Potentially probiotic Lactobacillus strains with anti-proliferative activity induce cytokine/chemokine production and neutrophil recruitment in mice

An Update on the Pivotal Roles of Probiotics, Their Components, and Metabolites in Preventing Colon Cancer

Diet, lifestyle, and gut microbiota composition are key risk factors for the progression of colon cancer. Probiotics are living microorganisms that can offer health benefits to the parasitifer when ingested in competent quantities. Several in vivo, in vitro, and clinical studies have demonstrated that probiotics can prevent and mitigate the development of colon cancer. The anti-colon cancer mechanisms of probiotics include the suppression of cell proliferation and the promotion of cancer cell apoptosis, immunomodulation, the modulation of intestinal microorganisms and their metabolism, strengthening the intestinal barrier, and antioxidant effects. This article describes the pathogenesis of colon cancer and the available therapeutic options. In addition, this paper reviews the mechanisms by which probiotics mitigate colon cancer as well as the mitigating effects of probiotic components and metabolites on colon cancer.

The Role of the Gut Microbiome in Cancer Immunotherapy: Current Knowledge and Future Directions

Cancer immunotherapy is a treatment modality that aims to stimulate the anti-tumor immunity of the host to elicit favorable clinical outcomes. Immune checkpoint inhibitors (ICIs) gained traction due to the lasting effects and better tolerance in patients carrying solid tumors in comparison to conventional treatment. However, a significant portion of patients may present primary or acquired resistance (non-responders), and thus, they may have limited therapeutic outcomes. Resistance to ICIs can be derived from host-related, tumor-intrinsic, or environmental factors. Recent studies suggest a correlation of gut microbiota with resistance and response to immunotherapy as well as with the incidence of adverse events. Currently, preclinical and clinical studies aim to elucidate the unique microbial signatures related to ICI response and anti-tumor immunity, employing metagenomics and/or multi-omics. Decoding this complex relationship can provide the basis for manipulating the malleable structure of the gut microbiota to enhance therapeutic success. Here, we delve into the factors affecting resistance to ICIs, focusing on the intricate gut microbiome–immunity interplay. Additionally, we review clinical studies and discuss future trends and directions in this promising field.

In silico genomic analysis of the potential probiotic Lactiplantibacillus pentosus CF2-10N reveals promising beneficial effects with health promoting properties

Lactiplantibacillus pentosus CF2-10 N, isolated from brines of naturally fermented Aloreña green table olives, exhibited high probiotic potential. High throughput sequencing and annotation of genome sequences underline the potential of L. pentosus CF2-10 N as excellent probiotic candidate of vegetable origin. In a previous study we could show the probiotic potential of CF2-10 N in vitro, while in this study in silico analysis of its genome revealed new insights into its safety and functionality. Our findings highlight the microorganism's ecological flexibility and adaptability to a broad range of environmental niches, food matrices and the gastrointestinal tract. These features are shared by both phylogenetically very close L. pentosus strains (CF2-10 N and MP-10) isolated from the same ecological niche with respect to their genome size (≅ 3.6 Mbp), the presence of plasmids (4-5) and several other properties. Nonetheless, additional and unique features are reported in the present study for L. pentosus CF2-10 N. Notably, the safety of L. pentosus CF2-10 N was shown by the absence of virulence determinants and the determination of acquired antibiotic resistance genes, i.e., resistome, which is mostly represented by efflux-pump resistance genes responsible for the intrinsic resistance. On the other hand, defense mechanisms of L. pentosus CF2-10 N include eight prophage regions and a CRISPR/cas system (CRISPR-I and CRISPR-II) as acquired immune system against mobile elements. Finally, the probiotic potential of this strain was further demonstrated by the presence of genes coding for proteins involved in adhesion, exopolysaccharide biosynthesis, tolerance to low pH and bile salts, immunomodulation, and vitamin and enzyme production. Taken together these results, we propose the use of L. pentosus CF2-10 N as a potential and promising probiotic candidate able to colonize several niches and adapt to different lifestyles. The strain can provide attractive functional and probiotic features necessary for its application as starter culture and probiotic.

The Probiotic Strains Bifidοbacterium lactis, Lactobacillus acidophilus, Lactiplantibacillus plantarum and Saccharomyces boulardii Regulate Wound Healing and Chemokine Responses in Human Intestinal Subepithelial Myofibroblasts

Bifidobacterium lactis, Lactobacillus acidophilus, Lactiplantibacillus plantarum and Saccharomyces boulardii are common probiotic supplements. Colonic subepithelial myofibroblasts (cSEMFs) are actively involved in mucosal wound healing and inflammation. cSEMFs, isolated from healthy individuals, were stimulated with 102 or 104 cfu/mL of these probiotic strains alone and in combination, and their effect on chemokine and wound healing factor expression was assessed by qRT-PCR, ELISA and Sircol Assay, and on cSEMFs migration, by Wound Healing Assay. These strains remained viable and altered cSEMFs’ inflammatory and wound healing behavior, depending on the strain and concentration. cSEMFs treated with a combination of the four probiotics had a moderate, but statistically significant, increase in the mRNA and/or protein expression of chemokines CXCL1, CXCL2, CXCL4, CXCL8, CXCL10, CCL2 and CCL5, and healing factors, collagen type I and III, fibronectin and tissue factor. In contrast, when each strain was administered alone, different effects were observed, with greater increase or decrease in chemokine and healing factor expression, which was balanced by the mixture. Overall, this study highlights that the use of multiple probiotic strains can potentially alert the gut mucosal immune system and promote wound healing, having a better effect on mucosal immunity than the use of single probiotics.

Genomic Insight Into Lacticaseibacillus paracasei SP5, Reveals Genes and Gene Clusters of Probiotic Interest and Biotechnological Potential

The Lacticaseibacillus paracasei species is comprised by nomadic bacteria inhabiting a wide variety of ecological niches, from fermented foodstuffs to host-associated microenvironments. Lc. paracasei SP5 is a novel strain, originally isolated from kefir grains that presents desirable probiotic and biotechnological attributes. In this study, we applied genomic tools to further characterize the probiotic and biotechnological potential of the strain. Firstly, whole genome sequencing and assembly, were performed to construct the chromosome map of the strain and determine its genomic stability. Lc. paracasei SP5 carriers several insertion sequences, however, no plasmids or mobile elements were detected. Furthermore, phylogenomic and comparative genomic analyses were utilized to study the nomadic attributes of the strain, and more specifically, its metabolic capacity and ability to withstand environmental stresses imposed during food processing and passage through the gastrointestinal (GI) tract. More specifically, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Carbohydrate-active enzyme (CAZymes) analyses provided evidence for the ability of the stain to utilize an array of carbohydrates as growth substrates. Consequently, genes for heat, cold, osmotic shock, acidic pH, and bile salt tolerance were annotated. Importantly bioinformatic analysis showed that the novel strain does not harbor acquired antimicrobial resistance genes nor virulence factors, in agreement with previous experimental data. Putative bacteriocin biosynthesis clusters were identified using BAGEL4, suggesting its potential antimicrobial activity. Concerning microbe-host interactions, adhesins, moonlighting proteins, exopolysaccharide (EPS) biosynthesis genes and pilins mediating the adhesive phenotype were, also, pinpointed in the genome of Lc. paracasei SP5. Validation of this phenotype was performed by employing a microbiological method and confocal microscopy. Conclusively, Lc. paracasei SP5 harbors genes necessary for the manifestation of the probiotic character and application in the food industry. Upcoming studies will focus on the mechanisms of action of the novel strain at multiple levels.

Probiotic and Antifungal Attributes of Lactic Acid Bacteria Isolates from Naturally Fermented Brazilian Table Olives

Research with fermented olives as a source of wild Lactic Acid Bacteria (LAB) strains with probiotic and biotechnological characteristics constitutes a promising field of work. The present study evaluated in vitro probiotic, antifungal, and antimycotoxigenic potential of LAB isolates from naturally fermented Brazilian table olives. Among fourteen LAB isolates, the Levilactobacillus brevis CCMA 1762, Lactiplantibacillus pentosus CCMA 1768, and Lacticaseibacillus paracasei subsp. paracasei CCMA 1770 showed potential probiotic and antifungal properties. The isolates showed resistance to pH 2.0 (survival ≥ 84.55), bile salts (survival ≥ 99.44), and gastrointestinal tract conditions (survival ≥ 57.84%); hydrophobic cell surface (≥27%); auto-aggregation (≥81.38%); coaggregation with Escherichia coli INCQS 00181 (≥33.97%) and Salmonella Enteritidis ATCC 564 (≥53.84%); adhesion to the epithelial cell line Caco-2 (≥5.04%); antimicrobial activity against the bacteria S. Enteritidis ATCC 564 (≥6 mm), Listeria monocytogenes ATCC 19117 (≥6 mm), Staphylococcus aureus ATCC 8702 (≥3 mm), and the fungi Penicillium nordicum MUM 08.16 (inhibition ≥ 64.8%). In addition, the strains showed the ability to adsorb the mycotoxins aflatoxin B1 (≥40%) and ochratoxin A (≥34%). These results indicate that LAB strains from naturally fermented Brazilian table olives are potentially probiotic and antifungal candidates that can be used for food biopreservation.

Current trends in the development of soy-based foods containing probiotics and paving the path for soy-synbiotics

In the world of highly processed foods, special attention is drawn to the nutrient composition and safety of consumed food products. Foods fortified with probiotic bacteria confer beneficial effects on human health and are categorized as functional foods. The salubrious activities of probiotics include the synthesis of vital bioactives, prevention of inflammatory diseases, anticancerous, hypocholesterolemic, and antidiarrheal effects. Soy foods are exemplary delivery vehicles for probiotics and prebiotics and there are diverse strategies to enhance their functionality like employing mixed culture fermentation, engineering probiotics, and incorporating prebiotics in fermented soy foods. High potential is ascribed to the concurrent use of probiotics and prebiotics in one product, termed as "synbiotics," which implicates synergy, in which a prebiotic ingredient particularly favors the growth and activity of a probiotic micro-organism. The insights on emended bioactive profile, metabolic role, and potential health benefits of advanced soy-based probiotic and synbiotic hold a promise which can be profitably implemented to meet consumer needs. This article reviews the available knowledge about strategies to enhance the nutraceutical potential, mechanisms, and health-promoting effects of advanced soy-based probiotics. Traditional fermentation merged with diverse strategies to improve the efficiency and health benefits of probiotics considered vital, are also discussed.

Lactobacillus gallinarum modulates the gut microbiota and produces anti-cancer metabolites to protect against colorectal tumourigenesis

OBJECTIVE

Using faecal shotgun metagenomic sequencing, we identified the depletion of Lactobacillus gallinarum in patients with colorectal cancer (CRC). We aimed to determine the potential antitumourigenic role of L. gallinarum in colorectal tumourigenesis.

DESIGN

The tumor-suppressive effect of L. gallinarum was assessed in murine models of CRC. CRC cell lines and organoids derived from patients with CRC were cultured with L. gallinarum or Escherichia coli MG1655 culture-supernatant to evaluate cell proliferation, apoptosis and cell cycle distribution. Gut microbiota was assessed by 16S ribosomal DNA sequencing. Antitumour molecule produced from L. gallinarum was identified by liquid chromatography mass spectrometry (LC-MS/MS) and targeted mass spectrometry.

RESULTS

L. gallinarum significantly reduced intestinal tumour number and size compared with E. coli MG1655 and phosphate-buffered saline in both male and female murine intestinal tumourigenesis models. Faecal microbial profiling revealed enrichment of probiotics and depletion of pathogenic bacteria in L. gallinarum-treated mice. Culturing CRC cells with L. gallinarum culture-supernatant (5%, 10% and 20%) concentration-dependently suppressed cell proliferation and colony formation. L. gallinarum culture-supernatant significantly promoted apoptosis in CRC cells and patient-derived CRC organoids, but not in normal colon epithelial cells. Only L. gallinarum culture-supernatant with fraction size <3 kDa suppressed proliferation in CRC cells. Using LC-MS/MS, enrichments of indole-3-lactic acid (ILA) was identified in both L. gallinarum culture-supernatant and the gut of L. gallinarum-treated mice. ILA displayed anti-CRC growth in vitro and inhibited intestinal tumourigenesis in vivo.

CONCLUSION

L. gallinarum protects against intestinal tumourigenesis by producing protective metabolites that can promote apoptosis of CRC cells.

Genomic and Phylogenetic Analysis of Lactiplantibacillus plantarum L125, and Evaluation of Its Anti-Proliferative and Cytotoxic Activity in Cancer Cells

Lactiplantibacillus plantarum is a diverse species that includes nomadic strains isolated from a variety of environmental niches. Several L. plantarum strains are being incorporated in fermented foodstuffs as starter cultures, while some of them have also been characterized as probiotics. In this study, we present the draft genome sequence of L. plantarum L125, a potential probiotic strain presenting biotechnological interest, originally isolated from a traditional fermented meat product. Phylogenetic and comparative genomic analysis with other potential probiotic L. plantarum strains were performed to determine its evolutionary relationships. Furthermore, we located genes involved in the probiotic phenotype by whole genome annotation. Indeed, genes coding for proteins mediating host–microbe interactions and bile salt, heat and cold stress tolerance were identified. Concerning the potential health-promoting attributes of the novel strain, we determined that L. plantarum L125 carries an incomplete plantaricin gene cluster, in agreement with previous in vitro findings, where no bacteriocin-like activity was detected. Moreover, we showed that cell-free culture supernatant (CFCS) of L. plantarum L125 exerts anti-proliferative, anti-clonogenic and anti-migration activity against the human colon adenocarcinoma cell line, HT-29. Conclusively, L. plantarum L125 presents desirable probiotic traits. Future studies will elucidate further its biological and health-related properties.

Probiotics in Counteracting the Role of Neutrophils in Cancer Metastasis

Neutrophils are known for their role geared towards pathogen clearance by different mechanisms that they initiate, primarily by the release of neutrophil extracellular traps (NETs). However, their immune-surveillance capacity accompanied with plasticity in existing as interchangeable subsets, discovered recently, has revealed their property to contribute to complex cancer pathologies including tumor initiation, growth, angiogenesis and metastasis. Although there is a growing body of evidence suggesting a critical balance between the protumoral and antitumoral neutrophil phenotypes, an in-depth signaling pathway analysis would aid in determination of anticipatory, diagnostic and therapeutic targets. This review presents a comprehensive overview of the potential pathways involved in neutrophil-triggered cancer metastasis and introduces the influence of the microbial load and avenues for probiotic intervention.

PRAK Promotes the Pathogen Clearance by Macrophage Through Regulating Autophagy and Inflammasome Activation

The p38 regulated/activated protein kinase (PRAK) is a protein kinase downstream of p38MAPK. The present study investigated its function in the macrophage. Myeloid-specific deletion of Prak resulted in a significant reduction in F4/80⁺CD11b⁺ peritoneal macrophages with decreased expression of MHC-II and CD80. Upon infection with Listeria monocytogenes, Prak-deficient mice demonstrated an increased mortality, which was accompanied by a higher bacterial load in multiple tissues and elevated levels of proinflammatory cytokines in the serum. While the Prak-deficient macrophage showed similar potency in phagocytosis assays, its bactericidal activity was severely impaired. Moreover, Prak deficiency was associated with defects in ROS production, inflammasome activation as well as autophagy induction. Therefore, PRAK critically contributes to the clearance of intracellular pathogens by affecting multiple aspects of the macrophage function.

Pro-biomics: Omics Technologies To Unravel the Role of Probiotics in Health and Disease

The comprehensive characterization of probiotic action has flourished during the past few decades, alongside the evolution of high-throughput, multiomics platforms. The integration of these platforms into probiotic animal and human studies has provided valuable insights into the holistic effects of probiotic supplementation on intestinal and extraintestinal diseases. Indeed, these methodologies have informed about global molecular changes induced in the host and residing commensals at multiple levels, providing a bulk of metagenomic, transcriptomic, proteomic, and metabolomic data. The meaningful interpretation of generated data remains a challenge; however, the maturation of the field of systems biology and artificial intelligence has supported analysis of results. In this review article, we present current literature on the use of multiomics approaches in probiotic studies, we discuss current trends in probiotic research, and examine the possibility of tailor-made probiotic supplementation. Lastly, we delve deeper into newer technologies that have been developed in the last few years, such as single-cell multiomics analyses, and provide future directions for the maximization of probiotic efficacy.

Harnessing the potential of Lactobacillus species for therapeutic delivery at the lumenal-mucosal interface

Lactobacillus species have been studied for over 30 years in their role as commensal organisms in the human gut. Recently there has been a surge of interest in their abilities to natively and recombinantly stimulate immune activities, and studies have identified strains and novel molecules that convey particular advantages for applications as both immune adjuvants and immunomodulators. In this review, we discuss the recent advances in Lactobacillus-related activity at the gut/microbiota interface, the efforts to probe the boundaries of the direct and indirect therapeutic potential of these bacteria, and highlight the continued interest in harnessing the native capacity for the production of biogenic compounds shown to influence nervous system activity. Taken together, these aspects underscore Lactobacillus species as versatile therapeutic delivery vehicles capable of effector production at the lumenal-mucosal interface, and further establish a foundation of efficacy upon which future engineered strains can expand.

Assessment of the Immunomodulatory Properties of the Probiotic Strain Lactobacillus paracasei K5 in vitro and In Vivo

Lactobacillus paracasei K5 is a lactic acid bacteria (LAB) strain that has been isolated from dairy products. Previous studies have established its probiotic potential in a series of in vitro tests, including molecular characterization, safety profiling, and tolerability of the gastrointestinal tract conditions. To characterize its beneficial actions on the host, we have shown previously that L. paracasei K5 adheres to Caco-2 cells and exerts anti-proliferative effects through the induction of apoptosis. In the present study, we focused on the immunomodulatory potential of this strain. We employed the dorsal-air-pouch mouse model of inflammation and recorded an eight-fold increase in the recruitment of immune cells in mice treated with the probiotic strain, compared to the control group. Analysis of the exudates revealed significant changes in the expression of pro-inflammatory mediators on site. Treatment of Caco-2 cells with L. paracasei K5 induced significant upregulation of cytokines interleukin-1α (IL-1α), ΙL-1β, IL-6, tumor necrosis factor-alpha (TNF-α), the chemokine C-X-C motif ligand 2 (CXCL2), and the inflammation markers soluble intercellular adhesion molecule (sICAM) and metallopeptidase inhibitor-1 (TIMP-1). Transient induction of the Toll-like receptors (TLRs) 2, 4, 6, and 9 expression levels was recorded by real-time PCR analysis. These results highlight the immunomodulatory potential of this strain and further support its probiotic character.

Involvement of TLR4/ CXCL9/ PREX-2 pathway in the development of hepatocellular carcinoma (HCC) and the promising role of early administration of lactobacillus plantarum in Wistar rats

BACKGROUND AND AIM

Improvement of gut microbiota may help in preventing the progression of cirrhosis. We supposed that Lactobacillus Plantarum (L. Plantarum) protects the cirrhotic liver through suppression of TLR4/ CXCL9/ PREX-2.

METHODOLOGY

Rats were divided into two groups. Group I, lasts for six weeks and Group II lasts for 12 weeks. Each group was subdivided into: naïve, Lactobacillus Plantarum (L. Plantarum), thioacetamide (TAA) and TAA + L. Plantarum. Liver function tests, α fetoprotein (AFP) levels, CXCL9, PREX-2 and TLR4 expression were assessed. Histological studies were performed.

RESULTS

TAA induced significant deterioration in liver functions and increased AFP. There was periportal cirrhosis, vacuolated hepatocytes, decrease hepatocyte parrafin-1 (hep par-1) expression, increase proliferating cell nuclear antigen (PCNA) positive nuclei and cytokeratin AE1/AE3. The PCR results showed significant increase in TLR4, CXCL9 and PREX-2 expression. Early administration of L. Plantarum significantly decreased the expression of TLR4, CXCL9 and PREX-2 together with improvement in liver function and prevented the pathological changes.

CONCLUSIONS

The cirrhotic complications induced by TAA are through activation of TLR4/ CXCL9/ PREX-2 pathway and could be prevented by the early administration of L. Plantarum.

Probiotics in Extraintestinal Diseases: Current Trends and New Directions

Probiotics are defined as live microorganisms that when administered in adequate amounts confer a health benefit to the host. Their positive supplementation outcomes on several gastrointestinal disorders are well defined. Nevertheless, their actions are not limited to the gut, but may also impart their beneficial effects at distant sites and organs. In this regard, in this review article we: (i) comprehensively describe the main mechanisms of action of probiotics at distant sites, including bones, skin, and brain; (ii) critically present their therapeutic potential against bone, skin, and neuronal diseases (e.g., osteoporosis, non-healing wounds and autoimmune skin illnesses, mood, behavior, memory, and cognitive impairments); (iii) address the current gaps in the preclinical and clinical research; and (iv) indicate new research directions and suggest future investigations.