Multidrug resistance profile in Lactobacillus delbrueckii: a food industry species with probiotic properties.

Lactobacillus delbrueckii, a widely used lactic acid bacterium in the food industry, has been studied for its probiotic properties and reservoir of antibiotic-resistant genes, raising safety concerns for probiotic formulations and fermented products. This review consolidates findings from 60 articles published between 2012 and 2023, focusing on the global antibiotic resistance profile and associated genetic factors in L. delbrueckii strains. Resistance to aminoglycosides, particularly streptomycin, kanamycin, and gentamicin, as well as resistance to glycopeptides (vancomycin), fluoroquinolones (ciprofloxacin), and tetracyclines was predominant. Notably, although resistance genes have been identified, they have not been linked to mobile genetic elements, reducing the risk of dissemination. However, a significant limitation is the insufficient exploration of responsible genes or mobile elements in 80% of studies, hindering safety assessments. Additionally, most articles originated from Asian and Middle Eastern countries, with strains often isolated from fermented dairy foods. Therefore, these findings underscore the necessity for comprehensive analyses of new strains of L. delbrueckii for potential industrial and biotherapeutic applications and in combating the rise of antibiotic-resistant pathogens.

Comprehensive probiogenomics analysis of the commensal Escherichia coli CEC15 as a potential probiotic strain.

BACKGROUND: Probiotics have gained attention for their potential maintaining gut and immune homeostasis. They have been found to confer protection against pathogen colonization, possess immunomodulatory effects, enhance gut barrier functionality, and mitigate inflammation. However, a thorough understanding of the unique mechanisms of effects triggered by individual strains is necessary to optimize their therapeutic efficacy. Probiogenomics, involving high-throughput techniques, can help identify uncharacterized strains and aid in the rational selection of new probiotics. This study evaluates the potential of the Escherichia coli CEC15 strain as a probiotic through in silico, in vitro, and in vivo analyses, comparing it to the well-known probiotic reference E. coli Nissle 1917. Genomic analysis was conducted to identify traits with potential beneficial activity and to assess the safety of each strain (genomic islands, bacteriocin production, antibiotic resistance, production of proteins involved in host homeostasis, and proteins with adhesive properties). In vitro studies assessed survival in gastrointestinal simulated conditions and adhesion to cultured human intestinal cells. Safety was evaluated in BALB/c mice, monitoring the impact of E. coli consumption on clinical signs, intestinal architecture, intestinal permeability, and fecal microbiota. Additionally, the protective effects of both strains were assessed in a murine model of 5-FU-induced mucositis. RESULTS: CEC15 mitigates inflammation, reinforces intestinal barrier, and modulates intestinal microbiota. In silico analysis revealed fewer pathogenicity-related traits in CEC15, when compared to Nissle 1917, with fewer toxin-associated genes and no gene suggesting the production of colibactin (a genotoxic agent). Most predicted antibiotic-resistance genes were neither associated with actual resistance, nor with transposable elements. The genome of CEC15 strain encodes proteins related to stress tolerance and to adhesion, in line with its better survival during digestion and higher adhesion to intestinal cells, when compared to Nissle 1917. Moreover, CEC15 exhibited beneficial effects on mice and their intestinal microbiota, both in healthy animals and against 5FU-induced intestinal mucositis. CONCLUSIONS: These findings suggest that the CEC15 strain holds promise as a probiotic, as it could modulate the intestinal microbiota, providing immunomodulatory and anti-inflammatory effects, and reinforcing the intestinal barrier. These findings may have implications for the treatment of gastrointestinal disorders, particularly some forms of diarrhea.

Synergistic synbiotic containing fructooligosaccharides and Lactobacillus delbrueckii CIDCA 133 alleviates chemotherapy-induced intestinal mucositis in mice.

Intestinal mucositis is a commonly reported side effect in oncology patients undergoing chemotherapy and radiotherapy. Probiotics, prebiotics, and synbiotics have been investigated as alternative therapeutic approaches against intestinal mucositis due to their well-known anti-inflammatory properties and health benefits to the host. Previous studies showed that the potential probiotic Lactobacillus delbrueckii CIDCA 133 and the prebiotic Fructooligosaccharides (FOS) alleviated the 5-Fluorouracil (5-FU) chemotherapy-induced intestinal mucosa damage. Based on these previous beneficial effects, this work evaluated the anti-inflammatory property of the synbiotic formulation containing L. delbrueckii CIDCA 133 and FOS in mice intestinal mucosa inflammation induced by 5-FU. This work showed that the synbiotic formulation was able to modulate inflammatory parameters, including reduction of cellular inflammatory infiltration, gene expression downregulation of Tlr2, Nfkb1, and Tnf, and upregulation of the immunoregulatory Il10 cytokine, thus protecting the intestinal mucosa from epithelial damage caused by the 5-FU. The synbiotic also improved the epithelial barrier function by upregulating mRNA transcript levels of the short chain fatty acid (SCFA)-associated GPR43 receptor and the occludin tight junction protein, with the subsequent reduction of paracellular intestinal permeability. The data obtained showed that this synbiotic formulation could be a promising adjuvant treatment to be explored against inflammatory damage caused by 5-FU chemotherapy.

Genistein and Ascorbic Acid Reduce Oxidative Stress-Derived DNA Damage Induced by the Antileishmanial Meglumine Antimoniate.

Meglumine antimoniate (Glucantime) is a pentavalent antimonial used to treat leishmaniasis, despite its acknowledged toxic effects, such as its ability to cause oxidative damage to lipids and proteins. Recently, our group demonstrated that meglumine antimoniate causes oxidative stress-derived DNA damage. Knowing that antioxidants modulate reactive oxygen species, we evaluated the capacity of genistein and ascorbic acid for preventing genotoxicity caused by meglumine antimoniate. For that, mice (n = 5/group) received genistein (via gavage) in doses of 5, 10, and 20 mg/kg for three consecutive days. After this period, they were treated with 810 mg/kg meglumine antimoniate via intraperitoneal (i.p.) route. Furthermore, mice (n = 5/group) simultaneously received ascorbic acid (i.p.) in doses of 30, 60, and 120 mg/kg and 810 mg/kg meglumine antimoniate. We also conducted post- and pretreatment assays, in which animals received ascorbic acid (60 mg/kg) 24 h prior to or after receiving meglumine antimoniate. Genomic instability and mutagenicity were analyzed through conventional comet assay and enzymatic assay using formamide pyrimidine DNA glycosylase (Fpg) enzyme, as well as the micronucleus test, respectively. Meglumine antimoniate induced an increase in the DNA damage after digestion with Fpg, reinforcing its mutagenic potential by oxidizing DNA bases, which was prevented by genistein. Similarly, ascorbic acid was capable of reducing mutagenic effects in simultaneous treatment as well as in posttreatment. Therefore, our results demonstrate that both compounds are efficient in preventing mutations in mammalian cells treated with meglumine antimoniate.

Meglumine Antimoniate (Glucantime) Causes Oxidative Stress-Derived DNA Damage in BALB/c Mice Infected by Leishmania (Leishmania) infantum.

Leishmaniasis is a neglected tropical disease caused by >20 species of the protozoan parasite Leishmania Meglumine antimoniate (Glucantime) is the first-choice drug recommended by the World Health Organization for the treatment of all types of leishmaniasis. However, the mechanisms of action and toxicity of pentavalent antimonials, including genotoxic effects, remain unclear. Therefore, the mechanism by which meglumine antimoniate causes DNA damage was investigated for BALB/c mice infected by Leishmania (Leishmania) infantum and treated with meglumine antimoniate (20 mg/kg for 20 days). DNA damage was analyzed by a comet assay using mouse leukocytes. Furthermore, comet assays were followed by treatment with formamidopyrimidine-DNA glycosylase and endonuclease III, which remove oxidized DNA bases. In addition, the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the animals' sera were assessed. To investigate mutagenicity, we carried out a micronucleus test. Our data demonstrate that meglumine antimoniate, as well as L. infantum infection, induces DNA damage in mammalian cells by the oxidation of nitrogenous bases. Additionally, the antileishmanial increased the frequency of micronucleated cells, confirming its mutagenic potential. According to our data, both meglumine antimoniate treatment and L. infantum infection promote oxidative stress-derived DNA damage, which promotes overactivation of the SOD-CAT axis, whereas the SOD-GPx axis is inhibited as a probable consequence of glutathione (GSH) depletion. Finally, our data enable us to suggest that a meglumine antimoniate regimen, as recommended by the World Health Organization, would compromise GPx activity, leading to the saturation of antioxidant defense systems that use thiol groups, and might be harmful to patients under treatment.

Lactococcus lactis as an Interleukin Delivery System for Prophylaxis and Treatment of Inflammatory and Autoimmune Diseases.

Target delivery of therapeutic agents with anti-inflammatory properties using probiotics as delivery and recombinant protein expression vehicles is a promising approach for the prevention and treatment of many diseases, such as cancer and intestinal immune disorders. Lactococcus lactis, a Lactic Acid Bacteria (LAB) widely used in the dairy industry, is one of the most important microorganisms with GRAS status for human consumption, for which biotechnological tools have already been developed to express and deliver recombinant biomolecules with anti-inflammatory properties. Cytokines, for  example, are immune system communication molecules present at virtually all levels of the immune response. They are essential in cellular and humoral processes, such as hampering inflammation or adjuvating in the adaptive immune response, making them good candidates for therapeutic approaches. This review discusses the advances in the development of new therapies and prophylactic approaches using LAB to deliver/express cytokines for the treatment of inflammatory and autoimmune diseases in the future.

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.

Lactobacillus delbrueckii CIDCA 133 fermented milk modulates inflammation and gut microbiota to alleviate acute colitis.

Lactobacillus delbrueckii subsp. lactis CIDCA 133 is a health-promoting bacterium that can alleviate gut inflammation and improve the epithelial barrier in a mouse model of mucositis. Despite these beneficial effects, the protective potential of this strain in other inflammation models, such as inflammatory bowel disease, remains unexplored. Herein, we examined for the first time the efficacy of Lactobacillus delbrueckii CIDCA 133 incorporated into a fermented milk formulation in the recovery of inflammation, epithelial damage, and restoration of gut microbiota in mice with dextran sulfate sodium-induced colitis. Oral administration of Lactobacillus delbrueckii CIDCA 133 fermented milk relieved colitis by decreasing levels of inflammatory factors (myeloperoxidase, N-acetyl-ß-D-glucosaminidase, toll-like receptor 2, nuclear factor-κB, interleukins 10 and 6, and tumor necrosis factor), secretory immunoglobulin A levels, and intestinal paracellular permeability. This immunobiotic also modulated the expression of tight junction proteins (zonulin and occludin) and the activation of short-chain fatty acids-related receptors (G-protein coupled receptors 43 and 109A). Colonic protection was effectively associated with acetate production and restoration of gut microbiota composition. Treatment with Lactobacillus delbrueckii CIDCA 133 fermented milk increased the abundance of Firmicutes members (Lactobacillus genus) while decreasing the abundance of Proteobacteria (Helicobacter genus) and Bacteroidetes members (Bacteroides genus). These promising outcomes influenced the mice's mucosal healing, colon length, body weight, and disease activity index, demonstrating that this immunobiotic could be explored as an alternative approach for managing inflammatory bowel disease.

Exploring the anti-inflammatory effects of postbiotic proteins from Lactobacillus delbrueckii CIDCA 133 on inflammatory bowel disease model.

Lactobacillus delbrueckii CIDCA 133 is a promising health-promoting bacterium shown to alleviate intestinal inflammation. However, the specific bacterial components responsible for these effects remain largely unknown. Here, we demonstrated that consuming extractable proteins from the CIDCA 133 strain effectively relieved acute ulcerative colitis in mice. This postbiotic protein fraction reduced the disease activity index and prevented colon shortening in mice. Furthermore, histological analysis revealed colitis prevention with reduced inflammatory cell infiltration into the colon mucosa. Postbiotic consumption also induced an immunomodulatory profile in colitic mice, as evidenced by both mRNA transcript levels (Tlr2, Nfkb1, Nlpr3, Tnf, and Il6) and cytokines concentration (IL1ß, TGFß, and IL10). Additionally, it enhanced the levels of secretory IgA, upregulated the transcript levels of tight junction proteins (Hp and F11r), and improved paracellular intestinal permeability. More interestingly, the consumption of postbiotic proteins modulated the gut microbiota (Bacteroides, Arkkemansia, Dorea, and Oscillospira). Pearson correlation analysis indicated that IL10 and IL1ß levels were positively associated with Bacteroides and Arkkemansia_Lactobacillus abundance. Our study reveals that CIDCA 133-derived proteins possess anti-inflammatory properties in colonic inflammation.

Recombinant probiotic Lactococcus lactis delivering P62 mitigates moderate colitis in mice.

Introduction and objective: p62 is a human multifunctional adaptor protein involved in key cellular processes such as tissue homeostasis, inflammation, and cancer. It acts as a negative regulator of inflammasome complexes. It may thus be considered a good candidate for therapeutic use in inflammatory bowel diseases (IBD), such as colitis. Probiotics, including recombinant probiotic strains producing or delivering therapeutic biomolecules to the host mucosal surfaces, could help prevent and mitigate chronic intestinal inflammation. The objective of the present study was to combine the intrinsic immunomodulatory properties of the probiotic Lactococcus lactis NCDO2118 with its ability to deliver health-promoting molecules to enhance its protective and preventive effects in the context of ulcerative colitis (UC). Material and methods: This study was realized in vivo in which mice were supplemented with the recombinant strain. The intestinal barrier function was analyzed by monitoring permeability, secretory IgA total levels, mucin expression, and tight junction genes. Its integrity was evaluated by histological analyses. Regarding inflammation, colonic cytokine levels, myeloperoxidase (MPO), and expression of key genes were monitored. The intestinal microbiota composition was investigated using 16S rRNA Gene Sequencing. Results and discussion: No protective effect of L. lactis NCDO2118 pExu:p62 was observed regarding mice clinical parameters compared to the L. lactis NCDO2118 pExu: empty. However, the recombinant strain, expressing p62, increased the goblet cell counts, upregulated Muc2 gene expression in the colon, and downregulated pro-inflammatory cytokines Tnf and Ifng when compared to L. lactis NCDO2118 pExu: empty and inflamed groups. This recombinant strain also decreased colonic MPO activity. No difference in the intestinal microbiota was observed between all treatments. Altogether, our results show that recombinant L. lactis NCDO2118 delivering p62 protein protected the intestinal mucosa and mitigated inflammatory damages caused by dextran sodium sulfate (DSS). We thus suggest that p62 may constitute part of a therapeutic approach targeting inflammation.

The genomic approach of antimicrobial resistance of Salmonella Typhimurium isolates from guinea pigs in Lima, Peru.

Salmonella Typhimurium is an important agent of foodborne diseases. In Peru, the emergence of multidrug-resistant isolates of S. Typhimurium from the food chain could be linked to guinea pig farming as a potential reservoir and their uncontrolled antibiotic treatment against salmonellosis. In this study, we performed the sequencing, genomic diversity, and characterization of resistance elements transmitted by isolates from farm and meat guinea pigs. The genomic diversity and antimicrobial resistance of S. Typhimurium isolates were performed using nucleotide similarity, cgMLST, serotyping, phylogenomic analyses, and characterization of resistance plasmids. We found at least four populations of isolates from farm guinea pigs and four populations from meat guinea pigs without finding isolated transmission between both resources. Genotypic resistance to antibiotics was observed in at least 50% of the isolates. Among the farm guinea pig isolates, ten were found to be resistant to nalidixic acid, and two isolates exhibited multidrug resistance to aminoglycosides, tetracycline-fluoroquinolone (carrying strA-strB-tetA-tetB genes and gyrA S83F mutation), or trimethoprim-sulfonamide (carrying AaadA1-drfA15-sul1 genes). Additionally, two isolates from the meat source were resistant to fluoroquinolones (one of which had enrofloxacin resistance). The transmissible resistance plasmids with insertion sequences (IS) such as IncI-gamma-K1-ISE3-IS6, IncI1-I (alpha)-IS21-Tn10, and Col (pHAD28) were commonly found in isolates belonging to the HC100-9757 cluster from both guinea pigs and human hosts. Altogether, our work provides resistance determinants profiles and Salmonella sp. circulating lineages using WGS data that can promote better sanitary control and adequate antimicrobial prescription.

Paraprobiotic Lacticaseibacillus rhamnosus Protects Intestinal Damage in an Experimental Murine Model of Mucositis.

Intestinal mucositis (IM) is a common side effect resulting from cancer treatment. However, the management so far has not been very effective. In the last years, the role of the gut microbiota in the development and severity of mucositis has been studied. Therefore, the use of probiotics and paraprobiotics could have a potential therapeutic effect on IM. The aim of our study was to investigate the impact of the administration of Lacticaseibacillus rhamnosus (L. rhamnosus) CGMCC1.3724 and the paraprobiotic on IM in mice. For 13 days, male Balb/c mice were divided into six groups: control (CTL) and mucositis (MUC)/0.1 mL of saline; CTL LrV and MUC LrV/0.1 mL of 108 CFU of viable Lr; CTL LrI and MUC LrI/0.1 mL of 108 CFU of inactivated Lr. On the 10th day, mice from the MUC, MUC LrV, and MUC LrI groups received an intraperitoneal injection (300 mg/kg) of 5-fluorouracil to induce mucositis. The results showed that the administration of the chemotherapeutic agent increased the weight loss and intestinal permeability of the animals in the MUC and MUC LrV groups. However, administration of paraprobiotic reduced weight loss and maintained PI at physiological levels. The paraprobiotic also preserved the villi and intestinal crypts, reduced the inflammatory infiltrate, and increased the mucus secretion, Muc2 gene expression, and Treg cells frequency.

Evaluation of Probiotic Properties of Novel Brazilian Lactiplantibacillus plantarum Strains.

Beneficial effects of Lactiplantibacillus plantarum strains have been widely reported. Knowing that the effects of probiotic bacteria are strain-dependent, this study aimed to characterize the probiotic properties and investigate the gastrointestinal protective effects of nine novel L. plantarum strains isolated from Bahia, Brazil. The probiotic functionality was first evaluated in vitro by characterizing bile salt and acidic tolerance, antibacterial activity, and adhesion to Caco-2 cells. Antibiotic resistance profile, mucin degradation, and hemolytic activity assays were also performed to evaluate safety features. In vivo analyses were conducted to investigate the anti-inflammatory effects of the strains on a mouse model of 5-Fluorouracil-induced mucositis. Our results suggest that the used L. plantarum strains have good tolerance to bile salts and low pH and can inhibit commonly gastrointestinal pathogens. Lp2 and Lpl1 strains also exhibited high adhesion rates to Caco-2 cells (13.64 and 9.05%, respectively). Phenotypical resistance to aminoglycosides, vancomycin, and tetracycline was observed for most strains. No strain showed hemolytic or mucolytic activity. Seven strains had a protective effect against histopathological and inflammatory damage induced by 5-FU. Gene expression analysis of inflammatory markers showed that five strains upregulated interleukin 10 (Il10), while four downregulated both interleukin 6 (Il6) and interleukin 1b (Il1b). Additionally, all strains reduced eosinophilic and neutrophilic infiltration; however, they could not prevent weight loss or reduced liquid/ food intake. Altogether, our study suggests these Brazilian L. plantarum strains present good probiotic characteristics and safety levels for future applications and can be therapeutically adjuvant alternatives to prevent/treat intestinal mucositis.

Growth differentiation factor 11 delivered by dairy Lactococcus lactis strains modulates inflammation and prevents mucosal damage in a mice model of intestinal mucositis.

Mucositis is an inflammation of the gastrointestinal mucosa that debilitate the quality of life of patients undergoing chemotherapy treatments. In this context, antineoplastic drugs, such as 5-fluorouracil, provokes ulcerations in the intestinal mucosa that lead to the secretion of pro-inflammatory cytokines by activating the NF-κB pathway. Alternative approaches to treat the disease using probiotic strains show promising results, and thereafter, treatments that target the site of inflammation could be further explored. Recently, studies reported that the protein GDF11 has an anti-inflammatory role in several diseases, including in vitro and in vivo results in different experimental models. Hence, this study evaluated the anti-inflammatory effect of GDF11 delivered by Lactococcus lactis strains NCDO2118 and MG1363 in a murine model of intestinal mucositis induced by 5-FU. Our results showed that mice treated with the recombinant lactococci strains presented improved histopathological scores of intestinal damage and a reduction of goblet cell degeneration in the mucosa. It was also observed a significant reduction of neutrophil infiltration in the tissue in comparison to positive control group. Moreover, we observed immunomodulation of inflammatory markers Nfkb1, Nlrp3, Tnf, and upregulation of Il10 in mRNA expression levels in groups treated with recombinant strains that help to partially explain the ameliorative effect in the mucosa. Therefore, the results found in this study suggest that the use of recombinant L. lactis (pExu:gdf11) could offer a potential gene therapy for intestinal mucositis induced by 5-FU.

Probiogenomics of Leuconostoc Mesenteroides Strains F-21 and F-22 Isolated from Human Breast Milk Reveal Beneficial Properties.

Bacteria of the Leuconostoc genus are Gram-positive bacteria that are commonly found in raw milk and persist in fermented dairy products and plant food. Studies have already explored the probiotic potential of L. mesenteroides, but not from a probiogenomic perspective, which aims to explore the molecular features responsible for their phenotypes. In the present work, probiogenomic approaches were applied in strains F-21 and F-22 of L. mesenteroides isolated from human milk to assess their biosafety at the molecular level and to correlate molecular features with their potential probiotic characteristics. The complete genome of strain F-22 is 1.99 Mb and presents one plasmid, while the draft genome of strain F-21 is 1.89 Mb and presents four plasmids. A high percentage of average nucleotide identity among other genomes of L. mesenteroides (≥ 96%) corroborated the previous taxonomic classification of these isolates. Genomic regions that influence the probiotic properties were identified and annotated. Both strains exhibited wide genome plasticity, cell adhesion ability, proteolytic activity, proinflammatory and immunomodulation capacity through interaction with TLR-NF-κB and TLR-MAPK pathway components, and no antimicrobial resistance, denoting their potential to be candidate probiotics. Further, the strains showed bacteriocin production potential and the presence of acid, thermal, osmotic, and bile salt resistance genes, indicating their ability to survive under gastrointestinal stress. Taken together, our results suggest that L. mesenteroides F-21 and F-22 are promising candidates for probiotics in the food and pharmaceutical industries.

Comparative genomic analysis of the Dietzia genus: an insight into genomic diversity, and adaptation.

Dietzia strains are widely distributed in the environment, presenting an opportunistic role, and some species have undetermined taxonomic characteristics. Here, we propose the existence of errors in the classification of species in this genus using comparative genomics. We performed ANI, dDDH, pangenome and genomic plasticity analyses better to elucidate the phylogenomic relationships between Dietzia strains. For this, we used 55 genomes of Dietzia downloaded from public databases that were combined with a newly sequenced. Sequence analysis of a phylogenetic tree based on genome similarity comparisons and dDDH, ANI analyses supported grouping different Dietzia species into four distinct groups. The pangenome analysis corroborated the classification of these groups, supporting the idea that some species of Dietzia could be reassigned in a possible classification into three distinct species, each containing less variability than that found within the global pangenome of all strains. Additionally, analysis of genomic plasticity based on groups containing Dietzia strains found differences in the presence and absence of symbiotic Islands and pathogenic islands related to their isolation site. We propose that the comparison of pangenome subsets together with phylogenomic approaches can be used as an alternative for the classification and differentiation of new species of the genus Dietzia.

Genomic Characterization of Lactobacillus delbrueckii Strains with Probiotics Properties.

Probiotics are health-beneficial microorganisms with mainly immunomodulatory and anti-inflammatory properties. Lactobacillus delbrueckii species is a common bacteria used in the dairy industry, and their benefits to hosting health have been reported. This study analyzed the core genome of nine strains of L. delbrueckii species with documented probiotic properties, focusing on genes related to their host health benefits. For this, a combined methodology including several software and databases (BPGA, SPAAN, BAGEL4, BioCyc, KEEG, and InterSPPI) was used to predict the most important characteristics related to L. delbrueckii strains probiose. Comparative genomics analyses revealed that L. delbrueckii probiotic strains shared essential genes related to acid and bile stress response and antimicrobial activity. Other standard features shared by these strains are surface layer proteins and extracellular proteins-encoding genes, with high adhesion profiles that interacted with human proteins of the inflammatory signaling pathways (TLR2/4-MAPK, TLR2/4-NF-κB, and NOD-like receptors). Among these, the PrtB serine protease appears to be a strong candidate responsible for the anti-inflammatory properties reported for these strains. Furthermore, genes with high proteolytic and metabolic activity able to produce beneficial metabolites, such as acetate, bioactive peptides, and B-complex vitamins were also identified. These findings suggest that these proteins can be essential in biological mechanisms related to probiotics' beneficial effects of these strains in the host.

Safety Evaluation of Lactobacillus delbrueckii subsp. lactis CIDCA 133: a Health-Promoting Bacteria.

Lactobacillus delbrueckii subsp. lactis CIDCA is a new potential probiotic strain whose molecular basis attributed to the host's benefit has been reported. This study investigated the safety aspects of Lactobacillus delbrueckii subsp. lactis CIDCA 133 based on whole-genome sequence and phenotypic analysis to avoid future questions about the harmful effects of this strain consumption. Genomic analysis showed that L. delbrueckii subsp. lactis CIDCA 133 harbors virulence, harmful metabolites, and antimicrobial resistance-associated genes. However, none of these genetic elements is flanked or located within prophage regions and plasmid sequence. At a phenotypic level, it was observed L. delbrueckii subsp. lactis CIDCA 133 antimicrobial resistance to aminoglycosides streptomycin and gentamicin antibiotics, but no hemolytic and mucin degradation activity was exhibited by strain. Furthermore, no adverse effects were observed regarding mice clinical and histopathological analysis after the strain consumption (5 × 107 CFU/mL). Overall, these findings reveal the safety of Lactobacillus delbrueckii subsp. lactis CIDCA 133 for consumption and future probiotic applications.

Paraprobiotics and Postbiotics of Lactobacillus delbrueckii CIDCA 133 Mitigate 5-FU-Induced Intestinal Inflammation.

Intestinal mucositis is a commonly reported side effect in oncology practice. Probiotics are considered an excellent alternative therapeutic approach to this debilitating condition; however, there are safety questions regarding the viable consumption of probiotics in clinical practice due to the risks of systemic infections, especially in immune-compromised patients. The use of heat-killed or cell-free supernatants derived from probiotic strains has been evaluated to minimize these adverse effects. Thus, this work evaluated the anti-inflammatory properties of paraprobiotics (heat-killed) and postbiotics (cell-free supernatant) of the probiotic Lactobacillus delbrueckii CIDCA 133 strain in a mouse model of 5-Fluorouracil drug-induced mucositis. Administration of paraprobiotics and postbiotics reduced the neutrophil cells infiltrating into the small intestinal mucosa and ameliorated the intestinal epithelium architecture damaged by 5-FU. These ameliorative effects were associated with a downregulation of inflammatory markers (Tlr2, Nfkb1, Il12, Il17a, Il1b, Tnf), and upregulation of immunoregulatory Il10 cytokine and the epithelial barrier markers Ocln, Cldn1, 2, 5, Hp and Muc2. Thus, heat-killed L. delbrueckii CIDCA 133 and supernatants derived from this strain were shown to be effective in reducing 5-FU-induced inflammatory damage, demonstrating them to be an alternative approach to the problems arising from the use of live beneficial microorganisms in clinical practice.

Lactobacillus delbrueckii CIDCA 133 Ameliorates Chemotherapy-Induced Mucositis by Modulating Epithelial Barrier and TLR2/4/Myd88/NF-κB Signaling Pathway.

Intestinal mucositis promoted by the use of anticancer drugs is characterized by ulcerative inflammation of the intestinal mucosa, a debilitating side effect in cancer patients undergoing treatment. Probiotics are a potential therapeutic option to alleviate intestinal mucositis due to their effects on epithelial barrier integrity and anti-inflammatory modulation. This study investigated the health-promoting impact of Lactobacillus delbrueckii CIDCA 133 in modulating inflammatory and epithelial barrier markers to protect the intestinal mucosa from 5-fluorouracil-induced epithelial damage. L. delbrueckii CIDCA 133 consumption ameliorated small intestine shortening, inflammatory cell infiltration, intestinal permeability, villus atrophy, and goblet cell count, improving the intestinal mucosa architecture and its function in treated mice. Upregulation of Muc2, Cldn1, Hp, F11r, and Il10, and downregulation of markers involved in NF-κB signaling pathway activation (Tlr2, Tlr4, Nfkb1, Il6, and Il1b) were observed at the mRNA level. This work suggests a beneficial role of L. delbrueckii strain CIDCA 133 on intestinal damage induced by 5-FU chemotherapy through modulation of inflammatory pathways and improvement of epithelial barrier function.