Sialidase-Chimeric Bioengineered Bacteria for Tumor-Sialoglycan-Triggered Solid Tumor Therapy.

Adoptive cell therapies for solid tumors are usually limited by off-target antigens, incapable tissue infiltration, and cell function exhaustion. In contrast, bacterial cells possess the inherent competencies of preferential tumor targeting, deep tissue penetration, and high intratumoral bioactivity and represent promising alternatives to overcome these challenges. Here, a sialic-acid-responsive regulatory gene circuit is engineered into Escherichia coli MG1655 to express cytolysin of hemolysin E (HlyE). Furthermore, sialidases are bioorthogonally decorated onto the surface of azido-functionalized bioengineered bacteria for recognizing tumor sialoglycans and cleaving their sialosides into free sialic acids. As chemical inducers, sialic acids feedbackingly activate the bacterial gene circuit to produce HlyE and lyse tumor cells. This study mimics the tumor antigen-induced cytotoxin production and cell lysis that occurs in chimeric antigen receptor T (CAR-T) cells yet surmounts the intrinsic limitations of adoptive cell therapies. Moreover, sialidase-mediated tumor cell desialylation also reverses the immunosuppressive effect of glycoimmune checkpoints and further improves the therapeutic effect of solid tumors.

Advancement of Engineered Bacteria for Orally Delivered Therapeutics.

The use of bacteria and their biotic components as therapeutics has shown great potential in the treatment of diseases. Orally delivered bacteria improve patient compliance compared with injection-administered bacteria and are considered the preferred mode. However, due to the harsh gastrointestinal environment, the viability and therapeutic efficacy of orally delivered bacteria are significantly reduced in vivo. In recent years, with the rapid development of synthetic biology and nanotechnology, bacteria and biotic components have been engineered to achieve directed genetic reprogramming for construction and precise spatiotemporal control in the gastrointestinal tract, which can improve viability and therapeutic efficiency. Herein, a state-of-the-art review on the current progress of engineered bacterial systems for oral delivery is provided. The different types of bacterial and biotic components for oral administration are first summarized. The engineering strategies of these bacteria and biotic components and their treatment of diseases are next systematically summarized. Finally, the current challenges and prospects of these bacterial therapeutics are highlighted that will contribute to the development of next-generation orally delivered bacteriotherapy.

The crosstalk between gut barrier impairment, mitochondrial dysfunction, and microbiota alterations in people living with HIV.

Functional and structural damage of the intestinal mucosal barrier significantly contribute to translocation of gut microbial products into the bloodstream and are largely involved in HIV-1 associated chronic immune activation. This microbial translocation is largely due to a progressive exhaustion of intestinal macrophage phagocytic function, which leads to extracellular accumulation of microbial derived components and results in HIV-1 disease progression. This study aims to better understand whether the modulation of gut microbiota promotes an intestinal immune restoration in people living with HIV (PLWH). Long-term virologically suppressed PLWH underwent blood, colonic, and fecal sampling before (T0) and after 6 months (T6) of oral bacteriotherapy. Age- and gender-matched uninfected controls (UC) were also included. 16S rRNA gene sequencing was applied to all participants' fecal microbiota. Apoptosis machinery, mitochondria, and apical junctional complex (AJC) morphology and physiological functions were analyzed in gut biopsies. At T0, PLWH showed a different pattern of gut microbial flora composition, lower levels of occludin (p = 0.002) and zonulin (p = 0.01), higher claudin-2 levels (p = 0.002), a reduction of mitochondria number (p = 0.002), and diameter (p = 0.002), as well as increased levels of lipopolysaccharide (LPS) (p = 0.018) and cCK18 (p = 0.011), compared to UC. At T6, an increase in size (p = 0.005) and number (p = 0.008) of mitochondria, as well as amelioration in AJC structures (p < 0.0001) were observed. Restoration of bacterial richness (Simpson index) and biodiversity (Shannon index) was observed in all PLWH receiving oral bacteriotherapy (p < 0.05). Increased mitochondria size (p = 0.005) and number (p = 0.008) and amelioration of AJC structure (p < 0.0001) were found at T6 compared to T0. Moreover, increased occludin and zonulin concentration were observed in PLWH intestinal tracts and decreased levels of claudin-2, LPS, and cCK18 were found after oral bacteriotherapy (T0 vs. T6, p < 0.05 for all these measures). Oral bacteriotherapy supplementation might restore the balance of intestinal flora and support the structural and functional recovery of the gut mucosa in antiretroviral therapy treated PLWH.

Dual mode imaging guided multi-functional bio-targeted oxygen production probes for tumor therapy.

Focused ultrasound ablation surgery (FUAS) is a novel therapy with a wide range of potential applications. However, synergists are crucial to the therapy process due to the ultrasonic energy's attenuation properties. As a result of the complex hypoxic environment in the tumor area and many factors, the existing synergists have limitations such as weak targeting, single imaging mode, and easy tumor recurrence after treatment. Because of the above deficiencies, this study intends to construct bio-targeted oxygen production probes consisting of Bifidobacterium that naturally target the hypoxia region of the tumor and multi-functional oxygen-producing nanoparticles equipped with IR780, perfluorohexane (PFH), CBP (carboplatin), and oxygen. The probes are expected to achieve targeted and synergistic FUAS therapy and dual-mode imaging to mediate tumor diagnosis and treatment. The oxygen and drugs carried in it are accurately released after FUAS stimulation, which is expected to alleviate tumor hypoxia, avoid tumor drug resistance, improve the effect of chemotherapy, and realize FUAS combined with chemotherapy antitumor therapy. This strategy is expected to make up for the deficiencies of existing synergists, improve the effectiveness and safety of treatment, and provide the foundation for future tumor therapy progress.

Evaluation of Antibacterial Efficacy of Two Commercially Available Probiotics as Intracanal Medicament against Enterococcus faecalis: An In Vitro Study.

AIM: This study was performed to evaluate the antibacterial efficacy of two commercially available probiotics (BIFILAC and VSL 3) as intracanal medicament against Enterococcus faecalis in endodontic therapy. MATERIALS AND METHODS: Microorganisms from commercially available probiotics (BIFILAC and VSL 3) were extracted via the manufacturer's recommendations and mixed by weight. About 30 microliters were then placed on sterile discs. The pathogenic test organism was E. faecalis set to a 1 McFarland standard challenge. A two-probiotic disc template on blood agar plates was inoculated with E. faecalis and incubated at 37°C for 48 hours and 1 week respectively. Phase-1 of the study was conducted by a disc diffusion assay test to evaluate zones of inhibition (ZOI) in millimeters (mm). Phase-2 was conducted by mixing 9 mL of 30% poloxamer 407 and MRS broth in a test tube, together with the two probiotic mixtures and E. faecalis, set at a 2 McFarland standard. Serial dilutions up to 108 were done and the mixture was placed inside root canals and incubated at 37ºC for 36 hours and evaluated for colony-forming unit (CFU)/mL counts. RESULTS: The results of phase-1 showed that probiotics Lactobacillus rhamnosus and Bifidobacterium species are effective in fighting against E. faecalis with the acceptable zone of inhibition. The results of phase-2 showed that both the probiotics are effective against E. faecalis with a reduction in the number of CFU after probiotic usage. CONCLUSION: Commercially available probiotics can be used effectively as an intracanal medicament to fight against E. faecalis, Poloxamer 407 is a promising vehicle for delivering probiotics inside the root canal system. Further in vitro and in vivo studies are needed to determine the full potential of "Bacteriotherapy" with an application of probiotics. CLINICAL SIGNIFICANCE: If probiotics are proved to be an effective intracanal medicament against E.faecalis they can be used as an alternative to calcium hydroxide as intracanal medicament with no side effects to the host.

Fecal Microbiota Transplantation Is Highly Effective in Real-World Practice: Initial Results From the FMT National Registry.

BACKGROUND & AIMS: Fecal microbiota transplantation (FMT) is used commonly for treatment of Clostridioides difficile infections (CDIs), although prospective safety data are limited and real-world FMT practice and outcomes are not well described. The FMT National Registry was designed to assess FMT methods and both safety and effectiveness outcomes from North American FMT providers. METHODS: Patients undergoing FMT in clinical practices across North America were eligible. Participating investigators enter de-identified data into an online platform, including FMT protocol, baseline patient characteristics, CDI cure and recurrence, and short and long-term safety outcomes. RESULTS: Of the first 259 participants enrolled at 20 sites, 222 had completed short-term follow-up at 1 month and 123 had follow-up to 6 months; 171 (66%) were female. All FMTs were done for CDI and 249 (96%) used an unknown donor (eg, stool bank). One-month cure occurred in 200 patients (90%); of these, 197 (98%) received only 1 FMT. Among 112 patients with initial cure who were followed to 6 months, 4 (4%) had CDI recurrence. Severe symptoms reported within 1-month of FMT included diarrhea (n = 5 [2%]) and abdominal pain (n = 4 [2%]); 3 patients (1%) had hospitalizations possibly related to FMT. At 6 months, new diagnoses of irritable bowel syndrome were made in 2 patients (1%) and inflammatory bowel disease in 2 patients (1%). CONCLUSIONS: This prospective real-world study demonstrated high effectiveness of FMT for CDI with a good safety profile. Assessment of new conditions at long-term follow-up is planned as this registry grows and will be important for determining the full safety profile of FMT.

Future prospects of bacteria-mediated cancer therapies: Affliction or opportunity?

Cancer, as a disease characterized by uncontrolled growth of cells, is recognized as one of the significant challenges in the field of health and medicine. There are various treatments for cancer like surgery, hormone therapy, chemotherapy, etc., but they have negative effects on the patient's lifestyle. Numerous side effects, and recently the emergence of drug resistance to these methods are weaknesses of these treatments. The utilization of bacteria as a treatment for cancer has attracted scientists' attention in the last decade. There are various methods of using bacteria to treat cancer, including the use of live, attenuated, or genetically engineered microbes, the use of bacterial toxins as an immunotoxin or conjugated to tumor antigens, bacteria-based cancer immunotherapy, bacterial vectors for gene-directed enzyme prodrug, and also the undeniable role of probiotics in treatment, are the cases that today are used for treatment. Bacterial therapy has shown a greater promise in cancer treatment due to its ability to lyse the tumor cells and deliver therapeutic products. However, the potential cytotoxicity of bacteria for healthy tissues, their inability to entirely lyse cancerous cells, and the possibility of mutations in their genomes are among the challenges of bacteriotherapy for cancer. Herein, we summarize the mechanism of bacteria, their potential benefits and harms, and the future of research in this field.

Bacteria-based nanodrug for anticancer therapy.

Bacteria-based immunotherapy has become a promising strategy to induce innate and adaptive responses for fighting cancer. The advantages of bacteriolytic tumor therapy mainly lie in stimulation of innate immunity and colonization of some bacteria targeting the tumor microenvironment (TME). These bacteria have cytotoxic proteins and immune modulating factors that can effectively restrain tumor growth. However, cancer is a multifactorial disease and single therapy is typically unable to eradicate tumors. Rapid progress has been made in combining bacteria with nanotechnology. Using the nanomolecular properties of bacterial products for tumor treatment preserves many features from the original bacteria while providing some unique advantages. Nano-bacterial therapy can enhance permeability and retention of drugs, increase the tolerability of the targeted drugs, promote the release of immune cell mediators, and induce immunogenic cell death pathways. In addition, combining nano-bacterial mediated antitumor therapeutic systems with modern therapy is an effective strategy for overcoming existing barriers in antitumor treatment and can achieve satisfactory therapeutic efficacy. Overall, exploring the immune antitumor characteristics of adjuvant clinical treatment with bacteria can provide potential efficacious treatment strategies for combatting cancer.

Gut Microbiota Modulation and Prevention of Dysbiosis as an Alternative Approach to Antimicrobial Resistance: A Narrative Review.

Background: The importance of gut microbiota in human health is being increasingly studied. Imbalances in gut microbiota have been associated with infection, inflammation, and obesity. Antibiotic use is the most common and significant cause of major alterations in the composition and function of the gut microbiota and can result in colonization with multidrug-resistant bacteria. Methods: The purpose of this review is to present existing evidence on how microbiota modulation and prevention of gut dysbiosis can serve as tools to combat antimicrobial resistance. Results: While the spread of antibiotic-resistant pathogens requires antibiotics with novel mechanisms of action, the number of newly discovered antimicrobial classes remains very low. For this reason, the application of alternative modalities to combat antimicrobial resistance is necessary. Diet, probiotics/prebiotics, selective oropharyngeal or digestive decontamination, and especially fecal microbiota transplantation (FMT) are under investigation with FMT being the most studied. But, as prevention is better than cure, the implementation of antimicrobial stewardship programs and strict infection control measures along with newly developed chelating agents could also play a crucial role in decreasing colonization with multidrug resistant organisms. Conclusion: New alternative tools to fight antimicrobial resistance via gut microbiota modulation, seem to be effective and should remain the focus of further research and development.

Prevention and treatment of upper respiratory diseases in the pandemic COVID-19 era.

In the pandemic coronavirus disease 2019 (COVID-19) era, the need to use preventive-curative treatments is compelling. A series of non-pharmacological compounds, including oligo-elements, vitamins, nutraceuticals, and bacteriotherapy, might affect the risk of COVID-19, both reinforcing the immune system and improving the inflammation resolution during respiratory infections. Non-pharmacological remedies are very popular and usually have no relevant side effects. Bacterial and natural products may potentiate the immune system against respiratory viruses. Moreover, these compounds also exert antiinflammatory and antioxidant activity. Consequently, these non-chemical remedies could be prescribed to build up the immune defence and adequately treat the upper respiratory infection. In this way, natural compounds could be used to manage people in the pandemic COVID-19 era.

Cognitive impairment and CSF proteome modification after oral bacteriotherapy in HIV patients.

OBJECTIVE: To investigate whether a probiotic supplementation to cART patients modifies the cerebrospinal fluid (CSF) proteome and improves neurocognitive impairment. METHODS: 26 CSF samples from 13 HIV-positive patients [six patients living with HIV (PLHIV) and seven patients with a history of AIDS (PHAIDS)] were analyzed. All patients underwent to neurocognitive evaluation and blood sampling at baseline and after 6 months of oral bacteriotherapy. Immune phenotyping and activation markers (CD38 and HLA-DR) were evaluated on peripheral blood mononuclear cells (PBMC). Plasma levels of IL-6, sCD14, and MIP-1ß were detected, by enzyme-linked immunosorbent assay (ELISA). Functional proteomic analysis of CSF sample was conducted by two-dimensional electrophoresis; a multivariate analysis was performed by principal component analysis (PCA) and data were enriched by STRING software. RESULTS: Oral bacteriotherapy leads to an improvement on several cognitive test and neurocognitive performance in both groups of HIV-positive subjects. A reduction in the percentage of CD4+CD38+HLA-DR+ T cells was also observed at peripheral level after the probiotic intake (p = 0.008). In addition, the probiotic supplementation to cART significantly modifies protein species composition and abundance at the CSF level, especially those related to inflammation (ß2-microglobulin p = 0.03; haptoglobin p = 0.06; albumin p = 0.003; hemoglobin p = 0.003; immunoglobulin heavy chains constant region p = 0.02, transthyretin p = 0.02) in PLHIV and PHAIDS. CONCLUSIONS: Our results suggest that oral bacteriotherapy as a supplement to cART could exert a role in the amelioration of inflammation state at peripheral and CNS level.

The bacterial instrument as a promising therapy for colon cancer.

OBJECTIVE: Colon cancer is a great health concern worldwide, as it is the second leading cause of cancer-related death. Conventional treatment of cancer such as surgery, radiotherapy, and chemotherapy are faced with limitations and side effects. Therefore, strategies for the treatment of cancer need to be modified or new strategies replacing the old one. AIMS: The aim of this study is to review the role of bacteria or their products (such as peptides, bacteriocins, and toxins) as a therapeutic agent for colon cancer. RESULTS AND CONCLUSION: Recently, the therapeutic role of bacteria and their products in colon cancer treatment holds promise as emerging novel anti-cancer agents. Unlike the conventional treatments, targeted therapy based on the use of bacteria that are able to directly target tumor cells without affecting normal cells is evolving as an alternative strategy. Moreover, several bacterial species were used in live, attenuated or genetically modified that are able to multiply selectively in tumors and inhibiting their growth.

Recent developments in the management of recurrent Clostridioides difficile infection.

Clostridioides (formerly Clostridium) difficile is responsible for a substantial burden of nosocomial infection. Recurrent C. difficile infection (rCDI) remains a concern due to its high morbidity, mortality, and cost. Despite the updated 2017 IDSA C. difficile treatment guidelines, there remains a lack of well-studied preventive control measures and treatment modalities for rCDI. There are ongoing efforts to develop novel therapies, such as new antibiotics with a lesser impact on gut microbiota and more targeted therapies, such as bacteriotherapy. This mini review highlights key rCDI management updates, preventive measures and ongoing research on novel treatment strategies including bacteriotherapy.

Microbes as Medicines: Harnessing the Power of Bacteria in Advancing Cancer Treatment.

Conventional anti-cancer therapy involves the use of chemical chemotherapeutics and radiation and are often non-specific in action. The development of drug resistance and the inability of the drug to penetrate the tumor cells has been a major pitfall in current treatment. This has led to the investigation of alternative anti-tumor therapeutics possessing greater specificity and efficacy. There is a significant interest in exploring the use of microbes as potential anti-cancer medicines. The inherent tropism of the bacteria for hypoxic tumor environment and its ability to be genetically engineered as a vector for gene and drug therapy has led to the development of bacteria as a potential weapon against cancer. In this review, we will introduce bacterial anti-cancer therapy with an emphasis on the various mechanisms involved in tumor targeting and tumor suppression. The bacteriotherapy approaches in conjunction with the conventional cancer therapy can be effective in designing novel cancer therapies. We focus on the current progress achieved in bacterial cancer therapies that show potential in advancing existing cancer treatment options and help attain positive clinical outcomes with minimal systemic side-effects.

Infected chronic ischemic wound topically treated with a multi-strain probiotic formulation: a novel tailored treatment strategy.

BACKGROUND: A wide debate is ongoing regarding the role of cutaneous dysbiosis in the pathogenesis and evolution of difficult-to-treat chronic wounds. Nowadays, probiotic treatment considered as an useful tool to counteract dysbiosis but the evidence in regard to their therapeutic use in the setting of difficult-to-treat cutaneous ulcers is still poor. AIM: CLINICAL REPORT: An 83-year-old woman suffering a critical limb ischemia and an infected difficult-to-treat ulcerated cutaneous lesion of the right leg, was complementary treated with local application of a mixture of probiotic bacteria. METHODS: Microbiological and metabolomic analysis were conducted on wound swabs obtained before and after bacteriotherapy. RESULTS: During the treatment course, a progressive healing of the lesion was observed with microbiological resolution of the polymicrobial infection of the wound. Metabolomic analysis showed a significant difference in the local concentration of propionate, 2-hydroxyisovalerate, 2-oxoisocaproate, 2,3-butanediol, putrescine, thymine, and trimethylamine before and after bacteriotherapy. CONCLUSION: The microbiological and metabolomic results seem to confirm the usefulness of complementary probiotic treatment in difficult-to-treat infected wounds. Further investigations are needed to confirm these preliminary findings.

Impact of probiotics on pathogen survival in an innovative human plasma biofilm model (hpBIOM).

BACKGROUND: Despite of medical advances, the number of patients suffering on non-healing chronic wounds is still increasing. This fact is attended by physical and emotional distress and an economic load. The majority of chronic wounds are infected of harmful microbials in a protecting extracellular matrix. These biofilms inhibit wound healing. Biofilm-growing bacteria developed unique survival properties, which still challenge the appropriate wound therapy. The present in-vitro biofilm models are not suitable for translational research. By means of a novel in-vivo like human plasma biofilm model (hpBIOM), this study systematically analysed the influence of 3 probiotics on the survival of five clinically relevant pathogenic microorganisms. METHODS: Human plasma was used to produce the innovate biofilm. Pathogenic microorganisms were administered to the plasma. By stimulating the production of a fibrin scaffold, stable coagula-like discs with integrated pathogens were produced. The five clinically relevant pathogens P. aeruginosa, S. aureus, S. epidermidis, E. faecium and C. albicans were challenged to the probiotics L. plantarum, B. lactis and S. cerevisiae. The probiotics were administered on top of the biofilm and the survival was quantified after 4 h and 24 h of incubation. For statistics, two-way ANOVA with post-hoc Tukey's HSD test was applied. P-value > 0.05 was considered to be significant. RESULTS: SEM micrographs depicted the pathogens on the surface of the fibrin scaffold, arranged in close proximity and produced the glycocalyx. The application of probiotics induced different growth-reducing capacities towards the pathogens. B. lactis and S. cerevisiae showed slight bacteria-reducing properties. The survival of C. albicans was not affected at all. The most antimicrobial activity was detected after the treatment with L. plantarum. CONCLUSIONS: This study successfully reproduced a novel human biofilm model, which provides a human wound milieu and individual immune competence. The success of bacteriotherapy is dependent on the strain combination, the number of probiotics and the activity of the immune cells. The eradicating effect of L. plantarum on P. aeruginosa should be emphasized.

Bacteriotherapy in Breast Cancer.

Breast cancer is the second most common cause of cancer-related mortality among women around the world. Conventional treatments in the fight against breast cancer, such as chemotherapy, are being challenged regarding their effectiveness. Thus, strategies for the treatment of breast cancer need to be continuously refined to achieve a better patient outcome. We know that a number of bacteria are pathogenic and some are even associated with tumor development, however, recent studies have demonstrated interesting results suggesting some bacteria may have potential for cancer therapy. Therefore, the therapeutic role of bacteria has aroused attention in medical and pharmaceutical studies. Furthermore, genetic engineering has been used in bacterial therapy and may led to greater efficacy with few side effects. Some genetically modified non-pathogenic bacterial species are more successful due to their selectivity for cancer cells but with low toxicity for normal cells. Some live, attenuated, or genetically modified bacterias are capable to multiply in tumors and inhibit their growth. This article aims to review the role of bacteria and their products including bacterial peptides, bacteriocins, and toxins for the treatment of breast cancer.

Fecal bacteriotherapy in the treatment of Clostridium difficile infection.

AIM: Using a prospective analysis to assess the success of faecal bacteriotherapy (FBT) in antibiotic-associated colitis due to Clostridium difficile. To analyse whether any of the factors according to which the treated patients can be categorized has a statistically significant effect on the therapeutic outcome. MATERIALS AND METHODS: During the 2-year study period (2015-2016), 71 patients received FBT. After treatment, the patients were followed up by means of clinic visits or by phone. If colitis did not recur within eight weeks of follow-up, the treatment was considered successful. RESULTS: The overall success rate was 76%, with statistically insignificant decline in recurrences. Subgroup analysis did not show any statistically significant difference in the success rate between the routes of administration, i.e. through a naso-enteral feeding tube and rectal enema. Likewise, there were no statistically significant differences in the success rate between the types of prior antibiotic therapy or between using fresh and cryo-stored stool suspension. No unexpected adverse event or lethality occurred during the study period. CONCLUSIONS: Faecal bacteriotherapy is a successful and safe therapeutic alternative for recurrent C. difficile infections.

Novel Indications for Fecal Microbial Transplantation: Update and Review of the Literature.

BACKGROUND AND AIMS: Fecal microbial transplantation (FMT) is an established successful treatment modality for recurrent Clostridium difficile infection (CDI). The safety profile and potential therapeutic advantages of FMT for diseases associated with dysbiosis and immune dysfunction have led to many publications, mainly case series, and while many studies and reviews have been published on the use of FMT for inflammatory bowel disease (IBD), its potential use for other disease conditions has not been thoroughly reviewed. The aim of this review was to investigate the evidence surrounding the use of FMT in conditions other than IBD and CDI. METHODS: A PubMed search was performed using the terms "Fecal microbiota transplantation" OR "FMT" OR "Bacteriotherapy." RESULTS: A total of 26 articles describing the use of FMT in a variety of both intra-and extraintestinal disease conditions including gastrointestinal, hematologic, neurologic, metabolic, infectious, and autoimmune disorders have been included in this review and have demonstrated some positive results. The studies included were case reports, case series, controlled trials, and cohort studies. CONCLUSIONS: The findings of these studies demonstrate that FMT, particularly in conditions associated with gastrointestinal dysbiosis, shows promise to provide another effective tool in the therapeutic armament of the practicing physician. FMT was found to be possibly effective in various diseases, mostly associated with enteric dysbiosis or with immune dysfunction. Randomized clinical studies on large populations should be performed to explore the effectiveness of this therapy, and basic research studies should be designed to gain understanding of the mechanisms through which impact these disorders.