Comprehensive approaches for assessing the safety of probiotic bacteria

Preclinical Safety Assessment of the Oral Administration of Lactobacillus plantarum GUANKE in Animal Models

Probiotics have a long history as fermented food or food supplements. The health benefits and safety profiles of probiotics are strain-specific and should be evaluated individually. The aim of this study was to assess the safety of the Lactobacillus plantarum GUANKE (GUANKE) strain by conducting pharmacological studies, oral toxicity assessments, and investigating the colonization and translocation of GUANKE in experimental animal models. Three pharmacological studies were conducted to examine the effects of oral administration of GUANKE on gastric emptying, bile secretion, and gastric juice secretion. In an acute toxicity study, rats were orally administrated with different doses of GUANKE and monitored for 14 days. In the subacute toxicity study, both rats and beagles were administrated with varying doses of GUANKE for 28 consecutive days to evaluate hematologic, biochemical, and histological effects. The results showed that GUANKE administration did not result in any adverse effect on hematological parameters, biochemical parameters, urinary parameters, and organ indices. Importantly, no translocation of GUANKE to extra-intestinal organs or blood was observed following administration of the CFDA-SE labeled strain. In summary, this study demonstrated the safety of GUANKE intake, which encourages its potential application as a probiotic in clinical trials.

Probiotic Characteristics and Whole Genome Analysis of Lactiplantibacillus plantarum PM8 from Giant Panda (Ailuropoda melanoleuca) Milk

Milk is a rich source of probiotics, particularly lactic acid bacteria (LAB), which have been shown to promote gut health, support the immune system, enhance digestion, and prevent pathogen colonization. This study aimed to isolate and identify LAB strains from giant panda (Ailuropoda melanoleuca) milk, evaluate their probiotic properties, and analyze the genomic characteristics of a promising strain. Thirteen LAB strains were isolated from 12 samples of giant panda milk. Among all LAB strains, Lactiplantibacillus plantarum PM8 (PM8) demonstrated probiotic properties and safety features. It exhibited strong growth performance, high antipathogenic activity against four pathogens, and strong survival rates under simulated gastrointestinal conditions. PM8 also showed excellent adhesion capabilities to Caco-2 cells. Additionally, safety assessment revealed no hemolysin production and minimal antibiotic resistance, making it a promising candidate for probiotic applications. The genome of PM8 consists of 3,227,035 bp with a GC content of 44.60% and contains 3171 coding sequences, including 113 carbohydrate-active enzyme genes and genes related to exopolysaccharides synthesis, vitamin B biosynthesis, adhesion, antioxidant activity, and bile salt hydrolysis. Notably, it contains genes involved in nonribosomally synthesized secondary metabolite and bacteriocin production. The genomic safety analysis confirmed that PM8 lacks the capacity to transmit bacterial antimicrobial resistance and is non-pathogenic to both humans and animals. These findings suggest that PM8 holds considerable potential for enhancing gut health and supporting the development of safe probiotic products.

Safety, Antagonistic Activity, and Probiotic Properties of Lactic Acid Bacteria Isolated from Jeotgal, Korean Fermented Seafoods

Probiotics are in high demand in the health functional food market as they effectively inhibit pathogens and improve host health. Therefore, in order to develop novel probiotic strains, new strains were isolated from various type of jeotgal, traditional Korean fermented seafood products, and their safety and probiotic properties have been evaluated. Based on 16S rRNA gene sequence analysis, six strains (JRD1, Pediococcus pentosaceus; JRD2, Lactiplantibacillus plantarum; JRD6, Pediococcus acidilactici; CLJ21, Lactiplantibacillus plantarum; CLJ24, Pediococcus pentosaceus; CLJ28, Leuconostoc mesenteroides subsp. dextranicum) were selected and subjected to further analysis. As a result, all six strains did not show hemolytic activity, antibiotics resistance, and cell cytotoxicity, confirming that they are safe for human use. Among them, JRD1, JRD6, and CLJ24 exhibited high survival rates under simulated gastrointestinal conditions. Additionally, these three strains demonstrated strong adhesion abilities on HT-29 cells, with values of 6.02, 5.77, and 5.86 log CFU/mL, respectively. Furthermore, JRD1, JRD6, and CLJ24 showed relatively high antagonistic activity against both Salmonella Typhimurium and Staphylococcus aureus through competition, exclusion, and displacement of their adhesion. Interestingly, cell-free supernatants (CFS) from three strains effectively inhibited the growth of both S. Typhimurium and S. aureus. Furthermore, CFS of CLJ24, JRD1, and JRD6 demonstrated anti-inflammatory effects in intestinal epithelial cells. The results suggest that CLJ24, JRD1, and JRD6 have potential to be development as functional probiotic strains with both antibacterial and anti-inflammatory activities.

Clinical and In Vitro Safety of Heyndrickxia coagulans AO 1167B: A Double-Blind, Placebo-Controlled Trial

(1) Background: Heyndrickxia coagulans, a lactic acid-producing bacterium, displays characteristics of both Lactobacillus and Bacillus genera. Clinical evidence suggests its potential health benefits. This study evaluated the safety of H. coagulans AO1167B as a candidate probiotic supplement. (2) Methods: Strain identification was confirmed through morphological, cultural, and genomic analyses, including 16S RNA and whole genome sequencing to assess antimicrobial resistance and virulence factors. Phenotypic tests, such as disk diffusion for antimicrobial resistance, and safety assays for cytotoxicity and hemolytic activity, were conducted. In a phase I, double-blind, placebo-controlled clinical trial, healthy adults were randomized into H. coagulans AO1167B and placebo groups for 60 days. Daily capsule consumption was monitored through clinical and hematological evaluations, adverse event tracking, and health surveys. (3) Results: The genome of H. coagulans AO1167B revealed no concerning features. Disk diffusion tests showed no antimicrobial resistance. The strain exhibited no cytotoxic or hemolytic activity, indicating in vitro safety. No significant differences in clinical or hematological parameters were observed between groups. The most common adverse event, gas, diminished over time. (4) Conclusions: H. coagulans AO1167B demonstrates a suitable safety profile, genetic stability, and probiotic potential for gastrointestinal health, justifying further clinical research.

Emerging antibiotic and heavy metal resistance in spore-forming bacteria from pig manure, manure slurry and fertilized soil

Spore-forming bacteria (SFB), like Bacillus, are the gram-positive bacteria with broad-spectrum activity that is one of the commonly used strains of probiotics. However, these bacteria also have significant resistance. In this study, we systematically investigated pig manure, manure slurry and soil by 16S rRNA high-throughput sequencing and traditional culture techniques. We found the SFB was widespread in manure, manure slurry and soil, Firmicutes was one of the main dominant phyla in pig manure, manure slurry and soil, the relative abundance of Bacillus were 0.98%, 0.01%, and 2.57%, respectively, and metals such as copper have complex relationships with bacteria. We isolated 504 SFB from 369 samples, with the highest number identified as Bacillus subtilis. SFB strains showed varying degrees of antibiotic resistance; the greatest against erythromycin, followed by imipenem. The MICs of SFB varied greatly against different heavy metals; with high (est) resistance against Zn2+, followed by Cu2+. Second-generation whole genome sequencing (WGS) revealed that nine Bacillus strains carried different subtypes of vancomycin resistance genes, among which vanRM had the highest frequency. The strain W129 included the vanRA-vanRM-vanSA-vanZF cluster. The nine Bacillus strains also contained antibiotic genes such as aminoglycoside (ant(9)-Ia), β-lactam (bcII), and macrolide (msrE). Twenty-six Bacillus isolates carried copper resistance clusters, including csoR-copZ, copA-copZ-csoR, and copZ-copA. WGS showed that strain W166 carried 11 vancomycin resistance genes and 11 copper resistance genes. There were 4 vancomycin resistance genes and 14 copper resistance genes on the W129 chromosome. Strain W129 also harbors the plasmid pLKYM01 that contains an intact transposon consisting of insertion sequence and vancomycin resistance genes vanYF and vanRA. This study explores the potential risks of using pig manure and fertilized soil to inform safe and effective use of probiotics in agriculture. It highlights scientific evidence for concern over the safe utilization and control of animal waste products.

Extensive genomic characterization, pre-clinical probiotic evaluation, and safety analysis of Bifidobacterium longum subsp. longum BL21 isolated from infant feces

OBJECTIVE

This study aimed to evaluate the safety and probiotic properties of Bifidobacterium longum subsp. longum BL21 isolated from infant feces for use as a commercial probiotic strain.

METHODS

Whole-genome sequencing; physiological and biochemical assessments; enzymatic assays; metabolite, antibiotic sensitivity, cell adhesion and cytotoxicity, and tolerance tests; and a 14-day oral toxicity study were conducted.

RESULTS

BL21 exhibited genetic integrity, and its genome lacked genes related to antibiotic resistance or virulence. It was found to be non-pathogenic, had efficient carbohydrate metabolism and mucin degradation ability, and was free from biogenic amines. It also showed susceptibility to antibiotics, strong cell adhesion, and resilience to adverse conditions. The aforementioned results confirm that BL21 is a functional probiotic strain with genetic stability, enzymatic capabilities, and non-pathogenic properties that mean it is safe for oral consumption, demonstrating that it is a promising candidate for probiotic applications.

CONCLUSION

The study demonstrates that BL21 is a genetically stable, non-pathogenic probiotic strain with metabolic potential. The strain lacks virulence and antibiotic resistance genes, and its resilience to gastrointestinal conditions, as well as the results of the 14-day oral toxicity study, suggest that BL21 is safe for oral consumption. However, further long-term studies and clinical trials are needed to confirm its safety and efficacy for therapeutic use.

Evaluation of a Burkholderia ambifaria strain from plants as a novel promising probiotic in dental caries management

Background

Probiotics serve as a novel preventive or therapeutic approach for dental caries owing to their ability to reverse dysbiosis and restore a healthy microbiota. Here, we identified Burkholderia ambifaria AFS098024 as a probiotic candidate isolated from plants.

Methods

The safety of B. ambifaria was evaluated by hemolytic activity, D-lactic acid production and antibiotic susceptibility. In vitro biofilm model derived from the saliva of caries-free and caries-active donors and in vivo rat caries model were used to assess the efficacy of B. ambifaria in caries prevention and treatment.

Results

B. ambifaria was safe as a probiotic candidate and it could integrate with in vitro biofilm model. It significantly reduced the biomass and lactate production of biofilms from caries-active donors and disrupted biofilm structures. B. ambifaria effectively reduced the severity of carious lesions in rat molars, regardless of the inoculation sequence. Molars pretreated or treated with B. ambifaria demonstrated notably higher enamel volumes. Additionally, colonization of rat molars by B. ambifaria persisted for 6 weeks.

Conclusion

The B. ambifaria strain used in this study holds promise as a probiotic for inhibiting dental caries, both in vitro and in vivo.

Screening for probiotic properties and potential immunogenic effects of lactobacilli strains isolated from various food products

Introduction

Deceleration of disease progression and re-establishment of microbial balance in the gut is often achieved by application of lactobacilli strains. Their beneficial effects are associated with probiotic properties, which may be accompanied by immunomodulatory action at mucosal surfaces.

Methods

To single out such strains, we screened almost three hundred lactobacilli isolates from eight genera and various food sources for acid and bile salt tolerance, adhesion to mucin as well as hemolytic activity and antibiotic susceptibility. Moreover, the immunomodulatory effects of cell-free supernatant (CFS) fractions of five lactobacilli strains were assessed using an in vitro cell line model.

Results and discussion

By our rationalized selection approach, we identified thirty-five strains with probiotic potential and biosafety features. Additionally, we showed that CFS from the Lactiplantibacillus L_4 strain downregulates proinflammatory cytokines IL-8 and IL-1β. In contrast, IL-8 expression was found to increase after treatment with CFSs of Lactiplantibacillus L_2 and L_5 and IL-1β was upregulated by CFSs of Lactiplantibacillus L_1 and Lactiplantibacillus L_3. Overall, our result delineate a rational approach of selecting lactobacilli strains for probiotic development to support the gut microbiota equilibrium and reinforce the host immune system.

Antibacterial Efficacy of Feline-Derived Lactic Acid Bacteria against Enteropathogenic Escherichia coli: A Comprehensive In Vitro Analysis

This study evaluated the antibacterial efficacy of 700 feline-derived lactic acid bacteria (LAB) strains against enteropathogenic Escherichia coli (EPEC), a common cause of diarrhea in cats. Following comprehensive screening, strains ZY25 and ZY35 were identified as the most effective, with inhibition zones of ≥22 mm. These strains demonstrated strong tolerance against stress conditions, such as low pH, bile salts, and gastrointestinal fluids, alongside high hydrophobicity and auto-aggregation abilities. Safety evaluations confirmed the absence of hemolytic activity, virulence factors, and antibiotic resistance genes. The antibacterial activity of these strains is attributed to the production of organic acids, particularly lactic acid and acetic acid. These findings suggest that strains ZY25 and ZY35 have potential as natural and effective probiotic treatments for managing EPEC-induced diarrhea in cats, thus offering an alternative to conventional antibiotics.

Unlocking the Potential of Probiotics: A Comprehensive Review on Research, Production, and Regulation of Probiotics

This review provides a comprehensive overview of the current state of probiotic research, covering a wide range of topics, including strain identification, functional characterization, preclinical and clinical evaluations, mechanisms of action, therapeutic applications, manufacturing considerations, and future directions. The screening process for potential probiotics involves phenotypic and genomic analysis to identify strains with health-promoting properties while excluding those with any factor that could be harmful to the host. In vitro assays for evaluating probiotic traits such as acid tolerance, bile metabolism, adhesion properties, and antimicrobial effects are described. The review highlights promising findings from in vivo studies on probiotic mitigation of inflammatory bowel diseases, chemotherapy-induced mucositis, dysbiosis, obesity, diabetes, and bone health, primarily through immunomodulation and modulation of the local microbiota in human and animal models. Clinical studies demonstrating beneficial modulation of metabolic diseases and human central nervous system function are also presented. Manufacturing processes significantly impact the growth, viability, and properties of probiotics, and the composition of the product matrix and supplementation with prebiotics or other strains can modify their effects. The lack of regulatory oversight raises concerns about the quality, safety, and labeling accuracy of commercial probiotics, particularly for vulnerable populations. Advancements in multi-omics approaches, especially probiogenomics, will provide a deeper understanding of the mechanisms behind probiotic functionality, allowing for personalized and targeted probiotic therapies. However, it is crucial to simultaneously focus on improving manufacturing practices, implementing quality control standards, and establishing regulatory oversight to ensure the safety and efficacy of probiotic products in the face of increasing therapeutic applications.

Inflammatory Modulation Effects of Probiotics: A Safe and Promising Modulator for Cancer Prevention

Chronic inflammation is the gate of many human illnesses and happens when the immune system is unable to suppress external attacks in the correct form. Nonetheless, the gut microbiome plays a pivotal role in keeping homeostasis in the human body and preventing inflammation. Imbalanced microbiota and many diseases can result in inflammation, which when not taken seriously, can be turned into chronic ones and ultimately lead to serious diseases such as cancer. One approach to maintaining hemostasis in the human body is consumption of probiotics as a supplement. Probiotics impact the immune functions of dendritic cells (DCs), T cells, and B cells in the gut-associated lymphoid tissue by inducing the secretion of an array of cytokines. They activate the innate immune response through their microbial-associated molecular pattern, and this activation is followed by multiple cytokine secretion and adaptive elicitation that mitigates pro-inflammatory expression levels and tumor incidence. Thus, according to several studies showing the benefit of probiotics application, alone or in combination with other agents, to induce potent immune responses in individuals against some inflammatory disorders and distinct types of cancers, this review is devoted to surveying the role of probiotics and the modulation of inflammation in some cancer models.

A Comprehensive Review of the Triangular Relationship among Diet-Gut Microbiota-Inflammation

The human gastrointestinal tract hosts a complex and dynamic community of microorganisms known as the gut microbiota, which play a pivotal role in numerous physiological processes, including digestion, metabolism, and immune function. Recent research has highlighted the significant impact of diet on the gut microbiota composition and functionality, and the consequential effects on host health. Concurrently, there is growing evidence linking the gut microbiota to inflammation, a key factor in many chronic diseases such as inflammatory bowel disease (IBD), obesity, diabetes, and cardiovascular diseases (CVDs). This review explores how dietary components influence the gut microbiota composition, how these microbial changes affect inflammatory pathways, and the therapeutic implications of modulating this axis for chronic inflammatory disease prevention and management. Beneficial dietary patterns, such as the Mediterranean diet (MD) and plant-based diets, promote a diverse and balanced gut microbiota composition, supporting anti-inflammatory pathways. Conversely, the Western diet (WD), high in saturated fats and refined sugars, is associated with dysbiosis and increased inflammation. With all the links between the three variables considered, this review attempts to offer a thorough examination of the triangle formed by inflammation, the gut microbiota, and food.

In Vitro Characterization and Identification of Potential Probiotic Yeasts Isolated from Zaopocu, a Traditional Fermented Dregs Vinegar from Hainan Island

Recently, there has been an increasing interest in researching fermented food-derived yeasts as probiotics because they offer a natural and diverse source of potential strains with unique functional properties and health benefits. In this study, 13 yeast strains isolated from Zaopocu (ZPC), a traditional fermented dregs vinegar on Hainan Island, China, were evaluated for their probiotic characteristics in vitro. Yeast identification was conducted through 5.8S-ITS region sequencing, revealing Kodamaea ohmeri as the predominantly isolated species (ZPC_Y3, Y5, Y6, Y11), followed by Pichia kudriavzevii (ZPC_Y2, Y13, Y14), Rhodotorula mucilaginosa (ZPC_Y9, Y10), Pichia fermentans (ZPC_Y8, Y12), Pichia kluyveri (ZPC_Y4), and Pichia occidentalis (ZPC_Y1). Except for ZPC_Y4, ZPC_Y8, and ZPC_Y12, all isolated yeasts exhibited stable growth at 37 °C. The survival rates of all test strains exceeded 60% under challenging conditions at pH = 2 and 0.3% bile salt, along with strong antioxidant activity (> 5 6%), notable autoaggregation (> 70%), and varying levels of cell hydrophobicity with xylene (ranging from 35.32 ± 8.57% to 89.73 ± 4.84%). In addition, all isolates showed resistance to multiple antibiotics, along with antagonistic activity, and were deemed safe as none exhibited hemolytic, gelatinase, or DNase activities. Significantly, two P. kudriavzevii strains (ZPC_Y2, Y14) exhibited the production of catalase, lipase, and β-galactosidase, along with the capacity to synthesize gamma-aminobutyric acid (GABA). In summary, this preliminary study represents the first attempt to identify and characterize potential probiotic yeast strains isolated from Zaopocu, providing a theoretical basis for exploring their application in developing novel therapeutic probiotics.

Modified montmorillonite armed probiotics with enhanced on-site mucus-depleted intestinal colonization and H2S scavenging for colitis treatment

Inflammatory bowel diseases (IBD) are often associated with dysregulated gut microbiota and excessive inflammatory microenvironment. Probiotic therapy combined with inflammation management is a promising approach to alleviate IBD, but the efficacy is hindered by the inferior colonization of probiotics in mucus-depleted inflammatory bowel segments. Here, we present modified montmorillonite armed probiotic Escherichia coli Nissle 1917 (MMT-Fe@EcN) with enhanced intestinal colonization and hydrogen sulfide (H2S) scavenging for synergistic alleviation of IBD. The montmorillonite layer that can protect EcN against environmental assaults in oral delivery and improve on-site colonization of EcN in the mucus-depleted intestinal segment due to its strong adhesive capability and electronegativity, with a 22.6-fold increase in colonization efficiency compared to EcN. Meanwhile, MMT-Fe@EcN can manage inflammation by scavenging H2S, which allows for enhancing probiotic viability and colonization for restoring the gut microbiota. As a result, MMT-Fe@EcN exhibits extraordinary therapeutic effects in the dextran sulfate sodium-induced mouse colitis models, including alleviating intestinal inflammation and restoring disrupted intestinal barrier function, and gut microbiota. These findings provide a promising strategy for clinical IBD treatment and potentially other mucus-depletion-related diseases.

Exploring Weissella confusa W1 and W2 Strains Isolated from Khao-Mahk as Probiotic Candidates: From Phenotypic Traits to Genomic Insights

Growing interest in probiotics has spurred research into their health benefits for hosts. This study aimed to evaluate the probiotic properties, especially antibacterial activities and the safety of two Weissella confusa strains, W1 and W2, isolated from Khao-Mahk by describing their phenotypes and genotypes through phenotypic assays and whole genome sequencing. In vitro experiments demonstrated that both strains exhibited robust survival under gastric and intestinal conditions, such as in the presence of low pH, bile salt, pepsin, and pancreatin, indicating their favorable gut colonization traits. Additionally, both strains showed auto-aggregation and strong adherence to Caco2 cells, with adhesion rates of 86.86 ± 1.94% for W1 and 94.74 ± 2.29% for W2. These high adherence rates may be attributed to the significant exopolysaccharide (EPS) production observed in both strains. Moreover, they exerted remarkable antimicrobial activities against Stenotrophomonas maltophilia, Salmonella enterica serotype Typhi, Vibrio cholerae, and Acinetobacter baumannii, along with an absence of hemolytic activities and antibiotic resistance, underscoring their safety for probiotic application. Genomic analysis corroborated these findings, revealing genes related to probiotic traits, including EPS clusters, stress responses, adaptive immunity, and antimicrobial activity. Importantly, no transferable antibiotic-resistance genes or virulence genes were detected. This comprehensive characterization supports the candidacy of W1 and W2 as probiotics, offering substantial potential for promoting health and combating bacterial infections.

Probiotics for oral health: a critical evaluation of bacterial strains

Oral health is critical for total body health and well-being; however, little improvement in oral health status has occurred in the U.S. over the past 20 years. Tooth decay and gum disease remain highly prevalent, with more than 90% and 50% of adults suffering from these conditions, respectively. To combat this lack of improvement, alternative approaches to dental care are now being suggested. One such alternative therapy is probiotics for oral care. In the oral cavity, probiotic strains have been shown to reduce levels of oral pathogens, inhibit the formation of dental caries, and reduce the levels of bacteria that cause halitosis. However, as the oral care probiotic market expands, many products contain bacterial species and strains with no documented health benefits leading to confusion and mistrust among consumers and clinicians. This confusion is enhanced by the regulatory status of probiotic products which puts the onus of safety and efficacy on the manufacturer rather than a central regulatory body. The overarching goal of this review is to provide consumers and clinicians with documented evidence supporting (or refuting) the health benefits of oral care probiotics marketed for sale in the United States. This includes defining what constitutes an oral care probiotic product and a strain level analysis of candidate probiotics from the genera Streptococcus, Lactobacillus, Bifidobacterium, and Bacillus. Additionally, prebiotics and postbiotics will be discussed. Finally, a set of considerations for consumers and clinicians is provided to empower probiotic product decision making. Together, this review will improve understanding of oral care probiotics marketed in the US for dental professionals and consumers.

Effect of folA gene in human breast milk-derived Limosilactobacillus reuteri on its folate biosynthesis

Introduction

Folate supplementation is crucial for the human body, and the chemically synthesized folic acid might have undesirable side effects. The use of molecular breeding methods to modify the genes related to the biosynthesis of folate by probiotics to increase folate production is currently a focus of research.

Methods

In this study, the folate-producing strain of Limosilactobacillus reuteri B1-28 was isolated from human breast milk, and the difference between B1-28 and folA gene deletion strain ΔFolA was investigated by phenotyping, in vitro probiotic evaluation, metabolism and transcriptome analysis.

Results

The results showed that the folate producted by the ΔFolA was 2-3 folds that of the B1-28. Scanning electron microscope showed that ΔFolA had rougher surface, and the acid-producing capacity (p = 0.0008) and adhesion properties (p = 0.0096) were significantly enhanced than B1-28. Transcriptomic analysis revealed that differentially expressed genes were mainly involved in three pathways, among which the biosynthesis of ribosome and aminoacyl-tRNA occurred in the key metabolic pathways. Metabolomics analysis showed that folA affected 5 metabolic pathways, involving 89 different metabolites.

Discussion

In conclusion, the editing of a key gene of folA in folate biosynthesis pathway provides a feasible pathway to improve folate biosynthesis in breast milk-derived probiotics.

Investigating the influence of probiotics in preventing Traveler's diarrhea: Meta-analysis based systematic review

INTRODUCTION

Approximately 10-40 million travelers get Traveler's Diarrhea (TD) yearly. A significant decrease in TD incidence has not been achieved by depending solely on antibiotic prophylaxis and educational initiatives. Using prebiotics to prevent TD has also not been examined in previous evaluations of probiotics for TD, which failed to consider the strain-specificity of probiotic efficacy. This review investigates the overall effects of probiotics on preventing TD, including the impact of dosage, duration, and age.

METHODS

Standard literature databases were searched without restriction on publication year or language. The following criteria are included: randomized controlled trials (RCTs) in English or non-English unrestricted to publication year, excluding animal and observational studies. This systematic review applied the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

Of the 166 screened papers, 10 RCTs were included. Lactobacillus acidophilus showed no efficacy in preventing TD except when mixed with other strains. Other genera of lactobacilli showed a protection rate of up to 39% against TD. Similarly, Saccharomyces cerevisiae and Saccharomyces boulardii have been effective in preventing TD.

CONCLUSION

Studies investigating probiotics as a preventive measure for TD remain limited. Only a few probiotics that reduce TD risk exist. Based on this systematic review and meta-analysis, specific probiotic strains, including L. acidophilus, L. rhamnosus, L. fermentum, S. cerevisiae, and S. boulardii, may prevent TD. The effect of additional probiotic strains on TD prevention must be further investigated.

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.

Safety considerations for dietary supplement manufacturers in the United States

Due to significant dietary supplement use in the US, product manufacturers must understand the importance of implementing a robust approach to establishing safety for all ingredients, including dietary ingredients, components, and finished dietary supplement products. Different regulatory pathways exist by which the safety of dietary ingredients can be established, and thus allowed to be marketed in a dietary supplement. For individual dietary ingredients, safety information may come from a variety of sources including history of safe use, presence of the ingredient in foods, and/or non-clinical and clinical data. On occasion safety data gaps are identified for a specific ingredient, particularly those of botanical origin. Modern toxicological methods and models can prove helpful in satisfying data gaps and are presented in this review. For finished dietary supplement products, issues potentially impacting safety to consider include claims, product labeling, overages, contaminants, residual solvents, heavy metals, packaging, and product stability. In addition, a safety assessment does not end once a product is marketed. It is important that manufacturers actively monitor and record the occurrence of adverse events reported in association with the use of their products, in accordance with the law. Herein, we provide a comprehensive overview of considerations for assessing dietary supplement safety.

Isolation, Characterization, and Safety Evaluation of the Novel Probiotic Strain Lacticaseibacillus paracasei IDCC 3401 via Genomic and Phenotypic Approaches

This study aimed to explore the safety and properties of Lacticaseibacillus paracasei IDCC 3401 as a novel probiotic strain via genomic and phenotypic analyses. In whole-genome sequencing, the genes associated with antibiotic resistance and virulence were not detected in this strain. The minimum inhibitory concentration test revealed that L. paracasei IDCC 3401 was susceptible to all the antibiotics tested, except for kanamycin. Furthermore, the strain did not produce toxigenic compounds, such as biogenic amines and D-lactate, nor did it exhibit significant toxicity in a single-dose acute oral toxicity test in rats. Phenotypic characterization of carbohydrate utilization and enzymatic activities indicated that L. paracasei IDCC 3401 can utilize various nutrients, allowing it to grow in deficient conditions and produce health-promoting metabolites. The presence of L. paracasei IDCC 3401 supernatants significantly inhibited the growth of enteric pathogens (p < 0.05). In addition, the adhesion ability of L. paracasei IDCC 3401 to intestinal epithelial cells was found to be as superior as that of Lacticaseibacillus rhamnosus GG. These results suggest that L. paracasei IDCC 3401 is safe for consumption and provides health benefits to the host.

Evaluation of Safety and Probiotic Traits from a Comprehensive Genome-Based In Silico Analysis of Ligilactobacillus salivarius P1CEA3, Isolated from Pigs and Producer of Nisin S

Ligilactobacillus salivarius is an important member of the porcine gastrointestinal tract (GIT). Some L. salivarius strains are considered to have a beneficial effect on the host by exerting different probiotic properties, including the production of antimicrobial peptides which help maintain a healthy gut microbiota. L. salivarius P1CEA3, a porcine isolated strain, was first selected and identified by its antimicrobial activity against a broad range of pathogenic bacteria due to the production of the novel bacteriocin nisin S. The assembled L. salivarius P1CEA3 genome includes a circular chromosome, a megaplasmid (pMP1CEA3) encoding the nisin S gene cluster, and two small plasmids. A comprehensive genome-based in silico analysis of the L. salivarius P1CEA3 genome reveals the presence of genes related to probiotic features such as bacteriocin synthesis, regulation and production, adhesion and aggregation, the production of lactic acid, amino acids metabolism, vitamin biosynthesis, and tolerance to temperature, acid, bile salts and osmotic and oxidative stress. Furthermore, the strain is absent of risk-related genes for acquired antibiotic resistance traits, virulence factors, toxic metabolites and detrimental metabolic or enzymatic activities. Resistance to common antibiotics and gelatinase and hemolytic activities have been discarded by in vitro experiments. This study identifies several probiotic and safety traits of L. salivarius P1CEA3 and suggests its potential as a promising probiotic in swine production.

Quality Management of Probiotics: Ensuring Safety and Maximizing Health Benefits

Consumption of probiotics, which are beneficial live microorganisms, has received a lot of attention because of their potential to improve health and wellness. Robust quality control measures are necessary to ensure the safety of probiotics and maximize their health effects. This review delves into the topic of quality management in probiotics, highlighting the significance of sticking to strict guidelines from manufacture to storage to distribution. Probiotic quality standards, Good Manufacturing Practices (GMP) implementation, quality control and testing techniques, and documentation and traceability systems are all discussed in detail. The importance of taking precautions to avoid microbial contamination, meeting all applicable regulations, and clearly marking and packaging probiotic products is also emphasized. In addition, it reviews the clinical evidence supporting the possible health advantages of probiotics and investigates the processes through which probiotics enhance health. The review continues by stressing the significance of educating and informing consumers about probiotics and their proper use in order to maximize health benefits. Probiotics' potential health benefits can be maximized and consumer faith in these helpful microbes can be bolstered by adopting thorough quality management measures to ensure their safety, efficacy, and consistency.

Safety assessment of Enterococcus lactis strains complemented with comparative genomics analysis reveals probiotic and safety characteristics of the entire species

BACKGROUND

The gut microbiota is considered a rich source for potential novel probiotics. Enterococcus genus is a normal component of a healthy gut microbiota, suggesting its vital role. Nosocomial infections caused mainly by E. facalis and E. faecium have been attributed to the plasticity of the Enterococcus genomes. In this study, we assessed the probiotic and safety characteristics of two E. lactis strains isolated from the human gut microbiota using in-vitro and in silico approaches. Additionally, the safety of the E. lactis species was evaluated using comparative genomics analysis.

RESULTS

The two E. lactis strains 10NA and 50NA showed resistance to bile salts and acid tolerance with antibacterial activity against Escherichia coli, Salmonella typhi, and Clostridioides difficile. For safety assays, the two strains did not display any type of hemolysis on blood agar, and the survival of Caco-2 cells was not significantly different (P-value > 0.05) compared to the control using cell free supernatants at 100% (v/v), 50% (v/v), 10% (v/v), and 5% (v/v) concentrations. Regarding antibiotic susceptibility, both strains were sensitive to vancomycin, tetracycline, and chloramphenicol. Comprehensive whole-genome analysis revealed no concerning associations between virulence or antibiotic resistance genes and any of the identified mobile genetic elements. Comparative genome analysis with closely related E. faecium species genomes revealed the distinctive genomic safety of the E. lactis species.

CONCLUSIONS

Our two E. lactis strains showed promising probiotic properties in-vitro. Their genomes were devoid of any transferable antibiotic resistance genes. In silico comparative analysis confirmed the safety of the E. lactis species. These results suggest that E. lactis species could be a potential source for safer Enterococcus probiotic supplements.

Extracellular vesicles of the probiotic bacteria E. coli O83 activate innate immunity and prevent allergy in mice

BACKGROUND

E. coli O83 (Colinfant Newborn) is a Gram-negative (G-) probiotic bacterium used in the clinic. When administered orally, it reduces allergic sensitisation but not allergic asthma. Intranasal administration offers a non-invasive and convenient delivery method. This route bypasses the gastrointestinal tract and provides direct access to the airways, which are the target of asthma prevention. G- bacteria such as E. coli O83 release outer membrane vesicles (OMVs) to communicate with the environment. Here we investigate whether intranasally administered E. coli O83 OMVs (EcO83-OMVs) can reduce allergic airway inflammation in mice.

METHODS

EcO83-OMVs were isolated by ultracentrifugation and characterised their number, morphology (shape and size), composition (proteins and lipopolysaccharide; LPS), recognition by innate receptors (using transfected HEK293 cells) and immunomodulatory potential (in naïve splenocytes and bone marrow-derived dendritic cells; BMDCs). Their allergy-preventive effect was investigated in a mouse model of ovalbumin-induced allergic airway inflammation.

RESULTS

EcO83-OMVs are spherical nanoparticles with a size of about 110 nm. They contain LPS and protein cargo. We identified a total of 1120 proteins, 136 of which were enriched in OMVs compared to parent bacteria. Proteins from the flagellum dominated. OMVs activated the pattern recognition receptors TLR2/4/5 as well as NOD1 and NOD2. EcO83-OMVs induced the production of pro- and anti-inflammatory cytokines in splenocytes and BMDCs. Intranasal administration of EcO83-OMVs inhibited airway hyperresponsiveness, and decreased airway eosinophilia, Th2 cytokine production and mucus secretion.

CONCLUSIONS

We demonstrate for the first time that intranasally administered OMVs from probiotic G- bacteria have an anti-allergic effect. Our study highlights the advantages of OMVs as a safe platform for the prophylactic treatment of allergy. Video Abstract.

Probiotic and functional potential of lactic acid bacteria isolated from pulque and evaluation of their safety for food applications

Pulque is a traditional Mexican non-distilled alcoholic beverage to which several beneficial functions are attributed, mainly associated with gastrointestinal health, which can be explained by the presence of probiotic bacteria in its microbiota. Therefore, the objective of this work was to evaluate the safety, probiotic activity, and functional characteristics of seven strains of lactic acid bacteria (LAB) isolated from pulque using the probiotic strain Lactobacillus acidophilus NCFM as control. The LAB isolates were identified by 16S rRNA sequencing and MALDI Biotyper® MS as belonging to three different Lactobacillaceae genera and species: Lactiplantibacillus plantarum, Levilactobacillus brevis and Lacticaseibacillus paracasei. Most strains showed resistance to gastric juice, intestinal juice and lysozyme (10 mg/L). In addition, all strains exhibited bile salt hydrolase (BSH) activity and antibacterial activity against the pathogenic strain Listeria monocytogenes. Additionally, cell surface characteristics of LAB were evaluated, with most strains showing good hydrophobicity, auto-aggregation, and co-aggregation towards enteropathogenic Escherichia coli and L. monocytogenes. In terms of safety, most of the strains were sensitive to the tested antibiotics and only the Lact. paracasei UTMB4 strain amplified a gene related to antibiotic resistance (mecA). The strains Lact. plantarum RVG2 and Lact. plantarum UTMB1 presented γ-hemolytic activity, and the presence of the virulence-related gene agg was identified only in UTMB1 strain. Regarding functional characterization, the tested bacteria showed good β-galactosidase activity, antioxidant activity and cholesterol reduction Based on principal component analysis (PCA) and heat mapping, and considering the strain Lact. acidophilus NCFM as the probiotic reference, the strains Lacticaseibacillus paracasei UTMB4, Lactiplantibacillus plantarum RVG4 and Levilactobacillus brevis UTMB2 were selected as the most promising probiotic strains. The results of this study highlighted the probiotic, functional and safety traits of LAB strains isolated from pulque thus supporting the health benefits attributed to this ancestral beverage.

Proteolysis and therapeutic potential of bioactive peptides derived from Cheddar cheese

Cheddar cheese-derived bioactive peptides are considered a potential component of functional foods. A positive impact of bioactive peptides on diet-related chronic, non-communicable diseases, like obesity, cardiovascular diseases, and diabetes, has been observed. Bioactive peptides possess multifunctional therapeutic potentials, including antimicrobial, immunomodulatory, antioxidant, enzyme inhibitory effects, anti-thrombotic, and phyto-pathological activities against various toxic compounds. Peptides can regulate human immune, gastrointestinal, hormonal, and neurological responses, which play an integral role in the deterrence and treatment of certain diseases like cancer, osteoporosis, hypertension, and other health disorders, as described in the present review. This review summarizes the categories of the Cheddar cheese-derived bioactive peptides, their general characteristics, physiological functions, and possible applications in healthcare.

Potential probiotic lactobacilli strains isolated from artisanal Mexican Cocido cheese: evidence-based biosafety and probiotic action-related traits on in vitro tests

The biosafety of four potentially probiotic lactobacilli strains, isolated from artisanal Mexican Cocido cheese, was assessed through in vitro tests aimed to determine (1) the antibiotic susceptibility profile by broth microdilution, (2) the transferability of antibiotic resistance determinants by filter-mating, and (3) the phenotypic and genotypic stability during serial batch sub-culture (100-day period) by evaluating physiological and probiotic features and RAPD-PCR fingerprinting. Lactobacilli strains exhibited multidrug-resistance; however, resistance determinants were not transferred in the filter-mating assay. Significant (p < 0.05) differences were observed in bacterial morphology and some functional and technological properties when strains were serially sub-cultured over 50 generations (G50), compared to the initial cultures (G0). Conversely, the strains did not show mucinolytic and hemolytic activities either at G0 or after 100 generations (G100). Genetic polymorphism and genomic template instability on selected strains were detected, which suggest possible evolutionary arrangements that may occur when these bacteria are largely cultured. Our findings suggest that the assessed strains did not raise in vitro biosafety concerns; however, complementary studies are still needed to establish the safe potential applications in humans and animals.

In Vivo Toxicity Assessment of the Probiotic Bacillus amyloliquefaciens HTI-19 Isolated from Stingless Bee (Heterotrigona itama) Honey

This study evaluated the acute and sub-acute toxicity of B. amyloliquefaciens HTI-19 (isolated from stingless bee honey) in female Sprague Dawley rats. In an acute toxicity study, the rats received a low dosage (1 × 10⁹ CFU·mL^-1), medium dosage (3 × 10⁹ CFU·mL^-1), or high dosage (1 × 10¹⁰ CFU·mL^-1) of B. amyloliquefaciens HTI-19 daily orally by syringe-feeding for 14 days. For the subacute toxicity study, rats received a low dosage (1 × 10⁹ CFU·mL^-1) or a high dosage (1 × 10¹⁰ CFU·mL^-1) for 28 days. The probiotic feeding in acute and sub-acute toxicity studies showed no mortality or significant abnormalities in rats throughout the experimental period. In week 2 of the acute study, the body weight of the rats showed a significant increase (p < 0.05) compared to the control. By gross and microscopic examination of organs, no evidently significant changes were observed in the morphology of organs. Serum biochemical tests and blood hematology tests also revealed no treatment-related changes. Overall, these data indicated that oral administration of B. amyloliquefaciens HTI-19 up to 1 × 10⁹ CFU·mL^-1 for 28 days can be considered safe.

In vitro safety assessment of electrohydrodynamically encapsulated Lactiplantibacillus plantarum CRD7 and Lacticaseibacillus rhamnosus CRD11 for probiotics use

The current study aimed to validate the safety of electrohydrodynamically encapsulated Lactiplantibacillus plantarum CRD7 and Lacticaseibacillus rhamnosus CRD11 in accordance with guidelines of FAO/WHO and ICMR/DBT. In vitro assays such as mucin degradation, hemolysis of blood cells, antimicrobial susceptibility pattern, possession of virulence factors, biogenic amine, and ammonia production were assessed. In results, the cross-streak and co-culture techniques revealed that CRD7 and CRD11 were compatible in vitro. Upon visual inspection through scanning electron and fluorescence microscopy, the integrity of bacterial cell membrane was confirmed even after the encapsulation process. CRD7 and CRD11 were non-hemolytic and showed negative responses to gelatinase, urease, and DNase activities. Non-mucinolytic activity of CRD7 and CRD11 was verified by measuring cell growth rate (p < 0.05) in different modified media followed by SDS-PAGE. High-performance liquid chromatography analysis revealed that both the strains did not produce biogenic amines (putrescine, cadaverine, histamine, and tyramine). Neither of the Lactobacillus strains produced ammonia after growing in BHI broth for 5 days at 37 °C. L-lactate production was highest (p < 0.05) in CRD11 (8.83 g/L), followed by CRD7 (8.16 g/L), whereas the lowest (p < 0.05) D-lactate was registered for encapsulated CRD11 (0.33 g/L) and CRD7 (0.49 g/L). The antibiogram profile determined through minimum inhibitory concentration showed that CRD7 and CRD11 were sensitive to key antibiotics suggested by EFSA except for gentamycin and kanamycin. PCR data on virulence genes demonstrated that both strains were safe for probiotic use. Moreover, CRD7 and CRD11 strains caused insignificant (p > 0.05) changes in the cell viability of Caco-2 cells as estimated by MTT (98.94-99.50%) and NR uptake (95.42-97.03%) assays and showed sensitivity to human serum. According to the results of these evaluated attributes, it is concluded that L. plantarum CRD7 and L. rhamnosus CRD11 are safe, non-toxic to human epithelial cells, and thus may be potentially suitable for various food/feed applications.

Pea (Pisum sativum L.) pod powder as a potential enhancer of probiotic Enterococcus faecium M74 in ice cream and its physicochemical, structural, and sensory effects

BACKGROUND

In this study, pea (Pisum sativum L.) pod powder (PPP) was incorporated (1% and 3% w/w) into a probiotic ice cream formulation containing Enterococcus faecium M74 to investigate the potential effect of PPP on the probiotic survivability in the ice cream throughout 60 days of frozen storage. Moreover, the produced symbiotic ice creams were evaluated for their physiochemical properties, stability, and sensory acceptability.

RESULTS

Incorporation of PPP into ice cream caused significantly (P < 0.05) increased protein and ash content and lower pH values. Besides that, the addition of PPP resulted in ice creams with higher hardness and lower overrun. A significant diminishing was observed in the melting rates of the ice creams as the percentage of PPP increased and storage time progressed. Ice cream with PPP presented lower lightness and higher greenness and yellowness compared with control. All ice creams had viable counts of E. faecium M74 of ≥6 log cfu g-1 during storage and provided the number of viable cells that the probiotic product should contain. On day 60, the viability of E. faecium M74 in ice cream containing 1% PPP (7.64 ± 0.02) was higher than the control (7.28 ± 0.00). Sensory analyses revealed that there was no statistical difference in ice cream with 1% PPP and the control without PPP in terms of general acceptability.

CONCLUSION

These results suggest that pea pods, which is a waste product of the pea industry and obtained at zero cost, could be used as a potential prebiotic and an agent to improve technological properties of dairy products. © 2022 Society of Chemical Industry.

Potential of Bifidobacterium lactis IDCC 4301 isolated from breast milk-fed infant feces as a probiotic and functional ingredient

Probiotics provide important health benefits to the host by improving intestinal microbial balance and have been widely consumed as dietary supplements. In this study, we investigated whether Bifidobacterium lactis IDCC 4301 (BL), isolated from feces of breast milk-fed infants, is safe to consume. Based on the guidelines established by the European Food Safety Authority (EFSA), safety tests such as antibiotic susceptibility, hemolysis, toxic compound formation (i.e., biogenic amine and d-lactate), single-dose acute oral toxicity, and extracellular enzymatic activities were performed. In addition, toxigenic genes, antibiotic resistance genes, and mobile genetic elements were investigated by analyzing the genome sequence of BL. BL was susceptible to eight antibiotics except for vancomycin and the absence of transferable resistance in the genome of this strain implied that vancomycin resistance is likely to be intrinsic. With regard to phenotypic characteristics, there was no concern of toxicity of this strain. Furthermore, BL utilized various carbohydrates and their conjugates through the activity of various endogenous carbohydrate-utilizing enzymes. Interestingly, the supernatant of the BL showed strong antipathogenic activity against various infectious pathogens. Therefore, we suggest that BL should be a safe probiotic and can be used as a functional ingredient in the food, cosmetic, and pharmaceutical industries.

Postbiotics against Obesity: Perception and Overview Based on Pre-Clinical and Clinical Studies

Overweight and obesity are significant global public health concerns that are increasing in prevalence at an alarming rate. Numerous studies have demonstrated the benefits of probiotics against obesity. Postbiotics are the next generation of probiotics that include bacteria-free extracts and nonviable microorganisms that may be advantageous to the host and are being increasingly preferred over regular probiotics. However, the impact of postbiotics on obesity has not been thoroughly investigated. Therefore, the goal of this review is to gather in-depth data on the ability of postbiotics to combat obesity. Postbiotics have been reported to have significant potential in alleviating obesity. This review comprehensively discusses the anti-obesity effects of postbiotics in cellular, animal, and clinical studies. Postbiotics exert anti-obesity effects via multiple mechanisms, with the major mechanisms including increased energy expenditure, reduced adipogenesis and adipocyte differentiation, suppression of food intake, inhibition of lipid absorption, regulation of lipid metabolism, and regulation of gut dysbiosis. Future research should include further in-depth studies on strain identification, scale-up of postbiotics, identification of underlying mechanisms, and well-defined clinical studies. Postbiotics could be a promising dietary intervention for the prevention and management of obesity.

Hepatotoxicity of polymeric proanthocyanidins is caused by translocation of bacterial lipopolysaccharides through impaired gut epithelium

Polymeric proanthocyanidins (P-PAC) induced hepatotoxicity in C57BL/6 mice. Mice were supplemented with P-PAC alone or with a mixture of probiotic bacteria (PB), Lactobacillus, Bifidobacterium, and Akkermansia muciniphila for 14 consecutive days. The liver tissues of sacrificed mice were analyzed by mass spectrometry to identify and quantify the P-PAC metabolites. Potential P-PAC metabolites, 2-hydroxyphenylacetic acid and pyrocatechol were detected in higher concentrations and 4-hydroxybenzoic acid was detected exclusively in the mice supplemented with P-PAC and PB. Supplementation with P-PAC alone or with PB caused no shift in the α-diversity of mice gut microbiota. P-PAC induced nonalcoholic steatohepatitis in mice through increasing liver exposure to intestinal bacterial lipopolysaccharides by reducing expression of gut epithelial tight junction proteins, claudin-3 and occludin. Lipopolysaccharide concentrations in the livers of mice supplemented with P-PAC were significantly high compared to the control mice. Furthermore, P-PAC downregulated the expressions of claudin-3 and claudin-4 tight junction proteins in cultured Caco-2 cell monolayers. PB biotransformed P-PAC into bioavailable metabolites and potentially reduced the toxicity of P-PAC. The toxicity of P-PAC and their synbiotics need to be critically evaluated for the safety of human consumption.

Postbiotic Lipoteichoic acid of probiotic Lactobacillus origin ameliorates inflammation in HT-29 cells and colitis mice

Lipoteichoic acid (LTA) is a key surface component of probiotic lactobacilli that is involved in important cellular functions including cross talk with the host immune cells. In this study, the anti-inflammatory and ameliorative properties of LTA from probiotic lactobacilli strains were assessed in in vitro HT-29 cells and in vivo colitis mice. The LTA was extracted with n-butanol and its safety was confirmed based on its endotoxin content and cytotoxicity in HT-29 cells. In the Lipopolysaccharide stimulated HT-29 cells, the LTA from the test probiotics evoked a visible but non-significant increase in IL-10 and decrease in TNF-α levels. During the colitis mice study, probiotic LTA treated mice showed substantial improvement in external colitis symptoms, disease activity score and weight gain. The treated mice also showed improvements in key inflammatory markers such as the gut permeability, myeloperoxidase activity and histopathological damages in colon, although non-significant improvements were recorded for the inflammatory cytokines. Furthermore, structural studies by NMR and FTIR revealed increased level of D-alanine substitution in the LTA of LGG strain over MTCC5690. The present study demonstrates the ameliorative effect of LTA as a postbiotic component from probiotics which can be helpful in building effective strategies for combating gut inflammatory disorders.

Recovery of Potential Starter Cultures and Probiotics from Fermented Sorghum (Ting) Slurries

Fermented foods are thought to provide a source of probiotics that promote gut health. Consequently, isolation and characterization of fermented food strains and their applications in a controlled fermentation process or as probiotics present a new facet in this area of research. Therefore, the current study sought to identify dominant strains in sorghum-fermented foods (ting) and characterize their probiotic potential in vitro. Recovered isolates were identified as Lactobacillus helveticus, Lactobacillus amylolyticus, Lacticaseibacillus paracasei, Lacticaseibacillus paracasei subsp paracasei, Lactiplantibacillus plantarum, Levilactobacillus brevis, Loigolactobacillus coryniformis and Loigolactobacillus coryniformis subsp torquens based on the their 16S rRNA sequences. Increased biomass was noted in seven out of nine under a low pH of 3 and a high bile concentration of 2% in vitro. Bactericidal activities of isolated LABs presented varying degrees of resistance against selected pathogenic bacteria ranging between (1.57 to 41 mm), (10 to 41 mm), and (11.26 to 42 mm) for Salmonella typhimurium ATTC 14028, Staphylococcus aureus ATTC 6538 and Escherichia coli ATTC8739, respectively. Ampicillin, erythromycin, mupirocin, tetracycline and chloramphenicol were able to inhibit growth of all selected LABs. Thus, isolates recovered from ting partially satisfy the potential candidacy for probiotics by virtue of being more tolerant to acid and bile, antibacterial activity and antibiotic resistance.

Lactobacilli and Their Probiotic Effects in the Vagina of Reproductive Age Women

In the present narrative review, the probiotic effects of vaginal Lactobacillus spp. are described in detail, covering the importance of the differential production of lactic acid, the lactic acid D/L isoforms, the questionable in vivo effect of hydrogen peroxide, as well as bacteriocins and other core proteins produced by vaginal Lactobacillus spp. Moreover, the microbe–host interaction is explained with emphasis on the vaginal mucosa. To understand the crucial role of Lactobacillus spp. dominance in the vaginal microbiota, different dysbiotic states of the vagina are explained including bacterial vaginosis and aerobic vaginitis. Finally, this review takes on the therapeutic aspect of live lactobacilli in the context of bacterial vaginosis. Until recently, there was very low-quality evidence to suggest that any probiotic might aid in reducing vaginal infections or dysbiosis. Therefore, clinical usage or over the counter usage of probiotics was not recommended. However, recent progress has been made, moving from probiotics that are typically regulated as food supplements to so-called live biotherapeutic products that are regulated as medical drugs. Thus, recently, a phase 2b trial using a Lactobacillus crispatus strain as a therapeutic add-on to standard metronidazole showed significant reduction in the recurrence of bacterial vaginosis by 12 weeks compared to placebo. This may constitute evidence for a brighter future where the therapeutic use of lactobacilli can be harnessed to improve women’s health.

Commercial probiotic products in public health: current status and potential limitations

Consumption of commercial probiotics for health improvement and disease treatment has increased in popularity among the public in recent years. The local shops and pharmacies are brimming with various probiotic products such as probiotic food, dietary supplement and pharmaceuticals that herald a range of health benefits, from nutraceutical benefits to pharmaceutical effects. However, although the probiotic market is expanding rapidly, there is increasing evidence challenging it. Emerging insights from microbiome research and public health demonstrate several potential limitations of the natural properties, regulatory frameworks, and market consequences of commercial probiotics. In this review, we highlight the potential safety and performance issues of the natural properties of commercial probiotics, from the genetic level to trait characteristics and probiotic properties and further to the probiotic-host interaction. Besides, the diverse regulatory frameworks and confusing probiotic guidelines worldwide have led to product consequences such as pathogenic contamination, overstated claims, inaccurate labeling and counterfeit trademarks for probiotic products. Here, we propose a plethora of available methods and strategies related to strain selection and modification, safety and efficacy assessment, and some recommendations for regulatory agencies to address these limitations to guarantee sustainability and progress in the probiotic industry and improve long-term public health and development.

Anti-inflammatory and Immunomodulatory Potency of Selenium-Enriched Probiotic Mutants in Mice with Induced Ulcerative Colitis

Selenium-enriched Lactobacillus plantarum and Bifidobacterium longum mutants were used as a protector against Piroxicam-induced ulcerative colitis (UC). In this study, 32 BALB/c male mice were distributed to four groups: the control group, the Piroxicam group which was given 0.8 mg Piroxicam, SP and SB groups which were given 0.8 mg Piroxicam, and plus Lactobacillus plantarum and Bifidobacterium longum selenium-enriched mutants, respectively. Bodyweight; serum content of IgG, IgM, TNF-α, IL-2, IL-6, and IL-10; CBC; myeloperoxidase enzyme activity; histopathological examination of colon and spleen; and expression of TNF-α, IL-2, IL-6, and IL-10 genes in colon and spleen with qRT-PCR were determined. Bodyweight was found to reduce in the Piroxicam group and then recovery in the SB group. Serum content of IgG, IL-2, and IL-10 reduced in the Piroxicam group, whereas IgG, TNF-α, and IL-6 increased in the Piroxicam group in comparison to the other groups. Myeloperoxidase activity witnessed a significant increase in the Piroxicam group compared with the other groups. No significant differences were observed between all groups in measurements of red cells, hemoglobin, neutrophil, monocyte, eosinophil, and basophil in blood. Meanwhile, the white blood cells and platelets recorded the highest and lowest value, respectively, in the Piroxicam group. The colon of the Piroxicam group showed a noticeably massive infiltration of inflammatory cells in the lamina propria. These inflammations were mildly reduced in the SP group, while the reduction in the SB group was significant. In the Piroxicam group, splenic parenchyma saw an increase in the number of melanomacrophages, while hypertrophic plasma cells were observed in the SP group. The spleen of the SB group exhibits a nearly normal form. TNF-α and IL-6 genes had significantly upregulated in the colon of the Piroxicam group compared to the control group, while they were significantly downregulated in the SB group. In contrast, IL-2 and IL-10 genes had upregulated in the colon of the SB group compared to the control groups, while they had downregulated in the Piroxicam group. The expression of these genes had not recorded significant differences between all groups in the spleen. Therefore, this study recommends Bifidobacterium longum selenium-enriched mutants as anti-inflammatory and immunomodulatory supplements.

Considerations for determining safety of probiotics: A USP perspective

A history of safe use is a backbone of safety assessments for many current probiotic species, however, there is no global harmonization regarding requirements for establishing probiotic safety for use in foods and supplements. As probiotic manufacturers are increasingly seeking to use new strains, novel species, and next-generation probiotics, justification based on a significant history of use may be challenged. There are efforts underway by a variety of stakeholders, including the United States Pharmacopeia (USP), to develop best practices guidelines for assessing the quality and safety of probiotics. A current initiative of the USP seeks to provide expert advice specific to safety considerations for probiotics. Toward this goal, this review provides a helpful summary guide to global regulatory guidelines. We question the suitability of traditional animal toxicology studies designed for testing chemicals for relevance in assessing probiotic safety. This includes discussion of the use of excessive dose levels, the length of repeated dose toxicity studies needed, and the most suitable animal species used in toxicology studies. In addition, the importance of proper manufacturing practices with regard to final product safety are also included. Thus, an outline of essential parameters of a comprehensive safety assessment for a probiotic are provided.

Probiotic Properties of Lactobacillus fermentum InaCC B1295 Encapsulated by Cellulose Microfiber from Oil Palm Empty Fruit Bunches

This study aims at an in vitro characterization of the acid and bile tolerance of Lactobacillus fermentum InaCC B1295 (LFB1295) encapsulated with hydrogel cellulose microfibers (CMF) from oil palm empty fruit bunches (OPEFBs). The viability at different storage temperatures was assessed. The experimental design used in this research was an in vitro trial. The microencapsulated probiotic was stored at 25 °C and 4 °C for 28 days. LFB1295 encapsulated with cellulose microfiber hydrogel from OPEFB showed a stable viability of probiotic bacteria at pH 2 and 0.5% (m/v) oxgall. In addition, the microencapsulation maintained the viability at 25 °C and 4 °C at 0, 14, and 28 days. The characterization of the encapsulant CMF-OPEFB showed that the thickness of CMF was in the range of 5–15 μm, and XRD patterns showed that CMF was of the cellulose I type with a crystallinity index of 77.08%. Based on its resistance to hydrogen peroxide, ability to scavenge DPPH radicals, and activity in scavenging hydroxyl radicals, LFB1295 encapsulated with CMF hydrogel of OPEFB exhibits antioxidant properties as good as the scavenging ability of DPPH radicals with IC50 of 36.880, 188.530, and 195.358 µg/mL, respectively, during storage for 0, 14, and 28 days at room and refrigerated temperature. Furthermore, hydroxyl radicals (HR)-scavenging activity showed an increased inhibition along with the increasing concentration of the Fenton reaction and decreasing concentration of cell-free supernatant (CFS) during storage time. In vitro safety tests, including hemolytic activity, biogenic amines, cytolysin, and gelatinase production, showed that the encapsulated LFB1295 was safe to use as a probiotic. The results of the inhibitory activity against hydrogen peroxide LFB1295 show that the higher the concentration of H2O2, the lower the inhibition value during 28 days of storage. Based on the storage temperature, the inhibition of LAB against H2O2 based on different storage temperatures showed a better level of the inhibition at cold temperatures compared to at room temperature.

The ameliorative effect of probiotics on diet-induced lipid metabolism disorders: A review

High-fat diet induces lipid metabolism disorders that has become one of the grievous public health problems and imposes a serious economic and social burden worldwide. Safety probiotics isolated from nature are regarded as a novel supplementary strategy for preventing and improving diet-induced lipid metabolism disorders and related chronic diseases. The present review summarized the latest researches of probiotics in high fat diet induced lipid metabolism disorders to provide a critical perspective on the regulatory function of probiotics for future research. Furthermore, the screening criteria and general sources of probiotics with lipid-lowering ability also outlined to enlarge microbial species resource bank instantly, which promoted the development of functional foods with lipid-lowering strains from nature. After critically reviewing the lipid-lowering potential of probiotics both in vitro and in vivo and even in clinical data of humans, we provided a perspective that probiotics activated AMPK signaling pathway to regulate fat synthesis and decomposition, as well as affected positively the gut microbiota structure, intestinal barrier function and systemic inflammatory response, then these beneficial effects are amplified along Gut-liver axis, which regulated intestinal flora metabolites such as SCFAs and BAs by HMGCR/FXR/SHP signaling pathway to improve high fat diet induced lipid metabolism disorders effectively.

In vitro investigation on lactic acid bacteria isolatedfrom Yak faeces for potential probiotics

In order to evaluate the potential and safety of lactic acid bacteria (LAB) isolated from faeces samples of Ganan yak as probiotic for prevention and/or treatment of yak diarrhea, four strains of LAB including Latilactobacillus curvatus (FY1), Weissella cibaria (FY2), Limosilactobacillus mucosae (FY3), and Lactiplantibacillus pentosus (FY4) were isolated and identified in this study. Cell surface characteristics (hydrophobicity and cell aggregation), acid resistance and bile tolerance, compatibility, antibacterial activity and in vitro cell adhesion tests were also carried out to evaluate the probiotic potential of LAB. The results showed that the four isolates had certain acid tolerance, bile salt tolerance, hydrophobicity and cell aggregation, all of which contribute to the survival and colonization of LAB in the gastrointestinal tract. There is no compatibility between the four strains, so they can be combined into a mixed probiotic formula. Antimicrobial tests showed that the four strains were antagonistic to Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium. Moreover, the in vitro safety of the four isolates were determined through hemolytic analysis, gelatinase activity, and antibacterial susceptibility experiments. The results suggest that all the four strains were considered as safe because they had no hemolytic activity, no gelatinase activity and were sensitive to most antibacterial agents. Moreover, the acute oral toxicity test of LAB had no adverse effect on body weight gain, food utilization and organ indices in Kunming mice. In conclusion, the four LAB isolated from yak feces have considerable potential to prevent and/or treat yak bacterial disease-related diarrhea.

Biodetoxification and Protective Properties of Probiotics

Probiotic consumption is recognized as being generally safe and correlates with multiple and valuable health benefits. However, the mechanism by which it helps detoxify the body and its anti-carcinogenic and antimutagenic potential is less discussed. A widely known fact is that globalization and mass food production/cultivation make it impossible to keep all possible risks under control. Scientists associate the multitude of diseases in the days when we live with these risks that threaten the population’s safety in terms of food. This review aims to explore whether the use of probiotics may be a safe, economically viable, and versatile tool in biodetoxification despite the numerous risks associated with food and the limited possibility to evaluate the contaminants. Based on scientific data, this paper focuses on the aspects mentioned above and demonstrates the probiotics’ possible risks, as well as their anti-carcinogenic and antimutagenic potential. After reviewing the probiotic capacity to react with pathogens, fungi infection, mycotoxins, acrylamide toxicity, benzopyrene, and heavy metals, we can conclude that the specific probiotic strain and probiotic combinations bring significant health outcomes. Furthermore, the biodetoxification maximization process can be performed using probiotic-bioactive compound association.

Current Therapeutic Landscape and Safety Roadmap for Targeting the Aryl Hydrocarbon Receptor in Inflammatory Gastrointestinal Indications

Target modulation of the AhR for inflammatory gastrointestinal (GI) conditions holds great promise but also the potential for safety liabilities both within and beyond the GI tract. The ubiquitous expression of the AhR across mammalian tissues coupled with its role in diverse signaling pathways makes development of a “clean” AhR therapeutically challenging. Ligand promiscuity and diversity in context-specific AhR activation further complicates targeting the AhR for drug development due to limitations surrounding clinical translatability. Despite these concerns, several approaches to target the AhR have been explored such as small molecules, microbials, PROTACs, and oligonucleotide-based approaches. These various chemical modalities are not without safety liabilities and require unique de-risking strategies to parse out toxicities. Collectively, these programs can benefit from in silico and in vitro methodologies that investigate specific AhR pathway activation and have the potential to implement thresholding parameters to categorize AhR ligands as “high” or “low” risk for sustained AhR activation. Exploration into transcriptomic signatures for AhR safety assessment, incorporation of physiologically-relevant in vitro model systems, and investigation into chronic activation of the AhR by structurally diverse ligands will help address gaps in our understanding regarding AhR-dependent toxicities. Here, we review the role of the AhR within the GI tract, novel therapeutic modality approaches to target the AhR, key AhR-dependent safety liabilities, and relevant strategies that can be implemented to address drug safety concerns. Together, this review discusses the emerging therapeutic landscape of modalities targeting the AhR for inflammatory GI indications and offers a safety roadmap for AhR drug development.

Safety Assessment of Lactiplantibacillus plantarum TWK10 Based on Whole-Genome Sequencing, Phenotypic, and Oral Toxicity Analysis

Lactiplantibacillus plantarum TWK10 (TWK10), isolated from Taiwanese pickled cabbage, has been demonstrated to exert beneficial probiotic effects in both mice and humans. Here, we comprehensively assessed the safety of TWK10 using both in vivo and in vitro approaches, including whole-genome sequence analysis, an assessment of hemolytic activity, and performing an antimicrobial susceptibility test, the Ames bacterial reverse mutation assay, the chromosomal aberration test, a rodent peripheral blood micronucleus test, and the 28-day subacute oral toxicity assay. The results showed that there was no significant increase in the incidence of reverse mutations or chromosomal aberrations following exposure to TWK10. Moreover, no significant changes were detected either in the number of reticulocytes or the incidence of micronuclei in ICR mice, and no subacute toxicity was recorded in SD rats at the oral TWK10 dosage of 2000 mg/kg body weight/day repeated for 28 days. Additionally, TWK10 exhibited no hemolytic activity and was susceptible to all the antibiotics tested, except kanamycin. However, no antimicrobial resistance genes, virulence factors, or genes involved in biogenic amine synthesis were found in the genome of TWK10. Our findings demonstrated that TWK10 has high potential of being safe for human consumption as a probiotic.

Determination of Antiviral Mechanism of Centenarian Gut-Derived Limosilactobacillus fermentum Against Norovirus

Although noroviruses are the causative agents of most non-bacterial foodborne disease outbreaks, effective antivirals are currently unavailable. Certain probiotic strains have been reported as active antivirals for norovirus infections, but their mechanisms have not been fully elucidated. Herein, we examined the antiviral potential of 122 lactic acid bacteria isolates against murine norovirus (MNV), a human norovirus surrogate. A centenarian gut-derived strain, Limosilactobacillus fermentum PV22, exhibited the strongest MNV antagonism and reduced the viral titer by 2.23 ± 0.38 (log-value) in 5 min with stable activity at 25°C (P < 0.01). Genome mining revealed that its antiviral activity can be attributed to the synthesis of γ-aminobutyric acid, and this finding was experimentally verified. Furthermore, we demonstrated the safety of the isolate and its high intestinal colonization ability. In conclusion, we discovered a centenarian gut-derived L. fermentum strain with strong anti-norovirus activity and identified its antiviral metabolite. Our results will offer new solutions for the prevention and treatment of food-related norovirus infections.

Functional and health-promoting properties of probiotics' exopolysaccharides; isolation, characterization, and applications in the food industry

Exopolysaccharides (EPS) are extracellular sugar metabolites/polymers of some slim microorganisms and, a wide variety of probiotics have been broadly investigated for their ability to produce EPS. EPS originated from probiotics have potential applications in food, pharmaceutical, cosmetology, wastewater treatment, and textiles industries, nevertheless slight is recognized about their function. The present review purposes to comprehensively discuss the structure, classification, biosynthesis, extraction, purification, sources, health-promoting properties, techno-functional benefits, application in the food industry, safety, toxicology, analysis, and characterization methods of EPS originated from probiotic microorganisms. Various studies have shown that probiotic EPS used as stabilizers, emulsifiers, gelling agents, viscosifiers, and prebiotics can alter the nutritional, texture, and rheological characteristics of food and beverages and play a major role in improving the quality of these products. Numerous studies have also proven the beneficial health effects of probiotic EPS, including antioxidant, antimicrobial, anti-inflammatory, immunomodulatory, anticancer, antidiabetic, antibiofilm, antiulcer, and antitoxin activities. Although the use of probiotic EPS has health effects and improves the organoleptic and textural properties of food and pharmaceutical products and there is a high tendency for their use in related industries, the production yield of these products is low and requires basic studies to support their products in large scale.