Probiotic Candidates Research Articles

A study for the genotoxicity assessment of substances containing probiotic candidates in the in vitro TK6 cell micronucleus test: Influence of low pH conditions and antibiotic supplementation on the test results

BackgroundWhen assessing the genotoxicity of substances containing probiotic candidates, such as lactic acid-producing bacteria, using the in vitro micronucleus test (MNT), bacterial growth in the test medium may reduce the pH of the medium. The low medium pH is known to induce cytotoxicity and false-positive results. In the TK6 cell system, it is difficult to completely remove the bacteria from the medium by washing post-treatment, leading to bacterial growth during the recovery period in the short-term treatment. In the present study, the low pH range yielding false positives in the TK6 cell MNT was investigated using media supplemented with acetic, lactic, or formic acids, which are non-genotoxic bacterial metabolites. Additionally, to suppress the bacterial growth during the recovery period using antibiotics, i.e., penicillin/streptomycin (P/S), gentamicin sulfate (GM), and amphotericin B (AP), the maximum applicable concentrations of them that did not affect TK6 cell growth or micronucleus induction were determined. Then, we conducted an MNT using a substance containing live lactic acid-producing bacteria to verify the effectiveness of the antibiotics.ResultsAcetic, lactic, and formic acids induced micronuclei in TK6 cells (false positive) at an initial pH of ≤ 6.2 and ≤ 6.0 in 3 h treatment with and without S9 mix, respectively, and of ≤ 6.7 in the continuous treatment. Media supplemented with P/S, GM, and AP did not affect TK6 cell growth or micronucleated cell frequencies in the negative and positive controls ≤ 400 unit/mL-400 µg/mL, ≤ 250, and ≤ 20 µg/mL, respectively. In an MNT with fermented milk containing live lactic acid-producing bacteria, supplementation with P/S or GM to media for the recovery cultures suppressed the bacterial growth, decreasing pH, and cytotoxicity.ConclusionThis study revealed the low pH ranges yielding false positives in the TK6 cell MNT under short-term and continuous treatment conditions. These values will serve as references for interpreting the biological relevance of results. Under short-term treatment, optimal antibiotic supplementation in recovery cultures suppressed bacterial growth in the test substance and prevented the decrease in pH that could yield false positives. This approach might be useful for evaluating the genotoxicity of test substances containing probiotic candidates using the MNT.

Promising Probiotic Candidates for Sustainable Aquaculture: An Updated Review

With the intensification of aquaculture to meet the rising demands of fish and shellfish, disease outbreaks during the larval and adult stages are a major challenge faced by aqua culturists. As the prophylactic use of vaccines and antibiotics has several limitations, research is now focused on sustainable alternatives to vaccines and antibiotics, e.g., medicinal plants, probiotics, postbiotics, prebiotics, and synbiotics, as promising candidates to strengthen the immune response of fish and shellfish and to control disease outbreaks. With respect to probiotics, numerous studies are available revealing their health-promoting and beneficial impacts in aquaculture. However, most studies focus on Bacillus and Lactobacillus species. Keeping in view the positive effects of probiotic lactic acid bacteria in aquaculture, researchers are now looking for other probiotic bacteria that can be used in aquaculture. Recently, many non-lactic acid bacteria (non-LAB), which are mainly host-associated, have been reported to reveal beneficial effects in fish and shellfish aquaculture. The main non-LAB probiotic genera are Bifidobacterium, Clostridium, Microbacterium, Micrococcus, Paenibacillus, Acinetobacter, Alcaligenes, Enterobacter, Phaeobacter Pseudoalteromonas, Pseudomonas, Pseudomonas, and Vibrio. Despite the promising effects of non-LAB probiotics, comparably, there is limited available information in this context. This review focuses only on probiotic strains that are non-LAB, mostly isolated from the host digestive tract or rearing water, and discusses their beneficial effects in fish and shellfish aquaculture. This review will provide detailed information on the use of various non-LAB bacteria and provide a roadmap to future studies on new probiotics for sustainable aquaculture.

Complete Genome Sequence and In Vitro Probiotic Assessment of Bacillus subtilis DC-11 Isolated from Traditionally Fermented Idli Batter.

In this study, we reported in vitro probiotic assessment and complete genome sequence of Bacillus subtilis DC-11 isolated from traditionally fermented Idli Batter. The strain was evaluated for probiotic properties, biofilm formation, and antimicrobial compound production. The phenotypic safety was determined by accessing the strain's ability to produce enterotoxins, degrade mucin, and antibiotic sensitivity. Whole genome sequencing (WGS) was performed to identify the strain and determine genetic safety by analyzing the presence of plasmids, antibiotic resistance genes, and virulence factors. In the results, B. subtilis DC-11 showed 88.98% viability in gastric juice, and 98.60% viability in intestinal juice. It showed 18.33 ± 0.44% autoaggregation, 32.53 ± 3.11% adhesion to xylene, 0.98 ± 0.05 OD unit's adhesion to mucin (crystal violet equivalence at 550nm), 21.2 ± 2.3% adhesion to Caco-2 cells, and - 22.3 ± 0.65mV zeta potential. The highest co-aggregation was recorded with Escherichia coli (23.62 ± 0.70%). The strain was found negative for enterotoxin production, mucin degradation, and antibiotic resistance to the commonly used therapeutic antibiotics. It formed a good biofilm and capable of producing antimicrobial peptide subtilosin A with a molecular mass of 3400Da. The peptide has inhibited the growth of methicillin-resistant Staphylococcus aureus (18.6 ± 0.58mm). In genetic safety, no plasmids, antibiotic-resistant genes, and virulence factors were detected. Moreover, the strain showed close similarity with B. subtilis ATCC 6051 and proteins involved in probiotic attributes. In conclusion, B. subtilis DC-11 is safe potential probiotic candidate.

Cell-free supernatant of Lactobacillus gasseri 1A-TV shows a promising activity to eradicate carbapenem-resistant Klebsiella pneumoniae colonization.

The use of beneficial bacteria like Lactobacillus spp. is a potential innovative approach to fight antibiotic-resistant pathogens. Klebsiella pneumoniae is one of the most concerning multi drug-resistant (MDR) pathogens, and its ability to colonize the human gut is considered to be the main reason for recurrent infections in critically ill patients. In this study, Lactobacillus gasseri 1A-TV, already described for its probiotic activity, was characterized at the genomic level. Moreover, its cell-free supernatant (CFS) was tested for antimicrobial activity against extended-spectrum β-lactamase (ESBL)- and carbapenemase (KPC)-producing K. pneumoniae clinical isolates. Whole-genome sequencing showed that the L. gasseri 1A-TV genome was of 2,018,898 bp in size with 34.9% GC content, containing 1,937 putative protein coding sequences, 55 tRNA, and 4 rRNA detected by RAST and classified in 20 functional groups by Cluster of Orthologous Genes (COG). BAGEL4 (BActeriocin GEnome minimal tooL) and the antiSMASH 7.0 pipeline identified two bacteriocin biosynthetic gene clusters (BBGCs), namely, BBGC1 that comprises two class IIc bacteriocins including gassericin A-like bacteriocin, and BBGC2 carrying the class III bacteriocin helveticin J. Strikingly, 1A-TV CFS inhibited the growth of all K. pneumoniae isolates only after 8 h of incubation, showing a bactericidal effect at 24 h and interfering, even at lower concentrations, with the biofilm production of biofilm-producer strains independently of a bactericidal effect. NMR analysis of CFS identified and quantified several metabolites involved in carbohydrate metabolism and amino acid metabolism, and organic acids like ethanol, lactate, acetate, and succinate. Finally, in vitro assays of 1A-TV showed significant co-aggregation effects against carbapenem-resistant K. pneumoniae, namely, strains 1, 2, 3, and 7. Our findings highlight the antimicrobial activity of 1A-TV as a probiotic candidate or its CFS as a natural bioproduct active against MDR K. pneumoniae strains, underlining the importance of novel therapeutic strategies for prevention and control of ESBL- and carbapenemase-producing K. pneumoniae colonization.

Evaluation of Safety and Probiotic Properties of Weissella spp. in Fermented Vegetables From Xi'an, Shaanxi, China

ABSTRACTThe genus Weissella, commonly found in fermented foods, is a significant group of lactic acid bacteria (LAB) with potential probiotic properties. Several Weissella strains have been proposed as probiotics due to their biotechnological capabilities. However, a few strains may exhibit opportunistic pathogenic behavior, which restricts the widespread use of all Weissella strains in food applications. This study sought to expand our understanding of the biotechnological capabilities of Weissella spp. by examining the safety and functional characteristics of strains isolated from spontaneous fermentation. In this investigation, nine Weissella strains were evaluated for their safety and probiotic potential. The safety assessment revealed that the antibiotic resistance profiles of strains 16‐2, 38‐3, 69‐3, 91‐3, 91‐5, 104‐4, and 106‐5 were comparable or superior to the reference strain LGG. Hemolytic activity and ammonia production were also evaluated, but no positive results were observed. Further probiotic experiments demonstrated that strain 91‐5 exhibited superior performance in several areas, including survival rates in simulated gastrointestinal fluids, cell surface properties (hydrophobicity and adhesion to Caco‐2 cells), ABTS+ scavenging ability, antimicrobial activity, and cholesterol assimilation in vitro. Additionally, strain 104‐4 produced an exopolysaccharide (EPS) yield of 35.11 g/L after 48 h of culture in MRS‐sucrose (60 g/L) medium, surpassing most previously reported values. These findings suggest that strains 91‐5 and 104‐4 show promise as potential probiotic candidates for the development of new functional food supplements. Furthermore, this research expands the theoretical basis for considering Weissella strains as novel probiotics.

In-depth genomic identification and safety evaluation of Lactobacillus Acidophilus LA85

In vitro tests assessed heat tolerance, bile salt hydrolysis, intestinal adhesion, gastrointestinal environmental tolerance, hemolysis, gelatin hydrolysis, antibiotic sensitivity, inhibition of pathogenic bacteria, and toxicity of Lactobacillus acidophilus LA85. The safety of LA85 was verified by acute oral toxicity test. Genome analysis revealed no virulence, pathogenicity, or biogenic amine synthesis genes in LA85, but one drug resistance gene. LA85 displayed strong heat tolerance, intestinal adhesion, and gastrointestinal environment tolerance, with bile salt and gelatin hydrolysis abilities, and no hemolysis. It was sensitive to European Food Safety Authority proposed antibiotics, had inhibitory effects on common pathogenic bacteria, and both its fermentation broth and cells were non-toxic. Acute oral toxicity test confirmed that LA85 (2 × 1010 CFU/kg) was safe and non-toxic in mice. The safety evaluation presented in this paper firmly establishes LA85 as a safe and effective probiotic candidate for use in a wide range of food and medical applications.

Influence of Tryptophan Metabolism on the Protective Effect ofWeissellaparamesenteroidesWpK4ina MurineModelofChemotherapy-InducedIntestinalMucositis.

Dysbiosis is a notable marker of intestinal mucositis, an inflammatory condition induced by antineoplastic chemotherapy. Scientific evidence supports the effectiveness of probiotics in managing dysbiosis associated with intestinal mucositis. It is known that tryptophan metabolism is a regulatory component in the multifactorial phenomenon of mucosal homeostasis. In the face of that, we aimed to investigate if oral administration of Weissella paramesenteroides WpK4, a probiotic candidate strain, has a protective effect in a murine model of intestinal mucositis induced by 5-fluorouracil (5-FU) and if tryptophan metabolism plays any role in this effect. Gavage with viable cells of W. paramesenteroides WpK4 increased intestinal mucus production, regeneration of villi, as well as control of dysbiosis in mice submitted to 5-FU chemotherapy, and resulted in 100% survival, unlike the control saline-treated group, which resulted in 60% survival of mice after mucositis induction. Weissella paramesenteroides WpK4 genome harbors sequences encoding enzymes for tryptophan production and catabolism and can synthesize tryptophan, tryptamine, and indole acetic acid in vitro. Besides, oral administration of WpK4 induced increased expression of molecules involved in tryptophan metabolism in mouse ileum and serum. Notably, simultaneous treatment with alfa-naphthoflavone, an aryl hydrocarbon receptor (AhR) inhibitor, abolished the protective effects exerted by W. paramesenteroides Wpk4, as manifested by a significant decline in body weight, suggesting that treatment with the probiotic strain modulates AhR activation. Our results suggest that tryptophan metabolism is potentially involved in the protective effects caused by oral administration of W. paramesenteroides WpK4 to mice during gut inflammatory conditions induced by 5-FU.

Randomized Clinical Trials Demonstrate the Safety Assessment of Alkalihalobacillus clausii AO1125 for Use as a Probiotic in Humans.

(1) Background: Alkalihalobacillus clausii AO1125 is a Gram-positive, motile, spore-forming bacterium with potential as a probiotic due to its broad-spectrum antimicrobial activity, inhibiting pathogens like Listeria monocytogenes, Staphylococcus aureus, and Clostridium difficile, as well as anti-rotavirus activity. Its resilience in gastrointestinal conditions suggests benefits for gut health. This study evaluates the safety and probiotic potential of A. clausii AO1125. (2) Methods: Genome annotation identified genes linked to probiotic traits such as stress resistance, gut colonization, immune modulation, and antimicrobial production. The genome was screened for antibiotic resistance genes using CARD, bacteriocin clusters using BAGEL4, and virulence factors via VFDB. Cytotoxicity was assessed on Vero cells and erythrocytes, and a Phase I, double-blind, placebo-controlled clinical trial was conducted with 99 healthy volunteers (50 AO1125, 49 placebo). (3) Results: Genomic analysis confirmed minimal antibiotic resistance genes and the absence of virulence factors, supporting safety. A. clausii AO1125 showed no pathogenicity, cytotoxicity, or hemolytic activity and was well-tolerated in clinical settings, with mild, transient abdominal gas as the most common adverse event. (4) Conclusions: The safety profile and genetic basis for probiotic and antimicrobial properties support A. clausii AO1125 as a promising probiotic candidate for gastrointestinal health, warranting further clinical research.

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

ABSTRACT 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.

Isolation and characterization of Bifidobacterium spp. From breast milk with different human milk oligosaccharides utilization and anti-inflammatory capacity

Breast milk is the best source of nutrition for infants. Human milk oligosaccharides (HMOs) and the corresponding HMOs-consuming Bifidobacterium positively influence infant health. This study aims to isolate and characterize Bifidobacterium from breast milk of healthy Chinese mothers, identifying the most efficacious strains for inclusion in simulated maternal milk formulas. Nine Bifidobacterium strains (two of B. breve and seven of B. infantis) were isolated, exhibiting a broad spectrum of probiotic potential. This included tolerance to simulated infant gastrointestinal conditions, notable adhesion, antibacterial, antioxidant activities, and HMOs utilization ability. Lacto-N-Tetraose (LNT) is preferred in early growth among Bifidobacterium isolates. B. breve showed a preference for LNT, whereas B. infantis showed a preference for fucosylated HMOs, and displayed reduced utilization of sialylated HMOs. They also exhibited robust safety profiles, including no hemolytic activity, an appropriate D/L lactate-producing ratio, and non-toxicity in an acute oral toxicity assay on mice. It is noteworthy that B. breve N-90, O-147, B. infantis O-161 and R-1 exhibited anti-inflammatory effects in LPS-induced RAW 264.7 cells. Specifically, a notable reduction in TNF-α levels was observed in pre-treatment, while a decrease in IL-1β and IL-6 levels in co-treatment. B. breve N-90 and B. infantis R-1 were identified finally as promising probiotic candidates. Their whole-genome sequencing analysis confirmed presence of functional genes associated with gastrointestinal colonization, antioxidation, and glycoside hydrolase activity on HMOs. The annotation for antibiotic resistance and virulence genes concurred with phenotypes, further validating the safety. Breast milk is a good source for Bifidobacteria isolation, while Bifidobacteria utilize HMOs in a strain-dependent manner. The two selected strains, B. breve N-90 and B. infantis R-1, are potential candidates for inclusion in simulated maternal milk formulas and deserved further in vivo investigation for their health-promoting effects.

Isolation and identification of probiotic Bacillus subtilis AJQ03 from the intestinal tract of Anguilla japonica (Japanese eel).

In recent years, the use of fish-derived probiotics in aquaculture has become more widespread. However, research on Anguilla japonica-derived probiotics is still limited. To evaluate the potential of probiotics for disease control in eel aquaculture, isolates were obtained from the intestinal tract of healthy Anguilla japonica. These isolates were assessed for their adhesion properties, inhibition of pathogen adhesion, and hydrolytic enzyme production. Morphological characteristics and 16S rRNA sequence analysis were used for identification. Results showed that the AJQ03 strain adhered to the intestinal mucus and inhibited common pathogenic bacteria through adhesion inhibition, and further produced amylase, lipase, protease, and cellulase. Based on morphological characteristics and 16S rRNA sequencing, AJQ03 was identified as Bacillus subtilis. The strain demonstrated tolerance to various extreme conditions, as well as survival in simulated gastrointestinal fluids and superior growth in intestinal fluid compared to Luria-Bertani (LB) broth. In vitro safety tests showed that AJQ03 was not resistant to 32 antibiotics and exhibited γ hemolysis on blood plate. In vivo safety tests demonstrated a 100% survival rate for the fish, with stable organ indices, reduced bacterial loads in the liver and spleen, and complete bacterial clearance by day 7 without residue. Intestinal bacterial load results confirmed effective colonization by strain AJQ03. Analysis of the impact of AJQ03 on the gut microbiota of A. japonica revealed a significant increase in the relative abundance of Bacillus at the genus level, corroborating the colonization efficiency of AJQ03. Additionally, the relative abundances of Klebsiella, Pseudomonas, and Aeromonas were significantly lower compared to the controls, indicating that strain AJQ03 effectively reduced harmful bacteria and improved gut microbiota composition. This study confirms that B. subtilis AJQ03, isolated from the intestine of A. japonica, can serve as a probiotic candidate in A. japonica aquaculture.

Optimum Level of Lactobacillus plantarum Supplementation as Probiotic on In Vitro Digestibility and Rumen Fermentation Products in Thai Native Cattle

The objective of this study was to determine in vitro gas production kinetics, and rumen fermentation products of total mixed ration (TMR) supplemented with different level of Lactobacillus plantarum supplementation in Thai native cattle. The experiment design was Completely Randomized Design (CRD). The in vitro procedure was completed using 200 mg DM of TMR and four different concentration of L. plantarum; CON (without supplementation of L. plantarum), T1 (107 CFU / mL of L. plantarum supplementation), T2 (108 CFU / mL of L. plantarum supplementation), and T3 (109 CFU / mL of L. plantarum supplementation). The samples were prepared in three replications and incubated for 96 hours for gas production. Rumen fermentation products (pH, NH3, VFA) and digestibility experiment were done in four replications and incubated for 24 hours. In vitro gas production for 96 hours, gas production from insoluble fraction (b), and potential extent of gas production (|a|+b) were improved in the T1 and T2 groups (P < 0.05). The in vitro dry matter and organic matter digestibility, and true digestibility were particularly enhanced in the T1 group compared to other treatments (P <0.05). The pH and NH3 in this study were significantly affected (P<0.05). The significant improvements on the in vitro rumen fermentation products and digestibility endorse L. plantarum supplementation at concentration of 107 CFU/mL as probiotic candidate.

Complete Genome Sequence and Probiotic Characterization of Lactobacillus delbrueckii subsp. Indicus DC-3 Isolated from Traditional Indigenous Fermented Milk.

In this study, Lactobacillus delbrueckii subsp. indicus DC-3 was isolated from Indian traditional indigenous fermented milk Dahi and identified using whole genome sequencing. The safety of the strain was evaluated using genetic and phenotypic analyses, such as the presence of virulence factors, mobile and insertion elements, plasmids, antibiotic resistance, etc. Besides this, the strain was comprehensively investigated for in vitro probiotic traits, biofilm formation, antibacterials, and exopolysaccharide (EPS) production. In results, the strain showed a single circular chromosome (3,145,837bp) with a GC content of 56.73%, a higher number of accessory and unique genes, an open pan-genome, and the absence of mobile and insertion elements, plasmids, virulence, and transmissible antibiotic resistance genes. The strain was capable of surviving in gastric juice (83% viability at 3h) and intestinal juice (71% viability at 6h) and showed 42.5% autoaggregation, adhesion to mucin, 8.7% adhesion to xylene, and 8.3% adhesion to Caco-2 cells. The γ-hemolytic nature, usual antibiotic susceptibility profile, and negative results for mucin and gelatin degradation ensure the safety of the strain. The strain produced 10.5g/L of D-lactic acid and hydrogen peroxide, capable of inhibiting and co-aggregating Escherichia coli MTCC 1687, Proteus mirabilis MTCC 425, and Candida albicans ATCC 14,053. In addition, the strain showed 90mg/L EPS (48h) and biofilm formation. In conclusion, this study demonstrates that L. delbrueckii subsp. indicus DC-3 is unique and different than previously reported L. delbrueckii subsp. indicus strains and is a safe potential probiotic candidate.

Probiotic and Postbiotic Potentials of Enterococcus faecalis EF-2001: A Safety Assessment.

Probiotics, which are live microorganisms that, when given in sufficient quantities, promote the host's health, have drawn a lot of interest for their ability to enhance gut health. Enterococcus faecalis, a member of the human gut microbiota, has shown promise as a probiotic candidate due to its functional attributes. However, safety concerns associated with certain strains warrant comprehensive evaluation before therapeutic application. In this study, E. faecalis EF-2001, originally isolated from fecal samples of a healthy human infant, was subjected to a multi-faceted assessment for its safety and probiotic potential. In silico analysis, CAZyme, biosynthetic, and stress-responsive proteins were identified. The genome lacked biogenic amine genes but contained some essential amino acid and vitamin synthetic genes, and carbohydrate-related enzymes essential for probiotic properties. The negligible difference of 0.03% between the 1st and 25th generations indicates that the genetic information of the E. faecalis EF-2001 genome remained stable. The live E. faecalis EF-2001 (E. faecalis EF-2001L) demonstrated low or no virulence potential, minimal D-Lactate production, and susceptibility to most antibiotics except some aminoglycosides. No bile salt deconjugation or biogenic amine production was observed in an in vitro assay. Hemolytic activity assessment showed a β-hemolytic pattern, indicating no red blood cell lysis. Furthermore, the EF-2001L did not produce gelatinase and tolerated simulated gastric and intestinal fluids in an in vitro study. Similarly, heat-killed E. faecalis EF-2001 (E. faecalis EF-2001HK) exhibits tolerance in both acid and base conditions in vitro. Further, no cytotoxicity of postbiotic EF-2001HK was observed in human colorectal adenocarcinoma HT-29 cells. These potential properties suggest that probiotic and postbiotic E. faecalis EF-2001 could be considered safe and retain metabolic activity suitable for human consumption.

Characterization of Human Breast Milk-Derived Limosilactobacillus reuteri MBHC 10138 with Respect to Purine Degradation, Anti-Biofilm, and Anti-Lipid Accumulation Activities.

Background: Human breast milk is a valuable source of potential probiotic candidates. The bacteria isolated from human breast milk play an important role in the development of the infant gut microbiota, exhibiting diverse biological functions. Methods: In this study, Limosilactobacillus reuteri MBHC 10138 isolated from breast milk was characterized in terms of its probiotic safety characteristics and potential efficacy in hyperuricemia, obesity, lipid liver, and dental caries, conditions which Korean consumers seek to manage using probiotics. Results: Strain MBHC 10138 demonstrated a lack of D-lactate and biogenic amine production as well as a lack of bile salt deconjugation and hemolytic activity. It also exhibited susceptibility to common antibiotics, tolerance to simulated oral-gastric-intestinal conditions, and superior biological activity compared to three L. reuteri reference strains, including KACC 11452 and MJ-1, isolated from feces, and a commercial strain isolated from human breast milk. Notably, L. reuteri MBHC 10138 showed high capabilities in assimilating guanosine (69.48%), inosine (81.92%), and adenosine (95.8%), strongly inhibited 92.74% of biofilm formation by Streptococcus mutans, and reduced lipid accumulation by 32% in HepG2 cells. Conclusions: These findings suggest that strain MBHC 10138, isolated from human breast milk, has potential to be developed as a probiotic for managing hyperuricemia, obesity, and dental caries after appropriate in vivo studies.

Oral supplementation with lactic acid bacteria improve the intestinal epithelial barrier and gut microbiota of broiler chicks to alleviate Salmonella Enteritidis infection

Lactic acid bacteria (LAB) play a key role in regulating the balance of gut microbiota and serve as a suitable alternative to antibiotics. This study aims to evaluate the characteristics of 2 LAB isolates Lactiplantibacillus plantarum Lp71 (L. plantarum Lp71) and Enterococcus faecium Ef72 (E. faecium Ef72), and their roles in alleviating Salmonella Enteritidis infection. Sixty 1-day-old chicks were randomly divided into 4 groups which treated with or without L. plantarum Lp71 and E. faecium Ef72 mixture for 21 d, and then intestinal samples were collected for gut microbiota analysis, pathological and immunohistochemical analysis at 24 h post infection with or without Salmonella Enteritidis on the 22nd d. The results showed that L. plantarum Lp71 and E. faecium Ef72 had the ability to anti-acid and anti-bile salt. Salmonella Enteritidis infection damaged the intestinal epithelial barrier and reduced the expression level of tight junction proteins (ZO-1, Claudin-1, Occludin). Oral supplementation with L. plantarum Lp71 and E. faecium Ef72 mixture could alleviated the damages to intestinal epithelial barrier by Salmonella Enteritidis infection. Salmonella Enteritidis could cause abnormal Akkermansia muciniphila proliferation and decrease the diversity of cecal microbiota in chicks. These conditions could have further led to reduce gut microbiota health index (GMHI), and improve microbial dysbiosis index (MDI). Moreover, oral supplementation with L. plantarum Lp71 and E. faecium Ef72 mixture could effectively prevent the aforementioned infection outcomes and increase the abundance proportions of the several key functions in metabolic pathways metabolic pathways such as transcription and signal transduction mechanisms. In summary, L. plantarum Lp71 and E. faecium Ef72 could be the probiotics candidates that used to prevent the damage from enteric pathogens such as Salmonella Enteritidis in broiler chicks.

Assessment of Potential Probiotic Yeasts Isolated from The Small Intestines of Cattle in Thailand

Y easts are widely studied and considered good candidates for probiotics due to their numerous benefits. This study aimed to investigate potential probiotic attributes of yeasts isolated from the small intestines of cattle in Thailand. Growth at body temperature, resistance to low pH, auto-aggregation capability, hydrophobicity, growth under gastrointestinal tract (GIT) conditions, safety profiles, antimicrobial activity, and extracellular enzyme production of yeast strains were evaluated in vitro. The results of sequential screening indicated that 829 out of 1,025 yeast strains could grow at both 37 and 39 °C, 682 strains could resist acidity at pH 2 for 24 h, 252 strains revealed greater than 83% auto-aggregation capability, and 97 strains showed higher than 90% hydrophobicity. Sixty strains grew well under simulated GIT conditions in the presence of pepsin, pancreatin, and bile salts. Thirteen strains of Diutina rugosa showed negative results for hemolytic, gelatinase, and phospholipase activities, while seven strains of Pichia kudriavzevii also showed negative results for the above activities, except for phospholipase. Neither D. rugosa nor P. kudriavzevii inhibited Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Additionally, 12 strains of D. rugosa and four strains of P. kudriavzevii produced phytase and cellulase, while only D. rugosa PCD3-6 exhibited protease and phytase activities. Therefore, D. rugosa (strains PCD3-6, PCD93-19, PYJ93-7, PYJ93-16, PCJ94-4, PCJ94-6, PCJ94-10, PYD100-8, CTD93-1, CTD93-2, CTJ93-5, CTJ93-6, and YTJ97-4) and P. kudriavzevii (strains PYI3-3, PCI3-4, PCJ90-7, and PYI91-15) were proposed as potential probiotic yeasts. They may be beneficially applied as feed additives to improve nutritional value and quality, thereby enhancing animal performance and health. Moreover, this work indicated useful preliminary results that could be a baseline for future research in human probiotic applications.

Exploring the probiotic potential of Lactiplantibacillus pentosus SM1: Resistance, anti-microbial activity, anti-biofilm, cytotoxic activity, and safety properties

Lactiplantibacillus pentosus SM1 displayed notable resistance to acidic environments, with over 76% survival after 3 h in low pH conditions, and demonstrated viability in simulated gastrointestinal fluids. The Lpb. pentosus SM1 exhibited surface hydrophobicity, auto-aggregation, co-aggregation, and adhesion values of 59.60%, 38.80%, 44.90%, and 13.10% respectively. The anti-adhesion capability of Lpb. pentosus SM1 against Listeria monocytogenes adhesion to Caco-2 cells was demonstrated by its ability to compete with, inhibit, and displace at rates of 54.10%, 48.80%, and 23.90%, respectively. The Lpb. pentosus SM1 exhibited broad-spectrum anti-microbial activity, particularly against Gram-positive bacteria, and inhibited biofilm formation. The strain also showcased antioxidant activity, effectively scavenging DPPH (57.60%) and ABTS (60.54%) radicals. Notably, it absorbed 51.60% of cholesterol, highlighting its potential for cholesterol-lowering benefits. The cytotoxicity values were measured at 36.57 mg/mL for HT-29 and 38.20 mg/mL for Hela cancer cell lines. Importantly, Lpb. pentosus SM1 was free of hemolytic activity and biogenic amines, demonstrating a favorable safety profile. Lpb. pentosus SM1 exhibited the strongest resistance to ampicillin, while its resistance to erythromycin was the weakest, with inhibition zones measuring 15.50 mm and 26.40 mm, respectively. These findings suggest that Lpb. pentosus SM1 has promising applications as a probiotic candidate for promoting gut health and preventing pathogenic infections.

A Study to Evaluate the Role of Probiotics in Allergic Rhinitis.

To compare treatment outcomes in allergic rhinitis patients with and without probiotics. The present study was conducted in the Out Patient Department of ENT in a Tertiary Care Hospital w.e.f. April 2023 till March 2024. Total 106 patients of allergic rhinits were included in the study and were divided randomly into 2 groups with 53 in each group. Group A was given probiotics along with standard treatment of antihistaminics and topical steroids and group B was given antihistaminics and topical steroids only. Total Nasal Symptoms Score (TNSS) of all patients was calculated at the time of enrollment and after 8 weeks post treatment. Based on the pre-treatment and post-treatment TNSS, an analysis was made whether probiotics could be an add-on therapy along with the standard treatment given for allergic rhinitis from past so many years. We conducted our study on 106 patients with mean age of 28.1 ± 8.91 years.44% were male and 56% were female. In group A pre-treatment TNSS was 8.057 + 2.307 and post treatment TNSS was 0.887 + 0.776. In group B pre-treatment TNSS was 9.45 + 0.514 and post treatment was 1.89 + 0.776. The mean post-treatment TNSS in group A was lower than the group B. This difference was statistically significant with p value of < 0.05. Based on the study we can suggest that probiotics could be a potential add-on strategy in the management of allergic rhinitis. Probiotic supplement action seems to be effective in ameliorating allergic rhinitis symptoms and improving the quality of life. However further clinical and molecular studies are required to improve our knowledge about interactions among candidate probiotics and host microbiome, cells and immune defenses, in order to create efficacious interventions.

Exploring the Potential Probiotic Properties of Bifidobacterium breve DSM 32583-A Novel Strain Isolated from Human Milk.

Human milk is the best nutrition for infants, providing optimal support for the developing immune system and gut microbiota. Hence, it has been used as source for probiotic strain isolation, including members of the genus Bifidobacterium, in an effort to provide beneficial effects to infants who cannot be exclusively breastfed. However, not all supplemented bifidobacteria can effectively colonise the infant gut, nor confer health benefits to the individual infant host; therefore, new isolates are needed to develop a range of dietary products for this specific age group. Here, we investigated the beneficial potential of Bifidobacterium breve DSM 32583 isolated from human milk. We show that in vitro B. breve DSM 32583 exhibited several characteristics considered fundamental for beneficial bacteria, including survival in conditions simulating those present in the digestive tract, adherence to human epithelial cell lines, and inhibition of growth of potentially pathogenic microorganisms. Its antibiotic resistance patterns were comparable to those of known beneficial bifidobacterial strains, and its genome did not contain plasmids nor virulence-associated genes. These results suggest that B. breve DSM 32583 is a potential probiotic candidate.