Emerging roles of lactic acid bacteria in protection against colorectal cancer

Exploring the Multifaceted Therapeutic Potential of Probiotics: A Review of Current Insights and Applications

The interplay between human health and the microbiome has gained extensive attention, with probiotics emerging as pivotal therapeutic agents due to their vast potential in treating various health issues. As significant modulators of the gut microbiota, probiotics are crucial in maintaining intestinal homeostasis and enhancing the synthesis of short-chain fatty acids. Despite extensive research over the past decades, there remains an urgent need for a comprehensive and detailed review that encapsulates probiotics' latest insights and applications. This review focusses on the multifaceted roles of probiotics in promoting health and preventing disease, highlighting the complex mechanisms through which these beneficial bacteria influence both gut flora and the human body at large. This paper also explores probiotics' neurological and gastrointestinal applications, focussing on their significant impact on the gut-brain axis and their therapeutic potential in a broad spectrum of pathological conditions. Current innovations in probiotic formulations, mainly focusing on integrating genomics and biotechnological advancements, have also been comprehensively discussed herein. This paper also critically examines the regulatory landscape that governs probiotic use, ensuring safety and efficacy in clinical and dietary settings. By presenting a comprehensive overview of recent studies and emerging trends, this review aims to illuminate probiotics' extensive therapeutic capabilities, leading to future research and clinical applications. However, besides extensive research, further advanced explorations into probiotic interactions and mechanisms will be essential for developing more targeted and effective therapeutic strategies, potentially revolutionizing health care practices for consumers.

Harnessing the power of probiotic strains in functional foods: nutritive, therapeutic, and next-generation challenges

Functional foods have become an essential element of the diet in developed nations, due to their health benefits and nutritive values. Such food products are only called functional if they, "In addition to basic nutrition, have valuable effects on one or multiple functions of the human body, thereby enhancing general and physical conditions and/or reducing the risk of disease progression". Functional foods are currently one of the most extensively researched areas in the food and nutrition sciences. They are fortified and improved food products. Presently, probiotics are regarded as the most significant and commonly used functional food product. Diverse probiotic food products and supplements are used according to the evidence that supports their strength, functionality, and recommended dosage. This review provides an overview of the current functional food market, with a particular focus on probiotic microorganisms as pivotal functional ingredients. It offers insights into current research endeavors and outlines potential future directions in the field.

Probiotics in Dermatology: An Evidence-based Approach

Probiotics are viable microorganisms that confer health benefits when administered to the host in adequate amounts. Over the past decade, there has been a growing demand for the use of oral and topical probiotics in several inflammatory conditions such as atopic dermatitis, psoriasis, acne vulgaris, etc., although their role in a few areas still remains controversial. The objective of this article is to shed light on understanding the origin and implications of microbiota in the pathophysiology of these dermatological conditions and the effect of probiotic usage. We have conducted a comprehensive search of the literature across multiple databases (PubMed, EMBASE, MEDLINE, and Google Scholar) on the role of probiotics in dermatological disorders. Commensal microbes of the skin and gastrointestinal tract play an important role in both health and disease. Increased use of probiotics has asserted a good safety profile, especially in this era of antibiotic resistance. With the advent of new products in the market, the indications, mechanism of action, efficacy, and safety profile of these agents need to be validated. Further studies are required. Oral and topical probiotics may be tried as a treatment or prevention modality in cutaneous inflammatory disorders, thus facilitating decreased requirement for topical or systemic steroids and antimicrobial agents. Tempering microbiota with probiotics is a safe and well-tolerated approach in this era of antimicrobial resistance.

A Critical Review on the Role of Probiotics in Lung Cancer Biology and Prognosis

Lung cancer remains the leading cause of cancer-related deaths worldwide. According to the American Cancer Society (ACS), it ranks as the second most prevalent type of cancer globally. Recent findings have highlighted bidirectional gut-lung interactions, known as the gut-lung axis, in the pathophysiology of lung cancer. Probiotics are live microorganisms that boost host immunity when consumed adequately. The immunoregulatory mechanisms of probiotics are thought to operate through the generation of various metabolites that impact both the gut and distant organs (e.g., the lungs) through blood. Several randomized controlled trials have highlighted the pivotal role of probiotics in gut health especially for the prevention and treatment of malignancies, with a specific emphasis on lung cancer. Current research indicates that probiotic supplementation positively affects patients, leading to a suppression in cancer symptoms and a shortened disease course. While clinical trials validate the therapeutic benefits of probiotics, their precise mechanism of action remains unclear. This narrative review aims to provide a comprehensive overview of the present landscape of probiotics in the management of lung cancer.

Oral bacteriome and oral potentially malignant disorders: A systematic review of the associations

INTRODUCTION

Periodontal bacteria can infiltrate the epithelium, activate signaling pathways, induce inflammation, and block natural killer and cytotoxic cells, all of which contribute to the vicious circle of carcinogenesis. It is unknown whether oral dysbiosis has an impact on the etiology or prognosis of OPMD.

AIMS

Within this paradigm, this work systemically investigated and reported on the composition of oral microbiota in patients with oral potentially malignant disorders (OPMD) versus healthy controls.

METHODS

Observational studies that reported next generation sequencing analysis of oral tissue or salivary samples and found at least three bacterial species were included. Identification, screening, citation analysis, and graphical synthesis were carried out.

RESULTS

For oral lichen planus (OLP), the bacteria with the highest abundance were Fusobacterium, Capnocytophaga, Gemella, Granulicatella, Porphyromonas, and Rothia; for oral leukoplakia (OLK), Prevotella. Streptococci levels in OLK and OLP were lower. The usage of alcohol or smoke had no effect on the outcomes.

CONCLUSIONS

An increase in periodontal pathogenic bacteria could promote the development and exacerbation of lichen. Effective bacteriome-based biomarkers are worthy of further investigation and application, as are bacteriome-based treatments.

Effects of prebiotics, probiotics, and synbiotics on the prevention and treatment of cervical cancer: Mexican consensus and recommendations

Gut microbiota plays a crucial role in modulating immune responses, including effector response to infection and surveillance of tumors. This article summarizes the current scientific evidence on the effects of supplementation with prebiotics, probiotics, and synbiotics on high-risk human papillomavirus (HPV) infections, precancerous lesions, and various stages of cervical cancer development and treatment while also examining the underlying molecular pathways involved. Our findings indicate that a higher dietary fiber intake is associated with a reduced risk of HPV infection, while certain probiotics have shown promising results in clearing HPV-related lesions. Additionally, certain strains of probiotics, prebiotics such as inulin and fructo-oligosaccharides, and synbiotics decrease the frequency of gastrointestinal adverse effects in cervical cancer patients. These agents attain their results by modulating crucial metabolic pathways, including the reduction of inflammation and oxidative stress, promoting apoptosis, inhibiting cell proliferation, and suppressing the activity of oncogenes, thus attenuating tumorigenesis. We conclude that although further human studies are necessary, robust evidence in preclinical models demonstrates that prebiotics, probiotics, and synbiotics play an essential role in cervical cancer, from infection to carcinogenesis and its medical treatment. Consequently, we strongly recommend conducting high-quality clinical trials using these agents as adjuvants since they have proven safe.

Association between gut microbiota and pan-dermatological diseases: a bidirectional Mendelian randomization research

Background

Gut microbiota has been associated with dermatological problems in earlier observational studies. However, it is unclear whether gut microbiota has a causal function in dermatological diseases.

Methods

Thirteen dermatological diseases were the subject of bidirectional Mendelian randomization (MR) research aimed at identifying potential causal links between gut microbiota and these diseases. Summary statistics for the Genome-Wide Association Study (GWAS) of gut microbiota and dermatological diseases were obtained from public datasets. With the goal of evaluating the causal estimates, five acknowledged MR approaches were utilized along with multiple testing corrections, with inverse variance weighted (IVW) regression serving as the main methodology. Regarding the taxa that were causally linked with dermatological diseases in the forward MR analysis, reverse MR was performed. A series of sensitivity analyses were conducted to test the robustness of the causal estimates.

Results

The combined results of the five MR methods and sensitivity analysis showed 94 suggestive and five significant causal relationships. In particular, the genus Eubacterium_fissicatena_group increased the risk of developing psoriasis vulgaris (odds ratio [OR] = 1.32, pFDR = 4.36 × 10-3), family Bacteroidaceae (OR = 2.25, pFDR = 4.39 × 10-3), genus Allisonella (OR = 1.42, pFDR = 1.29 × 10-2), and genus Bacteroides (OR = 2.25, pFDR = 1.29 × 10-2) increased the risk of developing acne; and the genus Intestinibacter increased the risk of urticaria (OR = 1.30, pFDR = 9.13 × 10-3). A reverse MR study revealed insufficient evidence for a significant causal relationship. In addition, there was no discernible horizontal pleiotropy or heterogeneity.

Conclusion

This study provides novel insights into the causality of gut microbiota in dermatological diseases and therapeutic or preventive paradigms for cutaneous conditions.

Genital tract microbiota composition profiles and use of prebiotics and probiotics in gynaecological cancer prevention: review of the current evidence, the European Society of Gynaecological Oncology prevention committee statement

Female genital tract (FGT) microbiota has been associated with the development of gynaecological cancers. Thus, the possibility of whether manipulation of the FGT microbiota can help in the prevention of disease should be investigated. Various prebiotics, probiotics, and other non-clinician prescribed agents have been reported to have therapeutic effects in cervical disease. Numerous studies have reported an association between human papillomavirus infection and subsequent cervical dysplasia and a decrease in the abundance of Lactobacillus species. A continuum of microbiota composition is observed from the vagina to the upper parts of the FGT, but no evidence suggests that manipulation of the vaginal microbiota can help to modify the composition of other FGT compartments. Although prebiotics and probiotics have been reported to be beneficial, the studies are small and of varying design, and high-quality evidence to support their use is lacking. Currently, no studies have examined these therapeutics in other gynaecological malignancies. Thus, recommendation of probiotics, prebiotics, or other over-the-counter supplements for the prevention of gynaecological cancers warrants larger, well designed studies.

Modulation of Caco-2 Colon Cancer Cell Viability and CYP2W1 Gene Expression by Hesperidin-treated Lacticaseibacillus rhamnosus GG (LGG) Cell-free Supernatants

BACKGROUND AND OBJECTIVE

Ensuring colon homeostasis is of significant influence on colon cancer and delicate balance is maintained by a healthy human gut microbiota. Probiotics can modulate the diversity of the gut microbiome and prevent colon cancer. Metabolites/byproducts generated by microbial metabolism significantly impact the healthy colonic environment. Hesperidin is a polyphenolic plant compound well known for its anticancer properties. However, low bioavailability of hesperidin after digestion impedes its effectiveness. CYP2W1 is a newly discovered oncofetal gene with an unknown function. CYP2W1 gene expression peaks during embryonic development and is suddenly silenced immediately after birth. Only in the case of some types of cancer, particularly colorectal and hepatocellular carcinomas, this gene is reactivated and its expression is correlated with the severity of the disease. This study aimed to investigate the effects of hesperidin-treated Lacticaseibacillus rhamnosus GG (LGG) cell-free supernatants on CaCo2 colon cancer cell viability and CYP2W1 gene expression.

METHODS

Alamar Blue cell viability assay was used to investigate the cytotoxic effect of cell-free supernatant of LGG grown in the presence of hesperidin on CaCo2 cells. To observe the effect of cell-free supernatants of LGG on the expression of CYP2W1 gene, qRT-PCR was performed.

RESULTS

Five times diluted hesperidin treated cell-free supernatant (CFS) concentration considerably reduced CaCo2 colon cancer cell viability. Furthermore, CYP2W1 gene expression was similarly reduced following CFS treatments and nearly silenced under probiotic bacteria CFS treatment.

CONCLUSION

The CYP2W1 gene expression was strongly reduced by cell-free supernatants derived from LGG culture, with or without hesperidin. This suggests that the suppression may be due to bacterial byproducts rather than hesperidin. Therefore, the CYP2W1 gene in the case of deregulation of these metabolites may cause CYP2W1-related colon cancer cell proliferation.

Colitis-associated carcinogenesis: crosstalk between tumors, immune cells and gut microbiota

Colorectal cancer (CRC) is the third most common cancer worldwide. One of the main causes of colorectal cancer is inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). Intestinal epithelial cells (IECs), intestinal mesenchymal cells (IMCs), immune cells, and gut microbiota construct the main body of the colon and maintain colon homeostasis. In the development of colitis and colitis-associated carcinogenesis, the damage, disorder or excessive recruitment of different cells such as IECs, IMCs, immune cells and intestinal microbiota play different roles during these processes. This review aims to discuss the various roles of different cells and the crosstalk of these cells in transforming intestinal inflammation to cancer, which provides new therapeutic methods for chemotherapy, targeted therapy, immunotherapy and microbial therapy.

Probiotic potentials of lactic acid bacteria isolated from Egyptian fermented food

Lactic acid bacteria (LAB) are of major concern due to their health benefits. Fermented food products comprise variable LAB demonstrating probiotic properties. Discovering and evaluating new probiotics in fermented food products poses a global economic and health importance. Therefore, the present work aimed to investigate and evaluate the probiotic potentials of LAB strains isolated from Egyptian fermented food. In this study, we isolated and functionally characterized 100 bacterial strains isolated from different Egyptian fermented food sources as probiotics. Only four LAB strains amongst the isolated LAB showed probiotic attributes and are considered to be safe for their implementation as feed or dietary supplements. Additionally, they were shown to exert antimicrobial activities against pathogenic bacteria and anticancer effects against the colon cancer cell line Caco-2. The Enterococcus massiliensis IS06 strain was exclusively reported in this study as a probiotic strain with high antimicrobial, antioxidant, and anti-colon cancer activity. Hitherto, few studies have focused on elucidating the impact of probiotic supplementation in vivo. Therefore, in the current study, the safety of the four strains was tested in vivo through the supplementation of rats with potential probiotic strains for 21 days. The results revealed that probiotic bacterial supplementation in rats did not adversely affect the general health of rats. The Lactiplantibacillus plantarum IS07 strain significantly increased the growth performance of rats. Furthermore, the four strains exhibited increased levels of antioxidants such as superoxide dismutase and glutathione in vivo. Consistently, all strains also showed high antioxidant activity of the superoxide dismutase enzyme in vitro. Overall, these findings demonstrated that these isolated potential probiotics harbor desirable characteristics and can be applied widely as feed additives for animals or as dietary supplements for humans to exert their health benefits and combat serious diseases.

Organic functional substance engineered living materials for biomedical applications

Modifying living materials with organic functional substances (OFS) is a convenient and effective strategy to control and monitor the transport, engraftment, and secretion processes in living organisms. OFSs, including small organic molecules and organic polymers, own the merit of design flexibility, satisfying performance, and excellent biocompatibility, which allow for living materials functionalization to realize real-time sensing, controlled drug release, enhanced biocompatibility, accurate diagnosis, and precise treatment. In this review, we discuss the different principles of OFS modification on living materials and demonstrate the applications of engineered living materials in health monitoring, drug delivery, wound healing, and tissue regeneration.

Personalized Medicine in Oral Oncology: Imaging Methods and Biological Markers to Support Diagnosis of Oral Squamous Cell Carcinoma (OSCC): A Narrative Literature Review

For decades, oral squamous cell carcinoma (OSCC) has been one of the most prevalent and mortal cancers worldwide. The gold standard for OSCC diagnosis is still histopathology but this narrative multidisciplinary review has the aim to explore the literature about conventional OSCC prognostic indicators related to the pTNM stage at the diagnosis such as the depth of invasion and the lymphovascular invasion associated with distant metastasis as indicators of poor life expectancy. Despite its multifactorial nature and recognizable precursors, its diagnosis at the early stages is still challenging. We wanted to highlight the importance of the screening as a primary weapon that a stomatologist should consider, intercepting all at-risk conditions and lesions associated with OSCC and its early stages. This narrative review also overviews the most promising imaging techniques, such as CT, MRI, and US-echography, and their application related to clinical and surgical practice, but also the most-investigated prognostic and diagnostic tissue and salivary biomarkers helpful in OSCC diagnosis and prognostic assessment. Our work highlighted remarkable potential biomarkers that could have a leading role in the future. However, we are still far from defining an appropriate and concrete protocol to apply in clinical practice. The hope is that the present and future research will overcome these limitations to benefit patients, clinicians, and welfare.

Association between Probiotics and Modulation of Gut Microbial Community Composition in Colorectal Cancer Animal Models: A Systematic Review (2010-2021)

Background

Colorectal cancer (CRC) is one of the most prevalent gastrointestinal malignancies and is considered the third major cause of mortality globally. Probiotics have been shown to protect against the CRC cascade in numerous studies.

Aims

The goal of this systematic review was to gather the preclinical studies that examined the impact of probiotics on the alteration of gut microbiota profiles (bacterial communities) and their link to colorectal carcinogenesis as well as the potential processes involved.

Methods

The search was performed using Scopus, Web of Science, and PubMed databases. Five parameters were used to develop search filters: "probiotics," "prebiotics," "synbiotics," "colorectal cancer," and "animal model."

Results

Of the 399 full texts that were screened, 33 original articles met the inclusion criteria. According to the current findings, probiotics/synbiotics could significantly attenuate aberrant crypt foci (ACF) formation, restore beneficial bacteria in the microbiota population, increase short-chain fatty acids (SCFAs), and change inflammatory marker expression.

Conclusions

The present systematic review results indicate that probiotics could modulate the gut microbial composition and immune regulation to combat/inhibit CRC in preclinical models. However, where the evidence is more limited, it is critical to transfer preclinical research into clinical data.

Methionine restriction-induced sulfur deficiency impairs antitumour immunity partially through gut microbiota

Restriction of methionine (MR), a sulfur-containing essential amino acid, has been reported to repress cancer growth and improve therapeutic responses in several preclinical settings. However, how MR impacts cancer progression in the context of the intact immune system is unknown. Here we report that while inhibiting cancer growth in immunocompromised mice, MR reduces T cell abundance, exacerbates tumour growth and impairs tumour response to immunotherapy in immunocompetent male and female mice. Mechanistically, MR reduces microbial production of hydrogen sulfide, which is critical for immune cell survival/activation. Dietary supplementation of a hydrogen sulfide donor or a precursor, or methionine, stimulates antitumour immunity and suppresses tumour progression. Our findings reveal an unexpected negative interaction between MR, sulfur deficiency and antitumour immunity and further uncover a vital role of gut microbiota in mediating this interaction. Our study suggests that any possible anticancer benefits of MR require careful consideration of both the microbiota and the immune system.

Recent progress in plant-derived polysaccharides with prebiotic potential for intestinal health by targeting gut microbiota: a review

Natural products of plant origin are of high interest and widely used, especially in the food industry, due to their low toxicity and wide range of bioactive properties. Compared to other plant components, the safety of polysaccharides has been generally recognized. As dietary fibers, plant-derived polysaccharides are mostly degraded in the intestine by polysaccharide-degrading enzymes secreted by gut microbiota, and have potential prebiotic activity in both non-disease and disease states, which should not be overlooked, especially in terms of their involvement in the treatment of intestinal diseases and the promotion of intestinal health. This review elucidates the regulatory effects of plant-derived polysaccharides on gut microbiota and summarizes the mechanisms involved in targeting gut microbiota for the treatment of intestinal diseases. Further, the structure-activity relationships between different structural types of plant-derived polysaccharides and the occurrence of their prebiotic activity are further explored. Finally, the practical applications of plant-derived polysaccharides in food production and food packaging are summarized and discussed, providing important references for expanding the application of plant-derived polysaccharides in the food industry or developing functional dietary supplements.

Antiproliferative effects of mesenchymal stem cells carrying Newcastle disease virus and Lactobacillus Casei extract on CT26 Cell line: synergistic effects in cancer therapy

BACKGROUND AND AIMS

Colorectal Cancer (CRC) is a frequent malignancy with a high mortality rate. Specific inherited and environmental influences can affect CRC. Oncolytic viruses and bacteria in treating CRC are one of the innovative therapeutic options. This study aims to determine whether mesenchymal stem cells (MSCs) infected with the Newcastle Disease Virus (NDV) in combination with Lactobacillus casei extract (L. casei) have a synergistic effects on CRC cell line growth.

MATERIALS AND METHODS

MSCs taken from the bone marrow of BALB/c mice and were infected with the 20 MOI of NDV. Then, using the CT26 cell line in various groups as a single and combined treatment, the anticancer potential of MSCs containing the NDV and L. casei extract was examined. The evaluations considered the CT26 survival and the rate at which LDH, ROS, and levels of caspases eight and nine were produced following various treatments.

RESULTS

NDV, MSCs-NDV, and L. casei in alone or combined treatment significantly increased apoptosis percent, LDH, and ROS production compared with the control group (P˂0.05). Also, NDV, in free or capsulated in MSCs, had anticancer effects, but in capsulated form, it had a delay compared with free NDV. The findings proved that L. casei primarily stimulates the extrinsic pathway, while NDV therapy promotes apoptosis through the activation of both intrinsic and extrinsic apoptosis pathways.

CONCLUSIONS

The results suggest that MSCs carrying oncolytic NDV in combination with L. casei extract as a potentially effective strategy for cancer immunotherapy by promoting the generation of LDH, ROS, and apoptosis in the microenvironment of the CT26 cell line.

Prevention and Health Benefits of Prebiotics, Probiotics and Postbiotics in Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is the most common type of leukemia in children, comprising 75-85% of cases. Aggressive treatment of leukemias includes chemotherapy and antibiotics that often disrupt the host microbiota. Additionally, the gut microbiota may play a role in the development and progression of acute leukemia. Prebiotics, probiotics, and postbiotics are considered beneficial to health. The role of prebiotics in the treatment and development of leukemia is not well understood, but inulin can be potentially used in the treatment of leukemia. Some probiotic bacteria such as Lactobacillus shows anticancer activity in in vitro studies. Additionally, Bifidobacterium spp., as a consequence of the inhibition of growth factor signaling and mitochondrial-mediated apoptosis, decrease the proliferation of cancer cells. Many bacterial metabolites have promising anticancer potential. The available research results are promising. However, more research is needed in humans, especially in the child population, to fully understand the relationship between the gut microbiota and acute leukemia.

Tumor-homing bacterium-adsorbed liposomes encapsulating perfluorohexane/doxorubicin enhance pulsed-focused ultrasound for tumor therapy

Objective: To make up for the insufficient ultrasound ablation of tumors, the energy output or synergist is increased but faces the big challenge of normal tissue damage. In this study, we report a tumor-homing bacterium, Bifidobacterium bifidum (B. bifidum), adsorbing liposomes that encapsulate perfluorohexane (PFH) and doxorubicin (DOX) to enhance the pulsed-focused ultrasound (PFUS) for tumor therapy, so as to improve the efficacy, safety and controllability of ultrasound treatment. Methods: The PFH and DOX co-loaded cationic liposomal nanoparticles (CL-PFH-DOX-NPs) were prepared for ultrasound (US) imaging, cell-killing, and B. bifidum adsorption for the reactive oxygen species (ROS) testing. The aggregation of B. bifidum and CL-PFH-DOX-NPs is called tumor-homing aggregation (B. bifidum@CL-PFH-DOX-NPs) in this study, and the synergistic effects of B. bifidum@CL-PFH-DOX-NPs were analyzed in vivo. Results: Comprehensive studies validated that CL-PFH-DOX-NPs can enhance US imaging and cell-killing and B. bifidum can promote ROS, and B. bifidum@CL-PFH-DOX-NPs achieve PFUS synergism in vivo. Importantly, active homing of B. bifidum facilitated the delivery and retention of CL-PFH-DOX-NPs in tumors, reducing dispersion in normal tissues, achieving the targeting ability of B. bifidum@CL-PFH-DOX-NPs. The best sonication time was chosen according to the distribution of CL-PFH-DOX-NPs in vivo to achieve efficient therapy. Especially, B. bifidum@CL-PFH-DOX-NPs amplified cavitation and the immune-boosting effects. Conclusion: Multifunctional B. bifidum@CL-PFH-DOX-NPs were successfully constructed with well targeting, which not only realized US imaging monitoring, strong cavitation and complementary killing during PFUS, but also achieved immunity enhancement after PFUS. The combination of PFUS, B. bifidum and CL-PFH-DOX-NPs provides a new idea for the potential application of ultrasound therapy in solid tumors.

Lactobacillus sp. Facilitate the Repair of DNA Damage Caused by Bile-Induced Reactive Oxygen Species in Experimental Models of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) leads to the accumulation of bile-induced reactive oxygen species and oxidative stress in esophageal tissues, causing inflammation and DNA damage. The progression sequence from healthy esophagus to GERD and eventually cancer is associated with a microbiome shift. Lactobacillus species are commensal organisms known for their probiotic and antioxidant characteristics in the healthy esophagus. This prompted us to investigate how Lactobacilli survive in a bile-rich environment during GERD, and to identify their interaction with the bile-injured esophageal cells. To model human reflux conditions, we exposed three Lactobacillus species (L. acidophilus, L. plantarum, and L. fermentum) to bile. All species were tolerant to bile possibly enabling them to colonize the esophageal epithelium under GERD conditions. Next, we assessed the antioxidant potential of Lactobacilli and role in bile injury repair: we measured bile-induced DNA damage using the ROS marker 8-oxo guanine and COMET assay. Lactobacillus addition after bile injury accelerated repair of bile-induced DNA damage through recruitment of pH2AX/RAD51 and reduced NFκB-associated inflammation in esophageal cells. This study demonstrated anti-genotoxic and anti-inflammatory effects of Lactobacilli, making them of significant interest in the prevention of Barrett's esophagus and esophageal adenocarcinoma in patients with GERD.

Potential Antitumor Effect of Functional Yogurts Formulated with Prebiotics from Cereals and a Consortium of Probiotic Bacteria

Various types of functional yogurts were obtained from normalized milk (with normalized lipid content) and a standardized probiotic consortium of probiotic bacteria named ABY3. All the types of yogurts obtained contained prebiotics from black or red rice; malt of barley, rye, wheat; or wheat bran. The physico-chemical analyses of all the functionalized products obtained showed that all of them met the quality standard for yogurt products. However, the sensorial analyses showed that the products obtained from black and red rice were of very good quality. The biological analyses indicated that all the types of products contained live probiotic bacteria, but wheat bran and red rice could increase their numbers. Tests performed on tumor cell line Caco-2 with corresponding postbiotics revealed cytotoxicity greater than 30% after 48 h of exposure in the case of yogurts obtained from milk with 0.8% lipid content and red rice or blond malt of barley. In the case of yogurts derived from milk with 2.5% lipid content, only the variants that contained blond malt of rye or wheat became cytotoxic against the Caco-2 cell line.

Probiotic powder ameliorates colorectal cancer by regulating Bifidobacterium animalis, Clostridium cocleatum, and immune cell composition

Based on the relationship between the gut microbiota and colorectal cancer, we developed a new probiotic powder for treatment of colorectal cancer. Initially, we evaluated the effect of the probiotic powder on CRC using hematoxylin and eosin staining, and evaluated mouse survival rate and tumor size. We then investigated the effects of the probiotic powder on the gut microbiota, immune cells, and apoptotic proteins using 16S rDNA sequencing, flow cytometry, and western blot, respectively. The results showed that the probiotic powder improved the intestinal barrier integrity, survival rate, and reduced tumor size in CRC mice. This effect was associated with changes in the gut microbiota. Specifically, the probiotic powder increased the abundance of Bifidobacterium animalis and reduced the abundance of Clostridium cocleatum. In addition, the probiotic powder resulted in decreased numbers of CD4+ Foxp3+ Treg cells, increased numbers of IFN-γ+ CD8+ T cells and CD4+ IL-4+ Th2 cells, decreased expression of the TIGIT in CD4+ IL-4+ Th2 cells, and increased numbers of CD19+ GL-7+ B cells. Furthermore, the expression of the pro-apoptotic protein BAX was significantly increased in tumor tissues in response to the probiotic powder. In summary, the probiotic powder ameliorated CRC by regulating the gut microbiota, reducing Treg cell abundance, promoting the number of IFN-γ+ CD8+ T cells, increasing Th2 cell abundance, inhibiting the expression of TIGIT in Th2 cells, and increasing B cell abundance in the immune microenvironment of CRC, thereby increasing the expression of BAX in CRC.

Enhanced metagenomic deep learning for disease prediction and consistent signature recognition by restructured microbiome 2D representations

Metagenomic analysis has been explored for disease diagnosis and biomarker discovery. Low sample sizes, high dimensionality, and sparsity of metagenomic data challenge metagenomic investigations. Here, an unsupervised microbial embedding, grouping, and mapping algorithm (MEGMA) was developed to transform metagenomic data into individualized multichannel microbiome 2D representation by manifold learning and clustering of microbial profiles (e.g., composition, abundance, hierarchy, and taxonomy). These 2D representations enable enhanced disease prediction by established ConvNet-based AggMapNet models, outperforming the commonly used machine learning and deep learning models in metagenomic benchmark datasets. These 2D representations combined with AggMapNet explainable module robustly identified more reliable and replicable disease-prediction microbes (biomarkers). Employing the MEGMA-AggMapNet pipeline for biomarker identification from 5 disease datasets, 84% of the identified biomarkers have been described in over 74 distinct works as important for these diseases. Moreover, the method also discovered highly consistent sets of biomarkers in cross-cohort colorectal cancer (CRC) patients and microbial shifts in different CRC stages.

A blood-based circulating microbial metagenomic panel for early diagnosis and prognosis of oesophageal adenocarcinoma

BACKGROUND

Emerging evidence indicates the potential clinical significance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in oesophageal adenocarcinoma (EAC) patients, particularly as novel non-invasive, early detection, surveillance and prognostic classifiers.

METHODS

Metagenome sequencing was performed on 81 serum specimens collected across EAC spectrum, with sequencing reads classified using Bracken and MetaPhlAn3. Followed by the Linear Discriminant Analysis effect size (LEfSe) method to identify microbial profiles between groups. Logistic regression and Kaplan-Meier analyses were used to build classifiers.

RESULTS

A significant loss of alpha and beta diversity was identified in serum specimens from EAC patients. We observed a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 (95% CI: 0.78-0.95; P < 0.001) and this panel in conjunction with the TNM stage was a robust predictor of overall survival (≥24 months; AUC = 0.84 (95% CI: 0.66-0.92; P = 0.006)).

CONCLUSION

This study firstly describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC.

TRANSLATIONAL RELEVANCE

Accumulating data indicates the clinical relevance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in patients with oesophageal adenocarcinoma (EAC). Herein, we performed metagenome sequencing in serum specimens from EAC patients 81 collected across EAC spectrum and observed a significant loss of alpha and beta diversity, with a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 and this panel, in conjunction with the TNM stage, was a robust predictor of overall survival. This study for the first time describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC.

Neospora caninum inhibits tumor development by activating the immune response and destroying tumor cells in a B16F10 melanoma model

Background

Melanoma is a malignant tumor with a high mortality rate. Some microorganisms have been shown to activate the immune system and limit cancer progression. The objective of this study is to evaluate the anti-melanoma effect of Neospora caninum, a livestock pathogen with no pathogenic activity in humans.

Methods

Neospora caninum tachyzoites were inoculated into a C57BL/6 mouse melanoma model by intratumoral and distal subcutaneous injections. Tumor volumes were measured, and cell death areas were visualized by hematoxylin and eosin staining and quantified. Apoptosis in cell cultures and whole tumors was detected by propidium iodide (PI) and TUNEL staining, respectively. Cytokine and tumor-associated factor levels in tumors and spleens were detected by real-time quantitative polymerase chain reaction. Infiltration of macrophages and CD8⁺ T cells in the tumor microenvironment (TME) were detected by immunohistochemistry with anti-CD68 and anti-CD8 antibodies, respectively. Finally, 16S rRNA sequencing of mice cecal contents was performed to evaluate the effect of N. caninum on gut microbial diversity.

Results

Intratumoral and distal subcutaneous injections of N. caninum resulted in significant inhibition of tumor growth (P < 0.001), and more than 50% of tumor cells were dead without signs of apoptosis. Neospora caninum treatment significantly increased the mRNA expression levels of IL-12, IFN-γ, IL-2, IL-10, TNF-α, and PD-L1 in the TME, and IL-12 and IFN-γ in the spleen of tumor-bearing mice (P < 0.05). An increase in the infiltration of CD8⁺ T cells and macrophages in the TME was observed with these cytokine changes. Neospora caninum also restored the abundance of gut microbiota Lactobacillus, Lachnospiraceae, Adlercreutzia, and Prevotellaceae associated with tumor growth, but the changes were not significant.

Conclusion

Neospora caninum inhibits B16F10 melanoma by activating potent immune responses and directly destroying the cancer cells. The stable, non-toxic, and efficacious properties of N. caninum demonstrate the potential for its use as a cancer treatment.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05456-8.

Do Bacteria Provide an Alternative to Cancer Treatment and What Role Does Lactic Acid Bacteria Play?

Cancer is one of the leading causes of mortality and morbidity worldwide. According to 2022 statistics from the World Health Organization (WHO), close to 10 million deaths have been reported in 2020 and it is estimated that the number of cancer cases world-wide could increase to 21.6 million by 2030. Breast, lung, thyroid, pancreatic, liver, prostate, bladder, kidney, pelvis, colon, and rectum cancers are the most prevalent. Each year, approximately 400,000 children develop cancer. Treatment between countries vary, but usually includes either surgery, radiotherapy, or chemotherapy. Modern treatments such as hormone-, immuno- and antibody-based therapies are becoming increasingly popular. Several recent reports have been published on toxins, antibiotics, bacteriocins, non-ribosomal peptides, polyketides, phenylpropanoids, phenylflavonoids, purine nucleosides, short chain fatty acids (SCFAs) and enzymes with anticancer properties. Most of these molecules target cancer cells in a selective manner, either directly or indirectly through specific pathways. This review discusses the role of bacteria, including lactic acid bacteria, and their metabolites in the treatment of cancer.

Therapeutic approaches to colorectal cancer via strategies based on modulation of gut microbiota

Colorectal cancer (CRC) ranks third in terms of global incidence and second in terms of death toll among malignant tumors. Gut microbiota are involved in the formation, development, and responses to different treatments of CRC. Under normal physiological conditions, intestinal microorganisms protect the intestinal mucosa, resist pathogen invasion, and regulate the proliferation of intestinal mucosal cells via a barrier effect and inhibition of DNA damage. The composition of gut microbiota and the influences of diet, drugs, and gender on the composition of the intestinal flora are important factors in the early detection of CRC and prediction of the results of CRC treatment. Regulation of gut microbiota is one of the most promising new strategies for CRC treatment, and it is essential to clarify the effect of gut microbiota on CRC and its possible mechanisms to facilitate the prevention and treatment of CRC. This review discusses the role of gut microbiota in the pathogenesis of CRC, the potential of gut microbiota as biomarkers for CRC, and therapeutic approaches to CRC based on the regulation of gut microbiota. It might provide new ideas for the use of gut microbiota in the prevention and treatment of CRC in the near future and thus reduce the incidence of CRC.

Biological roles of toll-like receptors and gut microbiota in colorectal cancer

Colorectal cancer (CRC) is one of the most considerably common malignancies of the alimentary system, with high mortality and incidence rates.  The present study suggested that the occurrence of CRC is closely related to bacteria, as the large intestine is a gathering place for human micro-organisms. However, the nosogenesis of bacteria leading to tumorigenesis is still obscure. Recently, many studies have reported that toll-like receptors and their related molecular pathways are involved in the process of gut micro-organisms generating CRC. Gut micro-organisms can promote or inhibit the development of CRC via binding to special toll-like receptors. In this paper, the authors review the relationship among toll-like receptors, gut micro-organisms and CRC in order to provide a reference for future tumor immunotherapy and targeted therapy.

Microbiota and Oral Cancer as A Complex and Dynamic Microenvironment: A Narrative Review from Etiology to Prognosis

A complex balanced equilibrium of the bacterial ecosystems exists in the oral cavity that can be altered by tobacco smoking, psychological stressors, bad dietary habit, and chronic periodontitis. Oral dysbiosis can promote the onset and progression of oral squamous cell carcinoma (OSCC) through the release of toxins and bacterial metabolites, stimulating local and systemic inflammation, and altering the host immune response. During the process of carcinogenesis, the composition of the bacterial community changes qualitatively and quantitatively. Bacterial profiles are characterized by targeted sequencing of the 16S rRNA gene in tissue and saliva samples in patients with OSCC. Capnocytophaga gingivalis, Prevotella melaninogenica, Streptococcus mitis, Fusobacterium periodonticum, Prevotella tannerae, and Prevotella intermedia are the significantly increased bacteria in salivary samples. These have a potential diagnostic application to predict oral cancer through noninvasive salivary screenings. Oral lactic acid bacteria, which are commonly used as probiotic therapy against various disorders, are valuable adjuvants to improve the response to OSCC therapy.

In Silico Genomic and Metabolic Atlas of Limosilactobacillus reuteri DSM 20016: An Insight into Human Health

Probiotics are bacterial strains that are known to provide host health benefits. Limosilactobacillus reuteri is a well-documented lactic acid bacterium that has been cultured from numerous human sites. The strain investigated was L. reuteri DSM 20016, which has been found to produce useful metabolites. The strain was explored using genomic and proteomic tools, manual searches, and databases, including KEGG, STRING, BLAST Sequence Similarity Search, and UniProt. This study located over 200 key genes that were involved in human health benefit pathways. L. reuteri DSM 20016 has metabolic pathways to produce acetate, propionate, and lactate, and there is evidence of a pathway for butanoate production through a FASII mechanism. The bacterium produces histamine through the hdc operon, which may be able to suppress proinflammatory TNF, and the bacterium also has the ability to synthesize folate and riboflavin, although whether they are secreted is yet to be explored. The strain can bind to human Caco2 cells through srtA, mapA/cnb, msrB, and fbpA and can compete against enteric bacteria using reuterin, which is an antimicrobial that induces oxidative stress. The atlas could be used for designing metabolic engineering approaches to improve beneficial metabolite biosynthesis and better probiotic-based cures.

Molecular identification of lactic acid bacteria SR6 strain and evaluation of its activity as an anticancer in T47D cell line

Background and Aim: Breast cancer is the most common type of cancer in women because it attacks the productive age. Preliminary studies showed that lactic acid bacteria (LAB) strain SR6 from the Bali cattle colon has the potential to act as a superior probiotic. It is also assumed that its bacteriocin structure is specific and has a strong relationship with the specificity of the ligand and its biological activity at a receptor. Therefore, this study aims to assess the use of local LAB strains, which produce bacteriocins as anticancer agents, as well as to identify the bacteria as potent producers molecularly. Materials and Methods: The study was initiated by cultivating LAB SR6 strain from stock isolates on De Man, Rogosa, and Sharpe (Oxoid, CM 0369, England) broth media. It was then confirmed molecularly through analysis of the 16S ribosomal ribonucleic acid gene. Subsequently, its anticancer activity was tested by assessing the cytotoxic activity in T47D cell culture using the 3-(4, 5 dimetiltiazol-2-yl)-2.5-diphenyl tetrazolium bromide (Invitrogen M6494, US) method. Results: The results showed that the LAB strain SR6 was identified molecularly as Pediococcus pentosaceus. Furthermore, it had a toxic effect on T47D cells, which was indicated by the number of deaths after treatment with the extracellular protein of the strain, especially at the 50% total cell volume level. Conclusion: Based on the toxic effect of the strain on human T47D cells, the LAB SR6 isolate, which was identified as P. pentosaceus has the potential to be developed as a good anticancer drug against breast cancer. However, there is a need to carry out an integrated study to fully explore the suitability of bacteriocins as in vivo therapeutics against the disease completely.

Role of the microbiome in oral cancer occurrence, progression and therapy

The oral cavity, like other digestive or mucosal sites, contains a site-specific microbiome that plays a significant role in maintaining health and homeostasis. Strictly speaking, the gastrointestinal tract starts from the oral cavity, with special attention paid to the specific flora of the oral cavity. In healthy people, the microbiome of the oral microenvironment is governed by beneficial bacteria, that benefit the host by symbiosis. When a microecological imbalance occurs, changes in immune and metabolic signals affect the characteristics of cancer, as well as chronic inflammation, disruption of the epithelial barrier, changes in cell proliferation and cell apoptosis, genomic instability, angiogenesis, and epithelial barrier destruction and metabolic regulation. These pathophysiological changes could result in oral cancer. Rising evidence suggests that oral dysbacteriosis and particular microbes may play a positive role in the evolution, development, progression, and metastasis of oral cancer, for instance, oral squamous cell carcinoma (OSCC) through direct or indirect action.

Alterations in co-abundant bacteriome in colorectal cancer and its persistence after surgery: a pilot study

There is growing interest in the role of gut microbiome in colorectal cancer (CRC), ranging from screening to disease recurrence. Our study aims to identify microbial markers characteristic of CRC and to examine if changes in bacteriome persist after surgery. Forty-nine fecal samples from 25 non-cancer (NC) individuals and 12 CRC patients, before and 6-months after surgery, were collected for analysis by bacterial 16S rRNA gene sequencing. Bacterial richness and diversity were reduced, while pro-carcinogenic bacteria such as Bacteroides fragilis and Odoribacter splanchnicus were increased in CRC patients compared to NC group. These differences were no longer observed after surgery. Comparison between pre-op and post-op CRC showed increased abundance of probiotic bacteria after surgery. Concomitantly, bacteria associated with CRC progression were observed to have increased after surgery, implying persistent dysbiosis. In addition, functional pathway predictions based on the bacterial 16S rRNA gene data showed that various pathways were differentially enriched in CRC compared to NC. Microbiome signatures characteristic of CRC comprise altered bacterial composition. Elements of these dysbiotic signatures persists even after surgery, suggesting possible field-change in remnant non-diseased colon. Future studies should involve a larger sample size with microbiome data collected at multiple time points after surgery to examine if these dysbiotic patterns truly persist and also correlate with disease outcomes.

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

Lactic acid bacteria (LAB) are Gram-positive bacteria which are considered for use as adjuvant therapeutics in management of various disease ailments, including obesity, irritable bowel syndrome, lactose intolerance and cancer. To investigate the possible use of Lactococcus lactis strains from our collection in treatment of gastrointestinal cancer, we tested them for the ability to arrest proliferation of human colorectal adenocarcinoma cells (Caco-2). Results of the BrdU assay showed that the anti-proliferative activity of L. lactis cells is strain-specific. We found that particularly, two strains, L. lactis IBB109 and L. lactis IBB417, exhibited the most potent inhibitory effect. Moreover, both strains triggered interleukin 18 gene expression, normally inhibited in Caco-2 (cancer) cells. To examine the probiotic potential of the two strains, we tested them for bile salts and acid tolerance, as well as adhesion properties. Both isolates exhibited probiotic potential—they survived in the presence of 0.3% bile salts and tolerated exposure to low pH and osmotic stress. Notably, we found that L. lactis IBB417 displayed better adherence to mucus and Caco-2 cells than L. lactis IBB109. Additionally, by microdilution tests we confirmed that both strains are sensitive to all nine antibiotics of human and veterinary importance listed by the European Food Safety Authority. Finally, by in silico investigations of whole genome sequencing data, we revealed the genetic features of L. lactis IBB109 and L. lactis IBB417 that can be associated with functional (e.g., adhesion and carbohydrate metabolic genes) and safety (e.g., virulence and antibiotic resistance) aspects of the strains, confirming their health-promoting potential.

Bacteriocin-Producing Probiotic Lactic Acid Bacteria in Controlling Dysbiosis of the Gut Microbiota

Several strains of lactic acid bacteria are potent probiotics and can cure a variety of diseases using different modes of actions. These bacteria produce antimicrobial peptides, bacteriocins, which inhibit or kill generally closely related bacterial strains and other pathogenic bacteria such as Listeria, Clostridium, and Salmonella. Bacteriocins are cationic peptides that kill the target cells by pore formation and the dissipation of cytosolic contents, leading to cell death. Bacteriocins are also known to modulate native microbiota and host immunity, affecting several health-promoting functions of the host. In this review, we have discussed the ability of bacteriocin-producing probiotic lactic acid bacteria in the modulation of gut microbiota correcting dysbiosis and treatment/maintenance of a few important human disorders such as chronic infections, inflammatory bowel diseases, obesity, and cancer.

The genomic basis of the Streptococcus thermophilus health-promoting properties

Background

Streptococcus thermophilus is a Gram-positive bacterium widely used as starter in the dairy industry as well as in many traditional fermented products. In addition to its technological importance, it has also gained interest in recent years as beneficial bacterium due to human health-promoting functionalities. The objective of this study was to inventory the main health-promoting properties of S. thermophilus and to study their intra-species diversity at the genomic and genetic level within a collection of representative strains.

Results

In this study various health-related functions were analyzed at the genome level from 79 genome sequences of strains isolated over a long time period from diverse products and different geographic locations. While some functions are widely conserved among isolates (e.g., degradation of lactose, folate production) suggesting their central physiological and ecological role for the species, others including the tagatose-6-phosphate pathway involved in the catabolism of galactose, and the production of bioactive peptides and gamma-aminobutyric acid are strain-specific. Most of these strain-specific health-promoting properties seems to have been acquired via horizontal gene transfer events. The genetic basis for the phenotypic diversity between strains for some health related traits have also been investigated. For instance, substitutions in the galK promoter region correlate with the ability of some strains to catabolize galactose via the Leloir pathway. Finally, the low occurrence in S. thermophilus genomes of genes coding for biogenic amine production and antibiotic resistance is also a contributing factor to its safety status.

Conclusions

The natural intra-species diversity of S. thermophilus, therefore, represents an interesting source for innovation in the field of fermented products enriched for healthy components that can be exploited to improve human health. A better knowledge of the health-promoting properties and their genomic and genetic diversity within the species may facilitate the selection and application of strains for specific biotechnological and human health-promoting purpose. Moreover, by pointing out that a substantial part of its functional potential still defies us, our work opens the way to uncover additional health-related functions through the intra-species diversity exploration of S. thermophilus by comparative genomics approaches.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08459-y.

Mucosal microbiome associates with progression to gastric cancer

Background & Aims: Dysbiosis is associated with gastric cancer (GC) development. However, no longitudinal study was carried out to identify key bacteria that could predict for GC progression. Here, we aimed to investigate changes in bacterial metagenome prior to GC and develop a microbiome-based predictive model to accurately classify patients at risk of GC.

Methods: Bacterial 16S rDNA was sequenced from 89 gastric antral biopsies obtained from 43 participants. This study was nested in a prospective, longitudinal study, whereby study participants underwent screening gastroscopy, with further 1-2 yearly surveillance gastroscopies for at least 5 years. Putative bacterial taxonomic and functional features associated with GC carcinogenesis were identified by comparing between controls, patients with gastric intestinal metaplasia (IM) and patients with early gastric neoplasia (EGN).

Results: Patients with EGN had enrichment of Proteobacteria (in particular Proteus genus) and depletion of Bacteroidetes (in particular S24-7 family) in their gastric mucosa. Sequencing identified more patients with Helicobacter pylori compared to histopathological assessment, while H. pylori was also significantly enriched in EGN. Furthermore, a total of 261 functional features, attributing to 97 KEGG pathways were differentially abundant at baseline between patients who subsequent developed EGN (n = 13/39) and those who did not. At the same time, a constellation of six microbial taxonomic features present at baseline, provided the highest classifying power for subsequent EGN (AUC = 0.82).

Conclusion: Our study highlights early microbial changes associated with GC carcinogenesis, suggesting a potential role for prospective microbiome surveillance for GC.

Roles of gut microbiota in colorectal carcinogenesis providing a perspective for early diagnosis and treatment

Colorectal cancer (CRC) is the third most prevalent malignant neoplasm in the world. CRC is influenced by both environmental and genetic factors. Through toxin-mediated DNA damage and promotion of persistent dysregulated inflammation, the gut microbiota plays a crucial role in the development of CRC. In this review, we discussed the correlation between the bacterial microbiota and CRC carcinogenesis as well as the mechanism by which Streptococcus bovis/gallolyticus, Fusobacterium nucleatum, Bacteroides fragilis, and Escherichia coli can cause CRC.

Albuca Bracteata Polysaccharides Attenuate AOM/DSS Induced Colon Tumorigenesis via Regulating Oxidative Stress, Inflammation and Gut Microbiota in Mice

Inflammation is an important risk factor in the development of inflammatory bowel disease (IBD) and colitis-associated colorectal cancer (CAC). Accumulating evidence indicates that some phytochemicals have anti-cancer properties. Polysaccharides extracted from Albuca bracteata (AB) have been reported to possess anti-neoplastic activities on colorectal cancer (CRC) models. However, it is still unclear whether they exert therapeutic effects on colorectal cancer. In this study, we investigate the properties of polysaccharides of A. bracteate, named ABP. The average molecular weight of ABP was 18.3 kDa and ABP consisted of glucose, mannose, galactose, xylose, galacturonic acid, glucuronic acid at a molar ratio of 37.8:8:2.5:1.7:1:1. An Azoxymethane/Dextran sodium sulfate (AOM/DSS) induced CAC mouse model was established. The CAC mice treated with ABP showed smaller tumor size and lower tumor incidence than untreated ones. ABP increased anti-inflammatory cytokine IL-10, inhibited secretion of pro-inflammatory cytokines (IL-6, IFN-γ, and TNF-α), mitigated oxidative stress by increasing GSH and decreasing MDA levels, suppressed the activation of STAT3 and expressions of its related genes c-Myc and cyclin D1. Moreover, ABP treatment increased the relative abundance of beneficial bacteria (f_Ruminococcaceae, g_Roseburia, g_Odoribacter, g_Oscillospira, and g_Akkermansia) and the levels of fecal short-chain fatty acid (SCFA) in CAC model mice. In summary, our data suggest that ABP could be a potential therapeutic agent for treating CAC.

Characterization of the Probiotic Potential of Lactic Acid Bacteria Isolated from Kimchi, Yogurt, and Baby Feces in Hong Kong and Their Performance in Soymilk Fermentation

Background: There are several potential healthy or nutritional benefits from the use of lactic acid bacteria (LAB) in foods. This study aimed to characterize the LAB isolates from kimchi, yogurt, and baby feces in the Hong Kong area and evaluate their performance in fermented soymilk, which allowed us to assess their potential use in future experiments. Methods: General characteristics including tolerance to acid, NaCl, bile salts and phenol, antimicrobial activity to various pathogens, and adhesive ability to Caco-2 cells were evaluated using 18 LAB in this study. To further demonstrate the influence of such isolates in soymilk fermentation, we measured viability by plating and noting changes in pH, amino acid content, aglyconic isoflavones content and antioxidant capacities in vitro, such as scavenging ability, and iron chelating ability. Results: In this study, various LAB isolates belonging to Lactobacillusrhamnosus, Lactobacillus sakei, Lactiplantibacillus plantarum, andLeuconostocmesenteroides isolated in Hong Kong were evaluated. L. plantarum isolates R7, AC12, and AC14.1, and L. rhamnosus AC1 showed higher tolerance to acid, NaCl, bile salts, and phenol as compared to the other isolates tested. L. plantarum isolates AC12, AC13 and AC14.1, and L. rhamnosus AC1 harbored strong antimicrobial activity. L. plantarum isolates R7, AC12, AC13 and AC14.1, and L. paracasei isolates R6 and R8 showed higher adhesive ability than the other tested isolates. In soymilk, the viable numbers of L. paracasei R5, L. plantarum R7, L. rhamnosus AC1, L. sakei AC2, and Leu. mesenteroides AC5 were much higher than the other tested isolates after 48 h of fermentation. The pH value measuring the lactic acid level in soymilk fermented by L. plantarum AC14.1 was the lowest in comparison to those in soymilk fermented by other isolates. In addition, the levels of free amino acids and isoflavones in the aglycone forms of L. rhamnosus AC1-fermented soymilk were the highest. L. rhamnosus AC1-fermented soymilk also showed the highest antioxidant potential, including DPPH scavenging ability and iron chelating ability. Conclusions: In general, L. plantarum isolates R7 and AC14.1 and L. rhamnosus AC1 exhibited higher tolerance to challenging conditions as compared to the other isolates. Moreover, L. rhamnosus AC1 exhibited superior performance in soymilk fermentation and potential as a starter and probiotic culture.

Toxicological Evaluation of a Probiotic-Based Delivery System for P8 Protein as an Anti-Colorectal Cancer Drug

Purpose

This study aimed to toxicological evaluate a probiotics-based delivery system for p8 protein as an anti-colorectal cancer drug.

Introduction

Lactic acid bacteria (LAB) have been widely ingested for many years and are regarded as very safe. Recently, a Pediococcus pentosaceus SL4 (PP) strain that secretes the probiotic-derived anti-cancer protein P8 (PP-P8) has been developed as an anti-colorectal cancer (CRC) biologic by Cell Biotech. We initially identified a Lactobacillus rhamnosus (LR)-derived anti-cancer protein, P8, that suppresses CRC growth. We also showed that P8 penetrates specifically into CRC cells (DLD-1 cells) through endocytosis. We then confirmed the efficacy of PP-P8, showing that oral administration of this agent significantly decreased tumor mass (~42%) relative to controls in a mouse CRC xenograft model. In terms of molecular mechanism, PP-P8 induces cell-cycle arrest in G₂ phase through down-regulation of Cyclin B1 and Cdk1. In this study, we performed in vivo toxicology profiling to obtain evidence that PP-P8 is safe, with the goal of receiving approval for an investigational new drug application (IND).

Methods

Based on gene therapy guidelines of the Ministry of Food and Drug Safety (MFDS) of Korea, the potential undesirable effects of PP-P8 had to be investigated in intact small rodent or marmoset models prior to first-in-human (FIH) administration. The estimated doses of PP-P8 for FIH are 1.0×10¹⁰ – 1.0×10¹¹ CFU/person (60 kg). Therefore, to perform toxicological investigations in non-clinical animal models, we orally administered PP-P8 at doses of 3.375 × 10¹¹, 6.75 × 10¹¹, and 13.5×10¹¹ CFU/kg/day; thus the maximum dose was 800–8000-fold higher than the estimated dose for FIH.

Results

In our animal models, we observed no adverse effects of PP-P8 on clinicopathologic findings, relative organ weight, or tissue pathology. In addition, we observed no inflammation or ulceration during pathological necropsy.

Conclusion

These non-clinical toxicology studies could be used to furnish valuable data for the safety certification of PP-P8.

Microbiota Targeted Interventions of Probiotic Lactobacillus as an Anti-Ageing Approach: A Review

With the implementation of modern scientific protocols, the average human lifespan has significantly improved, but age-related problems remain a challenge. With the advent of ageing, there are alterations in gut microbiota and gut barrier functions, weak immune responses, increased oxidative stress, and other age-related disorders. This review has highlighted and discussed the current understanding on the significance of gut microbiota dysbiosis and ageing and its inherent effects against age-related oxidative stress as well as on the gut health and gut-brain axis. Further, we have discussed the key mechanism of action of Lactobacillus strains in the longevity of life, alleviating gut dysbiosis, and improving oxidative stress and inflammation to provide an outline of the role of Lactobacillus strains in restoration of gut microbiota dysbiosis and alleviating certain conditions during ageing. Microbiota-targeted interventions of some characterized strains of probiotic Lactobacillus for the restoration of gut microbial community are considered as a potential approach to improve several neurological conditions. However, very limited human studies are available on this alarmed issue and recommend further studies to identify the unique Lactobacillus strains with potential anti-ageing properties and to discover its novel core microbiome-association, which will help to increase the therapeutic potential of probiotic Lactobacillus strains to ageing.

The immunomodulatory effects of Candida albicans isolated from the normal gastrointestinal microbiome of the elderly on colorectal cancer

The association of gut microbiota with occurrence and development of colorectal cancer (CRC) has been reported in recent studies. Probiotics have been shown to mediate anti-cancer effects through immune system. The aim of this study was to evaluate the efficacy of Lactobacillus plantarum and Candida albicans in the suppression of azoxymethane-induced CRC in male Fischer 344 rats. 30 adult male Fischer 344 rats were divided into 6 distinct groups (n = 5 per group): non-treated animals, fat-food intake group, fat-food and carcinogen intake group, CRC cancer-induced rats treated with the chemotherapy drug, CRC-induced rats treated with Lactobacillus plantarum, and CRC-induced rats treated with Candida albicans. Identification of Candida albicans isolated from human feces was performed by microbiological, biochemical, and PCR methods. The serum levels of IFN-γ, IL-4, TGF-β, and TNF-α were measured by ELISA. Pathological studies were performed through hematoxylin and eosin (H&E) staining method. The data were analyzed using one-way ANOVA and Tukey's post-hoc analysis. Shrinking cancer cells with very dark nuclei were observed in CRC-induced rats treated with the chemotherapy drug, Lactobacillus plantarum, and Candida albicans indicating the occurrence of apoptosis. Serum levels of IFN-γ, IL-4, and TGF-β significantly decreased compared to the control group (p < 0.05). Lactobacillus plantarum and Candida albicans isolated from the gastrointestinal tract of the elderly and healthy individuals can efficiently improve CRC.

Targeting of fluorescent Lactococcus lactis to colorectal cancer cells through surface display of tumour-antigen binding proteins

Development of targeted treatment for colorectal cancer is crucial to avoid side effects. To harness the possibilities offered by microbiome engineering, we prepared safe multifunctional cancer cell-targeting bacteria Lactococcus lactis. They displayed, on their surface, binding proteins for cancer-associated transmembrane receptors epithelial cell adhesion molecule (EpCAM) and human epidermal growth factor receptor 2 (HER2) and co-expressed an infrared fluorescent protein for imaging. Binding of engineered L. lactis to tumour antigens EpCAM and HER2 was confirmed and characterised in vitro using soluble receptors. The proof-of-principle of targeting was demonstrated on human cell lines HEK293, HT-29 and Caco-2 with fluorescent microscopy and flow cytometry. The highest L. lactis adhesion was seen for the HEK293 cells with the overexpressed tumour antigens, where colocalisation with their tumour antigens was seen for 39% and 67% of EpCAM-targeting and HER2-targeting bacteria, respectively. On the other hand, no binding was observed to HEK293 cells without tumour antigens, confirming the selectivity of the engineered L. lactis. Apart from cell targeting in static conditions, targeting ability of engineered L. lactis was also shown in conditions of constant flow of bacterial suspension over the HEK293 cells. Successful targeting by engineered L. lactis support the future use of these bacteria in biopharmaceutical delivery for the treatment of colorectal cancer.

The probiotic supplementation role in improving the immune system among people with ulcerative colitis: a narrative review

OBJECTIVES

The purpose of this paper is to summarize the current evidence on probiotics' uses as an adjuvant for ulcerative colitis (UC) and provide an understanding of the effect of probiotics supplement on the immune system and inflammatory responses among UC patients and subsequent therapeutic benefits.

CONTENT

A narrative review of all the relevant published papers known to the author was conducted.

SUMMARY

UC is a chronic inflammatory bowel disease (IBD) that results in inflammation and ulceration of the colon and rectum. The primary symptoms of active disease are diarrhea, abdominal pain, and rectal bleeding. About 70% of the human immune system (mucosal-associated lymphoid tissue) originates in the intestine. Probiotics are live microorganisms that help in stabilizing the gut microbiota (nonimmunologic gut defense), restores normal flora, and enhance the humoral immune system. Probiotics especially Bifidobacterium, Saccharomyces boulardii, and lactic acid-producing bacteria have been used as an adjunct therapy for treating UC to ameliorate disease-related symptoms and reduce relapse rate. Probiotics, in general, modulate the immune system through their ability to enhance the mucosal barrier function, or through their interaction with the local immune system to enhance regulatory T cell responses, decrease the pro-inflammatory cytokines such as tumor necrosis factor alpha and interleukin 1 beta and increase anti-inflammatory factor interleukin 10.

OUTLOOK

More studies are needed to explore the properties of the various probiotic bacterial strains, their different uses, as well as the dosage of probiotics and duration for treating different disorders. Further clinical investigations on mechanisms of action and how probiotics modulate the immune system may lead to further advances in managing IBD.

The probiotic supplementation role in improving the immune system among people with ulcerative colitis: a narrative review

OBJECTIVES

The purpose of this paper is to summarize the current evidence on probiotics' uses as an adjuvant for ulcerative colitis (UC) and provide an understanding of the effect of probiotics supplement on the immune system and inflammatory responses among UC patients and subsequent therapeutic benefits.

CONTENT

A narrative review of all the relevant published papers known to the author was conducted.

SUMMARY

UC is a chronic inflammatory bowel disease (IBD) that results in inflammation and ulceration of the colon and rectum. The primary symptoms of active disease are diarrhea, abdominal pain, and rectal bleeding. About 70% of the human immune system (mucosal-associated lymphoid tissue) originates in the intestine. Probiotics are live microorganisms that help in stabilizing the gut microbiota (nonimmunologic gut defense), restores normal flora, and enhance the humoral immune system. Probiotics especially Bifidobacterium, Saccharomyces boulardii, and lactic acid-producing bacteria have been used as an adjunct therapy for treating UC to ameliorate disease-related symptoms and reduce relapse rate. Probiotics, in general, modulate the immune system through their ability to enhance the mucosal barrier function, or through their interaction with the local immune system to enhance regulatory T cell responses, decrease the pro-inflammatory cytokines such as tumor necrosis factor alpha and interleukin 1 beta and increase anti-inflammatory factor interleukin 10.

OUTLOOK

More studies are needed to explore the properties of the various probiotic bacterial strains, their different uses, as well as the dosage of probiotics and duration for treating different disorders. Further clinical investigations on mechanisms of action and how probiotics modulate the immune system may lead to further advances in managing IBD.