Bacterial infection and microbiota in carcinogenesis and tumor development

Bacteria and Carcinogenesis and the Management of Cancer: A Narrative Review

There is a widely known relationship between certain microbes and cancer progression. For instance, Helicobacter pylori is associated with the occurrence of gastric cancer, while HPV is associated with cervical and head and neck cancers. Recent studies have uncovered novel and important associations between bacterial presence and tumor formation and treatment response. Apart from the influence of the intestinal microbiome on cancer, the local activity of bacteria affects disease properties as well. Bacteria can localize within tumors in less vascularized niches. Their presence mediates the activity of signaling pathways, which contribute to tumorigenesis. Furthermore, they affect the composition of the tumor microenvironment, a highly complex structure composed of immunoregulatory cells and secreted inflammatory mediators. Recently, researchers have analyzed the properties of bacteria to develop novel anticancer strategies. The aim of this review is to discuss the latest findings regarding the relationships between bacteria and cancer and the properties of bacteria that could be used to kill cancer cells.

Vaccination of people with solid tumors and diabetes: existing evidence and recommendations. A position statement from a multidisciplinary panel of scientific societies

Diabetes and cancer are two of the most common public health concerns worldwide. The complex interplay of these two conditions is a growing area of research, as patients with diabetes are at increased risk for developing cancer, and vice versa. Furthermore, both patient populations show increased risk of many communicable infectious diseases and their adverse consequences, while vaccination can play a crucial role in their prevention, improving patient outcomes. Vaccination should represent a standard part of care for patients with cancer, diabetes, and both the diseases simultaneously, including people undergoing cancer treatment or in remission. Several international guidelines provide recommendations for vaccinating people with cancer or diabetes, but the two conditions have not been specifically evaluated together. Here we present a multidisciplinary consensus position paper on vaccination in patients with cancer and diabetes. The position paper is the result of a collaborative effort between experts from the Italian Association of Medical Oncology (AIOM), Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), Italian Society of Endocrinology (SIE), and Italian Society of Pharmacology (SIF). The paper provides a comprehensive overview of the current state-of-the-art knowledge on vaccination in patients with cancer and diabetes. It discusses the importance of vaccination in preventing infections, focuses attention on the need to consider the unique challenges faced by patients with cancer and diabetes when it comes to vaccine administration, and highlights the need for coordinated care to optimize treatment outcomes. Overall, the consensus position paper provides healthcare professionals caring for patients with cancer and diabetes recommendations on the use of various vaccines, including influenza, COVID-19, HZV, and HPV vaccines, as well as guidance on how to address common concerns and challenges related to vaccine administration.

Clinical characteristics and risk factors of late-stage lung adenocarcinoma patients with bacterial pulmonary infection and its relationship with cellular immune function

Background

To research the clinical characteristics, risk factors, the correlation between bacterial pulmonary infection and immune function of advanced lung adenocarcinoma patients complicated with bacterial pulmonary infection.

Methods

334 stage III and IV lung adenocarcinoma patients admitted to the first affiliated hospital of Zhengzhou University from January 2020 to March 2023 were selected and divided into an infection group (n = 240) and a control group (n= 72) according to whether complicated with bacterial pulmonary infection. The clinical characteristics were analyzed. The pulmonary microbiota and human T lymphocyte subsets (CD3+, CD4+, CD8+) were detected. Multivariate logistic regression analysis was performed to explore the risk factors for pulmonary bacterial infection in advanced lung adenocarcinoma patients.

Results

Among 334 patients, 264 cases were complicated with pulmonary bacterial infection, and 70 cases had no pulmonary bacterial infection. In total, 544 pathogenic bacteria were isolated from the patients. Of these, 170 strains (31.25%) were Gram-negative bacilli, 162 strains (29.78%) were Gram-positive cocci, 27 strains (4.96%) Gram-positive bacilli. There were statistically significant differences in age, smoking, combined diseases, TNM staging, CD3+ T cell percentage, and CD4+ T cell percentage between the two groups (P < 0.05). Multivariate logistic regression analysis revealed smoking, bronchiectasis, and diabetes were independent risk factors leading to late-stage lung adenocarcinoma patients with bacterial pulmonary infection (P < 0.05). In those patients on immune checkpoint inhibitors, the lung Gram-positive group has a higher number of CD4+ T cells and CD4+/CD8+ T cell ratio than the Gram-negative group (P < 0.05).

Conclusion

Smoking, bronchiectasis, and diabetes are risk factors for lung bacterial infection in patients with advanced lung adenocarcinoma. The effect of immune checkpoint inhibitor treatment on T cells is more pronounced in Gram positive bacteria.

Strategic use of nanomaterials as double-edged therapeutics to control carcinogenesis via regulation of dysbiosis and bacterial infection: current status and future prospects

The human microbiome plays a crucial role in modulating health and disease susceptibility through a complex network of interactions with the host. When the delicate balance of this microbial ecosystem is disrupted, it often correlates with the onset of systemic diseases. An over-abundance of pathogenic microorganisms within the microbiome has been implicated as a driving factor in the development of disease conditions such as diabetes, obesity, and chronic infections. It has been observed that microbiome dysbiosis perturbs metabolic, inflammatory, and immunological pathways, potentially facilitating carcinogenesis. Furthermore, the metabolites associated with microbial dysbiosis exert multifaceted effects, including metabolic interference, host DNA damage, and tumor promotion, further underscoring the microbiome's significance in several of the cancers. This new exploration of microbiome involvement in carcinogenesis needs additional patient sample analysis, which could provide new insights into cancer diagnosis and treatment. However, treating these diseases using drugs, traditional methods, etc. has resulted in multi-drug resistance, and this has eventually made the situation worrisome. This review highlights the importance of nanotechnology, which may tackle these pathogenic conditions simultaneously by targeting common receptors present in bacteria and cancer. Herein, we have explained how nanotechnology may come to the forefront for these treatments. It explores the potential of non-antibiotic disinfectants, i.e., nanoparticles (NPs) with dual targeting capabilities against microbes and cancer cells, using mechanisms such as ROS generation and DNA damage while minimizing the chances of drug resistance.

Gut microbiota interact with breast cancer therapeutics to modulate efficacy

The gut microbiome, or the community of microorganisms residing in the gastrointestinal tract, has emerged as an important factor in breast cancer etiology and treatment. Specifically, the impact of gut bacterial populations on breast cancer therapeutic outcomes is an emerging area of research. The microbiota's role in modifying the pharmacokinetics of chemotherapy and endocrine-targeting therapies can alter drug efficacy and toxicity profiles. In addition, the gut microbiome's capacity to regulate systemic inflammation and immune responses may influence the effectiveness of both conventional and immunotherapeutic strategies for the treatment of breast cancer. Overall, while the bidirectional interactions between the gut microbiome and breast cancer therapies are still being studied, its impact is increasingly recognized. Future research may provide more definitive insights and help develop personalized therapeutic strategies to harness the microbiome to improve breast cancer treatment outcomes.

The Oral Microbiome and Cancer

There is growing evidence suggesting a strong association between members of the oral microbiota and various types of cancer, including oral cancer, colorectal cancer, esophageal squamous cell carcinoma, and pancreatic cancer. Periodontal diseases closely associated with pathogenic bacteria in the oral cavity have been shown to be correlated with the occurrence and development of cancers. Among the periodontal disease-associated bacteria in the oral cavity, two prominent oral pathogens, Porphyromonas gingivalis and Fusobacterium nucleatum, have been found to promote tumor cell proliferation, invasion, and migration, as well as to inhibit immune cell function, thereby facilitating tumor progression. The presence of other oral pathogenic bacteria, such as Treponema denticola, Tannerella forsythia, Parvimonas micra, and Aggregatibacter actinomycetemcomitans, has also been found to be associated with cancer worsening. Oral commensal bacteria play a crucial role in maintaining the normal oral homeostasis. However, the relationship between oral commensal bacteria and the occurrence and development of cancers remains controversial. Some studies suggest an increase in oral commensal bacteria during tumor development, while others suggest an association of certain commensal bacteria with lower tumor risk. The microbiota can significantly alter responses and toxicity to various forms of cancer treatment through interactions with the human body, thereby influencing disease progression. In this chapter, we provide a concise overview of current understanding of the role of the oral microbiota in cancer.

Fusobacterium nucleatum: a novel regulator of antitumor immune checkpoint blockade therapy in colorectal cancer

Neoadjuvant immune checkpoint blockade (ICB) has achieved significant success in treating various cancers, leading to improved therapeutic responses and survival rates among patients. However, in colorectal cancer (CRC), ICB has yielded poor results in tumors that are mismatch repair proficient, microsatellite-stable, or have low levels of microsatellite instability (MSI-L), which account for up to 95% of CRC cases. The underlying mechanisms behind the lack of immune response in MSI-negative CRC to immune checkpoint inhibitors remain an open conundrum. Consequently, there is an urgent need to explore the intrinsic mechanisms and related biomarkers to enhance the intratumoral immune response and render the tumor "immune-reactive". Intestinal microbes, such as the oral microbiome member Fusobacterium nucleatum (F. nucleatum), have recently been thought to play a crucial role in regulating effective immunotherapeutic responses. Herein, we advocate the idea that a complex interplay involving F. nucleatum, the local immune system, and the tumor microenvironment (TME) significantly influences ICB responses. Several mechanisms have been proposed, including the regulation of immune cell proliferation, inhibition of T lymphocyte, natural killer (NK) cell function, and invariant natural killer T (iNKT) cell function, as well as modification of the TME. This review aims to summarize the latest potential roles and mechanisms of F. nucleatum in antitumor immunotherapies for CRC. Additionally, it discusses the clinical application value of F. nucleatum as a biomarker for CRC and explores novel strategies, such as nano-delivery systems, for modulating F. nucleatum to enhance the efficacy of ICB therapy.

Bibliometric analysis of global research trends between gut microbiota and breast cancer: from 2013 to 2023

Background

Breast cancer is the most prevalent cancer globally and is associated with significant mortality. Recent research has provided crucial insights into the role of gut microbiota in the onset and progression of breast cancer, confirming its impact on the disease's management. Despite numerous studies exploring this relationship, there is a lack of comprehensive bibliometric analyses to outline the field's current state and emerging trends. This study aims to fill that gap by analyzing key research directions and identifying emerging hotspots.

Method

Publications from 2013 to 2023 were retrieved from the Web of Science Core Collection database. The VOSviewer, R language and SCImago Graphica software were utilized to analyze and visualize the volume of publications, countries/regions, institutions, authors, and keywords in this field.

Results

A total of 515 publications were included in this study. The journal Cancers was identified as the most prolific, contributing 21 papers. The United States and China were the leading contributors to this field. The University of Alabama at Birmingham was the most productive institution. Peter Bai published the most papers, while James J. Goedert was the most cited author. Analysis of highly cited literature and keyword clustering confirmed a close relationship between gut microbiota and breast cancer. Keywords such as "metabolomics" and "probiotics" have been prominently highlighted in the keyword analysis, indicating future research hotspots in exploring the interaction between metabolites in the breast cancer microenvironment and gut microbiota. Additionally, these keywords suggest significant interest in the therapeutic potential of probiotics for breast cancer treatment.

Conclusion

Research on the relationship between gut microbiota and breast cancer is expanding. Attention should be focused on understanding the mechanisms of their interaction, particularly the metabolite-microbiota-breast cancer crosstalk. These insights have the potential to advance prevention, diagnosis, and treatment strategies for breast cancer. This bibliometric study provides a comprehensive assessment of the current state and future trends of research in this field, offering valuable perspectives for future studies on gut microbiota and breast cancer.

The pH-Insensitive Antimicrobial and Antibiofilm Activities of the Frog Skin Derived Peptide Esc(1-21): Promising Features for Novel Anti-Infective Drugs

The number of antibiotic-resistant microbial infections is dramatically increasing, while the discovery of new antibiotics is significantly declining. Furthermore, the activity of antibiotics is negatively influenced by the ability of bacteria to form sessile communities, called biofilms, and by the microenvironment of the infection, characterized by an acidic pH, especially in the lungs of patients suffering from cystic fibrosis (CF). Antimicrobial peptides represent interesting alternatives to conventional antibiotics, and with expanding properties. Here, we explored the effects of an acidic pH on the antimicrobial and antibiofilm activities of the AMP Esc(1-21) and we found that it slightly lost activity (from 2- to 4-fold) against the planktonic form of a panel of Gram-negative bacteria, with respect to a ≥ 32-fold of traditional antibiotics. Furthermore, it retained its activity against the sessile form of these bacteria grown in media with a neutral pH, and showed similar or higher effectiveness against the biofilm form of bacteria grown in acidic media, simulating a CF-like acidic microenvironment, compared to physiological conditions.

Microbiome in gynecologic malignancies: a bibliometric analysis from 2012 to 2022

Microbiome and microbial dysbiosis have been proven to be involved in the carcinogenesis and treatment of gynecologic malignancies. However, there is a noticeable gap in the literature, as no comprehensive papers have covered general information, research status, and research frontiers in this field. This study addressed this gap by exploring the relationship between the gut and female reproductive tract (FRT) microbiome and gynecological cancers from a bibliometric perspective. Using VOSviewer 1.6.18, CiteSpace 6.1.R6, and HistCite Pro 2.1 software, we analyzed data retrieved from the Web of Science (WOS) Core Collection (WoSCC) database. Our dataset, consisting of 204 articles published from 2012 to 2022, revealed a consistent and upward publication trend. The United States and the United Kingdom were the primary driving forces, attributed to their prolificacy, high-quality output, and extensive cooperation. The University of Arizona Cancer Center, which is affiliated with the United States, ranked first among the top ten most prolific institutions. Frontiers in Cellular and Infection Microbiology emerged as the leading publisher. Herbst-Kralovetz MM led as the most productive author. Mitra A was the most influential author. Cervical cancer is notably associated with the microbiome, while endometrial and ovarian cancers are receiving increased attention in the last year. Intersections between the gut microbiome and estrogen are of growing importance. Current research focuses on identifying specific microbial species for etiological diagnosis, while frontiers mainly focus on the anticancer potential of microorganisms, such as regulating the effects of immune checkpoint inhibitors. In conclusion, this study sheds light on a novel and burgeoning direction of research, providing a one-stop overview of the microbiome in gynecologic malignancies. Its findings aim to help young researchers to identify research directions and future trends for ongoing investigations.

Mechanism of Action of Melatonin as a Potential Adjuvant Therapy in Inflammatory Bowel Disease and Colorectal Cancer

Inflammatory bowel disease (IBD), a continuum of chronic inflammatory diseases, is tightly associated with immune system dysregulation and dysbiosis, leading to inflammation in the gastrointestinal tract (GIT) and multiple extraintestinal manifestations. The pathogenesis of IBD is not completely elucidated. However, it is associated with an increased risk of colorectal cancer (CRC), which is one of the most common gastrointestinal malignancies. In both IBD and CRC, a complex interplay occurs between the immune system and gut microbiota (GM), leading to the alteration in GM composition. Melatonin, a neuroendocrine hormone, was found to be involved with this interplay, especially since it is present in high amounts in the gut, leading to some protective effects. Actually, melatonin enhances the integrity of the intestinal mucosal barrier, regulates the immune response, alleviates inflammation, and attenuates oxidative stress. Thereby, the authors summarize the multifactorial interaction of melatonin with IBD and with CRC, focusing on new findings related to the mechanisms of action of this hormone, in addition to its documented positive outcomes on the treatment of these two pathologies and possible future perspectives to use melatonin as an adjuvant therapy.