Microbiome, inflammation, and cancer

Gut microbiota: A new piece in understanding hepatocarcinogenesis

The gut microbiota forms a symbiotic relationship with the host and benefits the body in many critical aspects of life. However, immune system defects, alterations in the gut microbiota and environmental changes can destroy this symbiotic relationship and may lead to diseases, including cancer. Due to the anatomic and functional connection of the gut and liver, increasing studies show the important role of the gut microbiota in the carcinogenesis of hepatocellular carcinoma (HCC). In this manuscript, we review the available evidence and analyze some potential mechanisms of the gut microbiota, including bacterial dysbiosis, lipopolysaccharide (LPS), and genotoxins, in the progression and promotion of HCC. Furthermore, we discuss the possible therapeutic applications of probiotics, chemotherapy modulation, immunotherapy, targeted drugs and fecal microbiota transplantation (FMT) in targeting the gut microbiota.

MicroRNAs in Tumor Cell Metabolism: Roles and Therapeutic Opportunities

Dysregulated metabolism is a common feature of cancer cells and is considered a hallmark of cancer. Altered tumor-metabolism confers an adaptive advantage to cancer cells to fulfill the high energetic requirements for the maintenance of high proliferation rates, similarly, reprogramming metabolism confers the ability to grow at low oxygen concentrations and to use alternative carbon sources. These phenomena result from the dysregulated expression of diverse genes, including those encoding microRNAs (miRNAs) which are involved in several metabolic and tumorigenic pathways through its post-transcriptional-regulatory activity. Further, the identification of key actionable altered miRNA has allowed to propose novel targeted therapies to modulated tumor-metabolism. In this review, we discussed the different roles of miRNAs in cancer cell metabolism and novel miRNA-based strategies designed to target the metabolic machinery in human cancer.

Nanotechnology intervention of the microbiome for cancer therapy

The microbiome is emerging as a key player and driver of cancer. Traditional modalities to manipulate the microbiome (for example, antibiotics, probiotics and microbiota transplants) have been shown to improve efficacy of cancer therapies in some cases, but issues such as collateral damage to the commensal microbiota and consistency of these approaches motivates efforts towards developing new technologies specifically designed for the microbiome-cancer interface. Considering the success of nanotechnology in transforming cancer diagnostics and treatment, nanotechnologies capable of manipulating interactions that occur across microscopic and molecular length scales in the microbiome and the tumour microenvironment have the potential to provide innovative strategies for cancer treatment. As such, opportunities at the intersection of nanotechnology, the microbiome and cancer are massive. In this Review, we highlight key opportunistic areas for applying nanotechnologies towards manipulating the microbiome for the treatment of cancer, give an overview of seminal work and discuss future challenges and our perspective on this emerging area.

Untapped "-omics": the microbial metagenome, estrobolome, and their influence on the development of breast cancer and response to treatment

With the advent of next generation sequencing technologies, there is an increasingly complex understanding of the role of gastrointestinal and local breast microbial dysbiosis in breast cancer. In this review, we summarize the current understanding of the microbiome's role in breast carcinogenesis, discussing modifiable risk factors that may affect breast cancer risk by inducing dysbiosis as well as recent sequencing data illustrating breast cancer subtype-specific differences in local breast tissue microbiota. We outline how the 'estrobolome,' the aggregate of estrogen-metabolizing enteric bacterial genes, may affect the risk of developing postmenopausal estrogen receptor-positive breast cancer. We also discuss the microbiome's potent capacity for anticancer therapy activation and deactivation, an important attribute of the gastrointestinal microbiome that has yet to be harnessed clinically.

What Can Chemical Carcinogenesis Shed Light on the LNT Hypothesis in Radiation Carcinogenesis?

To protect the public’s health from exposure to physical, chemical, and microbiological agents, it is important that any policy be based on rigorous scientifically based research. The concept of “linear no-threshold” (LNT) has been implemented to provide guideline exposures to these agents. The practical limitation to testing this hypothesis is to provide sufficient samples for experimental or epidemiological studies. While there is no universally accepted understanding of most human diseases, there seems to be better understanding of cancer that might help resolve the “LNT” model. The public’s concern, after being exposed to radiation, is the potential of producing cancer. The most rigorous hypothesis of human carcinogenesis is the “multistage, multimechanism” chemical carcinogenesis model. The radiation carcinogenesis LNT model, rarely, if ever, built it into their support. It will be argued that this multistage, multimechanism model of carcinogenesis, involving the “initiation” of a single cell by a mutagen event, followed by chronic exposure to threshold levels of epigenetic agents or conditions that stimulate the clonal expansion of the “initiated” cell, can convert these benign cells to become invasive and metastatic. This “promotion” process can be interrupted, thereby preventing these initiated cells from transitioning to the “progression” process of invasion and metastasis.

Emerging roles of ECM remodeling processes in cancer

Extracellular matrix (ECM) plays a central and dynamic role in the creation of tumor microenvironment. Herein we discuss the emerging biophysical and biochemical aspects of ECM buildup and proteolysis in cancer niche formation. Dysregulated ECM remodeling by cancer cells facilitate irreversible proteolysis and crosslinking, which in turn influence cell signaling, micro environmental cues, angiogenesis and tissue biomechanics. Further, we introduce the emerging roles of cancer microbiome in aberrant tumor ECM remodeling and membrane bound nano-sized vesicles called exosomes in creation of distant pre-metastatic niches. A detailed molecular and biophysical understanding of the ECM morphologies and its components such as key enzymes, structural and signaling molecules are critical in identifying the next generation of therapeutic and diagnostic targets in cancer.

International Cancer Microbiome Consortium consensus statement on the role of the human microbiome in carcinogenesis

OBJECTIVE

In this consensus statement, an international panel of experts deliver their opinions on key questions regarding the contribution of the human microbiome to carcinogenesis.

DESIGN

International experts in oncology and/or microbiome research were approached by personal communication to form a panel. A structured, iterative, methodology based around a 1-day roundtable discussion was employed to derive expert consensus on key questions in microbiome-oncology research.

RESULTS

Some 18 experts convened for the roundtable discussion and five key questions were identified regarding: (1) the relevance of dysbiosis/an altered gut microbiome to carcinogenesis; (2) potential mechanisms of microbiota-induced carcinogenesis; (3) conceptual frameworks describing how the human microbiome may drive carcinogenesis; (4) causation versus association; and (5) future directions for research in the field.The panel considered that, despite mechanistic and supporting evidence from animal and human studies, there is currently no direct evidence that the human commensal microbiome is a key determinant in the aetiopathogenesis of cancer. The panel cited the lack of large longitudinal, cohort studies as a principal deciding factor and agreed that this should be a future research priority. However, while acknowledging gaps in the evidence, expert opinion was that the microbiome, alongside environmental factors and an epigenetically/genetically vulnerable host, represents one apex of a tripartite, multidirectional interactome that drives carcinogenesis.

CONCLUSION

Data from longitudinal cohort studies are needed to confirm the role of the human microbiome as a key driver in the aetiopathogenesis of cancer.

Microbial carcinogenesis: Lactic acid bacteria in gastric cancer

While Helicobacter pylori is a fundamental risk factor, gastric cancer (GC) aetiology involves combined effects of microbial (both H. pylori and non-H. pylori), host and environmental factors. Significant differences exist between the gastric microbiome of those with gastritis, intestinal metaplasia and GC, suggesting that dysbiosis in the stomach is dynamic and correlates with progression to GC. Most notably, a consistent increase in abundance of lactic acid bacteria (LAB) has been observed in GC patients including Streptococcus, Lactobacillus, Bifidobacterium and Lactococcus. This review summarises how LAB can influence GC by a number of mechanisms that include supply of exogenous lactate -a fuel source for cancer cells that promotes inflammation, angiogenesis, metastasis, epithelial-mesenchymal transition and immune evasion-, production of reactive oxygen species and N-nitroso compounds, as well as anti-H. pylori properties that enable colonization by other non-H. pylori carcinogenic pathobionts.

Elevated peripheral inflammatory markers are related with the recurrence and canceration of vocal fold leukoplakia

OBJECTIVE

To evaluate the predictive value of preoperative peripheral inflammatory markers in patients with vocal fold leukoplakia.

METHODS

A retrospective study was performed of the patients diagnosed with vocal fold leukoplakia and who accepted carbon dioxide (CO₂) laser resection in our center in the last 10 years. We calculated the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR) after collecting and analyzing the clinical, histopathological and laboratory data. The potential relation between blood indexes and clinical events as recurrence or canceration was evaluated.

RESULTS

A total of 589 patients were involved, including 300 cases without recurrence (group A), 198 with recurrence but not canceration (group B) and 91 transformed into squamous cancer (group C). Baseline analysis of NLR, PLR, and MLR showed no difference among the three groups before the first surgery. But all the indexes significantly elevated in groups B (P < 0.001, < 0.001, 0.023, respectively) and C (P = 0.009, 0.004, 0.007, respectively) in the last operation. The receiver-operating curve (ROC) analysis showed NLR as a potential marker of canceration of leukoplakia (AUC = 0.837) and the cutoff value was 2.505. When regrouping with pathological outcomes, severe dysplasia and squamous cell carcinoma (SCC) groups both revealed a higher level of NLR, PLR, and MLR comparing to the no dysplasia, mild dysplasia, and moderate dysplasia groups. NLR, PLR, and MLR in high-risk group (moderate, severe dysplasia and carcinoma) also elevated comparing to low-risk group (no dysplasia, mild dysplasia) (P = 0.039, 0.011, 0.007, respectively).

CONCLUSIONS

The peripheral inflammatory markers NLR, PLR, and MLR are closely connected with the development of vocal fold leukoplakia. NLR may be a potential marker to predict the poor outcomes (recurrence or canceration) of patients in first surgery.

C-type lectin receptor-mediated immune recognition and response of the microbiota in the gut

C-type lectin receptors (CLRs) are powerful pattern-recognition receptors that discern ‘self’ and ‘non-self’ in our body and protect us from invasive pathogens by mediating immune recognition and response. The gastrointestinal tract is very important for the maintenance of homeostasis; it is the largest shelter for the billions of microorganisms in the body and CLRs play a crucial regulatory role in this system. This study focuses on several CLRs, including Dectin-1, Dectin-2, Dectin-3 and Mincle. We summarize the roles of CLRs in maintaining gastrointestinal immune-system homeostasis, especially their functions in mediating immune recognition and responses in the gut, discuss their relationships to some diseases, highlight the significance of CLR-mediated sensing of microbial and non-microbial compounds in the gut immune system and identify new therapeutic targets.

The Small Bowel Cancer Incidence Enigma

Although the small bowel is a vast organ with a highly proliferative epithelium, the incidence of small bowel cancers is surprisingly low. Many factors could be involved in this unexpected cancer incidence, including difficult access to the exploration of the small bowel mucosa, which might lead to missed diagnoses of non-obstructive and non-bleeding small tumours. Moreover, possible factors that influence the low incidence include more efficient machinery of DNA replication and DNA repair enzymes, peculiarities in microbiota components, competence of the immune system, and the speed of intestinal transit. Importantly, the answer for the enigmatic risk of driver mutations caused by replication errors may be hidden in the small bowel, which is an obscure part of digestive tract that is usually inaccessible by endoscopic or colonoscopic conventional investigations. These observations warrant the necessity of an urgent exploration of small bowel features, including the evaluation of DNA replication controls and expression of DNA repair genes, in order to shed light on these obscure events.

Co-expression of TLR-9 and MMP-13 is associated with the degree of tumour differentiation in prostate cancer

In vitro experiments demonstrated that stimulation of Toll-like receptor 9 (TLR-9) by synthetic TLR-9 ligands induces the invasion of TLR-9-expressing prostate cancer cells through matrix metalloproteinase 13 (MMP-13). However, the clinical value of TLR-9 and MMP-13 co-expression in the pathophysiology of the prostate is unknown. In the study, we evaluated the expression levels and clinical significance of the TLR-9 and MMP-13 in a series of prostate tissues. One hundred and eighty prostate tissues including prostate cancer (PCa) (n = 137), high-grade prostatic intraepithelial neoplasia (HPIN) (n = 18) and benign prostatic hyperplasia (BPH) (n = 25) were immunostained for the TLR-9 and MMP-13 markers. Subsequently, the correlation between the TLR-9 and MMP-13 staining scores and clinicopathological parameters was obtained. Higher expressions of TLR-9 and MMP-13 were found in PCa and high-grade prostatic intraepithelial neoplasia compared to benign prostatic hyperplasia tissues. Among PCa samples, a positive relationship was revealed between the MMP-13 expression and Gleason score (P < 0.001). There was a significant correlation between TLR-9 expression and regional lymph node involvement (P = 0.04). The expression patterns of TLR-9 and MMP-13 markers demonstrated a reciprocal significant correlation between the two markers in the same series of prostate samples (P < 0.001). Furthermore, the Gleason score of TLR-9^high /MMP-13^high and TLR-9^low /MMP-13^low phenotypes showed a significant difference (P = 0.002). Higher expressions of TLR-9 and MMP-13 can confer aggressive behaviour to PCa. Therefore, these markers may be used as a valuable target for tailored therapy of PCa.

Veterinary ocular microbiome: Lessons learned beyond the culture

Ocular pathogens cause many painful and vision-threatening diseases such as infectious keratitis, uveitis, and endophthalmitis. While virulent pathogens and pathobionts play important roles in disease pathogenesis, the scientific community has long assumed disruption of the ocular surface occurs prior to microbial colonization and subsequent infection. While nonpathogenic bacteria are often detected in corneal and conjunctival cultures from healthy eyes, cultures also frequently fail to yield growth of common ocular pathogens or nonpathogenic bacteria. This prompts the following question: Is the ocular surface populated by a stable microbial population that cannot be detected using standard culture techniques? The study of the microbiome has recently become a widespread focus in physician and veterinary medicine. Research suggests a pivotal symbiotic relationship with these microbes to maintain healthy host tissues, and when altered is associated with various disease states ("dysbiosis"). The microbiota that lives within and on mammalian bodies have long been known to influence health and susceptibility to infection. However, limitations of traditional culture methods have resulted in an incomplete understanding of what many now call the "forgotten organ," that is, the microbiome. With the introduction of high-throughput sequencing, physician ophthalmology has recognized an ocular surface with much more diverse microbial communities than suspected based on traditional culture. This article reviews the salient features of the ocular surface microbiome and highlights important future applications following the advent of molecular techniques for microbial identification, including characterizing ocular surface microbiomes in our veterinary species and their potential role in management of infectious and inflammatory ocular diseases.

Dietary inflammatory index and risk of gynecological cancers: a systematic review and meta-analysis of observational studies

OBJECTIVE

There has been growing body of literatures showing that chronic inflammation might play an important role in cancer development. This meta-analysis aimed to assess the association between the dietary inflammation index (DII) score and gynecological cancers.

METHODS

A systematic search of PubMed, EMBASE and Web of Science up until October 20, 2018 was carried out to retrieve all related cohort and case-control studies. The summary risk assessments were pooled using random-effects models. The dose-response relationship was estimated by linear relationship model.

RESULTS

Twelve case-control studies (10,774 cases/15,958 controls) and six prospective cohort studies (330,363 participants/23,133 incident cases) were included in this meta-analysis. The pooled adjusted relative risk (RR) of gynecological cancers for the highest DII category compared to the lowest category was 1.38, (95% confidence intervals [CIs], 1.21-1.56, p<0.001]. A positive dose-response relationship was also noticed. Stratified by study design indicated that, the pooled RRs was significantly higher for case-control studies than cohort studies (p for interaction<0.001), for studies conducted among participants with body mass index (BMI) ≥25 kg/m² than participants with BMI <25 kg/m² (p for interaction=0.026), among participants with ovarian cancer and endometrial cancer than participants with breast cancer (p for interaction = 0.038). Meta-regression analysis further confirmed that study design significantly contributed to inter-study heterogeneity (p<0.001).

CONCLUSION

This meta-analysis suggests that elevated DII is independently associated with a higher risk of gynecological cancers, especially patients with ovarian cancer and endometrial cancer and among obese participants.

Metaproteomics of fecal samples of Crohn's disease and Ulcerative Colitis

Crohn's Disease (CD) and Ulcerative Colitis (UC) are chronic inflammatory bowel diseases (IBD) of the gastrointestinal tract. This study used non-invasive LC-MS/MS to find disease specific microbial and human proteins which might be used later for an easier diagnosis. Therefore, 17 healthy controls, 11 CD patients and 14 UC patients but also 13 Irritable Bowel Disease (IBS) patients, 8 Colon Adenoma (CA) patients, and 8 Gastric Carcinoma (GCA) patients were investigated. The proteins were extracted from the fecal samples with liquid phenol in a ball mill. Subsequently, the proteins were digested tryptically to peptides and analyzed by an Orbitrap LC-MS/MS. For protein identification and interpretation of taxonomic and functional results, the MetaProteomeAnalyzer software was used. Cluster analysis and non-parametric test (analysis of similarities) separated healthy controls from patients with CD and UC as well as from patients with GCA. Among others, CD and UC correlated with an increase of neutrophil extracellular traps and immune globulins G (IgG). In addition, a decrease of human IgA and the transcriptional regulatory protein RprY from Bacillus fragilis was found for CD and UC. A specific marker in feces for CD was an increased amount of the human enzyme sucrose-isomaltase. SIGNIFICANCE: Crohn's Disease and Ulcerative Colitis are chronic inflammatory diseases of the gastrointestinal tract, whose diagnosis required comprehensive medical examinations including colonoscopy. The impact of the microbial communities in the gut on the pathogenesis of these diseases is poorly understood. Therefore, this study investigated the impact of gut microbiome on these diseases by a metaproteome approach, revealing several disease specific marker proteins. Overall, this indicated that fecal metaproteomics has the potential to be useful as non-invasive tool for a better and easier diagnosis of both diseases.

The value of neutrophil to lymphocyte ratio and gamma-glutamyl transpeptidase to platelet ratio in patients with hepatocellular carcinoma

Our study aimed to evaluate the value of neutrophil to lymphocyte ratio (NLR) and gamma-glutamyl transpeptidase to platelet ratio (GPR) in patients with hepatocellular carcinoma (HCC).A total of 565 patients with pathological diagnosis of HCC were retrospectively analyzed and 414 patients diagnosed with cirrhosis were treated as a control group. All clinical materials were collected from the First Affiliated Hospital of Guangxi Medical University.The preintervention NLR, GPR, and α-fetoprotein (AFP) were significantly higher in HCC patients than in the controls (PNLR < .000, PGPR < .000, PAFP < .000). The NLR and GPR were correlated with the Barcelona clinic liver cancer (BCLC) stages, Child-Pugh grades, and tumor size, but not with Edmondson-Steiner grades. Combined use of NLR or GPR with AFP produced larger area under the curve (AUC) (AUCNLR+AFP = 0.916; AUCNLR+AFP = 0.953) than NLR (P < .000), GPR (P < .000), or AFP (P < .000) used alone.The preintervention hematologic parameters (NLR and GPR) studied herein were associated with the BCLC stages of HCC. Combined use of NLR or GPR with AFP may improve early detection and diagnosis of HCC.

Impact of the gut microbiome on the genome and epigenome of colon epithelial cells: contributions to colorectal cancer development

In recent years, the number of studies investigating the impact of the gut microbiome in colorectal cancer (CRC) has risen sharply. As a result, we now know that various microbes (and microbial communities) are found more frequently in the stool and mucosa of individuals with CRC than healthy controls, including in the primary tumors themselves, and even in distant metastases. We also know that these microbes induce tumors in various mouse models, but we know little about how they impact colon epithelial cells (CECs) directly, or about how these interactions might lead to modifications at the genetic and epigenetic levels that trigger and propagate tumor growth. Rates of CRC are increasing in younger individuals, and CRC remains the second most frequent cause of cancer-related deaths globally. Hence, a more in-depth understanding of the role that gut microbes play in CRC is needed. Here, we review recent advances in understanding the impact of gut microbes on the genome and epigenome of CECs, as it relates to CRC. Overall, numerous studies in the past few years have definitively shown that gut microbes exert distinct impacts on DNA damage, DNA methylation, chromatin structure and non-coding RNA expression in CECs. Some of the genes and pathways that are altered by gut microbes relate to CRC development, particularly those involved in cell proliferation and WNT signaling. We need to implement more standardized analysis strategies, collate data from multiple studies, and utilize CRC mouse models to better assess these effects, understand their functional relevance, and leverage this information to improve patient care.

Inflammatory dietary pattern and incident psoriasis, psoriatic arthritis, and atopic dermatitis in women: A cohort study

BACKGROUND

Diet is a modulator of inflammation that might impact inflammatory skin diseases.

OBJECTIVE

To assess the relationship between pro-inflammatory dietary patterns and incident psoriasis, psoriatic arthritis (PsA), and atopic dermatitis (AD).

METHODS

We conducted cohort studies among women in the Nurses' Health Study II. The Empirical Dietary Inflammatory Pattern (EDIP) score was calculated at baseline and every 4 years. Incident psoriasis, PsA, and AD were assessed by validated self-report. We used multivariable-adjusted Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between EDIP quintiles and risk for psoriasis, PsA, and AD.

RESULTS

We had 85,185 participants in the psoriasis analysis and 63,443 in the AD analysis. There were 1432 cases of psoriasis, 262 cases of PsA, and 403 cases of AD. Pro-inflammatory dietary patterns were not associated with the risk for outcomes in multivariable models (all P values for trend >.05). HRs comparing the highest to the lowest EDIP quintile were 0.99 (95% CI 0.83-1.18) for psoriasis, 1.22 (95% CI 0.81-1.83) for PsA, and 0.96 (95% CI 0.69-1.34) for AD.

LIMITATIONS

Recall and self-report.

CONCLUSION

Our findings do not support dietary inflammatory potential as a risk factor for psoriasis, PsA, or AD.

Lactobacillus rhamnosus GG strain mitigated the development of obstructive sleep apnea-induced hypertension in a high salt diet via regulating TMAO level and CD4+ T cell induced-type I inflammation

Obstructive sleep apnea (OSA) and high salt content in modern diet has been particularly implicated in systemic hypertension, leading to increased morbidity and mortality. Gut dysbiosis, associated with increased risk of systemic immunological imbalance, plays a causal role in the development of cardiovascular diseases. Here, we investigated the effect of Lactobacillus rhamnosus GG strain (LGG) on the development of hypertension induced by OSA and high salt diet. In this study, hypertension was modeled in rats by feeding a high salt diet (HSD) for 6 wk and exposuring to chronic intermittent hypoxia (CIH) during the sleep cycle. We found that OSA combined with HSD increased the severity of hypertension through increasing level of blood Trimethylamine-Oxide (TMAO), release of Th1-related cytokine (IFN-γ) and inhibition of anti-inflammatory cytokine (TGF-β1), and affected the gut microbiome in rats, particularly by depleting Lactobacillus. In addition, expression of PERK1/2, PAkt and PmTOR increased in the aorta from rats with a CIH exposure and HSD. Consequently, treatment of model rats with LGG prevented aggravation of hypertension by reducing blood TMAO levels, modulating Th1/Th2 cytokine imbalance and suppressing phosphorylation levels of ERK1/2, Akt and mTOR. In line with these findings, our results connect high salt diet to the gut-immune axis and highlight the gut microbiome as a potential therapeutic target to counteract the development of OSA-induced hypertension basing on a high salt diet.

The Interplay between Immunity and Microbiota at Intestinal Immunological Niche: The Case of Cancer

The gut microbiota is central to the pathogenesis of several inflammatory and autoimmune diseases. While multiple mechanisms are involved, the immune system clearly plays a special role. Indeed, the breakdown of the physiological balance in gut microbial composition leads to dysbiosis, which is then able to enhance inflammation and to influence gene expression. At the same time, there is an intense cross-talk between the microbiota and the immunological niche in the intestinal mucosa. These interactions may pave the way to the development, growth and spreading of cancer, especially in the gastro-intestinal system. Here, we review the changes in microbiota composition, how they relate to the immunological imbalance, influencing the onset of different types of cancer and the impact of these mechanisms on the efficacy of traditional and upcoming cancer treatments.

The effect of intestinal microbiota metabolites on HT29 cell line using MTT method in patients with colorectal cancer

AIM

The aim of this study was to evaluate the effect of intestinal microbiota metabolites in colorectal cancer patients on HT29 cell line using MTT assay.

BACKGROUND

Colorectal cancer is one of the most common malignant tumors. Human guts harbor abundant microbes that adjust many aspects of the host physiology. Increasing studies suggest that gut microbiota play a significant role in the incidence and expansion of CRC, as a result of virulence factors, bacterial metabolites, or inflammatory pathways.

METHODS

In this cross-sectional study, 60 biopsy samples including 30 cancerous and 30 adjacent healthy tissues were collected from patients with CRC during 2017. Biopsy samples were first cultured on Thioglycollate broth medium for 24hr after which the microbiota metabolites were filtered and stored at -20 C° for further evaluation. HT29 cells were treated by microbiota metabolites at different times (3, 6, 12, 18h) and its viability was assessed by MTT assay.

RESULTS

The cells treated with microbiota metabolites showed increased viability and proliferation in time-dependent analysis by MTT assay, but there was not significant differences between the two groups.

CONCLUSION

It seems that microbial metabolites are able to induce proliferation and increase cell viability and thus induce colorectal cancer.

Modeling the Role of the Microbiome in Evolution

There is undeniable evidence showing that bacteria have strongly influenced the evolution and biological functions of multicellular organisms. It has been hypothesized that many host-microbial interactions have emerged so as to increase the adaptive fitness of the holobiont (the host plus its microbiota). Although this association has been corroborated for many specific cases, general mechanisms explaining the role of the microbiota in the evolution of the host are yet to be understood. Here we present an evolutionary model in which a network representing the host adapts in order to perform a predefined function. During its adaptation, the host network (HN) can interact with other networks representing its microbiota. We show that this interaction greatly accelerates and improves the adaptability of the HN without decreasing the adaptation of the microbial networks. Furthermore, the adaptation of the HN to perform several functions is possible only when it interacts with many different bacterial networks in a specialized way (each bacterial network participating in the adaptation of one function). Disrupting these interactions often leads to non-adaptive states, reminiscent of dysbiosis, where none of the networks the holobiont consists of can perform their respective functions. By considering the holobiont as a unit of selection and focusing on the adaptation of the host to predefined but arbitrary functions, our model predicts the need for specialized diversity in the microbiota. This structural and dynamical complexity in the holobiont facilitates its adaptation, whereas a homogeneous (non-specialized) microbiota is inconsequential or even detrimental to the holobiont's evolution. To our knowledge, this is the first model in which symbiotic interactions, diversity, specialization and dysbiosis in an ecosystem emerge as a result of coevolution. It also helps us understand the emergence of complex organisms, as they adapt more easily to perform multiple tasks than non-complex ones.

Gut Microbiota as a Prospective Therapeutic Target for Curcumin: A Review of Mutual Influence

Background

Turmeric is a spice that has recently received much interest and has been widely used in Ayurvedic medicine. Turmeric products are diarylheptanoids and have been characterized as safe. They are termed as curcuminoids that consists essentially of three major compounds: curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Curcumin is a lipophilic polyphenol that has poor systemic bioavailability and suffers from biotransformation by human intestinal microflora to yield different metabolites that are easily conjugated to glucuronides and sulfate O-conjugated derivatives. Recently, an increasing number of studies have indicated that dysbiosis is linked with many metabolic diseases, though gut microbiota could be a novel potential therapeutic target.

Scope and Approach

Thus, it is suspected that curcumin and its derivatives exert direct regulative effects on the gut microbiota which could explain the paradox between curcumin's poor systemic bioavailability and its widely reported pharmacological activities.

Key Findings and Conclusions

This article summarizes a range of studies that highlight the interaction between curcumin and gut microbiota and considers opportunities for microbiome-targeting therapies using turmeric extract.

Protective effects of SKLB023 on a mouse model of unilateral ureteral obstruction by the modulation of gut microbiota

Renal interstitial fibrosis is the common pathway underlying the progression of chronic kidney disease (CKD) to end-stage renal disease (ESRD) and the corresponding therapies are limited. Quantitative and qualitative alterations in gut microbiota are noted in patients with CKD and ESRD. In our previous study, SKLB023 exhibited antifibrotic effects by interfering TGF-β1/Smad3 signaling in obstructive nephropathy. However, it remained unclear that oral administration of SKLB023 drives the alteration of gut microbiota to attenuate renal fibrosis. In the study, the marked inflammation and interstitial fibrosis were found in the kidney tissues of unilateral ureteral obstruction (UUO) mice. While treatment with SKLB023 significantly alleviated renal interstitial fibrosis and reduced serum proinflammatory cytokines TNF-α, IL-6 levels. Importantly, SKLB023 derived the modulation of gut microbiota with the increasing similarity between the composition of gut microbiota in the control and UUO. The number of Turicibacter and Candidatus_Arthromitus was significantly decreased following UUO surgery and recovered by SKLB023, which positively correlated with pro-inflammatory cytokine expression. These results indicated the potential relationship between the antifibrotic benefits of SKLB023 and gut microbiota alteration, which provided new insights into drug therapy via gut microbiota modulation in obstructive nephropathy.

Renal fibrosis is the common pathway underlying the progression of CKD to ESRD and quantitative and qualitative alterations in gut microbiota are noted in patients with CKD. Our results indicated SKLB023 drives the alteration of gut microbiota to attenuate renal fibrosis.

Characterization of human breast tissue microbiota from core needle biopsies through the analysis of multi hypervariable 16S-rRNA gene regions

Breast microbiota compositions are not well understood, and a few recent reports have begun to explore the correlation between breast tissue dysbiosis and cancer. Given that various methods for breast microbiota detection were used, the aim of the present paper was to clarify which hypervariable region of the 16S-rRNA gene (V2, V3, V4, V6 + 7, V8, and V9) is the most informative for breast tissue microbiota. Core needle biopsies (CNBs) were compared with surgical excision biopsies (SEBs) to find a less invasive form of recovery useful for the analysis of a larger statistical population and potentially for diagnostic use of breast tissue microbiota. Finally, this study was the first to analyse the breast microbiota of tumours and paired normal tissues of a Mediterranean population. Our findings showed that the V3 region is the most informative for breast tissue microbiota, accounting for 45% of all reads. No significant differences were found between CNB and SEB specimens in terms of total reads and numbers of Operational Taxonomic Units (OTUs). Moreover, we find that more similarities than differences exist between tumours and adjacent normal tissues. Finally, the presence of the Ralstonia genus is associated with breast tissue.

Diabetes, Obesity, and Breast Cancer

The rates of obesity and diabetes are increasing worldwide, whereas the age of onset for both obesity and diabetes are decreasing steadily. Obesity and diabetes are associated with multiple factors that contribute to the increased risk of a number of different cancers, including breast cancer. These factors are hyperinsulinemia, elevated IGFs, hyperglycemia, dyslipidemia, adipokines, inflammatory cytokines, and the gut microbiome. In this review, we discuss the current understanding of the complex signaling pathways underlying these multiple factors involved in the obesity/diabetes-breast cancer link, with a focus particularly on the roles of the insulin/IGF system and dyslipidemia in preclinical breast cancer models. We review some of the therapeutic strategies to target these metabolic derangements in cancer. Future research directions and potential therapeutic strategies are also discussed.

Bioactivity-based analysis and chemical characterization of anti-inflammatory compounds from Curcuma zedoaria rhizomes using LPS-stimulated RAW264.7 cells

Inflammation is not only a self-defense response of the innate immune system, but also the pathogenesis mechanism of multiple diseases such as arthritis, neurodegeneration, and cancer. Curcuma zedoaria Roscoe (Zingiberaceae), an indigenous plant of India, has been used traditionally in Ayurveda and folk medicine. As part of our ongoing efforts to screen traditional medicinal plants exhibiting pharmacological potential and to characterize the compounds involved, we examined the anti-inflammatory effects of the MeOH extract of C. zedoaria rhizomes using lipopolysaccharide (LPS)-stimulated RAW264.7 murine macrophage cells and found that MeOH extract inhibited the synthesis of nitric oxide (NO) in a dose-dependent manner (IC₅₀: 23.44 ± 0.77 μg/mL). In our efforts to characterize the compounds responsible for these anti-inflammatory effects, bioactivity-guided fractionation of the MeOH extract and chemical investigation of its active hexane-soluble fraction led to the successful isolation of five sesquiterpenes (1-5), the structures of which were elucidated by NMR spectroscopic analysis and LC/MS analysis. Among them, curcuzedoalide (5) exhibited potent inhibitory effects on NO synthesis (IC₅₀: 12.21 ± 1.67 μM) and also suppressed pre-inflammatory protein expression of iNOS and COX-2. Curcuzedoalide (5) was thus determined to be a contributor to the anti-inflammatory effect of C. zedoaria rhizomes and could be a potential candidate for therapeutic applications.

Understanding Urogenital Schistosomiasis-Related Bladder Cancer: An Update

Infection with Schistosoma haematobium leads to urogenital schistosomiasis, which has been correlated with the occurrence of bladder cancer. However, mechanisms responsible for this association have not yet been clearly identified. In this short review, we provide an update, highlighting the most recent studies on schistosome-associated bladder cancer, including those that focus on identifying changes in host biology during S. haematobium infection, as well as studies for the identification of potentially pro-carcinogenic parasite molecules, and we offer a discussion on some possible mechanisms driving schistosomal bladder cancer.

Proinflammatory diet is associated with increased risk of squamous cell head and neck cancer

Diets high in fruits and vegetables and low in red meat intake have been associated with decreased risk of head and neck cancer. Additionally, chronic inflammation pathways and their association with cancer have been widely described. We hypothesized a proinflammatory diet, as measured by the dietary inflammatory index (DII^® ), is associated with increased risk of head and neck cancer. We used the Carolina Head and Neck Cancer (CHANCE) study, a population-based case-control study of head and neck squamous cell carcinoma. Cases were recruited from a 46-county region in central North Carolina. Controls, frequency-matched on age, race, and sex were identified through the North Carolina Department of Motor Vehicle records. The DII score, adjusted for energy using the density approach (E-DII), was calculated from a food frequency questionnaire and split into four quartiles based on the distribution among controls. Adjusted odds ratios (ORs) were estimated with unconditional logistic regression. Cases had higher E-DII scores (i.e., a more proinflammatory diet) compared with controls (mean: -0.14 vs. -1.50; p value < 0.001). When compared with the lowest quartile, the OR for the highest quartile was 2.91 (95% confidence interval (CI): 2.16-3.95), followed by 1.93 (95% CI: 1.43-2.62) for the third quartile, and 1.37 (95% CI: 1.00-1.89) for the second quartile. Both alcohol and smoking had a significant additive interaction with E-DII (smoking relative excess risk due to interaction (RERI): 2.83; 95% CI: 1.36-4.30 and alcohol RERI: 1.75; 95% CI: 0.77-2.75). These results provide additional evidence for the association between proinflammatory diet and head and neck cancer.

Microbiota, Epithelium, Inflammation, and TGF-β Signaling: An Intricate Interaction in Oncogenesis

Microbiota has been widely considered to play a critical role in human carcinogenesis. Recent evidence demonstrated that microbiota, epithelial barrier and inflammation has made up a tightly interdependent triangle during the process of carcinogenesis. Hence, we discussed the triangle relationship of microbiota dysbiosis, epithelial barrier dysfunction and dysregulated immune responses to elucidate the mechanisms by which microbiota induces carcinogenesis, especially highlighting the reciprocal crosstalk between transforming growth factor-β signaling and every side of the tumorigenic triangle. This sophisticated interaction will provide insight into the basic mechanisms of carcinogenesis and may bring new hope to cancer prevention and therapeutic intervention.

The Pivotal Role of DNA Repair in Infection Mediated-Inflammation and Cancer

Pathogenic and commensal microbes induce various levels of inflammation and metabolic disease in the host. Inflammation caused by infection leads to increased production of reactive oxygen species (ROS) and subsequent oxidative DNA damage. These in turn cause further inflammation and exacerbation of DNA damage, and pose a risk for cancer development. Helicobacter pylori-mediated inflammation has been implicated in gastric cancer in many previously established studies, and Fusobacterium nucleatum presence has been observed with greater intensity in colorectal cancer patients. Despite ambiguity in the exact mechanism, infection-mediated inflammation may have a link to cancer development through an accumulation of potentially mutagenic DNA damage in surrounding cells. The multiple DNA repair pathways such as base excision, nucleotide excision, and mismatch repair that are employed by cells are vital in the abatement of accumulated mutations that can lead to carcinogenesis. For this reason, understanding the role of DNA repair as an important cellular mechanism in combatting the development of cancer will be essential to characterizing the effect of infection on DNA repair proteins and to identifying early cancer biomarkers that may be targeted for cancer therapies and treatments.

The triune of intestinal microbiome, genetics and inflammatory status and its impact on the healing of lower gastrointestinal anastomoses

Gastrointestinal resections are a common operation and most involve an anastomosis to rejoin the ends of the remaining bowel to restore gastrointestinal (GIT) continuity. While most joins heal uneventfully, in up to 26% of patients healing fails and an anastomotic leak (AL) develops. Despite advances in surgical technology and techniques, the rate of anastomotic leaks has not decreased over the last few decades raising the possibility that perhaps we do not yet fully understand the phenomenon of AL and are thus ill-equipped to prevent it. As in all complex conditions, it is necessary to isolate each different aspect of disease for interrogation of its specific role, but, as we hope to demonstrate in this article, it is a dangerous oversimplification to consider any single aspect as the full answer to the problem. Instead, consideration of important individual observations in parallel could illuminate the way forward towards a possibly simple solution amidst the complexity. This article details three aspects that we believe intertwine, and therefore should be considered together in wound healing within the GIT during postsurgical recovery: the microbiome, the host genetic make-up and their relationship to the perioperative inflammatory status. Each of these, alone or in combination, has been linked with various states of health and disease, and in combining these three aspects in the case of postoperative recovery from bowel resection, we may be nearer an answer to preventing anastomotic leaks than might have been thought just a few years ago.

The Complex Interplay between Chronic Inflammation, the Microbiome, and Cancer: Understanding Disease Progression and What We Can Do to Prevent It

Cancer is a multifaceted condition, in which a senescent cell begins dividing in an irregular manner due to various factors such as DNA damage, growth factors and inflammation. Inflammation is not typically discussed as carcinogenic; however, a significant percentage of cancers arise from chronic microbial infections and damage brought on by chronic inflammation. A hallmark cancer-inducing microbe is Helicobacter pylori and its causation of peptic ulcers and potentially gastric cancer. This review discusses the recent developments in understanding microbes in health and disease and their potential role in the progression of cancer. To date, microbes can be linked to almost every cancer, including colon, pancreatic, gastric, and even prostate. We discuss the known mechanisms by which these microbes can induce cancer growth and development and how inflammatory cells may contribute to cancer progression. We also discuss new treatments that target the chronic inflammatory conditions and their associated cancers, and the impact microbes have on treatment success. Finally, we examine common dietary misconceptions in relation to microbes and cancer and how to avoid getting caught up in the misinterpretation and over inflation of the results.

16S rRNA amplicon sequencing identifies microbiota associated with oral cancer, human papilloma virus infection and surgical treatment

Systemic inflammatory events and localized disease, mediated by the microbiome, may be measured in saliva as head and neck squamous cell carcinoma (HNSCC) diagnostic and prognostic biomonitors. We used a 16S rRNA V3-V5 marker gene approach to compare the saliva microbiome in DNA isolated from Oropharyngeal (OPSCC), Oral Cavity Squamous Cell Carcinoma (OCSCC) patients and normal epithelium controls, to characterize the HNSCC saliva microbiota and examine their abundance before and after surgical resection.The analyses identified a predominance of Firmicutes, Proteobacteria and Bacteroidetes, with less frequent presence of Actinobacteria and Fusobacteria before surgery. At lower taxonomic levels, the most abundant genera were Streptococcus, Prevotella, Haemophilus, Lactobacillus and Veillonella, with lower numbers of Citrobacter and Neisseraceae genus Kingella. HNSCC patients had a significant loss in richness and diversity of microbiota species (p<0.05) compared to the controls. Overall, the Operational Taxonomic Units network shows that the relative abundance of OTU's within genus Streptococcus, Dialister, and Veillonella can be used to discriminate tumor from control samples (p<0.05). Tumor samples lost Neisseria, Aggregatibacter (Proteobacteria), Haemophillus (Firmicutes) and Leptotrichia (Fusobacteria). Paired taxa within family Enterobacteriaceae, together with genus Oribacterium, distinguish OCSCC samples from OPSCC and normal samples (p<0.05). Similarly, only HPV positive samples have an abundance of genus Gemellaceae and Leuconostoc (p<0.05). Longitudinal analyses of samples taken before and after surgery, revealed a reduction in the alpha diversity measure after surgery, together with an increase of this measure in patients that recurred (p<0.05). These results suggest that microbiota may be used as HNSCC diagnostic and prognostic biomonitors.

Gut Microbiota-Immune System Crosstalk and Pancreatic Disorders

Gut microbiota is key to the development and modulation of the mucosal immune system. It plays a central role in several physiological functions, in the modulation of inflammatory signaling and in the protection against infections. In healthy states, there is a perfect balance between commensal and pathogens, and microbiota and the immune system interact to maintain gut homeostasis. The alteration of such balance, called dysbiosis, determines an intestinal bacterial overgrowth which leads to the disruption of the intestinal barrier with systemic translocation of pathogens. The pancreas does not possess its own microbiota, and it is believed that inflammatory and neoplastic processes affecting the gland may be linked to intestinal dysbiosis. Increasing research evidence testifies a correlation between intestinal dysbiosis and various pancreatic disorders, but it remains unclear whether dysbiosis is the cause or an effect. The analysis of specific alterations in the microbiome profile may permit to develop novel tools for the early detection of several pancreatic disorders, utilizing samples, such as blood, saliva, and stools. Future studies will have to elucidate the mechanisms by which gut microbiota is modulated and how it tunes the immune system, in order to be able to develop innovative treatment strategies for pancreatic disorders.

Altered Toll-like receptor expression and function in HPV-associated oropharyngeal carcinoma

Toll-like receptors (TLRs) have been widely investigated due to their importance in the inflammatory response and possible links to tumor promotion/regression and prognosis. In cancers with an infective etiology, such as human papillomavirus (HPV)-associated Oropharyngeal Squamous Cell Carcinoma (OPSCC), TLR responses may be activated and play a role in tumorigenesis. Our aim was to assess the expression of all TLRs in OPSCC cell lines (both HPV+ and HPV-) by qPCR, Western Blot and flow cytometry and assess their response to TLR ligands lipopolysaccharide (LPS), LPS ultra-pure (LPS-UP) and peptidoglycan (PGN) by analyzing IL-8 and IL-6 production. We also immunostained 61 OPSCC tissue samples with anti-TLR4. Results showed lower TLR1 and TLR6 mRNA expression and higher TLR9 protein expression in HPV+ when compared to HPV-OPSCC cells. TLR4 expression did not vary by HPV status in OPSCC cells, but TLR4 expression was significantly lower in HPV+OPSCC tissues. After stimulation with PGN, only one cell line (HPV+) did not secrete IL-6 or IL-8. Furthermore, HPV+OPSCC lines showed no IL-6 or IL-8 production on treatment with LPS/LPS-UP. The data suggest changes in TLR4 signaling in HPV+OPSCC, since we have shown lower tissue expression of TLR4 and no pro-inflammatory response after stimulation with LPS and LPS-UP. Also, it suggests that OPSCC may respond to HPV infection by increased expression of TLR9. This study demonstrates differences in expression and function of TLRs in OPSCC, which are dependent on HPV status, and may indicate subversion of the innate immune response by HPV infection.

Identification and Antimicrobial Susceptibility Testing of Anaerobic Bacteria: Rubik's Cube of Clinical Microbiology?

Anaerobic bacteria have pivotal roles in the microbiota of humans and they are significant infectious agents involved in many pathological processes, both in immunocompetent and immunocompromised individuals. Their isolation, cultivation and correct identification differs significantly from the workup of aerobic species, although the use of new technologies (e.g., matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, whole genome sequencing) changed anaerobic diagnostics dramatically. In the past, antimicrobial susceptibility of these microorganisms showed predictable patterns and empirical therapy could be safely administered but recently a steady and clear increase in the resistance for several important drugs (β-lactams, clindamycin) has been observed worldwide. For this reason, antimicrobial susceptibility testing of anaerobic isolates for surveillance purposes or otherwise is of paramount importance but the availability of these testing methods is usually limited. In this present review, our aim was to give an overview of the methods currently available for the identification (using phenotypic characteristics, biochemical testing, gas-liquid chromatography, MALDI-TOF MS and WGS) and antimicrobial susceptibility testing (agar dilution, broth microdilution, disk diffusion, gradient tests, automated systems, phenotypic and molecular resistance detection techniques) of anaerobes, when should these methods be used and what are the recent developments in resistance patterns of anaerobic bacteria.

Can intestinal microbiota be associated with non-intestinal cancers?

While the role of intestinal microbiota is increasingly recognized in the etiology of digestive cancers, its effects on the development of cancer in other parts of the body have been little studied. Through new-generation sequencing, we aimed to identify an association between the structure of intestinal microbiota and the presence of eye disc tumor in Drosophila larvae. First, we observed a parental effect on the diversity and structure of bacterial communities. Second, we identified a bacterial signature (at the family level) of cancer: cancerous larvae host a significantly lower relative abundance of Bacillaceae than individuals that did not develop the tumor. Thus, for the first time, we showed that a non-digestive cancer, i.e., in the brain, could be associated with an altered composition of the gut microbial community. Finally, we discuss the potential implications of the immune system in the gut-brain axis concept to explain the long-distant effect of intestinal microbiota on brain tumors. We also highlight the potential of our results in a therapeutic perspective for brain cancer that could be generalized for other cancers.

Meta-analysis of the association between dietary inflammatory index (DII) and cancer outcomes

Proinflammatory dietary patterns have been associated with increased cancer risk and mortality. We present a systematic review and meta-analysis of the current published literature on a dietary inflammatory index (DII) score and its association with cancer risk and mortality outcomes. Published articles from online databases (PubMed, Scopus, and Embase) examining the association between DII and any cancer risk, incidence, or mortality between 1980 and November 2016 were selected for review. Results of studies meeting inclusion criteria were summarized and meta-analyzed using STATA to generate summary measures of association across studies. Sixty-three published articles were identified from the search, and following title, abstract and full-text review, twenty-four studies met inclusion criteria. All articles calculated DII scores based on study-specific food-frequency questionnaires using methodology from the same article. Of the 24 included studies, 13 were case-control, 6 were prospective cohort, 1 was a retrospective cohort, 3 were RCTs, and 1 did not specify study design. The most common cancers examined were colorectal, breast, lung, and prostate. Individuals in the highest versus lowest DII categories had 25% increased risk of overall cancer incidence (RR: 1.25, 95% CI: 1.16-1.35), 75% higher odds of cancer (OR: 1.75, 95% CI: 1.43-2.16) and 67% increased risk of cancer mortality (RR: 1.67, 95% CI: 1.13-2.48). Upon stratification for cancer type, positive associations remained (RR_breast : RR: 1.12, 95% CI: 1.03-1.22) (RR_colorectal : 1.33, 95% CI: 1.22-1.46) (RR_lung : 1.30, 95% CI: 1.13-1.50). There were consistent and significant positive associations between higher DII and cancer incidence and mortality across cancer types, study populations, and study design.

Bridging the Gap between Gut Microbial Dysbiosis and Cardiovascular Diseases

The human gut is heavily colonized by a community of microbiota, primarily bacteria, that exists in a symbiotic relationship with the host and plays a critical role in maintaining host homeostasis. The consumption of a high-fat (HF) diet has been shown to induce gut dysbiosis and reduce intestinal integrity. Recent studies have revealed that dysbiosis contributes to the progression of cardiovascular diseases (CVDs) by promoting two major CVD risk factors-atherosclerosis and hypertension. Imbalances in host-microbial interaction impair homeostatic mechanisms that regulate health and can activate multiple pathways leading to CVD risk factor progression. Dysbiosis has been implicated in the development of atherosclerosis through metabolism-independent and metabolite-dependent pathways. This review will illustrate how these pathways contribute to the various stages of atherosclerotic plaque progression. In addition, dysbiosis can promote hypertension through vascular fibrosis and an alteration of vascular tone. As CVD is the number one cause of death globally, investigating the gut microbiota as a locus of intervention presents a novel and clinically relevant avenue for future research, with vast therapeutic potential.

Human Gut Microbiota: Toward an Ecology of Disease

Composed of trillions of individual microbes, the human gut microbiota has adapted to the uniquely diverse environments found in the human intestine. Quickly responding to the variances in the ingested food, the microbiota interacts with the host via reciprocal biochemical signaling to coordinate the exchange of nutrients and proper immune function. Host and microbiota function as a unit which guards its balance against invasion by potential pathogens and which undergoes natural selection. Disturbance of the microbiota composition, or dysbiosis, is often associated with human disease, indicating that, while there seems to be no unique optimal composition of the gut microbiota, a balanced community is crucial for human health. Emerging knowledge of the ecology of the microbiota-host synergy will have an impact on how we implement antibiotic treatment in therapeutics and prophylaxis and how we will consider alternative strategies of global remodeling of the microbiota such as fecal transplants. Here we examine the microbiota-human host relationship from the perspective of the microbial community dynamics.

Key players in the immune response to biomaterial scaffolds for regenerative medicine

The compatibility of biomaterials is critical to their structural and biological function in medical applications. The immune system is the first responder to tissue trauma and to a biomaterial implant. The innate immune effector cells, most notably macrophages, play a significant role in the defense against foreign bodies and the formation of a fibrous capsule around synthetic implants. Alternatively, macrophages participate in the pro-regenerative capacity of tissue-derived biological scaffolds. Research is now elucidating the role of the adaptive immune system, and T cells in particular, in directing macrophage response to synthetic and biological materials. Here, we review basic immune cell types and discuss recent research on the role of the immune system in tissue repair and its potential relevance to scaffold design. We will also discuss new emerging immune cell types relevant to biomaterial responses and tissue repair. Finally, prospects for specifically targeting and modulating the immune response to biomaterial scaffolds for enhancing tissue repair and regeneration will be presented.

miR-29a suppresses MCF-7 cell growth by downregulating tumor necrosis factor receptor 1

Tumor necrosis factor receptor 1 is the main receptor mediating many tumor necrosis factor-alpha-induced cellular events. Some studies have shown that tumor necrosis factor receptor 1 promotes tumorigenesis by activating nuclear factor-kappa B signaling pathway, while other studies have confirmed that tumor necrosis factor receptor 1 plays an inhibitory role in tumors growth by inducing apoptosis in breast cancer. Therefore, the function of tumor necrosis factor receptor 1 in breast cancer requires clarification. In this study, we first found that tumor necrosis factor receptor 1 was significantly increased in human breast cancer tissues and cell lines, and knockdown of tumor necrosis factor receptor 1 by small interfering RNA inhibited cell proliferation by arresting the cell cycle and inducing apoptosis. In addition, miR-29a was predicted as a regulator of tumor necrosis factor receptor 1 by TargetScan and was shown to be inversely correlated with tumor necrosis factor receptor 1 expression in human breast cancer tissues and cell lines. Luciferase reporter assay further confirmed that miR-29a negatively regulated tumor necrosis factor receptor 1 expression by binding to the 3' untranslated region. In our functional study, miR-29a overexpression remarkably suppressed cell proliferation and colony formation, arrested the cell cycle, and induced apoptosis in MCF-7 cell. Furthermore, in combination with tumor necrosis factor receptor 1 transfection, miR-29a significantly reversed the oncogenic role caused by tumor necrosis factor receptor 1 in MCF-7 cell. In addition, we demonstrated that miR-29a suppressed MCF-7 cell growth by inactivating the nuclear factor-kappa B signaling pathway and by decreasing cyclinD1 and Bcl-2/Bax protein levels. Taken together, our results suggest that miR-29a is an important regulator of tumor necrosis factor receptor 1 expression in breast cancer and functions as a tumor suppressor by targeting tumor necrosis factor receptor 1 to influence the growth of MCF-7 cell.

The oral cavity microbiota: between health, oral disease, and cancers of the aerodigestive tract

Many studies show that the human microbiome plays a critical role in the chronic pathologies of obesity, inflammatory bowel diseases, and diabetes. More recently, the interaction between cancer and the microbiome has been highlighted. Most studies have focused on the gut microbiota because it represents the most extensive bacterial community, and the body of evidence correlating it with gut syndromes is increasing. However, in the strict sense, the gastrointestinal (GI) tract begins in the oral cavity, and special attention should be paid to the specific flora of this cavity. This study reviewed the current knowledge about the various microbial ecosystems of the upper part of the GI tract and discussed their potential link to carcinogenesis. The overall composition of the microbial communities, as well as the presence or absence of "key species", in relation to carcinogenesis is addressed. Alterations in the oral microbiota can potentially be used to predict the risk of cancer. Molecular advances and the further monitoring of the microbiota will increase our understanding of the role of the microbiota in carcinogenesis and open new perspectives for future therapeutic and prophylactic modalities.

p-Cresyl Sulfate

If chronic kidney disease (CKD) is associated with an impairment of kidney function, several uremic solutes are retained. Some of these exert toxic effects, which are called uremic toxins. p-Cresyl sulfate (pCS) is a prototype protein-bound uremic toxin to which many biological and biochemical (toxic) effects have been attributed. In addition, increased levels of pCS have been associated with worsening outcomes in CKD patients. pCS finds its origin in the intestine where gut bacteria metabolize aromatic amino acids, such as tyrosine and phenylalanine, leading to phenolic end products, of which pCS is one of the components. In this review we summarize the biological effects of pCS and its metabolic origin in the intestine. It appears that, according to in vitro studies, the intestinal bacteria generating phenolic compounds mainly belong to the families Bacteroidaceae, Bifidobacteriaceae, Clostridiaceae, Enterobacteriaceae, Enterococcaceae, Eubacteriaceae, Fusobacteriaceae, Lachnospiraceae, Lactobacillaceae, Porphyromonadaceae, Staphylococcaceae, Ruminococcaceae, and Veillonellaceae. Since pCS remains difficult to remove by dialysis, the gut microbiota could be a future target to decrease pCS levels and its toxicity, even at earlier stages of CKD, aiming at slowing down the progression of the disease and decreasing the cardiovascular burden.

Gut microbiome and kidney disease: a bidirectional relationship

Recent technological advances and efforts, including powerful metagenomic and metatranscriptomic analyses, have led to a tremendous growth in our understanding of microbial communities. Changes in microbial abundance or composition of human microbial communities impact human health or disease state. However, explorations into the mechanisms underlying host-microbe interactions in health and disease are still in their infancy. Although changes in the gut microbiota have been described in patients with kidney disease, the relationships between pathogenesis, mechanisms of disease progression, and the gut microbiome are still evolving. Here, we review changes in the host-microbiome symbiotic relationship in an attempt to explore the bidirectional relationship in which alterations in the microbiome affect kidney disease progression and how kidney disease may disrupt a balanced microbiome. We also discuss potential targeted interventions that may help re-establish this symbiosis and propose more effective ways to deploy traditional treatments in patients with kidney disease.