communication systems and potentially reducing virulence factor such as, violacein production in C. violaceum, pyocyanin production in P. aeruginosa and prodigiosin production in S. marcescens. Additionally, AgNPs-LS also exhibited notable antifungal activity towards a different pathogenic fungus (F. proliferatum, P. purpurogenum, A. niger and R. stolonifer). In terms of health applications, the AgNPs-LS displayed significant antioxidant activity, effectively scavenging DPPH• (IC50 = 42.65 μg/mL) and ABTS•+ (IC50 = 53.77 μg/mL) free radicals. Furthermore, AgNPs-LS showed cytotoxicity against breast cancer cells (MCF-7) (IC50 = 52.29 μg/mL), positioning them as promising candidates for cancer therapy. Moreover, AgNPs-LS were also shown promising anticoagulant and thrombolytic activities under practical conditions. Therefore, the biogenic synthesis of AgNPs-LS using L. salivarius offers a sustainable and cost-effective route for producing AgNPs with an array of biological activities. These AgNPs-LS have the potential to address various challenges in healthcare, ranging from antimicrobial, anticancer applications to biofilm inhibition, antioxidant therapy, anticoagulant and thrombolytic agents.

Short term effect of antimicrobial photodynamic therapy and probiotic L. salivarius WB21 on halitosis: A controlled and randomized clinical trial

OBJECTIVE

This study aimed to evaluate the effect of antimicrobial photodynamic therapy (aPDT) and the use of probiotics on the treatment of halitosis.

METHODS

Fifty-two participants, aged from 18 to 25 years, exhaling sulfhydride (H2S) ≥ 112 ppb were selected. They were allocated into 4 groups (n = 13): Group 1: tongue scraper; Group 2: treated once with aPDT; Group 3: probiotic capsule containing Lactobacillus salivarius WB21 (6.7 x 108 CFU) and xylitol (280mg), 3 times a day after meals, for 14 days; Group 4: treated once with aPDT and with the probiotic capsule for 14 days. Halimetry with gas chromatography (clinical evaluation) and microbiological samples were collected from the dorsum of the tongue before and after aPDT, as well as after 7, 14, and 30 days. The clinical data failed to follow a normal distribution; therefore, comparisons were made using the Kruskal-Wallis test (independent measures) and Friedman ANOVA (dependent measures) followed by appropriate posthoc tests, when necessary. For the microbiological data, seeing as the data failed to follow a normal distribution, the Kruskal-Wallis rank sum test was performed with Dunn's post-test. The significance level was α = 0.05.

RESULTS

Clinical results (halimetry) showed an immediate significant reduction in halitosis with aPDT (p = 0.0008) and/or tongue scraper (p = 0.0006). Probiotics showed no difference in relation to the initial levels (p = 0.7530). No significant differences were found in the control appointments. The amount of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were not altered throughout the analysis (p = 0.1616, p = 0.2829 and p = 0.2882, respectively).

CONCLUSION

There was an immediate clinical reduction of halitosis with aPDT and tongue scraping, but there was no reduction in the number of bacteria throughout the study, or differences in the control times, both in the clinical and microbiological results. New clinical trials are necessary to better assess the tested therapies.

TRIAL REGISTRATION

Clinical Trials NCT03996044.

Examining the Efficacy of Five Lactobacillus Species in Treating and Preventing Atopic Dermatitis: A Systemic Literature Review

Probiotics have garnered increasing attention, particularly within the realm of atopic dermatitis (AD). Although classified as dietary supplements by the Food and Drug Administration, probiotics are being explored for their potential to modify immune system responses and aid in disease recovery. This review aims to provide a current understanding of probiotics, specifically various lactobacilli strains, as a therapeutic option in preventing and treating AD. The concept of the gut-skin axis has gained substantial recognition, emphasizing the complex relationship between the gut microbiome and skin health. Dysfunctional gut barriers and metabolites produced by gut microorganisms can exert profound influences on skin conditions, including AD. Lactobacilli species are particularly noteworthy for their resilience and stability within the gastrointestinal tract, making these bacteria ideal candidates for probiotic supplementation. Various lactobacilli strains (Lactobacillus salivarius, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus reuteri, and Lactobacillus rhamnosus) were included in this study due to their current uses in mitigating AD symptomatology. This systemic review article aims to shed light on the potential of probiotics as a therapeutic approach for AD, highlighting their stellar safety profile and promising therapeutic efficacy. Given the compelling preliminary findings and the constraints associated with conventional treatments, probiotics, particularly lactobacilli strains, emerge as a considerable alternative or adjuvant option for individuals grappling with AD. Further exploration is imperative to establish probiotics as a promising therapeutic option, providing renewed hope for those seeking effective strategies for managing AD.

Association between gut health and gut microbiota in a polluted environment

Animals host complex bacterial communities in their gastrointestinal tracts, with which they share a mutualistic interaction. The numerous effects these interactions grant to the host include regulation of the immune system, defense against pathogen invasion, digestion of otherwise undigestible foodstuffs, and impacts on host behaviour. Exposure to stressors, such as environmental pollution, parasites, and/or predators, can alter the composition of the gut microbiome, potentially affecting host-microbiome interactions that can be manifest in the host as, for example, metabolic dysfunction or inflammation. However, whether a change in gut microbiota in wild animals associates with a change in host condition is seldom examined. Thus, we quantified whether wild bank voles inhabiting a polluted environment, areas where there are environmental radionuclides, exhibited a change in gut microbiota (using 16S amplicon sequencing) and concomitant change in host health using a combined approach of transcriptomics, histological staining analyses of colon tissue, and quantification of short-chain fatty acids in faeces and blood. Concomitant with a change in gut microbiota in animals inhabiting contaminated areas, we found evidence of poor gut health in the host, such as hypotrophy of goblet cells and likely weakened mucus layer and related changes in Clca1 and Agr2 gene expression, but no visible inflammation in colon tissue. Through this case study we show that inhabiting a polluted environment can have wide reaching effects on the gut health of affected animals, and that gut health and other host health parameters should be examined together with gut microbiota in ecotoxicological studies.

A Review of Probiotic Ingredient Safety Supporting Monograph Development Conducted by the United States Pharmacopeia (USP)

The United States Pharmacopeia (USP) is an independent, nonprofit science-based organization whose mission is to improve global health through public standards and related products for medicines, food and dietary supplements. Probiotic-based dietary supplements are increasingly popular in the marketplace and USP has developed fourteen monographs specific to probiotic ingredients, including representatives from the Genera Lactobacillus, Bacillus, Streptococcus, and Bifidobacterium. These monographs include the definition of the article, tests for identification, quantification assays (enumeration in the case of probiotics), limits for contaminants, and other quality parameters when appropriate. In addition to quality, the USP also considers the safety of probiotics for monograph development. This report includes an overview of the USP admission evaluation process for probiotics as well as a tabular summary of the probiotic monographs currently available. Pharmacopeia monographs can guide manufacturers and brand owners and protect consumers through establishment of quality standards.

Effects of elevated temperature and different crystal structures of TiO2 nanoparticles on the gut microbiota of mussel Mytilus coruscus

Coastal habitats are exposed to increasing pressure of nanopollutants commonly combined with warming due to the seasonal temperature cycles and global climate change. To investigate the toxicological effects of TiO2 nanoparticles (TiO2 NPs) and elevated temperature on the intestinal health of the mussels (Mytilus coruscus), the mussels were exposed to 0.1 mg/L TiO2 NPs with different crystal structures for 14 days at 20 °C and 28 °C, respectively. Compared to 20 °C, the agglomeration of TiO2 NPs was more serious at 28 °C. Exposure to TiO2 NPs led to elevated mortality of M. coruscus and modified the intestinal microbial community as shown by 16S rRNA sequence analysis. Exposure to TiO2 NPs changed the relative abundance of Bacteroidetes, Proteobacteria and Firmicutes. The relative abundances of putative mutualistic symbionts Tenericutes and Fusobacteria increased in the gut of M. coruscus exposed to anatase, which have contributed to the lower mortality in this group. LEfSe showed the combined stress of warming and TiO2 NPs increased the risk of M. coruscus being infected with potential pathogenic bacteria. This study emphasizes the toxicity differences between crystal structures of TiO2 NPs, and will provides an important reference for analyzing the physiological and ecological effects of nanomaterial pollution on bivalves under the background of global climate change.

Ligilactobacillus salivarius CNCM I-4866, a potential probiotic candidate, shows anti-inflammatory properties in vitro and in vivo

INTRODUCTION

The aim of this work was to characterize a new strain of Ligilactobacillus salivarius (CNCM I-4866) (CNCM I-4866) to address its potential as probiotic with a special focus on intestinal inflammation. Potential anti-inflammatory abilities of this strain were evaluated through in vivo and in vitro experiments.

METHODS

Firstly, the strain was tested in a murine acute inflammation colitis model induced by DNBS. In vitro characterization was then performed with diverse tests: modulation capability of intestinal permeability; study of the impact on immunity profile through cytokines dosage; capacity to inhibit pathogens and adhere to intestinal cells lines. Production of metabolites, antibiotic resistance and survival to gastro-intestinal tract conditions were also tested.

RESULTS

In vitro assay has shown a reduction of colonic damage and markers of inflammation after treatment with CNCM I-4866. Transcriptomic analysis performed on colons showed the capacity of the strain to down-regulate pro-inflammatory cytokines. L. salivarius CNCM I-4866 exerted anti-inflammatory profile by reducing IL-8 production by TNF-α stimulated cell and modulated cytokines profile on peripheral blood mononuclear cells (PBMC). It protected intestinal integrity by increasing trans-epithelial electrical resistance (TEER) on Caco-2 TNF-α inflamed cells. Additionally, L. salivarius CNCM I-4866 displayed inhibition capacity on several intestinal pathogens and adhered to eukaryotic cells. Regarding safety and technical concerns, CNCM I-4866 was highly resistant to 0.3% of bile salts and produced mainly L-lactate. Finally, strain genomic characterization allowed us to confirm safety aspect of our strain, with no antibiotic gene resistance found.

DISCUSSION

Taken together, these results indicate that L. salivarius CNCM I-4866 could be a good probiotic candidate for intestinal inflammation, especially with its steady anti-inflammatory profile.

Cooperative interactions between Veillonella ratti and Lactobacillus acidophilus ameliorate DSS-induced ulcerative colitis in mice

Veillonella and Lactobacillus species are key regulators of a healthy gut environment through metabolic cross-feeding, influencing lactic acid and short-chain fatty acid (SCFA) levels, which are crucial for gut health. This study aims to investigate how Veillonella ratti (V. ratti) and Lactobacillus acidophilus (LA) interact with each other and alleviate dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in a mouse model. We assess their metabolic interactions regarding carbon sources through co-culturing in a modified medium. In the in vitro experiments, V. ratti and LA were inoculated in mono-cultures and co-culture, and viable cell counts, OD600, pH, lactic acid, glucose and SCFAs were measured. For the in vivo experiment, 60 C57BL/6 mice were randomly divided into five groups and administered V. ratti and LA alone or in combination via oral gavage (1 × 109 CFU mL-1 per day per mouse) for 14 days. On the seventh day, 2.5% DSS was added to the drinking water to induce colitis. The effects of these probiotics on UC were evaluated by assessing intestinal barrier integrity and intestinal inflammation in the gut microenvironment. In vitro results demonstrated that co-culturing V. ratti with LA significantly increased viable cell numbers, lactic acid production, and SCFA production, while reducing pH and glucose levels in the medium. In vivo findings revealed that intervention with V. ratti, particularly in combination with LA, alleviated symptoms, including weight loss, colon shortening, and tissue damage. These probiotics mitigated intestinal inflammation by down-regulating pro-inflammatory molecules, such as IL-6, IL-1β, IL-γ, iNOS, and IFN-γ, as well as oxidative stress markers, including MDA and MPO. Concurrently, they upregulated the activity of anti-inflammatory enzymes, namely, SOD and GSH, and promoted the production of SCFAs. The combined intervention of V. ratti and LA significantly increased acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and total SCFAs in cecal contents. Furthermore, the intervention of V. ratti and LA increased the abundance of beneficial bacteria, such as Akkermansia, while reducing the abundance of harmful bacteria, such as Escherichia-Shigella and Desulfovibrio, thereby mitigating excessive inflammation. These findings highlight the enhanced therapeutic effects resulting from the interactions between V. ratti and LA, demonstrating the potential of this combined probiotic approach.

Gut microbiome supplementation as therapy for metabolic syndrome

The gut microbiome is defined as an ecological community of commensal symbiotic and pathogenic microorganisms that exist in our body. Gut microbiome dysbiosis is a condition of dysregulated and disrupted intestinal bacterial homeostasis, and recent evidence has shown that dysbiosis is related to chronic inflammation, insulin resistance, cardiovascular diseases (CVD), type 2 diabetes mellitus (T2DM), and obesity. It is well known that obesity, T2DM and CVD are caused or worsened by multiple factors like genetic predisposition, environmental factors, unhealthy high calorie diets, and sedentary lifestyle. However, recent evidence from human and mouse models suggest that the gut microbiome is also an active player in the modulation of metabolic syndrome, a set of risk factors including obesity, hyperglycemia, and dyslipidemia that increase the risk for CVD, T2DM, and other diseases. Current research aims to identify treatments to increase the number of beneficial microbiota in the gut microbiome in order to modulate metabolic syndrome by reducing chronic inflammation and insulin resistance. There is increasing interest in supplements, classified as prebiotics, probiotics, synbiotics, or postbiotics, and their effect on the gut microbiome and metabolic syndrome. In this review article, we have summarized current research on these supplements that are available to improve the abundance of beneficial gut microbiota and to reduce the harmful ones in patients with metabolic syndrome.

Assessment of beneficial effects and identification of host adaptation-associated genes of Ligilactobacillus salivarius isolated from badgers

BACKGROUND

Ligilactobacillus salivarius has been frequently isolated from the gut microbiota of humans and domesticated animals and has been studied as a candidate probiotic. Badger (Meles meles) is known as a "generalist" species that consumes complex foods and exhibits tolerance and resistance to certain pathogens, which can be partly attributed to the beneficial microbes such as L. salivarius in the gut microbiota. However, our understanding of the beneficial traits and genomic features of badger-originated L. salivarius remains elusive.

RESULTS

In this study, nine L. salivarius strains were isolated from wild badgers' feces, one of which exhibited good probiotic properties. Complete genomes of the nine L. salivarius strains were generated, and comparative genomic analysis was performed with the publicly available complete genomes of L. salivarius obtained from humans and domesticated animals. The strains originating from badgers harbored a larger genome, a higher number of protein-coding sequences, and functionally annotated genes than those originating from humans and chickens. The pan-genome phylogenetic tree demonstrated that the strains originating from badgers formed a separate clade, and totally 412 gene families (12.6% of the total gene families in the pan-genome) were identified as genes gained by the last common ancestor of the badger group. The badger group harbored significantly more gene families responsible for the degradation of complex carbohydrate substrates and production of polysaccharides than strains from other hosts; many of these were acquired by gene gain events.

CONCLUSIONS

A candidate probiotic and nine L. salivarius complete genomes were obtained from the badgers' gut microbiome, and several beneficial genes were identified to be specifically present in the badger-originated strains that were gained in the evolution. Our study provides novel insights into the adaptation of L. salivarius to the intestinal habitat of wild badgers and provides valuable strain and genome resources for the development of L. salivarius as a probiotic.

Insights into the mechanisms of L. salivarius CECT5713 resistance to freeze-dried storage

Ligilactobacillus salivarius is a lactic acid bacterium exhibiting several health benefits. However, it is sensitive to freeze-drying and storage in the dried state, thus limiting its commercial exploitation. Our objective was to identify markers of cell resistance by applying multiscale characterization to L. salivarius CECT5713 cell populations exhibiting different resistance to freeze-dried storage. Cells were produced under two different sets of production conditions differing in the culture parameters (temperature, neutralizing solution, and harvesting time) and the protective formulation composition. The culturability, membrane integrity, and cell biochemical composition assessed by Fourier transform infrared (FTIR) micro-spectroscopy were evaluated after freezing, freeze-drying, and subsequent storage at 37 °C. Membrane properties (fatty acid composition, membrane fluidity, and phospholipid organization), as well as matrix physical properties (glass transition temperature and water activity), were determined. The most resistant cells to freeze-dried storage exhibited the highest cyclic fatty acid content and the most rigid membrane. Freeze-drying and storage induced damage to membrane integrity, proteins, nucleic acids, and constituents of the peptidoglycan cell wall. From the FTIR spectra analysis, we propose the minimization of the variations of the 1058 and 1714 cm-1 vibration bands (that arise mainly from symmetric C-O-C stretching and CO stretching, respectively) induced by the freeze-drying process as a marker of storage stability. We confirmed that a matrix with a glass transition temperature at least 50 °C higher than the storage temperature is crucial for L. salivarius CECT5713 storage stability. In addition, this work explored promising FTIR methods for a better understanding of the protection mechanisms involved.

Treating asthma patients with probiotics: a systematic review and meta-analysis

Introduction

Objective: To evaluate the role of probiotics in the treatment of asthma patients by meta-analysis. Methods: PubMed, Embase, The Cochrane Library, Web of Science, and other databases were searched by computer, and the relevant literature on the treatment of asthma by probiotics that met the inclusion criteria was screened by manual retrieval. Meta-analysis was performed using Revman 5.4 software and the combined effect was evaluated by odds ratio (OR) or mean difference (MD) and 95 % confidence interval (CI). Results: a total of ten references were included, all of which were randomized controlled studies, and a total of 1,101 people were investigated. Fractional exhaled nitric oxide (FeNO) (MD = -7.17, 95 % CI: -12.81, -1.54), asthma symptom severity (MD = -0.07, 95 % CI: -0.10, -0.04), Childhood Asthma Control Test (CACT) (MD = 2.26, 95 % CI: 1.14, 3.39), and the number of acute episodes of asthma (OR = 0.30, 95 % CI: 0.19, 0.47) in the probiotics group were better than those in the control group. There was no significant difference in forced expiratory volume in the first second (FEV1) (MD = 0.11, 95 % CI: -0.05, 0.26) and FEV1/FVC (%) (MD = 0.32, 95 % CI: -1.48, 2.12). Conclusion: the use of probiotics in patients with asthma can improve lung inflammation and asthma symptoms, reduce the number of asthma attacks, and have no effect on lung function.

Beneficial Effects of Bacillus amyloliquefaciens D1 Soy Milk Supplementation on Serum Biochemical Indexes and Intestinal Health of Bearded Chickens

This study investigated the effects of dietary supplementation with Bacillus amyloliquefaciens D1 (B. amyloliquefaciens D1) on growth performance, serum anti-inflammatory cytokines, and intestinal microbiota composition and diversity in bearded chickens. To investigate the effects of Bacillus amyloliquefaciensa and fermented soy milk, 7-day-old broilers were orally fed different doses of Bacillus amyloliquefaciens D1 fermented soy milk for 35 days, with the unfermented soy milk group as the Placebo group. This study found that B. amyloliquefaciens D1 fermented soy milk improved the intestinal microbiota of broilers, significantly increasing the abundance of beneficial bacteria and decreasing the abundance of harmful bacteria in the gut. B. amyloliquefaciens D1 fermented soy milk also significantly reduced the serum lipopolysaccharide (LPS) content. The body weight and daily weight gain of broilers were increased. In conclusion, the results of this study are promising and indicate that supplementing the diets of bearded chickens with B. amyloliquefaciens D1 fermented soy milk has many beneficial effects in terms of maintaining intestinal microbiota balance and reducing inflammation in chickens.

Comparative Evaluation of the Inhibitory Effect of Lactobacillus rhamnosus on Halitosis-Causing Bacteria: An Invitro Microbiological Study

AIM

 To determine the effectiveness of Lactobacillus rhamnosus in inhibiting halitosis-causing bacteria relative to other possible inhibitors, such as mouthwashes.

MATERIALS AND METHODS

 This in vitro study was done using a diffusion test with three groups with 11 samples in each group: group A, Porphyromonas gingivalis; group B, Tannerella forsythia; and group C, Prevotella intermedia. At 24, 48, and 72 hours, the inhibitory effect of L. rhamnosus was tested.

RESULTS

A statistically significant difference was seen for halo formation in group A, where all 11 samples showed an inhibitory effect after 72 hours. After 48 hours, seven of the 11 samples in group B and nine of the 11 samples in group C showed inhibitory effects.

CONCLUSION

 The study found that L. rhamnosus had an inhibitory effect on halitosis-causing bacteria like P. gingivalis after 72 hours, which was statistically significant. The same was true for T. forsythia and P. intermedia after 48 hours. This means that L. rhamnosus has an inhibitory effect on halitosis-causing bacteria like P. gingivalis.

Potential Antitumor Effect of Functional Yogurts Formulated with Prebiotics from Cereals and a Consortium of Probiotic Bacteria

Various types of functional yogurts were obtained from normalized milk (with normalized lipid content) and a standardized probiotic consortium of probiotic bacteria named ABY3. All the types of yogurts obtained contained prebiotics from black or red rice; malt of barley, rye, wheat; or wheat bran. The physico-chemical analyses of all the functionalized products obtained showed that all of them met the quality standard for yogurt products. However, the sensorial analyses showed that the products obtained from black and red rice were of very good quality. The biological analyses indicated that all the types of products contained live probiotic bacteria, but wheat bran and red rice could increase their numbers. Tests performed on tumor cell line Caco-2 with corresponding postbiotics revealed cytotoxicity greater than 30% after 48 h of exposure in the case of yogurts obtained from milk with 0.8% lipid content and red rice or blond malt of barley. In the case of yogurts derived from milk with 2.5% lipid content, only the variants that contained blond malt of rye or wheat became cytotoxic against the Caco-2 cell line.

Feeding broiler chickens with arginine above recommended levels: effects on growth performance, metabolism, and intestinal microbiota

BACKGROUND

Arginine is an essential amino acid for chickens and feeding diets with arginine beyond the recommended levels has been shown to influence the growth performance of broiler chickens in a positive way. Nonetheless, further research is required to understand how arginine supplementation above the widely adopted dosages affects metabolism and intestinal health of broilers. Therefore, this study was designed to assess the effects of arginine supplementation (i.e., total arginine to total lysine ratio of 1.20 instead of 1.06-1.08 recommended by the breeding company) on growth performance of broiler chickens and to explore its impacts on the hepatic and blood metabolic profiles, as well as on the intestinal microbiota. For this purpose, 630 one-day-old male Ross 308 broiler chicks were assigned to 2 treatments (7 replicates each) fed a control diet or a crystalline L-arginine-supplemented diet for 49 d.

RESULTS

Compared to control birds, those supplemented with arginine performed significantly better exhibiting greater final body weight at D49 (3778 vs. 3937 g; P < 0.001), higher growth rate (76.15 vs. 79.46 g of body weight gained daily; P < 0.001), and lower cumulative feed conversion ratio (1.808 vs. 1.732; P < 0.05). Plasma concentrations of arginine, betaine, histidine, and creatine were greater in supplemented birds than in their control counterparts, as were those of creatine, leucine and other essential amino acids at the hepatic level. In contrast, leucine concentration was lower in the caecal content of supplemented birds. Reduced alpha diversity and relative abundance of Firmicutes and Proteobacteria (specifically Escherichia coli), as well as increased abundance of Bacteroidetes and Lactobacillus salivarius were found in the caecal content of supplemented birds.

CONCLUSIONS

The improvement in growth performance corroborates the advantages of supplementing arginine in broiler nutrition. It can be hypothesized that the performance enhancement found in this study is associated with the increased availability of arginine, betaine, histidine, and creatine in plasma and the liver, as well as to the ability of extra dietary arginine to potentially ameliorate intestinal conditions and microbiota of supplemented birds. However, the latter promising property, along with other research questions raised by this study, deserve further investigations.

Effects of a novel direct-fed microbial on growth performance, carcass characteristics, nutrient digestibility, and ruminal morphology of beef feedlot steers

The effects of a novel direct-fed microbial (DFM) on feedlot performance, carcass characteristics, digestibility, ruminal morphology, and volatile fatty acid (VFA) profile of finishing steers were evaluated. Single-source Angus-crossbred yearling steers (n = 144; initial body weight (BW) = 371 ± 19 kg) were used in a randomized complete block design. Steers were blocked by initial BW and randomly assigned to treatments (12 pens/treatment; 4 steers/pen). Treatments included (A) CONTROL (no DFM, tylosin, or monensin, (B) MONTY (monensin sodium [330 mg/animal-daily] and tylosin phosphate [90 mg/animal-daily]), and (C) MONPRO (monensin sodium [same as previous] and Lactobacillus salivarius L28 [1 × 106 CFU/animal-daily]). Treatments were included in a steam-flaked corn-based finisher diet offered once daily using a clean-bunk management for ~149 d. The digestibility assessment was performed from days 70 to 74. Ruminal fluid and rumen tissue samples were collected at the slaughter for VFA profile and papillae morphology analyses, respectively. Data were analyzed using the GLIMMIX procedure of SAS with pen serving as the experimental unit, treatment as fixed effect, and BW block as random effect. Steers offered MONPRO had on average 5.3% less (P < 0.01) dry matter intake (9.56 kg/d) compared with either CONTROL (10.16 kg/d) or MONTY (9.96 kg/d). The carcass-adjusted final BW (613 kg; P = 0.23), overall average daily gain (1.64 kg/d; P = 0.23), and gain-efficiency (0.165; P = 0.61) were not affected by treatments. Steers offered CONTROL had greater (P < 0.01) marbling score and tended (P = 0.06) to have less carcasses grading Select and tended (P = 0.10) to have more carcasses grading Upper-Choice, while other carcass characteristics and liver-abscesses were not affected (P ≥ 0.23) by treatments. The digestibility of nutrients (P ≥ 0.13) and the ruminal VFA profile (P ≥ 0.12) were not affected by treatments. Steers offered MONPRO tended (P = 0.09) to have 16% greater average papillae number compared to other treatments. Yearlings offered finishing diets containing L. salivarius L28 plus monensin did not affect growth performance, digestibility, or ruminal VFA, but reduced feed intake. Carcass quality was negatively affected by treatments, while animals consuming L. salivarius L28 and monensin tended to improve ruminal morphology. Current findings in ruminal morphology and feed intake may warrant further assessment of diets containing L. salivarius L28 on beef cattle food safety aspects.

Lactobacillus for the treatment and prevention of atopic dermatitis: Clinical and experimental evidence

Atopic dermatitis (AD) is a chronic inflammatory skin disease, accompanied by itching and swelling. The main pathological mechanism of AD is related to the imbalance between Type 2 helper cells (Th2 cells) and Type 1 helper cells (Th1 cells). Currently, no safe and effective means to treat and prevent AD are available; moreover, some treatments have side effects. Probiotics, such as some strains of Lactobacillus, can address these concerns via various pathways: i) facilitating high patient compliance; ii) regulating Th1/Th2 balance, increasing IL-10 secretion, and reducing inflammatory cytokines; iii) accelerating the maturation of the immune system, maintaining intestinal homeostasis, and improving gut microbiota; and iv) improving the symptoms of AD. This review describes the treatment and prevention of AD using 13 species of Lactobacillus. AD is commonly observed in children. Therefore, the review includes a higher proportion of studies on AD in children and fewer in adolescents and adults. However, there are also some strains that do not improve the symptoms of AD and even worsen allergies in children. In addition, a subset of the genus Lactobacillus that can prevent and relieve AD has been identified in vitro. Therefore, future studies should include more in vivo studies and randomized controlled clinical trials. Given the advantages and disadvantages mentioned above, further research in this area is urgently required.

Updates on the Role of Probiotics against Different Health Issues: Focus on Lactobacillus

This review article is built on the beneficial effects of Lactobacillus against different diseases, and a special focus has been made on its effects against neurological disorders, such as depression, multiple sclerosis, Alzheimer's, and Parkinson's disease. Probiotics are live microbes, which are found in fermented foods, beverages, and cultured milk and, when administered in an adequate dose, confer health benefits to the host. They are known as "health-friendly bacteria", normally residing in the human gut and involved in maintaining homeostatic conditions. Imbalance in gut microbiota results in the pathophysiology of several diseases entailing the GIT tract, skin, immune system, inflammation, and gut-brain axis. Recently, the use of probiotics has gained tremendous interest, because of their profound effects on the management of these disease conditions. Recent findings suggest that probiotics enrichment in different human and mouse disease models showed promising beneficial effects and results in the amelioration of disease symptoms. Thus, this review focuses on the current probiotics-based products, different disease models, variable markers measured during trials, and evidence obtained from past studies on the use of probiotics in the prevention and treatment of different diseases, covering the skin to the central nervous system diseases.

Lactobacillus salivarius HHuMin-U Activates Innate Immune Defense against Norovirus Infection through TBK1-IRF3 and NF-κB Signaling Pathways

The composition of commensal bacteria plays a critical role in controlling immune responses in the intestine. Studies have shown that specific bacterial strains may have the capacity to enhance host immune defense against gastrointestinal viral infections. While norovirus is known to be the most common cause of gastroenteritis, leading to an estimated 200,000 deaths every year, identification of bacterial strains with protective effects against norovirus infection remains elusive. Here, we discovered Lactobacillus salivarius HHuMin-U (HHuMin-U) as a potent antiviral strain against norovirus infection. HHuMin-U significantly suppressed murine norovirus replication and lowered viral RNA titers in macrophages. The transcriptome sequencing (RNA sequencing) analysis revealed that HHuMin-U markedly enhanced the expression level of antiviral interferon-stimulated genes compared to mock treatment. HHuMin-U treatment dose-dependently induced type I interferons (IFN-α and IFN-β) and tumor necrosis factor-α production in mouse and human macrophages, promoting antiviral innate responses against norovirus infection. Investigation on the molecular mechanism demonstrated that HHuMin-U can activate nuclear factor κB and TANK-binding kinase 1 (TBK1)-interferon regulatory factor 3 signaling pathways, leading to the phosphorylation of signal transducer and activator of transcription 1 and signal transducer and activator of transcription 2, the key mediators of interferon-stimulated genes. Finally, oral administration of HHuMin-U increased IFN-β levels in the ileum of mice and altered the gut microbiome profile. These results suggest the species/strain-specific importance of gut microbial composition for antiviral immune responses and the potential use of HHuMin-U as a probiotic agent.

Reduction of Pathogens in Feces and Lymph Nodes Collected from Beef Cattle Fed Lactobacillus salivarius (L28), Lactobacillus acidophilus (NP51) and Propionibacterium freudenreichii (NP28), Commercially Available Direct-Fed Microbials

The purpose of the study was to evaluate the prevalence and concentration of foodborne pathogens in the feces and peripheral lymph nodes (PLNs) of beef cattle when supplemented with direct-fed microbials (DFMs) in feedlots. Fecal samples were collected from the pen floors over a 5-month period at three different feedlots in a similar geographical location in Nebraska, where each feed yard represented a treatment group: (i.) control: no supplement, (ii.) Bovamine Defend: supplemented with NP51 and NP24 at a target dose of 9 log₁₀CFU/g/head/day, and (iii.) Probicon: supplemented with L28 at a target dose of 6 log₁₀CFU/g/head/day. Each fecal sample was tested for the prevalence of E. coli O157:H7 and Salmonella, and concentration of E. coli O157:H7, Enterobacteriaceae and Clostridium perfringens. Cattle were harvested and PLNs were collected on the harvest floor. Real-time Salmonella PCR assays were performed for each PLN sample to determine Salmonella presence. The cattle supplemented with both DFMs had reduced foodborne pathogens in fecal samples, but feces collected from the pens housing the cattle supplemented with Probicon consistently had significantly less E. coli O157:H7 and Salmonella prevalence as well as a lower C. perfringens concentration. While DFMs do not eliminate foodborne pathogens in fecal shedding and PLNs, the use of DFMs as a pre-harvest intervention allows for an effective way to target multiple pathogens reducing the public health risks and environmental dissemination from cattle.

Safety assessment and characterisation of Ligilactobacillus salivarius PS21603 as potential feed additive for swine

The present study aimed to characterise in vitro properties of the strain Ligilactobacillus salivarius PS21603 and evaluate in vivo piglets’ tolerance for its use as feed additive in swine. The ability of L. salivarius PS21603 of inhibiting enteropathogens’ growth in vitro was evaluated using a co-culture assay. Low pH tolerance, bile tolerance, and resistance to osmotic changes were evaluated. The antibiotic susceptibility profile of L. salivarius PS21603 was assessed through broth microdilution method. Whole genome sequencing (WGS) was performed to exclude the presence of antibiotic resistance genes. L. salivarius PS21603 showed a high antimicrobial activity in vitro, reducing in a mean of 6.16 log cfu/ml eight different enterotoxigenic Escherichia coli strains. Moreover, L. salivarius PS21603 showed resistance to osmotic changes and was able to survive to a pH above 3.5 during 24 h and up to pH 2 at least during 2 h. In addition, WGS revealed that L. salivarius PS21603 did not harbour any resistance genes and thus there was no risk of transmissibility. Finally, an in vivo 28-days safety and tolerance study was performed. For that, 384 healthy piglets (28±2 days old and 7.5±1.5 kg, at weaning) were divided into three treatment groups receiving a different dose of L. salivarius PS21603: T1, 109 cfu/day; T2, 107 cfu/day; T3, control. Piglet’s health status was daily controlled. Individual bodyweight and feed intake per pen were weekly recorded to determine performance parameters. Blood samples were collected in 16 piglets from each treatment group on days 0 and 28 for determination of cytokine profiles. L. salivarius PS21603 was safe and well tolerated by piglets, there were no differences in performance nor cytokine profile between treatment groups. In conclusion, L. salivarius PS21603 is a potential candidate for a probiotic prevention strategy against pig diarrhoea.

Effects of Dietary Pectin and Lactobacillus salivarius ATCC 11741 on Growth Performance, Immunocompetence, Gut Microbiota, Antioxidant Capacity, and Disease Resistance in Narrow-Clawed Crayfish, Postantacus leptodactylus

The present study was conducted to clarify the effects of Lactobacillus salivarius (LS) ATCC 11741 and pectin (PE) on growth performance, digestive enzymes activity, gut microbiota composition, immune parameters, antioxidant defense as well as disease resistance against Aeromonas hydrophila in narrow-clawed crayfish, Postantacus leptodactylus. During 18 weeks trial feeding, 525 narrow-clawed crayfish juvenile (8.07 ± 0.1 g) fed with seven experimental diets including control (basal diet), LS1 (1 × 10⁷ CFU/g), LS2 (1 × 109 CFU/g), PE1 (5 g/kg), PE2 (10 g/kg), LS1PE1 (1 × 10⁷ CFU/g +5 g/kg), and LS2PE2 (1 × 109 CFU/g +10 g/kg). After 18 weeks, growth parameters (final weight, weight gain, and specific growth rate) and feed conversion rate were significantly improved in all treatments (P < 0.05). Besides, diets incorporated with LS1PE1 and LS2PE2 significantly increased the activity of amylase and protease enzymes compared to LS1, LS2, and control groups (P < 0.05). Microbiological analyses revealed that the total heterotrophic bacteria count (TVC) and lactic acid bacteria (LAB) of narrow-clawed crayfish fed diets containing LS1, LS2, LS1PE1, and LS2PE2 were higher than control group. The highest total haemocyte count (THC), large-granular (LGC) and semigranular cells (SGC) count, and hyaline count (HC) was obtained in LS1PE1 (P < 0.05). Similarly, higher immunity activity (lysozyme (LYZ), phenoloxidase (PO), nitroxidesynthetase (NOs), and alkaline phosphatase (AKP)) observed in the LS1PE1 treatment compared to the control group (P < 0.05). The glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity remarkably enhanced in LS1PE1 and LS2PE2, while malondialdehyde (MDA) content reduced in these two treatments. In addition, specimens belonging to LS1, LS2, PE2, LS1PE1, and LS2PE2 groups presented higher resistance against A. hydrophila compared to the control group. In conclusion, feeding narrow-clawed crayfish with synbiotic had higher efficiency on growth parameters, immunocompetence, and disease resistance compared to single consumption of prebiotics and probiotics.

Toxicokinetics and toxicodynamics of plastic and metallic nanoparticles: A comparative study in shrimp

Nanoplastic is recognized as an emerging environmental pollutant due to the anticipated ubiquitous distribution, increasing concentration in the ocean, and potential adverse health effects. While our understanding of the ecological impacts of nanoplastics is still limited, we benefit from relatively rich toxicological studies on other nanoparticles such as nano metal oxides. However, the similarity and difference in the toxicokinetic and toxicodynamic aspects of plastic and metallic nanoparticles remain largely unknown. In this study, juvenile Pacific white shrimp Litopenaeus vannamei was exposed to two types of nanoparticles at environmentally relative low and high concentrations, i.e., 100 nm polystyrene nanoplastics (nano-PS) and titanium dioxide nanoparticles (nano-TiO₂) via dietary exposure for 28 days. The systematic toxicological evaluation aimed to quantitatively compare the accumulation, excretion, and toxic effects of nano-PS and nano-TiO₂. Our results demonstrated that both nanoparticles were ingested by L. vannamei with lower egestion of nano-TiO₂ than nano-PS. Both nanoparticles inhibited the growth of shrimps, damaged tissue structures of the intestine and hepatopancreas, disrupted expression of immune-related genes, and induced intestinal microbiota dysbiosis. Nano-PS exposure caused proliferative cells in the intestinal tissue, and the disturbance to the intestinal microbes was also more serious than that of nano-TiO₂. The results indicated that the effect of nano-PS on the intestinal tissue of L. vannamei was more severe than that of nano-TiO₂ with the same particle size. The study provides new theoretical basis of the similarity and differences of their toxicity, and highlights the current lack of knowledge on various aspects of absorption, distribution, metabolism, and excretion (ADME) pathways of nanoplastics.

Whole genome analysis of host-associated lactobacillus salivarius and the effects on hepatic antioxidant enzymes and gut microorganisms of Sinocyclocheilus grahami

As a fish unique to Yunnan Province in China, Sinocyclocheilus grahami hosts abundant potential probiotic resources in its intestinal tract. However, the genomic characteristics of the probiotic potential bacteria in its intestine and their effects on S. grahami have not yet been established. In this study, we investigated the functional genomics and host response of a strain, Lactobacillus salivarius S01, isolated from the intestine of S. grahami (bred in captivity). The results revealed that the total length of the genome was 1,737,623 bp (GC content, 33.09%), comprised of 1895 genes, including 22 rRNA operons and 78 transfer RNA genes. Three clusters of antibacterial substances related genes were identified using antiSMASH and BAGEL4 database predictions. In addition, manual examination confirmed the presence of functional genes related to stress resistance, adhesion, immunity, and other genes responsible for probiotic potential in the genome of L. salivarius S01. Subsequently, the probiotic effect of L. salivarius S01 was investigated in vivo by feeding S. grahami a diet with bacterial supplementation. The results showed that potential probiotic supplementation increased the activity of antioxidant enzymes (SOD, CAT, and POD) in the hepar and reduced oxidative damage (MDA). Furthermore, the gut microbial community and diversity of S. grahami from different treatment groups were compared using high-throughput sequencing. The diversity index of the gut microbial community in the group supplemented with potential probiotics was higher than that in the control group, indicating that supplementation with potential probiotics increased gut microbial diversity. At the phylum level, the abundance of Proteobacteria decreased with potential probiotic supplementation, while the abundance of Firmicutes, Actinobacteriota, and Bacteroidota increased. At the genus level, there was a decrease in the abundance of the pathogenic bacterium Aeromonas and an increase in the abundance of the potential probiotic bacterium Bifidobacterium. The results of this study suggest that L. salivarius S01 is a promising potential probiotic candidate that provides multiple benefits for the microbiome of S. grahami.

Biomarkers for monitoring the equine large intestinal inflammatory response to stress-induced dysbiosis and probiotic supplementation

Large intestine barrier disturbances can have serious consequences for the health of horses. The loss of mucosal integrity that leads to increased intestinal permeability may result from a local inflammatory immune response following alterations of the microbiota, known as dysbiosis. Therefore, our research aimed to identify noninvasive biomarkers for studying the intestinal permeability and the local inflammatory immune response in horses. Regarding the biomarkers used in other mammalian species, we measured the concentrations of lipopolysaccharides (LPS), reflected by 3-OH C14, C16, and C18 fatty acids, in blood, and fecal secretory immunoglobulin-A (SIgA). These biomarkers were evaluated in two trials including 9 and 12 healthy horses, which developed large intestinal dysbiosis experimentally induced by 5 d of antibiotic administration (trimethoprim sulfadiazine [TMS]) or 5 d of abrupt introduction of high starch levels (barley) into the diet. Horses were either control or supplemented with Lactobacillus acidophilus, Ligilactobacillus salivarius, and Bifidobacterium lactis. Correlations were performed between biomarkers and fecal bacterial diversity, composition, and function. No significant interaction between day and supplementation, or supplementation effect were observed for each biomarker. However, with the dietary stressor, a significant increase in blood concentrations of 3-OH C16 (P = 0.0125) and C14 (P = 0.0252) fatty acids was measured 2 d after the cessation of barley administration. Furthermore, with the antibiotic stressor, blood levels of 3-OH C16 progressively increased (P = 0.0114) from the first day to 2 d after the end of TMS administration. No significant day effect was observed for fecal SIgA concentrations for both stressors. These results indicate that both antibiotic- and diet-induced dysbiosis resulted in a local translocation of LPS 2 d after the cessation of the stressor treatments, suggesting an impairment of intestinal permeability, without detectable local inflammation. Blood LPS and fecal SIgA concentrations were significantly correlated with several bacterial variations in the large intestine, which are features of antibiotic- and diet-induced dysbiosis. These findings support the hypothesis that a relationship exists between dysbiosis and the loss of mucosal integrity in the large intestine of horses.

Characterizing the chicken gut colonization ability of a diverse group of bacteria

The development of probiotics for chickens is a rapidly expanding field. The main approach to probiotics is to administer the probiotic strain throughout the bird's life, usually through incorporation in the feed. However, probiotics which would utilize bacterial strains capable of permanently colonizing the gut after a single exposure are likely to have a greater impact on the developing gut community as well as on the host, would simplify probiotic use and also reduce costs in an industrial setting. Finally, very limited and conflicting information about the colonization ability of different bacterial strains has been reported. Here we report 2 colonization experiments using 14 different bacterial strains from diverse phylogenetic groups. In both experiments, groups of chicks were orally inoculated on the day of hatch with different bacterial strains that had been previously isolated from adult heavy breeders. In the first experiment, colonization of the bacterial strains in broiler chicks was determined 7 d after treatment. In the second experiment, colonization was followed in layer chicks until d 17. Ten of the bacterial strains, including Lactobacillales and Bacteroidales strains, were able to colonize chicks after a single exposure for the duration of the experiment. For a few of these strains, exposure had little effect compared to non-treated chicks due to natural background colonization. Only 4 strains failed to colonize the chicks. Moreover, it is shown that fecal samples are useful to identify and provide a dynamic view of colonization. We further analyzed the effects of artificial colonization on microbiota composition. Some of the strains used in this research were found to reduce Enterobacteriaceae family abundance, implying that they might be useful in reducing relevant pathogen levels. To conclude, our results show that the development of single exposure based probiotics is possible.

Characterization of an MDR Lactobacillus salivarius isolate harbouring the phenicol-oxazolidinone-tetracycline resistance gene poxtA

OBJECTIVES

To characterize the oxazolidinone resistance gene poxtA in a Lactobacillus salivarius isolate of pig origin.

METHODS

L. salivarius isolate BNS11 was investigated for the presence of mobile oxazolidinone resistance genes by PCR. Antimicrobial susceptibility testing was performed by broth microdilution. Transfer experiments were conducted to assess horizontal transferability of the gene poxtA. WGS was carried out using a combination of Oxford Nanopore MinION/Illumina HiSeq platforms. The presence of translocatable units (TUs) carrying resistance genes was studied by PCR assays and subsequent sequence analysis.

RESULTS

L. salivarius isolate BNS11 was positive for poxtA. WGS showed that it harboured two gene copies each of the poxtA and the fexB genes, which were located on the broad-host-range Inc18 plasmid pBNS11-37kb and in the chromosomal DNA, respectively. The plasmid-borne poxtA gene together with the genes fexB, vat(E) and erm(C) were located in an MDR region on plasmid pBNS11-37kb. Analysis of the genetic context showed that an approx. 11 kb poxtA-fexB fragment was integrated into the chromosomal DNA and two novel IS elements ISLasa1 and ISLasa2 were identified in this inserted fragment. PCR assays revealed that five different IS1216E-based TUs carrying the resistance genes poxtA, fexB, vat(E) or erm(C) were formed.

CONCLUSIONS

To the best of our knowledge, this is the first report of the transferable oxazolidinone resistance gene poxtA in the genus Lactobacillus. In addition, the presence of IS1216E-based TUs will contribute to the persistence and accelerate the dissemination of resistance genes, including poxtA.

Ligilactobacillus salivarius functionalities, applications, and manufacturing challenges

Ligilactobacillus salivarius is a lactic acid bacteria that has been gaining attention as a promising probiotic. Numerous strains exhibit functional properties with health benefits such as antimicrobial activity, immunological effects, and the ability to modulate the intestinal microbiota. However, just a small number of them are manufactured at an industrial scale and included in commercial products. The under exploitation of L. salivarius strains that remain in the freezer of companies is due to their incapacity to overcome the environmental stresses induced by production and stabilization processes.The present study summarizes the functionalities and applications of L. salivarius reported to date. It aims also at providing a critical evaluation of the literature available on the manufacturing steps of L. salivarius concentrates, the bacterial quality after each step of the process, and the putative degradation and preservation mechanisms. Here, we highlight the principal issues and future research challenges for improving the production and long-term preservation at the industrial scale of this microorganism, and probably of other probiotics.Key points• L. salivarius beneficial properties and commercialized products.• Production conditions and viability of L. salivarius after stabilization processes.• Prospects for identifying preservation mechanisms to improve L. salivarius stability.

A New Formulation of Probiotics Attenuates Calcipotriol-Induced Dermatitis by Inducing Regulatory Dendritic Cells

Atopic dermatitis (AD) is a recurrent chronic inflammatory skin disease affecting up to 30% of the children population, and immuno-regulatory therapy that could modify the course of disease is urgently needed. Probiotics have demonstrated therapeutic effects on AD and could potentially regulate the disease process. However, the efficacy of probiotics for AD is inconsistent among different studies, which is mainly due to the elusive mechanism and different species and (or) strains used. In this study, we designed a mixture of five strains of probiotics (named IW5) and analyzed the effect and mechanism of IW5 on calcipotriol (MC903)-induced AD-like dermatitis. We found that IW5 significantly alleviated skin inflammation of the MC903-induced AD in mice. Administration with IW5 induced increased production of regulatory T cells and regulatory dendritic cells (DCregs) in the mesenteric lymph nodes. We also found that the diversity of the gut microbiota in the mice with MC903-induced dermatitis was increased after IW5 administration, and the level of butyrate in the gut was elevated. In cell culture, butyrate induced the production of DCregs. Our study revealed the therapeutic effects of a newly designed probiotics mixture and uncovered a possible mechanism, providing a foundation for future clinical studies.

The Role of Short-Chain Fatty Acids in Mediating Very Low-Calorie Ketogenic Diet-Infant Gut Microbiota Relationships and Its Therapeutic Potential in Obesity

As the very low-calorie ketogenic diet (VLCKD) gains increased interest as a therapeutic approach for many diseases, little is known about its therapeutic use in childhood obesity. Indeed, the role of VLCKD during pregnancy and lactation in influencing short chain fatty acid (SCFA)-producing bacteria and the potential mechanisms involved in the protective effects on obesity are still unclear. Infants are characterized by a diverse gut microbiota composition with higher abundance of SCFA-producing bacteria. Maternal VLCKD during pregnancy and lactation stimulates the growth of diverse species of SCFA-producing bacteria, which may induce epigenetic changes in infant obese gene expression and modulate adipose tissue inflammation in obesity. Therefore, this review aims to determine the mechanistic role of SCFAs in mediating VLCKD-infant gut microbiota relationships and its protective effects on obesity.

The Recent Trend in the Use of Multistrain Probiotics in Livestock Production: An Overview

It has been established that introducing feed additives to livestock, either nutritional or non-nutritional, is beneficial in manipulating the microbial ecosystem to maintain a balance in the gut microbes and thereby improving nutrient utilization, productivity, and health status of animals. Probiotic use has gained popularity in the livestock industry, especially since antimicrobial growth promoter's use has been restricted due to the challenge of antibiotic resistance in both animals and consumers of animal products. Their usage has been linked to intestinal microbial balance and improved performance in administered animals. Even though monostrain probiotics could be beneficial, multistrain probiotics containing two or more species or strains have gained considerable attention. Combining different strains has presumably achieved several health benefits over single strains due to individual isolates' addition and positive synergistic adhesion effects on animal health and performance. However, there has been inconsistency in the effects of the probiotic complexes in literature. This review discusses multistrain probiotics, summarizes selected literature on their effects on ruminants, poultry, and swine productivity and the various modes by which they function.

Screening of Lactic Acid Bacterial Strains with Antiviral Activity Against Porcine Epidemic Diarrhea

Newly emerging and re-emerging viral infectious diseases cause significant economic losses in swine production. Efficacious vaccines have not yet been developed for several major swine infectious diseases, including porcine epidemic diarrhea virus (PEDV). We used the PEDV-infected Vero cell model to screen lactic acid bacteria (LAB) strains with antiviral activity. Sixty LAB strains were isolated from the feces of nursing piglets. After the elimination of LAB strains with high cytotoxicity to Vero cells, the protective effects of the remaining 6 strains against PEDV infection were determined. Vero cells pretreated with the intracellular extracts or cell wall fractions of YM22 and YM33 strains for 24 h before infection with PEDV showed significantly higher cell viabilities and lower mRNA expression of PEDV nucleocapsid (PEDV-N) than the unpretreated cells, indicating that the intracellular extracts and cell wall fractions of YM22 and YM33 possessed prophylactic effects on Vero cells against PEDV infection. PEDV-infection significantly increased the mRNA expression of proinflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) in Vero cells. However, pretreatment of Vero cells with the cell wall fractions of YM22 and YM33 decreased the mRNA expression of TNF-α and IL-8, which could be a mechanism associated with the protective effects of YM22 and YM33 against PEDV. Based on the biochemical characteristics and phylogenetic analyses, YM22 and YM33 were identified as Ligilactobacillus agilis (basonym: Lactobacillus agilis) and Ligilactobacillus salivarius (basonym: Lactobacillus salivarius), respectively. These findings suggest that L. agilis YM22 and L. salivarius YM33 could provide some levels of protective effects against PEDV infections.

Probiotic biomarkers and models upside down: From humans to animals

Probiotics development for animal farming implies thorough testing of a vast variety of properties, including adhesion, toxicity, host cells signaling modulation, and immune effects. Being diverse, these properties are often tested individually and using separate biological models, with great emphasis on the host organism. Although being precise, this approach is cost-ineffective, limits the probiotics screening throughput and lacks informativeness due to the 'one model - one test - one property' principle. There is а solution coming from human-derived cells and in vitro systems, an extraordinary example of human models serving animal research. In the present review, we focus on the current outlooks of employing human-derived in vitro biological models in probiotics development for animal applications, examples of such studies and the analysis of concordance between these models and host-derived in vivo data. In our opinion, human-cells derived screening systems allow to test several probiotic properties at once with reasonable precision, great informativeness and less expenses and labor effort.

Impact of oral galenic formulations of Lactobacillus salivarius on probiotic survival and interactions with microbiota in human in vitro gut models

Health benefits of probiotics in humans essentially depend on their ability to survive during gastrointestinal (GI) transit and to modulate gut microbiota. To date, there is few data on the impact of galenic formulations of probiotics on these parameters. Even if clinical studies remain the gold standard to evaluate the efficacy of galenic forms, they stay hampered by technical, ethical and cost reasons. As an alternative approach, we used two complementary in vitro models of the human gut, the TNO gastrointestinal (TIM-1) model and the Artificial Colon (ARCOL), to study the effect of three oral formulations of a Lactobacillus salivarius strain (powder, capsule and sustained-release tablet) on its viability and interactions with gut microbiota. In the TIM-1 stomach, no or low numbers of bacteria were respectively released from the capsule and tablet, confirming their gastro-resistance. The capsule was disintegrated in the jejunum on average 76 min after administration while the core of sustained-release tablet was still intact at the end of digestion. Viability in TIM-1 was significantly influenced by the galenic form with survival percentages of 0.003±0.004%, 2.8±0.6% and 17.0±1.8% (n=3) for powder, capsule and tablet, respectively. In the ARCOL, the survival of the strain tended to be higher in the post-treatment phase with the tablet compared to capsule, but gut microbiota composition and activity were not differently modulated by the two formulations. In conclusion, the sustained-release tablet emerged as the formulation that most effectively preserved viability of the tested strain during GI passage. This study highlights the usefulness of in vitro gut models for the pre-screening of probiotic pharmaceutical forms. Their use could also easily be extended to the evaluation of the effects of food matrices and age on probiotic survival and activity during GI transit.

Protective Action of L. salivarius SGL03 and Lactoferrin against COVID-19 Infections in Human Nasopharynx

In this study, we used live viral particles from oral secretions from 17 people infected with SARS-CoV-2 and from 17 healthy volunteers, which were plated on a suitable medium complete for all microorganisms and minimal for L.salivarius growth. Both types of media also contained an appropriately prepared vector system pGEM-5Zf (+) based on the lactose operon (beta-galactosidase system). Incubation was carried out on both types of media for 24 h with the addition of 200 μL of Salistat SGL03 solution in order to test its inhibitory effect on the coronavirus contained in the oral mucosa and nasopharynx, visible as light blue virus particles on the test plates, which gradually disappeared in the material collected from infected persons over time. Regardless of the conducted experiments, swabs were additionally taken from the nasopharynx of infected and healthy people after rinsing the throat and oral mucosa with Salistat SGL03. In both types of experiments, after 24 h of incubation on appropriate media with biological material, we did not find any virus particles. Results were also confirmed by MIC and MBC tests. Results prove that lactoferrin, as one of the ingredients of the preparation, is probably a factor that blocks the attachment of virus particles to the host cells, determining its anti-viral properties. The conducted preliminary experiments constitute a very promising model for further research on the anti-viral properties of the ingredients contained in the Salistat SGL03 dietary supplement.

Baicalin-Aluminum Modulates the Broiler Gut Microbiome

Baicalin-aluminum regulates the gut microbiome of piglets with diarrhea. However, whether it affects poultry gut microbiome composition and function remains unknown. In this study, we used metagenomic sequencing to explore the effects of baicalin-aluminum on gut microbiome changes in poultry when compared with animals administered colistin sulfate. Our data showed that important gut microbiome components consisted of Ruminococcaceae, Subdoligranulum, Bifidobacterium, Bifidobacterium pseudolongum, and Pseudoflavonifractor when broilers were administered baicalin-aluminum compared with colistin. At the species level, Lactobacillus salivarius, Bacteroides uniformis, Oscillibacter unclassified, Bacteroides fragilis, Ruminococcus torques, and Subdoligranulum unclassified abundance were significantly upregulated upon baicalin-aluminum treatment when compared with colistin administration. In addition, Gene Ontology (GO) enrichment analysis indicated that functional differentially expressed genes, which were in the top 30 GO enrichment terms, were associated with metabolic processes, catalytic activity, and cellular processes. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that ABC transporters, oxidative phosphorylation, and phosphotransferase systems were the dominant signaling pathways in the baicalin-aluminum group when compared with the colistin group. Taken together, our data indicated that baicalin-aluminum modified broiler gut microbiome composition. These observations enhance our physiological insights of baicalin-aluminum-mediated functions in the broiler microbiome and potentially provide a novel therapy to manage both animal and human health.

Zearalenone Adsorbent Based on a Lyophilized Indigenous Bacterial Lactobacillus plantarum Strain as Feed Additive for Pigs: A Preliminary Study In Vivo

Feed contamination with naturally occurring mycotoxins is an unavoidable condition of significant concern in intensive productions. The presence of high concentrations of zearalenone >1 ppm in the diet can cause major reproductive disorders, particularly in swine. In order to reduce the consequences of intoxication, mycotoxin adsorbents are incorporated into feed. In the present study, zearalenone adsorption capacity of a lyophilized indigenous strain of Lactobacillus plantarum (L4; previously isolated from pig's rectal swabs) was first evaluated in vitro. A preliminary study in vivo was then performed in which the indigenous Lactobacillus plantarum strain was lyophilized and the powder obtained (L-L4) was incorporated into the diet of gilts two gilts received basal diet (control) and two received basal diet containing 2 g/kg L-L4 (treated). After an adaptation period, all the feed was contaminated with zearalenone at a dose of 0.93 mg ZEA/kg. Results from in vitro assay showed that L-L4 adsorbed 87.9% (SD 3.97) of zearalenone in 0.9% NaCl solution. In the in vivo exploratory study, higher daily weight gain and lower vulva area were observed in gilts that incorporated L-L4 to the diet. Additionally, higher zearalenone concentrations were eliminated in faeces from treated animals. The use of a product based on a lyophilized indigenous Lactobacillus strain to protect gilts from detrimental effects of zearalenone consumption has shown promising results so far. However, further studies are required in order to accurately assess its impact and evaluate doses according to different degrees of mycotoxins contamination.

The Influence of Diet on Oxidative Stress and Inflammation Induced by Bacterial Biofilms in the Human Oral Cavity

The article is a concise compendium of knowledge on the etiology of pathogenic microorganisms of all complexes causing oral diseases. The influence of particular components of the diet and the role of oxidative stress in periodontal diseases were described. The study investigated the bacteriostatic effect of the diet of adults in in vivo and in vitro tests on the formation of bacterial biofilms living in the subgingival plaque, causing diseases called periodontitis. If left untreated, periodontitis can damage the gums and alveolar bones. Anaerobic bacteria, called periopathogens or periodontopathogens, play a key role in the etiopathogenesis of periodontitis. The most important periopathogens of the oral microbiota are bacteria of all complexes, including the red complex. The obtained results suggest the possibility of using a specific diet in the prevention and treatment of periodontal diseases-already treated as a disease of civilization. The quoted article is an innovative compilation of knowledge on this subject and it can be a valuable source of knowledge for professional hygienists, dentists, peridontologists, dentistry students and anyone who cares about proper oral hygiene. The obtained results suggest the possibility of using this type of diet in the prophylaxis of the oral cavity in order to avoid periodontitis.

Impact of the Diet on the Formation of Oxidative Stress and Inflammation Induced by Bacterial Biofilm in the Oral Cavity

The diet is related to the diversity of bacteria in the oral cavity, and the less diverse microbiota of the oral cavity may favor the growth of pathogenic bacteria of all bacterial complexes. Literature data indicate that disturbances in the balance of the bacterial flora of the oral cavity seem to contribute to both oral diseases, including periodontitis, and systemic diseases. If left untreated, periodontitis can damage the gums and alveolar bones. Improper modern eating habits have an impact on the oral microbiome and the gut microbiome, which increase the risk of several chronic diseases, including inflammatory bowel disease, obesity, type 2 diabetes, cardiovascular disease and cancer. The subject of our consideration is the influence of the traditional diet on the formation of oxidative stress and inflammation caused by bacterial biofilm in the oral cavity. Through dental, biomedical and laboratory studies, we wanted to investigate the effect of individual nutrients contained in specific diets on the induction of oxidative stress inducing inflammation of the soft tissues in the oral cavity in the presence of residual supra- and subgingival biofilm. In our research we used different types of diets marked as W, T, B, F and noninvasively collected biological material in the form of bacterial inoculum from volunteers. The analyzed material was grown on complete and selective media against specific strains of all bacterial complexes. Additionally, the zones of growth inhibition were analyzed based on the disc diffusion method. The research was supplemented with dental and periodontological indicators. The research was supplemented by the application of molecular biology methods related to bacterial DNA isolation, PCR reactions and sequencing. Such selected methods constitute an ideal screening test for the analysis of oral bacterial microbiota. The obtained results suggest that certain types of diet can be an effective prophylaxis in the treatment of civilization diseases such as inflammation of the oral cavity along with periodontal tissues and gingival pockets.

The use of probiotics in animal feeding for safe production and as potential alternatives to antibiotics

Although the production of safe food for human consumption is the primary purpose for animal rearing, the environment and well-being of the animals must also be taken into consideration. Based on microbiological point of view, the production of healthy food from animals involves considering foodborne pathogens, on the one hand and on the other hand, the methods used to fight against germs during breeding. The conventional method to control or prevent bacterial infections in farming is the use antibiotics. However, the banning of these compounds as growth promoters caused many changes in animal breeding and their use has since been limited to the treatment and prevention of bacterial infections. In this function, their importance no longer needs to be demonstrated, but unfortunately, their excessive and abusive use have led to a double problem which can have harmful consequences on consumer health: Resistance to antibiotics and the presence of antibiotic residues in food. The use of probiotics appears to be a suitable alternative to overcome these problems because of their ability to modulate the immune system and intestinal microflora, and further considering their antagonistic role against certain pathogenic bacteria and their ability to play the role of growth factor (sometimes associated with prebiotics) when used as feed additives. This review aims to highlight some of the negative effects of the use of antibiotics in animal rearing as well as emphasize the current knowledge on the use of probiotics as a feed additive, their influence on animal production and their potential utility as an alternative to conventional antibiotics, particularly in poultry, pig, and fish farming.

Nanoplastics impair the intestinal health of the juvenile large yellow croaker Larimichthys crocea

Microplastics (MPs) have become a severe concern in marine environment worldwide. Micro-polystyrene particles have been proved to accumulate in vivo and caused disorders of digestion, antioxidant system, immunity and intestinal microflora, but little is known about the effects of nano-polystyrene (nano-PS). In order to understand response mechanism of marine fish to nano-PS, the effects of nanoplastics on the intestinal health and growth performance of the juvenile Larimichthys crocea were investigated. After 14-d exposure, the reduced digestive enzyme activities indicated that nano-PS had a negative impact on the digestion and absorption of juvenile fish. Moreover, analysis of the intestinal microbiota showed that the proportion of the three-dominant bacterial phyla (Bacteroidetes, Proteobacteria and Firmicutes) in the gut changed significantly, accompanied by a significant increase of potentially pathogenic bacteria (Parabacteroides and Alistipes). In addition, lysozyme activity and specific growth rate (SGR) were significantly reduced, and total mortality of juvenile fish was significantly increased. Overall, nano-PS exposure was harmful for the health of juvenile fish, which might threaten their population in the long term.

Effect of Ligilactobacillus salivarius and Other Natural Components against Anaerobic Periodontal Bacteria

In this present study, the bacteriostatic effect of Salistat SGL03 and the Lactobacillus salivarius strain contained in it was investigated in adults in in vivo and in vitro tests on selected red complex bacteria living in the subgingival plaque, inducing a disease called periodontitis, i.e., chronic periodontitis. Untreated periodontitis can lead to the destruction of the gums, root cementum, periodontium, and alveolar bone. Anaerobic bacteria, called periopathogens or periodontopathogens, play a key role in the etiopathogenesis of periodontitis. The most important periopathogens of the oral microbiota are: Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola and others. Our hypothesis was verified by taking swabs of scrapings from the surface of the teeth of female hygienists (volunteers) on full and selective growth media for L. salivarius. The sizes of the zones of growth inhibition of periopathogens on the media were measured before (in vitro) and after consumption (in vivo) of Salistat SGL03, based on the disk diffusion method, which is one of the methods of testing antibiotic resistance and drug susceptibility of pathogenic microorganisms. Additionally, each of the periopathogens analyzed by the reduction inoculation method, was treated with L. salivarius contained in the SGL03 preparation and incubated together in Petri dishes. The bacteriostatic activity of SGL03 preparation in selected periopathogens was also analyzed using the minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) tests. The obtained results suggest the possibility of using the Salistat SGL03 dietary supplement in the prophylaxis and support of the treatment of periodontitis-already treated as a civilization disease.