Chemoprevention in gastrointestinal physiology and disease. Natural products and microbiome

Progress in the study of curcumin metabolism in vivo

Curcumin has diverse biological functions, especially antioxidant and anti-inflammatory properties, but clinical trials have been hindered by its low bioavailability and pharmacokinetic properties. To achieve therapeutic efficacy, understanding curcumin's in vivo metabolism is crucial. We reviewed current research on curcumin metabolism in PubMed, Google Scholar, and CNKI. This article outlines curcumin's metabolic processes in the body via oral and intravenous injection. It suggests that upon entering the human body, curcumin may undergo oxidation, reduction, binding, and microbial community influence.

Small Intestinal Bacterial Overgrowth

Purpose of review

Small intestinal bacterial overgrowth (SIBO) is a chronic gastrointestinal disorder wherein excessive and abnormal growth of bacteria in the small bowel generally causes abdominal pain, bloating, and change in bowel habits. Our understanding of the underlying pathology and microbiome changes in SIBO has advanced greatly in the last 20 years in parallel with advances in treatment methods and diagnostics. Here, we review many of the latest findings that describe the pathophysiology of SIBO as well as its risk factors, clinical behavior, diagnosis, and management.

Recent findings

Studies have begun to employ advanced molecular assays to sequence the small bowel microbiome to reveal the changes evident in SIBO. An increase in the abundance of members of the Enterobacteriaceae is the main alteration to the gut microbiome that correlates with SIBO diagnosis and symptom severity, and enhancement of specific gas-producing pathways has been demonstrated in SIBO. Diagnostic methods continue to evolve with novel methods of small bowel aspiration and changes to interpretation of hydrogen breath tests. Elemental diets are the newest treatment modality that offer an exciting alternative to antibiotic therapy.

Summary

The study of SIBO provides valuable insights into the small bowel microbiome, particularly using molecular testing. Exciting changes to our understanding and treatment of SIBO are already in progress. Future work will be able to better elucidate not only the altered microbiology, but also its gold standard of diagnosis, treatment modalities, and secondary prevention.

The Gut Microbiota Impacts Gastrointestinal Cancers through Obesity, Diabetes, and Chronic Inflammation

The gut microbiota's pivotal role in human health is increasingly evident, particularly in chronic conditions like obesity, diabetes, and inflammatory diseases. This intricate symbiotic relationship influences metabolic balance and immune responses. Notably, gut microbial dysbiosis is linked to obesity's metabolic disruption and chronic low-grade inflammation. Similarly, in diabetes, the microbiota's impact on insulin resistance and glucose metabolism is becoming evident. Chronic inflammation, a common denominator in these conditions, is also a recognized precursor to carcinogenesis. This intersection prompts a compelling question: does the gut microbiota's influence extend to gastrointestinal cancers like colorectal and pancreatic cancer? These malignancies are closely intertwined with inflammation and metabolic dysregulation. Exploring whether the microbial signatures associated with chronic conditions overlap with precancerous or cancerous states offers new perspectives. This article reviews emerging evidence on the interplay between the gut microbiota, chronic conditions, and gastrointestinal cancers. By elucidating these connections, we aim to uncover potential avenues for innovative diagnostic, preventative, and therapeutic strategies in colorectal and pancreatic cancer management.

miRNA, phytometabolites and disease: Connecting the dots

miRNAs are tiny noncoding ribonucleotides that function as critical regulators of gene-expression in eukaryotes. A single miRNA may be involved in the regulation of several target mRNAs forming complex cellular networks to regulate diverse aspects of development in an organism. The deregulation of miRNAs has been associated with several human diseases. Therefore, miRNA-based therapeutics is gaining interest in the pharmaceutical industry as the next-generation drugs for the cure of many diseases. Medicinal plants have also been used for the treatment of several human diseases and their curative potential is attributed to their reserve in bioactive metabolites. A role for miRNAs as regulators of the phytometabolic pathways in plants has emerged in the recent past. Experimental studies have also indicated the potential of plant encoded secondary phytometabolites to act as cross-regulators of mammalian miRNAs and transcripts to regulate human diseases (like cancer). The evidence for this cross-kingdom gene regulation through miRNA has gathered considerable enthusiasm in the scientific field, even though there are on-going debates regarding the reproducibility and the effectiveness of these findings. In this review, we provide information to connect the medicinal and gene regulatory properties of secondary phytometabolites, their regulation by miRNAs in plants and their effects on human miRNAs for regulating downstream metabolic or pathological processes. While further extensive research initiatives and good clinical evidence are required to prove or disapprove these findings, understanding of these regulations will have important implications in the potential use of synthetic or artificial miRNAs as effective alternatives for providing health benefits.

Molecular crosstalk between polyphenols and gut microbiota in cancer prevention

A growing body of evidence suggests that cancer remains a significant global health challenge, necessitating the development of novel therapeutic approaches. In recent years, the molecular crosstalk between polyphenols and gut microbiota has emerged as a promising pathway for cancer prevention. Polyphenols, abundant in many plant-based foods, possess diverse bioactive properties, including antioxidant, anti-inflammatory, and anticancer activities. The gut microbiota, a complex microbial community residing in the gastrointestinal tract, plays a crucial role in a host's health and disease risks. This review highlights cancer suppressive and oncogenic mechanisms of gut microbiota, the intricate interplay between gut microbiota modulation and polyphenol biotransformation, and the potential therapeutic implications of this interplay in cancer prevention. Furthermore, this review explores the molecular mechanisms underpinning the synergistic effects of polyphenols and the gut microbiota, such as modulation of signaling pathways and immune response and epigenetic modifications in animal and human studies. The current review also summarizes the challenges and future directions in this field, including the development of personalized approaches that consider interindividual variations in gut microbiota composition and function. Understanding the molecular crosstalk could offer new perspectives for the development of personalized cancer therapies targeting the polyphenol-gut axis. Future clinical trials are needed to validate the potential role of polyphenols and gut microbiota as innovative therapeutic strategies for cancer treatment.

Unraveling the intricate relationship: Influence of microbiome on the host immune system in carcinogenesis

BACKGROUND

Cancer is an outcome of various disrupted or dysregulated metabolic processes like apoptosis, growth, and self-cell transformation. Human anatomy harbors trillions of microbes, and these microbes actively influence all kinds of human metabolic activities, including the human immune response. The immune system which inherently acts as a sentinel against microbes, curiously tolerates and even maintains a distinct normal microflora in our body. This emphasizes the evolutionarily significant role of microbiota in shaping our adaptive immune system and even potentiating its function in chronic ailments like cancers. Microbes interact with the host immune cells and play a part in cancer progression or regression by modulating immune cells, producing immunosuppressants, virulence factors, and genotoxins.

RECENT FINDINGS

An expanding plethora of studies suggest and support the evidence of microbiome impacting cancer etiology. Several studies also indicate that the microbiome can supplement various cancer therapies, increasing their efficacy. The present review discusses the relationship between bacterial and viral microbiota with cancer, discussing different carcinogenic mechanisms influenced by prokaryotes with special emphasis on their immunomodulatory axis. It also elucidates the potential of the microbiome in transforming the efficacy of immunotherapeutic treatments.

CONCLUSION

This review offers a thorough overview of the complex interaction between the human immune system and the microbiome and its impact on the development of cancer. The microbiome affects the immune responses as well as progression of tumor transformation, hence microbiome-based therapies can vastly improve the effectiveness of cancer immunotherapies. Individual variations of the microbiome and its dynamic variability in every individual impacts the immune modulation and cancer progression. Therefore, further research is required to understand these underlying processes in detail, so as to design better microbiome-immune system axis in the treatment of cancer.

Nutrition in Alzheimer's disease: a review of an underappreciated pathophysiological mechanism

Alzheimer's disease (AD) is the leading cause of dementia in older individuals and is an escalating challenge to global public health. Pharmacy therapy of AD is one of the well-funded areas; however, little progress has been made due to the complex pathogenesis. Recent evidence has demonstrated that modifying risk factors and lifestyle may prevent or delay the incidence of AD by 40%, which suggests that the management should pivot from single pharmacotherapy toward a multipronged approach because AD is a complex and multifaceted disease. Recently, the gut-microbiota-brain axis has gained tremendous traction in the pathogenesis of AD through bidirectional communication with multiple neural, immune, and metabolic pathways, providing new insights into novel therapeutic strategies. Dietary nutrition is an important and profound environmental factor that influences the composition and function of the microbiota. The Nutrition for Dementia Prevention Working Group recently found that dietary nutrition can affect cognition in AD-related dementia directly or indirectly through complex interactions of behavioral, genetic, systemic, and brain factors. Thus, considering the multiple etiologies of AD, nutrition represents a multidimensional factor that has a profound effect on AD onset and development. However, mechanistically, the effect of nutrition on AD is uncertain; therefore, optimal strategies or the timing of nutritional intervention to prevent or treat AD has not been established.Thus, this review summarizes the current state of knowledge concerning nutritional disorders, AD patient and caregiver burden, and the roles of nutrition in the pathophysiology of AD. We aim to emphasize knowledge gaps to provide direction for future research and to establish optimal nutrition-based intervention strategies for AD.

Plant Polyphenols as Inhibitors of Hydrolases are Regulators of Digestion

BACKGROUND

There are numerous reports on the use of polyphenol-containing foods and various medicinal plant preparations for the prophylaxis and therapy of metabolic diseases, such as metabolic syndrome and diabetes mellitus, respectively. One unifying aspect to the effect of these natural compounds is their ability to inhibit digestive enzymes, which is the focus of this review.

SUMMARY

Polyphenols inhibit nonspecifically hydrolytic enzymes included in the digestion process, e.g., amylases, proteases, lipases. By that, the digestion process is protracted with different consequences as result of the incomplete absorption of monosaccharides, fatty acids, and amino acids as well as for the enhanced availability of substrates for the microbiome in ileum and colon. The resulting postprandial blood concentration of monosaccharides, fatty, and amino acids is lowered and by that different metabolic pathways proceed more slowly. As another positive result, polyphenols can also modulate the intestinal microbiome and thus mediate additional beneficial health effects.

KEY MESSAGES

Many medicinal plants possess a broad spectrum of different polyphenols, thereby mediating the nonspecific inhibition of all hydrolytic enzyme activities in the gastrointestinal digestive process. As a consequence of the slowing down of digestive processes, risk factors for the development of metabolic disorders are reduced and the health of the patients with metabolic syndrome improves.

Hintergrund

Es gibt zahlreiche Berichte über die Verwendung von polyphenolhaltigen Lebensmitteln und verschiedenen Arzneilpflanzenpräparaten zur Prophylaxe und Therapie von Stoffwechselkrankheiten wie dem metabolischen Syndrom und Diabetes mellitus. Ein übergreifender Aspekt der Wirkung dieser Naturstoffe ist ihre Fähigkeit, Verdauungsenzyme zu hemmen, was im Mittelpunkt dieser Übersicht steht.

Zusammenfassung

Polyphenole hemmen unspezifisch hydrolytische Enzyme, die am Verdauungsprozess beteiligt sind, z.B. Amylasen, Proteasen, Lipasen. Dadurch wird der Verdauungsprozess verzögert, was sich in einer unvollständigen Resorption von Monosacchariden, Fettsäuren und Aminosäuren sowie in einer erhöhten Verfügbarkeit von Substraten für das Mikrobiom im Ileum und Kolon äußert. Dadurch wird die postprandiale Blutkonzentration von Monosacchariden, Fettsäuren und Aminosäuren gesenkt und verschiedene Stoffwechselwege laufen langsamer ab. Ein weiteres positives Ergebnis ist, dass Polyphenole auch das intestinale Mikrobiom modulieren können und damit zusätzliche positive Gesundheitseffekte vermitteln.

Kernaussagen

Viele Arzneipflanzen verfügen über ein breites Spektrum verschiedener Polyphenole, die eine unspezifische Hemmung aller hydrolytischen Enzymaktivitäten im gastrointestinalen Verdauungsprozess bewirken. Durch die Verlangsamung der Verdauungsprozesse werden Risikofaktoren für die Entwicklung von Stoffwechselstörungen reduziert und der Gesundheitszustand von Patienten mit metabolischem Syndrom verbessert.

Phenolic Phytochemicals for Prevention and Treatment of Colorectal Cancer: A Critical Evaluation of In Vivo Studies

Colorectal cancer (CRC) is the third most diagnosed and second leading cause of cancer-related death worldwide. Limitations with existing treatment regimens have demanded the search for better treatment options. Different phytochemicals with promising anti-CRC activities have been reported, with the molecular mechanism of actions still emerging. This review aims to summarize recent progress on the study of natural phenolic compounds in ameliorating CRC using in vivo models. This review followed the guidelines of the Preferred Reporting Items for Systematic Reporting and Meta-Analysis. Information on the relevant topic was gathered by searching the PubMed, Scopus, ScienceDirect, and Web of Science databases using keywords, such as "colorectal cancer" AND "phenolic compounds", "colorectal cancer" AND "polyphenol", "colorectal cancer" AND "phenolic acids", "colorectal cancer" AND "flavonoids", "colorectal cancer" AND "stilbene", and "colorectal cancer" AND "lignan" from the reputed peer-reviewed journals published over the last 20 years. Publications that incorporated in vivo experimental designs and produced statistically significant results were considered for this review. Many of these polyphenols demonstrate anti-CRC activities by inhibiting key cellular factors. This inhibition has been demonstrated by antiapoptotic effects, antiproliferative effects, or by upregulating factors responsible for cell cycle arrest or cell death in various in vivo CRC models. Numerous studies from independent laboratories have highlighted different plant phenolic compounds for their anti-CRC activities. While promising anti-CRC activity in many of these agents has created interest in this area, in-depth mechanistic and well-designed clinical studies are needed to support the therapeutic use of these compounds for the prevention and treatment of CRC.

Spice-Derived Bioactive Compounds Confer Colorectal Cancer Prevention via Modulation of Gut Microbiota

Colorectal cancer (CRC) is the second most frequent cause of cancer-related mortality among all types of malignancies. Sedentary lifestyles, obesity, smoking, red and processed meat, low-fiber diets, inflammatory bowel disease, and gut dysbiosis are the most important risk factors associated with CRC pathogenesis. Alterations in gut microbiota are positively correlated with colorectal carcinogenesis, as these can dysregulate the immune response, alter the gut's metabolic profile, modify the molecular processes in colonocytes, and initiate mutagenesis. Changes in the daily diet, and the addition of plant-based nutraceuticals, have the ability to modulate the composition and functionality of the gut microbiota, maintaining gut homeostasis and regulating host immune and inflammatory responses. Spices are one of the fundamental components of the human diet that are used for their bioactive properties (i.e., antimicrobial, antioxidant, and anti-inflammatory effects) and these exert beneficial effects on health, improving digestion and showing anti-inflammatory, immunomodulatory, and glucose- and cholesterol-lowering activities, as well as possessing properties that affect cognition and mood. The anti-inflammatory and immunomodulatory properties of spices could be useful in the prevention of various types of cancers that affect the digestive system. This review is designed to summarize the reciprocal interactions between dietary spices and the gut microbiota, and highlight the impact of dietary spices and their bioactive compounds on colorectal carcinogenesis by targeting the gut microbiota.

Microbial dysbiosis and epigenetics modulation in cancer development - A chemopreventive approach

An overwhelming number of research articles have reported a strong relationship of the microbiome with cancer. Microbes have been observed more commonly in the body fluids like urine, stool, mucus of people with cancer compared to the healthy controls. The microbiota is responsible for both progression and suppression activities of various diseases. Thus, to maintain healthy human physiology, host and microbiota relationship should be in a balanced state. Any disturbance in this equilibrium, referred as microbiome dysbiosis becomes a prime cause for the human body to become more prone to immunodeficiency and cancer. It is well established that some of these microbes are the causative agents, whereas others may encourage the formation of tumours, but very little is known about how these microbial communications causing change at gene and epigenome level and trigger as well as encourage the tumour growth. Various studies have reported that microbes in the gut influence DNA methylation, DNA repair and DNA damage. The genes and pathways that are altered by gut microbes are also associated with cancer advancement, predominantly those implicated in cell growth and cell signalling pathways. This study exhaustively reviews the current research advancements in understanding of dysbiosis linked with colon, lung, ovarian, breast cancers and insights into the potential molecular targets of the microbiome promoting carcinogenesis, the epigenetic alterations of various potential targets by altered microbiota, as well as the role of various chemopreventive agents for timely prevention and customized treatment against various types of cancers.

Targeting the Gut Microbiome for Inflammation and Pain Management in Orthopedic Conditions

The human gut microbiome can be altered with probiotics, prebiotics, synbiotics, and anti-inflammatory foods and spices as part of an evidence-based strategy that targets inflammation and pain in common orthopedic conditions. Implementing these strategies avoids adverse effects associated with nonsteroidal anti-inflammatory drugs and minimizes the potential for opioid use. This review focuses exclusively on human trials studying the effects of gut microbiome alterations to address pain and inflammatory markers in common orthopedic conditions: osteoarthritis, rheumatoid arthritis, fractures/osteoporosis, and bone pain associated with chemotherapy. Individualized supplementation strategies can be further explored with the information in this review. [Orthopedics. 2022;45(5):e226-e234.].

Polyphenols and Small Phenolic Acids as Cellular Metabolic Regulators

Polyphenols and representative small phenolic acids and molecules derived from larger constituents are dietary antioxidants from fruits, vegetables and largely other plant-based sources that have ability to scavenge free radicals. What is often neglected in polyphenol metabolism is bioavailability and the role of the gut microbiota (GMB), which has an essential role in health and disease and participates in co-metabolism with the host. The composition of the gut microbiota is in constant flux and is modified by multiple intrinsic and extrinsic factors, including antibiotics. Dietary or other factors are key modulators of the host gut milieu. In this review, we explore the role of polyphenols and select phenolic compounds as metabolic or intrinsic biochemistry regulators and explore this relationship in the context of the microbiota–gut–target organ axis in health and disease.

Modulating Microbiota as a New Strategy for Breast Cancer Prevention and Treatment

Breast cancer (BC) is the most common cancer in women in the United States. There has been an increasing incidence and decreasing mortality rate of BC cases over the past several decades. Many risk factors are associated with BC, such as diet, aging, personal and family history, obesity, and some environmental factors. Recent studies have shown that healthy individuals and BC patients have different microbiota composition, indicating that microbiome is a new risk factor for BC. Gut and breast microbiota alterations are associated with BC prognosis. This review will evaluate altered microbiota populations in gut, breast tissue, and milk of BC patients, as well as mechanisms of interactions between microbiota modulation and BC. Probiotics and prebiotics are commercially available dietary supplements to alleviate side-effects of cancer therapies. They also shape the population of human gut microbiome. This review evaluates novel means of modulating microbiota by nutritional treatment with probiotics and prebiotics as emerging and promising strategies for prevention and treatment of BC. The mechanistic role of probiotic and prebiotics partially depend on alterations in estrogen metabolism, systematic immune regulation, and epigenetics regulation.

Interactions between dietary polyphenols and aging gut microbiota: A review

Aging induces significant shifts in the composition of gut microbiota associated with decreased microbial diversity. Age-related changes in gut microbiota include a loss of commensals and an increase in disease-associated pathobionts. These alterations are accelerated by lifestyle factors, such as poor nutritional habits, physical inactivity, and medications. Given that diet is one of the main drivers shaping the gut microbiota, nutritional interventions for restoring gut homeostasis are of great importance to the overall health of older adults. Polyphenols, ubiquitously present in fruits and vegetables, have emerged as promising anti-aging candidates because of their ability to modulate some of the common denominators of aging, including gut dysbiosis. These compounds can influence the composition of the gut microbiota, and gut bacteria metabolize polyphenols into bioactive compounds that produce relevant health effects. Although the role of polyphenols on the aging gut has not been fully characterized, accumulating evidence suggests that these compounds exert selective effects on the gut microbial community. Here, we discuss the reciprocal interactions between polyphenols and gut microbiota and summarize the latest findings on the effects of polyphenols on modulating intestinal bacteria during aging.

Interaction between Gut Microbiota and Curcumin: A New Key of Understanding for the Health Effects of Curcumin

Curcumin, a lipophilic polyphenol contained in the rhizome of Curcuma longa (turmeric), has been used for centuries in traditional Asian medicine, and nowadays it is widely used in food as dietary spice worldwide. It has received considerable attention for its pharmacological activities, which appear to act primarily through anti-inflammatory and antioxidant mechanisms. For this reason, it has been proposed as a tool for the management of many diseases, among which are gastrointestinal and neurological diseases, diabetes, and several types of cancer. However, the pharmacology of curcumin remains to be elucidated; indeed, a discrepancy exists between the well-documented in vitro and in vivo activities of curcumin and its poor bioavailability and chemical instability that should limit any therapeutic effect. Recently, it has been hypothesized that curcumin could exert direct regulative effects primarily in the gastrointestinal tract, where high concentrations of this polyphenol have been detected after oral administration. Consequently, it might be hypothesized that curcumin directly exerts its regulatory effects on the gut microbiota, thus explaining the paradox between its low systemic bioavailability and its wide pharmacological activities. It is well known that the microbiota has several important roles in human physiology, and its composition can be influenced by a multitude of environmental and lifestyle factors. Accordingly, any perturbations in gut microbiome profile or dysbiosis can have a key role in human disease progression. Interestingly, curcumin and its metabolites have been shown to influence the microbiota. It is worth noting that from the interaction between curcumin and microbiota two different phenomena arise: the regulation of intestinal microflora by curcumin and the biotransformation of curcumin by gut microbiota, both of them potentially crucial for curcumin activity. This review summarizes the most recent studies on this topic, highlighting the strong connection between curcumin and gut microbiota, with the final aim of adding new insight into the potential mechanisms by which curcumin exerts its effects.

Microbiome dysbiosis in cancer: Exploring therapeutic strategies to counter the disease

Cancer being a multiplex disease which involves many genomic and physiological alterations that occur consistently in the cancerous tissue, making the treatment and management of the disease even more complicated. The human gut microbiota (GM) harbors collective genomes of microbes comprising of trillions of bacteria along with fungi, archaea, and viruses that have the tendency to affect the development and progression of cancer. Moreover, inter-microbial interactions, diversity and distinct differences among the GM populations could influence the course of disease, making the microbiome an ideal target or to be modulated in such a way so as to improve cancer therapeutics with better efficacy and reduced toxicity. Current review focuses upon exploring the association of gut microbiota with the progression of cancer for which a structured search of bibliographic databases for peer-reviewed research literature has been carried out using focused review questions and inclusion/exclusion criteria. Through this review one could envisage a wide-spectrum role of microbiota in maintaining host metabolism, immune homeostasis paving the way for an anticancer diagnostic and therapeutic solution that has the potential to counter the menace of anti-cancer drug resistance as well.

Selected Indonesian Medicinal Plants for the Management of Metabolic Syndrome: Molecular Basis and Recent Studies

Increased prevalence of metabolic syndrome (MetS) in the world influences quality of health in all respective countries, including Indonesia. Data from Indonesian Family Life Survey reported in 2019 showed that the prevalence of MetS in Indonesia currently is 21.66%, estimated with the provincial incidence ranging up to 50%; additionally, the most common components of MetS discovered in Indonesia were poor high-density lipoprotein (HDL) cholesterol and hypertension. Management treatment of MetS involves a combination of lifestyle changes and pharmacological interventions to decrease cerebrovascular disease. Various natural substances have been shown to govern any cardiovascular or metabolic disorders through different mechanisms, such as triggering anti-inflammation, lipid profile correction, sensitization of insulin reception, or blood glucose control. In Indonesia, the utilization of natural compounds is part of the nation's culture. The community widely uses them; even though in general, their effectiveness and safety have not been thoroughly assessed by rigorous clinical trials. Scientific evidence suggested that cinnamon, mangosteen, and curcumin, as well as their derived components possess a broad spectrum of pharmacological activity. In this review, an enormous potential of cinnamon, mangosteen, and curcumin, which originated and are commonly used in Indonesia, could be treated against MetS, such as diabetes, hyperlipidemia, hypertension, and obesity. The findings suggested that cinnamon, mangosteen, curcumin and their derivatives may reflect areas of promise in the management of MetS.

Mutual Two-Way Interactions of Curcumin and Gut Microbiota

Curcumin, an herbal naturally occurring polyphenol, has recently been proposed for the treatment of neurodegenerative, neurological and cancer diseases due to its pleiotropic effect. Recent studies indicated that dysbiosis is associated with the abovementioned and other diseases, and gut microflora may be a new potential therapeutic target. The new working hypothesis that could explain the curative role of curcumin, despite its limited availability, is that curcumin acts indirectly on the brain, affecting the “gut–brain–microflora axis”, a complex two-way system in which the gut microbiome and its composition, are factors that preserve and determine brain health. It is therefore suspected that curcumin and its metabolites have a direct regulatory effect on gut microflora and vice versa, which may explain the paradox between curcumin’s poor bioavailability and its commonly reported therapeutic effects. Curcumin and its metabolites can have health benefits by eliminating intestinal microflora dysbiosis. In addition, curcumin undergoes enzymatic modifications by bacteria, forming pharmacologically more active metabolites than their parent, curcumin. In this review, we summarize a number of studies that highlight the interaction between curcumin and gut microbiota and vice versa, and we consider the possibility of microbiome-targeted therapies using curcumin, particularly in disease entities currently without causal treatment.

Natural products: An upcoming therapeutic approach to cancer

Cancer is one of the leading causes of death across the world. Different environmental and anthropogenic factors initiate mutations in different functional genes of growth factors and their receptors, anti-apoptotic proteins, self-renewal developmental proteins, tumor suppressors, transcription factors, etc. This phenomenon leads to altered protein homeostasis of the cell which in turn induces cancer initiation, development, progression and survival. From ancient times various natural products have been used as traditional medicine against different diseases. Natural products are readily applicable, inexpensive, accessible and acceptable therapeutic approach with minimum cytotoxicity. As most of the target-specific anticancer drugs failed to achieve the expected result so far, new multi-targeted therapies using natural products have become significant. In this review, we have summarized the efficacy of different natural compounds against cancer. They are capable of modulating cancer microenvironment and diverse cell signaling cascades; thus playing a major role in combating cancer. These compounds are found to be effective against several signaling pathways, mainly cell death pathways (apoptosis and autophagy) and embryonic developmental pathways (Notch pathway, Wnt pathway and Hedgehog pathway). This review article is expected to be helpful in understanding the recent progress of natural product research for the development of anticancer drug.

Piperlongumine, a piper alkaloid targets Ras/PI3K/Akt/mTOR signaling axis to inhibit tumor cell growth and proliferation in DMH/DSS induced experimental colon cancer

Colorectal cancer (CRC) is the most common carcinoma of the digestive tract. The slow growing nature of CRC offers a great opportunity for prevention strategies. The concept of chemoprevention of colorectal cancer using plant derived natural products is gaining substantial attention because it is an inherently safe and cost-effective alternative to conventional cancer therapies. Piperlongumine (PL), a natural alkaloid present in Piper longum Linn has been reported to exhibit notable anticancer effects in various in vitro studies. Nonetheless, the chemopreventive potential of PL has not been studied in experimentally induced colon cancer yet. Ras/PI3K/Akt/mTOR signaling axis plays a central role in promoting tumor cell growth, proliferation and survival by inhibiting apoptosis. In the present study, we demonstrated, for the first time, the chemopreventive effects of PL in DMH + DSS induced colon carcinogenesis animal model. We showed that PL displayed potent antineoplastic activity against colon cancer cell growth by targeting Ras proteins and PI3K/Akt signaling cascade. PL mediated inhibition of tumor cell growth was associated with inhibition of Ras protein levels and its preferred companion protein PI3K levels that led to suppressed activity of Akt/NF-κB, c-Myc and cyclin D1. It was also found that PL arrested the cell cycle progression at G2/M phase and induced mitochondrial apoptotic pathway by downregulating Bcl-2 levels. Furthermore, the results of liver and kidney toxicity suggested that PL exhibit no toxicity in animals. Our results suggest that PL may be an effective chemopreventive agent for colon cancer.

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.

Human Gut Microbiota and Gastrointestinal Cancer

Human gut microbiota play an essential role in both healthy and diseased states of humans. In the past decade, the interactions between microorganisms and tumors have attracted much attention in the efforts to understand various features of the complex microbial communities, as well as the possible mechanisms through which the microbiota are involved in cancer prevention, carcinogenesis, and anti-cancer therapy. A large number of studies have indicated that microbial dysbiosis contributes to cancer susceptibility via multiple pathways. Further studies have suggested that the microbiota and their associated metabolites are not only closely related to carcinogenesis by inducing inflammation and immune dysregulation, which lead to genetic instability, but also interfere with the pharmacodynamics of anticancer agents. In this article, we mainly reviewed the influence of gut microbiota on cancers in the gastrointestinal (GI) tract (including esophageal, gastric, colorectal, liver, and pancreatic cancers) and the regulation of microbiota by diet, prebiotics, probiotics, synbiotics, antibiotics, or the Traditional Chinese Medicine. We also proposed some new strategies in the prevention and treatment of GI cancers that could be explored in the future. We hope that this review could provide a comprehensive overview of the studies on the interactions between the gut microbiota and GI cancers, which are likely to yield translational opportunities to reduce cancer morbidity and mortality by improving prevention, diagnosis, and treatment.

Human Gut Microbiota and Gastrointestinal Cancer

Human gut microbiota play an essential role in both healthy and diseased states of humans. In the past decade, the interactions between microorganisms and tumors have attracted much attention in the efforts to understand various features of the complex microbial communities, as well as the possible mechanisms through which the microbiota are involved in cancer prevention, carcinogenesis, and anti-cancer therapy. A large number of studies have indicated that microbial dysbiosis contributes to cancer susceptibility via multiple pathways. Further studies have suggested that the microbiota and their associated metabolites are not only closely related to carcinogenesis by inducing inflammation and immune dysregulation, which lead to genetic instability, but also interfere with the pharmacodynamics of anticancer agents. In this article, we mainly reviewed the influence of gut microbiota on cancers in the gastrointestinal (GI) tract (including esophageal, gastric, colorectal, liver, and pancreatic cancers) and the regulation of microbiota by diet, prebiotics, probiotics, synbiotics, antibiotics, or the Traditional Chinese Medicine. We also proposed some new strategies in the prevention and treatment of GI cancers that could be explored in the future. We hope that this review could provide a comprehensive overview of the studies on the interactions between the gut microbiota and GI cancers, which are likely to yield translational opportunities to reduce cancer morbidity and mortality by improving prevention, diagnosis, and treatment.

The skin microbiome and immune system: Potential target for chemoprevention?

There has been increasing interest in understanding the role of the human microbiome in skin diseases. Microbiome studies are being utilized in skin cancer research in numerous ways. Commensal bacteria are being studied as a potential tool to judge the biggest environmental risk of skin cancer, ultraviolet (UV) radiation. Owing to the recognized link of skin microbes in the process of inflammation, there have been theories linking commensal bacteria to skin cancer. Viral metagenomics has also provided insight into virus linked forms of skin cancers. Speculations can be drawn for skin microbiome that in a manner similar to gut microbiome, they can be involved in chemoprevention of skin cancer. Nonetheless, there are definitely huge gaps in our knowledge of the relationship of microbiome and skin cancers, especially in relation to chemoprevention. The utilization of microbiome in skin cancer research seems to be a promising field and may help yield novel skin cancer prevention and treatment options. This review focuses on recent utilization of the microbiome in skin cancer research, and it explores the potential of utilizing the microbiome in prevention, earlier diagnosis, and treatment of skin cancers.

Colonic Mucosal Bacteria Are Associated with Inter-Individual Variability in Serum Carotenoid Concentrations

BACKGROUND

Relatively high serum carotenoid levels are associated with reduced risks of chronic diseases, but inter-individual variability in serum carotenoid concentrations is modestly explained by diet. The bacterial community in the colon could contribute to the bioaccessibility of carotenoids by completing digestion of plant cells walls and by modulating intestinal permeability.

OBJECTIVE

To evaluate whether colonic bacterial composition is associated with serum and colon carotenoid concentrations.

DESIGN

The study was a randomized dietary intervention trial in healthy individuals who were at increased risk of colon cancer. Colon mucosal biopsy samples were obtained before and after 6 months of intervention without prior preparation of the bowels.

PARTICIPANTS/SETTING

Participants were recruited from Ann Arbor, MI, and nearby areas from July 2007 to November 2010. Biopsy data were available from 88 participants at baseline and 82 participants after 6 months.

METHODS

Study participants were randomized to counseling for either a Mediterranean diet or a Healthy Eating diet for 6 months.

RESULTS

At baseline, bacterial communities in biopsy samples from study participants in the highest vs the lowest tertile of total serum carotenoid levels differed by several parameters. Linear discriminant analysis effect size identified 11 operational taxonomic units that were significantly associated with higher serum carotenoid levels. In linear regression analyses, three of these accounted for an additional 12% of the variance in serum total carotenoid concentrations after including body mass index, smoking, and dietary intakes in the model. These factors together explained 36% of the inter-individual variance in serum total carotenoid concentrations. The bacterial community in the colonic mucosa, however, was resistant to change after dietary intervention with either a Mediterranean diet or Healthy Eating diet, each of which doubled fruit and vegetable intakes.

CONCLUSIONS

The colonic mucosal bacterial community was associated with serum carotenoid concentrations at baseline but was not appreciably changed by dietary intervention.

Small molecules related to adrenomedullin reduce tumor burden in a mouse model of colitis-associated colon cancer

To investigate the contribution of adrenomedullin (AM) and its gene-related peptide, proadrenomedullin N-terminal 20 peptide (PAMP), to the progression and potential treatment of colon cancer we studied the effects of four small molecules (SM) related to AM and PAMP on a mouse model of colon cancer. For each SM, four experimental groups of male mice were used: (i) Control group; (ii) SM group; (iii) DSS group (injected with azoxymethane [AOM] and drank dextran sulfate sodium [DSS]); and (iv) DSS + SM group (treated with AOM, DSS, and the SM). None of the mice in groups i and ii developed tumors, whereas all mice in groups iii and iv developed colon neoplasias. No significant differences were found among mice treated with PAMP modulators (87877 and 106221). Mice that received the AM negative modulator, 16311, had worse colitis symptoms than their control counterparts, whereas mice injected with the AM positive modulator, 145425, had a lower number of tumors than their controls. SM 145425 regulated the expression of proliferation marker Lgr5 and had an impact on microbiota, preventing the DSS-elicited increase of the Bacteroides/Prevotella ratio. These results suggest that treatment with AM or with positive modulator SMs may represent a novel strategy for colon cancer.

Exploring the Association between Alzheimer's Disease, Oral Health, Microbial Endocrinology and Nutrition

Longitudinal monitoring of patients suggests a causal link between chronic periodontitis and the development of Alzheimer’s disease (AD). However, the explanation of how periodontitis can lead to dementia remains unclear. A working hypothesis links extrinsic inflammation as a secondary cause of AD. This hypothesis suggests a compromised oral hygiene leads to a dysbiotic oral microbiome whereby Porphyromonas gingivalis, a keystone periodontal pathogen, with its companion species, orchestrates immune subversion in the host. Brushing and chewing on teeth supported by already injured soft tissues leads to bacteremias. As a result, a persistent systemic inflammatory response develops to periodontal pathogens. The pathogens, and the host’s inflammatory response, subsequently lead to the initiation and progression of multiple metabolic and inflammatory co-morbidities, including AD. Insufficient levels of essential micronutrients can lead to microbial dysbiosis through the growth of periodontal pathogens such as demonstrated for P. gingivalis under low hemin bioavailability. An individual’s diet also defines the consortium of microbial communities that take up residency in the oral and gastrointestinal (GI) tract microbiomes. Their imbalance can lead to behavioral changes. For example, probiotics enriched in Lactobacillus genus of bacteria, when ingested, exert some anti-inflammatory influence through common host/bacterial neurochemicals, both locally, and through sensory signaling back to the brain. Early life dietary behaviors may cause an imbalance in the host/microbial endocrinology through a dietary intake incompatible with a healthy GI tract microbiome later in life. This imbalance in host/microbial endocrinology may have a lasting impact on mental health. This observation opens up an opportunity to explore the mechanisms, which may underlie the previously detected relationship between diet, oral/GI microbial communities, to anxiety, cognition and sleep patterns. This review suggests healthy diet based interventions that together with improved life style/behavioral changes may reduce and/or delay the incidence of AD.

Black Raspberries and Their Anthocyanin and Fiber Fractions Alter the Composition and Diversity of Gut Microbiota in F-344 Rats

Natural compounds can alter the diversity and composition of the gut microbiome, potentially benefiting our health. We previously demonstrated chemopreventive effects of black raspberries (BRBs) in colorectal cancer, which is associated with gut dysbiosis. To investigate the effects of whole BRBs and their fractions on gut microbiota, we fed F-344 rats a control diet, 5% BRBs, the BRB anthocyanin fraction, or the BRB residue fraction for 6 weeks. Feces were collected at baseline and at weeks 3 and 6, and bacterial sequence counts were analyzed. We observed distinct patterns of microbiota from different diet groups. Beta diversity analysis suggested that all diet groups exerted time-dependent changes in the bacterial diversity. Hierarchical clustering analysis revealed that post-diet fecal microbiota was segregated from baseline fecal microbiota within each diet. It is interesting to note that fractions of BRBs induced different changes in gut bacteria compared to whole BRBs. The abundance of specific microbial species known to have anti-inflammatory effects, such as Akkermansia and Desulfovibrio, was increased by whole BRBs and their residue. Further, butyrate-producing bacteria, e.g., Anaerostipes, were increased by whole BRBs. Our results suggest that whole BRBs and their fractions alter the gut microbiota in ways that could significantly influence human health.

Cautiously using natural medicine to treat liver problems

Natural medicine is a system of therapy that administrates natural agents and their derivatives to treat human diseases. This medicine has been used to treat many kinds of human diseases for thousands of years. The treatment protocols of natural medicine are integrative in nature, and are required to utilize the most appropriate therapies to address the needs of the individual patient. Because of the relative convenience, safety and efficacy, natural medicine is now increasing worldwide. Naturopathic doctors are licensed in many areas of the world and regulated partly by law in these areas, which is quite different from various other forms of complementary and alternative medicine. Liver diseases, such as hepatitis, liver cirrhosis and liver carcinoma, are serious health problems worldwide. Nearly half of the natural agents used in treatment of liver diseases today are natural products and their derivatives. Although natural medicine is beneficial and safe, physicians should pay close attention to the potential side-effects of the naturopathic agents, which lead to liver injury, interstitial pneumonia and acute respiratory failure. Therefore, when administrating naturopathic protocols to patients for the treatment of liver diseases, we should try our best to prevent and avoid as much as possible the negative impact of these medicines. This article highlights the current practice and recommended improvement of natural medicines in the treatment of liver diseases and gives some specific examples to emphasize the prevention and management of adverse reactions of the natural agents and suggests that natural medicine should be cautiously used to treat liver problems.

Stromal contributions to the carcinogenic process

Tumor-associated stromal cells are dynamic characters that endorse the carcinogenic process in a multitude of ways. The tumor microenvironment plays a crucial role throughout the tumor progression, which includes initiation, growth, invasion, and metastasis. The tumor microenvironment consists of cellular and non-cellular components. Tumor-associated stromal cell types include the microbiome, immune cells including macrophages, dendritic and T-cells, cells associated with blood and lymphatic vessels including pericytes and endothelial cells, fibroblasts, neuronal cells, and adipocytes. The non-cellular components of the microenvironment include matrix proteins and secreted factors. The development of therapies that target the mechanisms by which stromal cells contribute to successful tumorigenesis is major goal of upcoming cancer research. The purpose of this review is to present a comprehensive discussion of the role of each of the tumor-associated stromal cell types in the carcinogenic process with a special focus on target development and therapeutic intervention. © 2016 Wiley Periodicals, Inc.

Capsaicin Inhibits Dimethylnitrosamine-Induced Hepatic Fibrosis by Inhibiting the TGF-β1/Smad Pathway via Peroxisome Proliferator-Activated Receptor Gamma Activation

Capsaicin (CPS) exerts many pharmacological effects, but any possible influence on liver fibrosis remains unclear. Therefore, we evaluated the inhibitory effects of CPS on dimethylnitrosamine (DMN) and TGF-β1-induced liver fibrosis in rats and hepatic stellate cells (HSCs). CPS inhibited DMN-induced hepatotoxicity, NF-κB activation, and collagen accumulation. CPS also suppressed the DMN-induced increases in α-SMA, collagen type I, MMP-2, and TNF-α. In addition, CPS inhibited DMN-induced TGF-β1 expression (from 2.3 ± 0.1 to 1.0 ± 0.1) and Smad2/3 phosphorylation (from 1.5 ± 0.1 to 1.1 ± 0.1 and from 1.6 ± 0.1 to 1.1 ± 0.1, respectively) by activating Smad7 expression (from 0.1 ± 0.0 to 0.9 ± 0.1) via PPAR-γ induction (from 0.2 ± 0.0 to 0.8 ± 0.0) (p < 0.05). Furthermore, in HSCs, CPS inhibited the TGF-β1-induced increases in α-SMA and collagen type I expression, via PPAR-γ activation. These results indicate that CPS can ameliorate hepatic fibrosis by inhibiting the TGF-β1/Smad pathway via PPAR-γ activation.

Role of gut microbiota and nutrients in amyloid formation and pathogenesis of Alzheimer disease

It has been hypothesized that alterations in the composition of the gut microbiota might be associated with the onset of certain human pathologies, such as Alzheimer disease, a neurodegenerative syndrome associated with cerebral accumulation of amyloid-β fibrils. It has been shown that bacteria populating the gut microbiota can release significant amounts of amyloids and lipopolysaccharides, which might play a role in the modulation of signaling pathways and the production of proinflammatory cytokines related to the pathogenesis of Alzheimer disease. Additionally, nutrients have been shown to affect the composition of the gut microbiota as well as the formation and aggregation of cerebral amyloid-β. This suggests that modulating the gut microbiome and amyloidogenesis through specific nutritional interventions might prove to be an effective strategy to prevent or reduce the risk of Alzheimer disease. This review examines the possible role of the gut in the dissemination of amyloids, the role of the gut microbiota in the regulation of the gut-brain axis, the potential amyloidogenic properties of gut bacteria, and the possible impact of nutrients on modulation of microbiota composition and amyloid formation in relation to the pathogenesis of Alzheimer disease.

Cellular and Molecular Mechanisms of 3,3'-Diindolylmethane in Gastrointestinal Cancer

Studies in humans have shown that 3,3′-diindolylmethane (DIM), which is found in cruciferous vegetables, such as cabbage and broccoli, is effective in the attenuation of gastrointestinal cancers. This review presents the latest findings on the use, targets, and modes of action of DIM for the treatment of human gastrointestinal cancers. DIM acts upon several cellular and molecular processes in gastrointestinal cancer cells, including apoptosis, autophagy, invasion, cell cycle regulation, metastasis, angiogenesis, and endoplasmic reticulum (ER) stress. In addition, DIM increases the efficacy of other drugs or therapeutic chemicals when used in combinatorial treatment for gastrointestinal cancer. The studies to date offer strong evidence to support the use of DIM as an anticancer and therapeutic agent for gastrointestinal cancer. Therefore, this review provides a comprehensive understanding of the preventive and therapeutic properties of DIM in addition to its different perspective on the safety of DIM in clinical applications for the treatment of gastrointestinal cancers.

Microbiome, Metabolome and Inflammatory Bowel Disease

Inflammatory Bowel Disease (IBD) is a multifactorial disorder that conceptually occurs as a result of altered immune responses to commensal and/or pathogenic gut microbes in individuals most susceptible to the disease. During Crohn’s Disease (CD) or Ulcerative Colitis (UC), two components of the human IBD, distinct stages define the disease onset, severity, progression and remission. Epigenetic, environmental (microbiome, metabolome) and nutritional factors are important in IBD pathogenesis. While the dysbiotic microbiota has been proposed to play a role in disease pathogenesis, the data on IBD and diet are still less convincing. Nonetheless, studies are ongoing to examine the effect of pre/probiotics and/or FODMAP reduced diets on both the gut microbiome and its metabolome in an effort to define the healthy diet in patients with IBD. Knowledge of a unique metabolomic fingerprint in IBD could be useful for diagnosis, treatment and detection of disease pathogenesis.

Targeting MicroRNA in Cancer Using Plant-Based Proanthocyanidins

Proanthocyanidins are oligomeric flavonoids found in plant sources, most notably in apples, cinnamon, grape skin and cocoa beans. They have been also found in substantial amounts in cranberry, black currant, green tea, black tea and peanut skins. These compounds have been recently investigated for their health benefits. Proanthocyanidins have been demonstrated to have positive effects on various metabolic disorders such as inflammation, obesity, diabetes and insulin resistance. Another upcoming area of research that has gained widespread interest is microRNA (miRNA)-based anticancer therapies. MicroRNAs are short non-coding RNA segments, which plays a crucial role in RNA silencing and post-transcriptional regulation of gene expression. Currently, miRNA based anticancer therapies are being investigated either alone or in combination with current treatment methods. In this review, we summarize the current knowledge and investigate the potential of naturally occurring proanthocyanidins in modulating miRNA expression. We will also assess the strategies and challenges of using this approach as potential cancer therapeutics.

Lessons from Nature: Sources and Strategies for Developing AMPK Activators for Cancer Chemotherapeutics

Adenosine Monophosphate-Activated Protein Kinase or AMPK is a highly-conserved master-regulator of numerous cellular processes, including: Maintaining cellular-energy homeostasis, modulation of cytoskeletaldynamics, directing cell growth-rates and influencing cell-death pathways. AMPK has recently emerged as a promising molecular target in cancer therapy. In fact, AMPK deficiencies have been shown to enhance cell growth and proliferation, which is consistent with enhancement of tumorigenesis by AMPK-loss. Conversely, activation of AMPK is associated with tumor growth suppression via inhibition of the Mammalian Target of Rapamycin Complex-1 (mTORC1) or the mTOR signal pathway. The scientific communities' recognition that AMPK-activating compounds possess an anti-neoplastic effect has contributed to a rush of discoveries and developments in AMPK-activating compounds as potential anticancer-drugs. One such example is the class of compounds known as Biguanides, which include Metformin and Phenformin. The current review will showcase natural compounds and their derivatives that activate the AMPK-complex and signaling pathway. In addition, the biology and history of AMPK-signaling and AMPK-activating compounds will be overviewed, their anticancer-roles and mechanisms-of-actions will be discussed, and potential strategies for the development of novel, selective AMPK-activators with enhanced efficacy and reduced toxicity will be proposed.

An ornamental plant targets epigenetic signaling to block cancer stem cell-driven colon carcinogenesis

Phytochemicals modulate key cellular signaling pathways and have proven anticancer effects. Alcea rosea(AR; Hollyhock) is an ornamental plant with known anti-inflammatory properties. This study explored its role as an anticancer agent. The AR seed extract (AR extract) inhibited proliferation and colony formation in a dose- and time-dependent manner and promoted apoptosis as was evidenced by cleavage of PARP and increased expression of Bax accompanying reduced levels of BCL-xl protein in HCT116 and SW480 cells, respectively. In addition, AR extract-arrested cells at Go/G1 phase of cell cycle and exhibited decreases in Cyclin D1. AR extract-treated cells exhibited reduced number and size of colonospheres in a dose-dependent manner concomitant with decreases in cancer stem cell (CSC) markers ALDH1A1 and Dclk1. Relative levels of β-catenin, Notch-ICD, Hes1 and EZH2 were also attenuated by AR extract. TOP-flash reporter activity, a measure of Wnt signaling, decreased significantly in response to treatment while overexpression of wild type but not mutant EZH2, reversed the inhibitory effects. Moreover, WIF1 (a Wnt antagonist) promoter activity increased dramatically following treatment with AR extract which phenocopied increases in WIF1 reporter activity following EZH2 knockdown.In vivo, AR extract attenuated tumor growth due probably to reduced levels of EZH2, β-catenin, CyclinD1 and Ki-67 along with reduced levels of CSC markers. Since partial purification via HPLC yielded a prominent peak, efforts are underway to identify the active ingredient(s). Taken together, the results clearly suggest that AR extract/active component(s) can be an effective preventative/therapeutic agent to target colon cancer.

Metabolic Interactions in the Gastrointestinal Tract (GIT): Host, Commensal, Probiotics, and Bacteriophage Influences

Life on this planet has been intricately associated with bacterial activity at all levels of evolution and bacteria represent the earliest form of autonomous existence. Plants such as those from the Leguminosae family that form root nodules while harboring nitrogen-fixing soil bacteria are a primordial example of symbiotic existence. Similarly, cooperative activities between bacteria and animals can also be observed in multiple domains, including the most inhospitable geographical regions of the planet such as Antarctica and the Lower Geyser Basin of Yellowstone National Park. In humans bacteria are often classified as either beneficial or pathogenic and in this regard we posit that this artificial nomenclature is overly simplistic and as such almost misinterprets the complex activities and inter-relationships that bacteria have with the environment as well as the human host and the plethora of biochemical activities that continue to be identified. We further suggest that in humans there are neither pathogenic nor beneficial bacteria, just bacteria embraced by those that tolerate the host and those that do not. The densest and most complex association exists in the human gastrointestinal tract, followed by the oral cavity, respiratory tract, and skin, where bacteria—pre- and post-birth—instruct the human cell in the fundamental language of molecular biology that normally leads to immunological tolerance over a lifetime. The overall effect of this complex output is the elaboration of a beneficial milieu, an environment that is of equal or greater importance than the bacterium in maintaining homeostasis.

Anthocyanins as inflammatory modulators and the role of the gut microbiota

The health benefits of consuming fruits that are rich in polyphenols, especially anthocyanins, have been the focus of recent in vitro and in vivo investigations. Thus, greater attention is being directed to the reduction of the inflammatory process associated with the intestinal microbiota and the mechanism underlying these effects because the microbiota has been closely associated with the metabolism of these compounds in the gastrointestinal tract. Further interest lies in the ability of these metabolites to modulate the growth of specific intestinal bacteria. Thus, this review examines studies involving the action of the anthocyanins that are present in many fruits and their effect in the modulating the inflammatory process associated with the interaction between the host and the gut microbiota. The findings of both in vitro and in vivo studies suggest a potential antiinflammatory effect of these compounds, which seem to inhibit activation of the signaling pathway mediated by the transcription factor NFκB. This effect is associated with modulation of a beneficial gut microbiota, particularly an increase in Bifidobacterium strains.

Microbiome and potential targets for chemoprevention of esophageal adenocarcinoma

Esophageal cancer is one of the deadliest cancers, with a dismal prognosis. It is increasingly recognized that esophageal cancer is a heterogeneous disease. It can be subdivided into two distinct groups: squamous cell carcinoma and adenocarcinoma, based on histological appearance. In the Western world, the incidence of squamous cell carcinoma was considerably higher than esophageal adenocarcinoma (EA) until the 1990s when, due to a dramatic increase, the incidence of EA surpassed that of squamous cell carcinoma. EA typically follows a well-established stepwise evolution from chronic inflammation due to reflux esophagitis (RE) that progresses to metaplasia (Barrett's esophagus [BE]) to dysplasia, which often culminates in EA. The pathophysiology of EA is complex and involves diverse factors, including gastroesophageal reflux, gastric acid secretion, dysfunction of the antireflux barrier, gastric emptying disturbances, and abnormalities in esophageal defense mechanisms. The current understanding of the etiology of EA is mainly derived from epidemiological studies of risk factors such as cigarette smoking, obesity, gastroesophageal reflux disorders (GERD), and low fruit and vegetable consumption. Numerous studies have been done, but the factors that drive the dynamic increase in the incidence of EA remain elusive. The advent of widespread antibiotic use occurred in the 1950s, preceding the surge of EA. Based on this temporal sequence, it has been hypothesized that antibiotics alter the microbiome to which the esophagus is exposed in patients who have GERD and that chronic exposure to this abnormal microbiome (ie, changes in species diversity or abundance) accounts for the increase in EA. If changes in the proposed factors alter the stepwise progression (RE-BE-dysplasia-EA), they may represent potential targets for chemoprevention. New discoveries will help improve our understanding of the biology and pathogenesis of these cancers, and aid in finding novel therapeutic targets.

Dysbiotic drift: mental health, environmental grey space, and microbiota

Advances in research concerning the mental health implications of dietary patterns and select nutrients have been remarkable. At the same time, there have been rapid increases in the understanding of the ways in which non-pathogenic microbes can potentially influence many aspects of human health, including those in the mental realm. Discussions of nutrition and microbiota are often overlapping. A separate, yet equally connected, avenue of research is that related to natural (for example, green space) and built environments, and in particular, how they are connected to human cognition and behaviors. It is argued here that in Western industrial nations a ‘disparity of microbiota’ might be expected among the socioeconomically disadvantaged, those whom face more profound environmental forces. Many of the environmental forces pushing against the vulnerable are at the neighborhood level. Matching the developing microbiome research with existing environmental justice research suggests that grey space may promote dysbiosis by default. In addition, the influence of Westernized lifestyle patterns, and the marketing forces that drive unhealthy behaviors in deprived communities, might allow dysbiosis to be the norm rather than the exception in those already at high risk of depression, subthreshold (subsyndromal) conditions, and subpar mental health. If microbiota are indeed at the intersection of nutrition, environmental health, and lifestyle medicine (as these avenues pertain to mental health), then perhaps the rapidly evolving gut-brain-microbiota conversation needs to operate through a wider lens. In contrast to the more narrowly defined psychobiotic, the term eco-psychotropic is introduced.