Health-Promoting Nature of Lactococcus lactis IBB109 and Lactococcus lactis IBB417 Strains Exhibiting Proliferation Inhibition and Stimulation of Interleukin-18 Expression in Colorectal Cancer Cells

The power of microbes: the key role of gut microbiota in the initiation and progression of colorectal cancer

Colorectal cancer (CRC) is ranked as the third most prevalent malignancy and is a leading cause of cancer-related mortality globally, significantly affecting the health and longevity of middle-aged individuals and the elderly. The primary risk factors for CRC are mainly due to unhealthy dietary habits and lifestyle choices, and they have been shown to profoundly influence the composition of the gut microbiota. Given that dietary patterns are critical determinants of gut microbial diversity, a compelling association exists between gut microbiota and the pathogenesis of CRC. Recent research has increasingly focused on the intricate interplay between gut microbiota and CRC, exploring its role in disease initiation, progression, and the modulation of host immune responses. Investigations have demonstrated that certain specific microbial communities can promote inflammation, disrupt metabolic pathways, and produce carcinogenic compounds, thereby contributing to the development of CRC. Conversely, a diverse and balanced gut microbiome may confer protective effects against cancer through mechanisms such as the production of short-chain fatty acids and the enhancement of intestinal barrier integrity. This article provides a comprehensive overview of the characteristics of the gut microbial community and its complex relationship with CRC. It highlights potential mechanisms through which gut microbiota may influence CRC pathogenesis, including chronic inflammation, toxins, metabolites, epigenetic dysregulation, and immune regulatory dysfunction. Additionally, this review summarizes innovative strategies for CRC prevention and treatment, emphasizing the therapeutic potential of probiotics and natural plant extracts. By elucidating these connections, this work aims to enhance the understanding of the gut microbiome's role in CRC.

Synergistic Interactions Between Probiotics and Anticancer Drugs: Mechanisms, Benefits, and Challenges

Research into the role of probiotics-often referred to as "living supplements"-in cancer therapy is still in its early stages, and uncertainties regarding their effectiveness remain. Relevantly, chemopreventive and therapeutic effects of probiotics have been determined. There is also substantial evidence supporting their potential in cancer treatment such as immunotherapy. Probiotics employ various mechanisms to inhibit cancer initiation and progression. These include colonizing and protecting the gastrointestinal tract (GIT), producing metabolites, inducing apoptosis and autophagy, exerting anti-inflammatory properties, preventing metastasis, enhancing the effectiveness of immune checkpoint inhibitors (ICIs), promoting cancer-specific T cell infiltration, arresting the cell cycle, and exhibiting direct or indirect synergistic effects with anticancer drugs. Additionally, probiotics have been shown to activate tumor suppressor genes and inhibit pro-inflammatory transcription factors. They also increase reactive oxygen species production within cancer cells. Synergistic interactions between probiotics and various anticancer drugs, such as cisplatin, cyclophosphamide, 5-fluorouracil, trastuzumab, nivolumab, ipilimumab, apatinib, gemcitabine, tamoxifen, sorafenib, celecoxib and irinotecan have been observed. The combination of probiotics with anticancer drugs holds promise in overcoming drug resistance, reducing recurrence, minimizing side effects, and lowering treatment costs. In addition, fecal microbiota transplantation (FMT) and prebiotics supplementation has increased cytotoxic T cells within tumors. However, probiotics may leave some adverse effects such as risk of infection and gastrointestinal effects, antagonistic effects with drugs, and different responses among patients. These findings highlight insights for considering specific strains and engineered probiotic applications, preferred doses and timing of treatment, and personalized therapies to enhance the efficacy of cancer therapy. Accordingly, targeted interventions and guidelines establishment needs extensive randomized controlled trials as probiotic-based cancer therapy has not been approved by Food and Drug Administration (FDA).

Lactococcus lactis subsp. lactis boosts stress resistance and host defense mechanisms in Caenorhabditis elegans

AIMS

To investigate the effects of Lactococcus lactis subsp. lactis strains LL100933 and LL12007 on the host defense mechanisms of Caenorhabditis elegans against pathogenic infections and stressors.

METHODS AND RESULTS

Caenorhabditis elegans fed a 1:1 mixture of Escherichia coli OP50 and LL100933 (OP50 + LL100933) or E. coli OP50 and LL12007 (OP50 + LL12007) had significantly higher survivability than the control diet (OP50). Moreover, when OP50 + LL100933 and OP50 + LL12007 were fed to C. elegans deficient in daf-16 and pmk-1, survival did not exceed that of control-fed worms under Salmonella infection. Therefore, these strains may enhance the survivability of C. elegans through the p38 MAPK and DAF-16-related pathways. Gene expressions responsible for these enhanced defense responses were estimated using RNA sequencing and gene ontology analysis. The test groups showed significant upregulation of glutathione S-transferase (gsto-1, gst-5, and gst-17), UDP-glucuronyl transferase (ugt-13, ugt-16, and ugt-21), heme-responsive (hrg-4), invertebrate-type lysozyme (ilys-2), and C-type lectin (clec-52) genes compared to those in the control group.

CONCLUSION

Lactococcus lactis subsp. lactis LL100933 and LL12007 strains demonstrated promising benefits as probiotics for enhancing host defense mechanisms in C. elegans.

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

Introduction

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

Methods

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

Results and discussion

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

Lactococcus lactis HkyuLL 10 suppresses colorectal tumourigenesis and restores gut microbiota through its generated alpha-mannosidase

OBJECTIVE

Probiotic Lactococcus lactis is known to confer health benefits to humans. Here, we aimed to investigate the role of L. lactis in colorectal cancer (CRC).

DESIGN

L. lactis abundance was evaluated in patients with CRC (n=489) and healthy individuals (n=536). L. lactis was isolated from healthy human stools with verification by whole genome sequencing. The effect of L. lactis on CRC tumourigenesis was assessed in transgenic Apc Min/+ mice and carcinogen-induced CRC mice. Faecal microbiota was profiled by metagenomic sequencing. Candidate proteins were characterised by nano liquid chromatography-mass spectrometry. Biological function of L. lactis conditioned medium (HkyuLL 10-CM) and functional protein was studied in human CRC cells, patient-derived organoids and xenograft mice.

RESULTS

Faecal L. lactis was depleted in patients with CRC. A new L. lactis strain was isolated from human stools and nomenclated as HkyuLL 10. HkyuLL 10 supplementation suppressed CRC tumourigenesis in Apc Min/+ mice, and this tumour-suppressing effect was confirmed in mice with carcinogen-induced CRC. Microbiota profiling revealed probiotic enrichment including Lactobacillus johnsonii in HkyuLL 10-treated mice. HkyuLL 10-CM significantly abrogated the growth of human CRC cells and patient-derived organoids. Such protective effect was attributed to HkyuLL 10-secreted proteins, and we identified that α-mannosidase was the functional protein. The antitumourigenic effect of α-mannosidase was demonstrated in human CRC cells and organoids, and its supplementation significantly reduced tumour growth in xenograft mice.

CONCLUSION

HkyuLL 10 suppresses CRC tumourigenesis in mice through restoring gut microbiota and secreting functional protein α-mannosidase. HkyuLL 10 administration may serve as a prophylactic measure against CRC.

Dietary Supplementation of Lactococcus lactis subsp. lactis BIONCL17752 on Growth Performance, and Gut Microbiota of Broiler Chickens

The rapid rise of antimicrobial resistance (AMR) is a global concern, being triggered by the overuse or misuse of antibiotics in poultry farming sector. We evaluated Lactococcus lactis subsp. lactis BIONCL17752 strain, and characterized its probiotic potential to endure hostile gastrointestinal conditions. Genome sequencing analysis revealed probiotics traits, and gene clusters involved in bacteriocins, lactococcin A, and sactipeptides production. The absence of genes for antibiotic resistance, virulence, and biogenic amine production indicates the potential of probiotic strain. The BIONCL17752 strain was explored for antibiotic-free feed supplement for growth promotor in broiler chicken. The feed supplemented with 4 × 109 CFU/kg of probiotic strain, in combination with various concentrations of fructooligosaccharides (FOS) 1.0, 2.5, and 5.0 kg/tonne in starter, grower, and finisher diets, respectively. A significant improvement of body weight 152 to 171 g/bird (p < 0.05), and a low feed conversion ratio (FCR) of 1.62, was achieved without using synthetic antibiotics for growth promotion. The results of biochemical, hematological, and histological examinations showed normal features, indicating that the treatment had no harmful effects on the bird's health. Reduced levels of cholesterol, triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) in serum are an indication of the health benefits for the treated birds. Microbial community analysis of fecal samples of poultry birds exhibited a higher abundance of Bacteroidetes, Firmicutes, Proteobacteria, Actinobacteria, and Fusobacteria. Probiotic treatment resulted in reduced Firmicutes and increased Bacteroidetes (F/B ratio) in the broiler's gut which highlights the benefits of probiotic dietary supplements. Importantly, the probiotic-fed group exhibited a high abundance of carbohydrate-active enzymes (CAZyme) such as glycoside hydrolases (GH), glycoside transferases (GT), and carbohydrate-binding module (CBM) hydrolases which are essential for the degradation of complex sugar molecules. The probiotic potential of the BIONCL17752 strain contributes to broilers' health by positively affecting intestinal microbiota, achieving optimal growth, and lowering mortality, demonstrating the economic benefits of probiotic treatment in organic poultry farming.

Effects of Lactococcus lactis on colorectal cancer in various terms: a narrative review

Introduction

Colorectal cancer is one of the most common cancers with an increasing number of cases. Various studies have found an association between the gut microbiota balance and colorectal cancer incidence. Lactococcus lactis is a probiotic bacterium found in fermented foods, particularly yogurt and cheese. This probiotic has been shown to reduce various anti-inflammatory and pro-inflammatory agents that trigger cancer, such as interleukin (IL)-6, IL-18, tumour necrosis factor-alpha (TNF-α), and natural killer (NK) cells.

Methods

Full-text articles and original research published in the last ten years were used as references, and "Lactococcus and colorectal cancer" as keywords. The reference search is on several databases, such as PubMed, ScienceDirect, ProQuest, and Nature. Searching results obtained eleven articles.

Discussion

Lactococcus lactis does have a perfect role in suppressing cancer cells. Lactococcus lactis has anti-proliferative effects associated with decreased cyclin D1 expression in SW480 cell lines, decreased NK cells, reduced cancer cell viability, decreased IL-8 levels, and decreased IL-6.

Conclusion

Lactococcus lactis contains nisin, which can suppress various gene, protein, and cytokine expressions that play a role in cancer cell growth. Probiotics can inhibit colorectal cancer without significant side effects.

The strain-dependent cytostatic activity of Lactococcus lactis on CRC cell lines is mediated through the release of arginine deiminase

BACKGROUND

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers, posing a serious public health challenge that necessitates the development of new therapeutics, therapies, and prevention methods. Among the various therapeutic approaches, interventions involving lactic acid bacteria (LAB) as probiotics and postbiotics have emerged as promising candidates for treating and preventing CRC. While human-isolated LAB strains are considered highly favorable, those sourced from environmental reservoirs such as dairy and fermented foods are also being recognized as potential sources for future therapeutics.

RESULTS

In this study, we present a novel and therapeutically promising strain, Lactococcus lactis ssp. lactis Lc4, isolated from dairy sources. Lc4 demonstrated the ability to release the cytostatic agent - arginine deiminase (ADI) - into the post-cultivation supernatant when cultured under conditions mimicking the human gut environment. Released arginine deiminase was able to significantly reduce the growth of HT-29 and HCT116 cells due to the depletion of arginine, which led to decreased levels of c-Myc, reduced phosphorylation of p70-S6 kinase, and cell cycle arrest. The ADI release and cytostatic properties were strain-dependent, as was evident from comparison to other L. lactis ssp. lactis strains.

CONCLUSION

For the first time, we unveil the anti-proliferative properties of the L. lactis cell-free supernatant (CFS), which are independent of bacteriocins or other small molecules. We demonstrate that ADI, derived from a dairy-Generally Recognized As Safe (GRAS) strain of L. lactis, exhibits anti-proliferative activity on cell lines with different levels of argininosuccinate synthetase 1 (ASS1) expression. A unique feature of the Lc4 strain is also its capability to release ADI into the extracellular space. Taken together, we showcase L. lactis ADI and the Lc4 strain as promising, potential therapeutic agents with broad applicability.

Strategies to enhance stress tolerance in lactic acid bacteria across diverse stress conditions

Lactic acid bacteria (LAB) hold significant importance in diverse fields, including food technology, industrial biotechnology, and medicine. As basic components of starter cultures, probiotics, immunomodulators, and live vaccines, LAB cells resist a variety of stressors, including temperature fluctuations, osmotic and pH shocks, exposure to oxidants and ultraviolet radiation, substrate deprivation, mechanical damage, and more. To stay alive in these adversities, LAB employ a wide range of stress response strategies supported by various mechanisms, for example rearrangement of metabolism, expression of specialized biomolecules (e.g., chaperones and antioxidants), exopolysaccharide synthesis, and complex repair and regulatory systems. LAB can coordinate responses to various stressors using global regulators. In this review, we summarize current knowledge about stress response strategies used by LAB and consider mechanisms of response to specific stressful factors, supported by illustrative examples. In addition, we discuss technical approaches to increase the stress resistance of LAB, including pre-adaptation, genetic modification of strains, and adjustment of cultivation conditions. A critical analysis of the recent findings in this field augments comprehension of stress tolerance mechanisms in LAB, paving the way for prospective research directions with implications in fundamental and practical areas.

Improvement of Locomotion Caused by Lactococcus lactis subsp. lactis in the Model Organism Caenorhabditis elegans

Lactococcus lactis subsp. lactis exhibits probiotic properties in humans. Considering that Caenorhabditis elegans can be used to study the effects of microorganisms on animal behavior, owing to its simple nervous system, we assessed the impacts of two strains of Lactococcus lactis subsp. Lactis-a non-nisin-producing strain, NBRC 100933 (LL100933), and a nisin-producing strain, NBRC 12007 (LL12007)-on the lifespan, locomotion, reproductive capacity of, and lipid accumulation in, C. elegans. The lifespan of adult C. elegans fed a mixture (1:1) of Escherichia coli OP50 and LL100933 or LL12007 did not show a significant increase compared to that of the group fed a standard diet of E. coli OP50. However, the nematodes fed Lactococcus strains showed notable enhancement in their locomotion at all of the tested ages. Further, the beneficial effects of LL100933 and LL12007 were observed in the daf-16 mutants, but not in the skn-1 and pmk-1 mutants. The lipid accumulation in the worms of the Lactococcus-fed group was lower than that in the control group at all experimental ages. Overall, LL100933 and LL12007 enhance the locomotor behavior of C. elegans, likely by modulating the PMK-1/p38 MAPK and SKN-1/Nrf2 transcription factors.

Lactococcus lactis, a bacterium with probiotic functions and pathogenicity

Lactococcus lactis (L. lactis) is the primary organism for lactic acid bacteria (LAB) and is a globally recognized safe microorganism for the regulation of the intestinal micro-ecological balance of animals and improving the immune performance of the host. L. lactis is known to play a commercially important role in feed fortification, milk fermentation, and vaccine production, but pathogenic L. lactis has been isolated from many clinical cases in recent years, such as the brain of silver carp with Lactococcosis, the liver and spleen of diseased waterfowl, milk samples and padding materials with cow mastitis, and blood and urine from human patients with endocarditis. In dairy farming, where L. lactis has been used as a probiotic in the past, however, some studies have found that L. lactis can cause mastitis in cows, but the lack of understanding of the pathogenesis of mastitis in cows caused by L. lactis has become a new problem. The main objective of this review is to analyze the increasingly serious clinical mastitis caused by L. lactis and combined with the wide application of L. lactis as probiotics, to comprehensively discuss the characteristics and diversity of L. lactis.

Comparative Genomic Analysis Reveals the Functional Traits and Safety Status of Lactic Acid Bacteria Retrieved from Artisanal Cheeses and Raw Sheep Milk

Lactic acid bacteria (LAB) are valuable for the production of fermented dairy products. We investigated the functional traits of LAB isolated from artisanal cheeses and raw sheep milk, assessed their safety status, and explored the genetic processes underlying the fermentation of carbohydrates. Lactiplantibacillus plantarum had the largest and more functional genome compared to all other LAB, while most of its protein-encoding genes had unknown functions. A key finding of our analysis was the overall absence of acquired resistance genes (RGs), virulence genes (VGs), and prophages, denoting that all LAB isolates fulfill safety criteria and can be used as starter or adjunct cultures. In this regard, the identified mobile genetic elements found in LAB, rather than enabling the integration of RGs or VGs, they likely facilitate the uptake of genes involved in beneficial functions and in the adaptation of LAB in dairy matrices. Another important finding of our study was that bacteriocins and CAZymes were abundant in LAB though each species was associated with specific genes, which in turn had different activity spectrums and identified applications. Additionally, all isolates were able to metabolize glucose, lactose, maltose, and sucrose, but Lactiplantibacillus plantarum was strongly associated with the fermentation of rhamnose, mannose, cellobiose, and trehalose whereas Levilactobacillus brevis with the utilization of arabinose and xylose. Altogether these results suggest that to fully exploit the beneficial properties of LAB, a combination of strains as food additives may be necessary. Interestingly, biological processes involved in the metabolism of carbohydrates that are not of direct interest for the dairy industry may yield valuable metabolites or activate pathways associated with beneficial health effects. Our results provide useful information for the development of new probiotic artisanal cheeses and probiotic starter cultures.

Research Progress of Intestinal Microecology in the Pathogenesis of Colorectal Adenoma and Carcinogenesis

Colorectal adenoma is a precancerous lesion that may progress to colorectal cancer. Patients with colorectal adenoma had a 4-fold higher risk of developing colorectal malignancy than the rest of the population, with approximately 80% of colorectal cancer originating from colorectal adenoma. Therefore, preventing the occurrence and progression of colorectal adenoma is crucial in reducing the risk for colorectal cancer. The human intestinal microecology is a complex system consisting of numerous microbial communities with a sophisticated structure. Interactions among intestinal microorganisms play crucial roles in maintaining normal intestinal structure, digestion, absorption, metabolism, and other functions. The colorectal system is the largest microbial bank or fermentation system in the human body. Studies suggest that intestinal microecological imbalance, one of the most important environmental factors, may play an essential role in the occurrence and development of colorectal adenoma and colorectal cancer. Based on the complexity of studying the gut microbiota ecosystem, its specific role in the occurrence and development of colorectal adenoma is yet to be elucidated. In addition, further studies are expected to provide new insights regarding the prevention and treatment of colorectal adenoma. This article reviews the relationship and mechanism of the diversity of the gut microbiota, the relevant inflammatory response, immune regulation, and metabolic changes in the presence of colorectal adenomas.

Functional Gastrointestinal Disorders with Psychiatric Symptoms: Involvement of the Microbiome-Gut-Brain Axis in the Pathophysiology and Case Management

Functional Gastrointestinal Disorders have been an important cause of poor life quality in affected populations. The unclear etiology and pathophysiological mechanism alter the clinical evolution of the patient. Although a strong connection with psychological stress has been observed, it was not until recently that the gut-brain axis involvement has been revealed. Furthermore, the current literature not only promotes the gut-brain axis modulation as a therapeutical target for functional digestive disorders but also states that the gut microbiome has a main role in this bi-directional mechanism. Psychiatric symptoms are currently recognized as an equally important aspect of the clinical manifestation and modulation of both the digestive and central nervous systems and could be the best approach in restoring the balance. As such, this article proposes a detailed description of the physiology of the microbiome-gut-brain axis, the pathophysiology of the functional gastrointestinal disorders with psychiatric symptoms and current perspectives for therapeutical management, as revealed by the latest studies in the scientific literature.

Novel exopolysaccharide derived from probiotic Lactobacillus pantheris TCP102 strain with immune-enhancing and anticancer activities

Probiotics are gaining attention due to their functions of regulating the intestinal barrier and promoting human health. The production of exopolysaccharide (EPS) is one of the important factors for probiotics to exert beneficial properties. This study aimed to screen exopolysaccharides-producing lactic acid bacteria (LAB) and evaluate the probiotic potential. we obtained three exopolysaccharide fractions (EPS1, EPS2, and EPS3) from Lactobacillus pantheris TCP102 and purified by a combination of ion-exchange chromatography and gel permeation chromatography. The structures of the fractions were characterized by FT-IR, UV, HPLC, and scanning electron microscopy (SEM) analysis. The Mw of EPS1, EPS2, and EPS3 were approximately 20.3, 23.0, and 19.3 kDa, and were mainly composed of galactose, glucose, and mannose, with approximate molar ratios of 2.86:1:1.48, 1.26:1:1, 1.58:1.80:1, respectively. Furthermore, SEM analysis demonstrated that the three polysaccharide fractions differ in microstructure and surface morphology. Additionally, preliminary results for immune-enhancing and anticancer activities reveal that these EPSs significantly induced the production of nitric oxide (NO), TNF-α, and IL-6 in Ana-1 cells and peritoneal macrophage cells. Meanwhile, the EPSs also significantly suppressed the proliferation of HCT-116, BCG-803, and particularly A-2780 cells. The results suggest that the three novel EPSs isolated from Lactobacillus pantheris TCP102 can be regarded as potential application value in functional food and natural antitumor drugs.