Bugs on the brain; brain in the gut--seeking explanations for common gastrointestinal symptoms

Effect of the standard herbal preparation, STW5, treatment on dysbiosis induced by dextran sodium sulfate in experimental colitis

BACKGROUND

The standardized herbal preparation, STW 5, is effective clinically in functional gastrointestinal disorders and experimentally in ulcerative colitis (UC). The present study explores whether the beneficial effect of STW 5 involves influencing the intestinal microbiota.

METHODS

UC was induced in Wistar rats by feeding them 5% dextran sodium sulfate (DSS) in drinking water for 7 days. Rats were treated concurrently with STW 5 and sacrificed 24 h after last drug administration. Fecal samples were used to determine changes in the abundance of selected microbial phyla and genera using real-time PCR.

RESULTS

Induction of UC led to dysbiosis and changes in the gut microbiota. The changes included an increase in some genera of the Firmicutes, namely Enterococcus, and a decrease in others, namely Blautia, Clostridium, and Lactobacillus. DSS further induced a marked increase in the abundance of Bacteroidetes and Proteobacteria as well as in the relative abundance of Actinobacteria and its genus Bifidobacterium. Methanobrevibacter levels (phylum Euryarchaeota) were also increased. Microbial dysbiosis was associated with changes in various parameters of colonic inflammation. STW 5 effectively guarded against those changes and significantly affected the indices of edema and inflammation in the UC model. Changes in colon length, colon mass index, inflammatory and apoptotic markers, and histological changes induced by DSS were also prevented.

CONCLUSIONS

Dysbiosis plays a contributing role in the development of DSS-induced UC. Derangements in the microbial flora and associated inflammatory processes were largely prevented by STW 5, suggesting that this effect might contribute towards its beneficial usefulness in this condition.

Probiotic treatment induced change of inflammation related metabolites in IBS-D patients/double-blind, randomized, placebo-controlled trial

There have been many studies suggesting that probiotics are effective in patients with diarrhea-predominant irritable bowel syndrome (IBS-D). However, its mechanism of action as well as prediction of response is still to be elucidated. In the present study, to find out metabolomic characteristics of probiotic effect in IBS-D, we compared IBS symptom changes and metabolomic characteristics in the subjects' urine samples between multi-strain probiotics (one strain of Lactobacillus sp. and four strains of Bifidobacterium sp.) group (n = 32) and placebo group (n = 31). After 8 weeks' administration (3 times/day), dissatisfaction in bowel habits and stool frequencies were significantly improved. Also, probiotics group had significantly changed seven metabolites including palmitic acid methyl ester (PAME) and 4,6-dihydroxyquinoline, 4-(2-aminophenyl)-2,4-dioxobutanoic acid (DOBA). According to IBS-SSS and IBS-QoL questionnaires, IBS-SSS responders showed higher PAME levels and IBS-QoL responders showed lower DOBA levels. This suggests potential role of these metabolites as a biomarker to predict probiotics effect in IBS-D patients.

Pharmabiotic Manipulation of the Microbiota in Gastrointestinal Disorders: A Clinical Perspective

The advent and widespread availability of high-throughput technology has revolutionized the assessment of the communities of microorganisms that inhabit the gastrointestinal tract––the gut microbiota. As our understanding of the role of the microbiota in health and human disease increases, so also do efforts to prevent and treat disease through the modulation of the microbiota. Several strategies are available to us and range from time honored approaches, such as antibiotics and probiotics, to changes in diet, the administration of prebiotics as food supplements, and fecal microbiota transplantation. Of these, diet is perhaps the most pervasive but often ignored modulator of the microbiota, and a failure to recognize its impact complicates the interpretation of many microbiota studies. The impacts of antibiotics on the microbiota are more complex than originally thought and, though antibiotics can be life-saving, their effects on commensal bacterial populations can be clinically significant. Though there have been many studies of, and even more claims made for, probiotics, the majority of available studies suffer from significant deficits in study design and execution and many claims remain to be substantiated. Though holding much promise, the study of prebiotics in human disease is still in its infancy. Possibilities other than the administration of live organisms have been identified through efforts to mine the microbiota for novel therapeutics and include: dead organisms, bacterial components, small molecules elaborated by bacteria, and even bacterial DNA. Accordingly, the term pharmabiotic has been introduced to encompass the full range of therapeutic possibilities that the microbiota offers.

The gut microbiome and irritable bowel syndrome: State of art review

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract, the physiology of which is not very well understood. There are multiple factors and pathways involved in pathogenesis of this entity. Among all, dysmotility, dysregulation of the brain-gut axis, altered intestinal microbiota and visceral hypersensitivity play a major role. Over the last years, research has shown that the type of gut microbiome present in an individual plays a significant role in the pathophysiology of IBS. Multiple studies have consistently shown that subjects diagnosed with IBS have disruption in gut microbiota balance. It has been established that host immune system and its interaction with metabolic products of gut microbiota play an important role in the gastrointestinal tract. Therefore, probiotics, prebiotics and antibiotics have shown some promising results in managing IBS symptoms via modulating the interaction between the above. This paper discusses the various factors involved in pathophysiology of IBS, especially gut microbiota.

The Gut-Brain Axis and the Microbiome: Clues to Pathophysiology and Opportunities for Novel Management Strategies in Irritable Bowel Syndrome (IBS)

Irritable bowel syndrome (IBS) is one of the most common of all medical disorders worldwide and, while for some it represents no more than a nuisance, for others it imposes significant negative impacts on daily life and activities. IBS is a heterogeneous disorder and may well have a number of causes which may lie anywhere from the external environment to the contents of the gut lumen and from the enteric neuromuscular apparatus and the gut immune system to the central nervous system. Consequently, the paradigm of the gut-brain axis, which includes the participation of these various factors, has proven a useful model to assist clinicians and patients alike in understanding the genesis of symptoms in IBS. Now, given the widespread interest in the gut microbiome in health and disease, in general, reports of disordered enteric bacterial communities in IBS, and experimental data to indicate that components of the gut microbiota can influence brain morphology and function, as well as behavior and cognition, this concept has been extended to encompass the microbiota-gut-brain axis. The implications of this novel concept to the assessment and management of IBS will be explored in this review.

Migraine in young females with irritable bowel syndrome: still a challenge

Migraine without aura is frequently reported in female patients with irritable bowel syndrome (IBS), but knowledge about the relationship between these two conditions is still lacking. This study was aimed to explore the particularities of migraine without aura in young female patients with IBS in order to establish a possible link between them. From a cohort of young female patients hospitalized with IBS in the Internal Medicine Department, 30 joined this pilot study, and they were assigned into two groups on the basis of presence or absence of migraine. In this sample, 15 patients have mild to moderate migraine without aura, with a recently taken normal brain scan, and 15 were without migraine. Diseases and conditions not related to migraine and other possible specific female comorbidities were ruled out. Patients undertook a thorough clinical examination in order to assess fibromyalgia (FM) and chronic pelvic pain (CPP), Questionnaires for migraine disability assessment (MIDAS) and generalized anxiety disorder (GAD) were performed. Laboratory testing of blood, urine, and stool were also performed. Optimized lymphocyte proliferation test for food allergy (FA) and a fecal microbiota (microbiological semiquantitative method) for dysbiosis (DB) assessment were performed. Based on the results, migraine-positive group displayed more severe comorbidities: FM (p=0.0002), FA (p=0.0006), CPP (p=0.026), higher scores of anxiety (GAD, p=0.0008), and more severe DB (p=0.0009). We noticed a strong positive correlation between MIDAS and GAD (r=0.83), a good positive correlation between MIDAS and DB (r=0.56), and a moderate positive correlation between MIDAS, FM, and FA (r=0.46 and 0.41). In conclusion, young female patients with IBS and migraine without aura displayed more severe associated issues - anxiety, intestinal DB, FM, FA, and CPP. The severity of migraine correlated well with anxiety range and DB magnitude and moderately with FM and FA.

Correlation between brain gut peptides, traditional Chinese medicine syndrome and course of gastroesophageal reflux disease

AIM: To investigate the relationship between plasma brain gut peptides, traditional Chinese medicine (TCM) syndrome and the course of gastroesophageal reflux disease (GERD).

METHODS: One hundred and sventy-eight GERD patients were included. They had five TCM syndromes: liver stomach heat, gas exchange resistance, phlegm stagnation and blood stasis, Qi deficiency, and Qi stagnation and blood stasis. Plasma levels of brain gut peptides including 5-hydroxytryptamine, somatostatin, vasoactive intestinal peptide, endothelin, and motilin were detected.

RESULTS: In the 178 patients with GERD, the proportion of patients with liver stomach heat syndrome was significantly higher in the reflux esophagitis (RE) group than in the non-erosive gastroesophageal reflux disease (NERD) group (P < 0.05), while the proportions of patients with phlegm stagnation and blood stasis syndrome and Qi deficiency syndrome were significantly higher in the NERD group than in the RE group (P < 0.05). Of the 178 GERD patients, 73 (41%) had a disease course < 1 year, 72 (40.5%) had a disease course between 1 and 5 years, and 33 (18.5%) had a course > 5 years. The proportion of patients with a course > 5 years was significantly higher in the NERD group than in the RE group (P < 0.05). The proportion of patients with a course < 1 year or between 1 and 5 years in patients with liver stomach heat syndrome was significantly higher that of patients with a course > 5 years (P < 0.05), the proportion of patients with a course between 1-5 years or > 5 years in patients with Qi deficiency syndrome was significantly higher than that of patients with a course < 1 year (P < 0.05), and the proportion of patients with a course > 5 years in patients with phlegm stagnation and blood stasis was significantly higher than that of patients with a course less than 1 year (P < 0.05). Motilin levels were significantly lower in patients with a course > 5 years than in patients with a course < 1 year (P < 0.05), and there was significant differences between the three groups (P < 0.05); 5-hydroxytryptamine and endothelin levels were higher in patients with a course > 5 years than in patients with a course between 1-5 years, but the difference was not significant.

CONCLUSION: The course of GERD patients with different TCM syndromes is different. The course of NERD patients is more likely to increase. GERD patients with a long course of disease often show Qi deficiency syndrome, liver stomach heat syndrome, and phlegm stagnation and blood stasis. Plasma 5-hydroxytryptamine, endothelin and motilin levels may be related to the prolongation of GERD.

Overlapping irritable bowel syndrome and inflammatory bowel disease: less to this than meets the eye?

Though distinct in terms of pathology, natural history and therapeutic approach, irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) have some features in common. These include shared symptomatology and largely similar demographics. However, in most instances, clinical presentation, together with laboratory, imaging and endoscopic findings will readily permit the differentiation of active IBD from IBS. More problematic is the situation where a subject with IBD, in apparent remission, continues to complain of symptoms which, in aggregate, satisfy commonly employed criteria for the diagnosis of IBS. Access to methodologies, such the assay for levels of calprotectin in feces, now allows identification of ongoing inflammation in some such individuals and prompts appropriate therapy. More challenging is the IBD patient with persisting symptoms and no detectable evidence of inflammation; is this coincident IBS, IBS triggered by IBD or an even more subtle level of IBD activity unrecognized by available laboratory or imaging methods? Arguments can be advanced for each of these proposals; lacking definitive data, this issue remains unresolved. The occurrence of IBS-type symptoms in the IBD patient, together with some data suggesting a very subtle level of 'inflammation' or 'immune activation' in IBS, raises other questions: is IBS a prodromal form of IBD; and are IBS and IBD part of the spectrum of the same disease? All of the available evidence indicates that the answer to both these questions should be a resounding 'no'. Indeed, the whole issue of overlap between IBS and IBD should be declared moot given their differing pathophysiologies, contrasting natural histories and divergent treatment paths. The limited symptom repertoire of the gastrointestinal tract may well be fundamental to the apparent confusion that has, of late, bedeviled this area.

Probiotics in Irritable Bowel Syndrome: The Science and the Evidence

Although probiotics have been used for many years by those who suffer from what would now be defined as irritable bowel syndrome (IBS), a scientific rationale for their use in this indication and clinical evidence to support their benefits have only emerged very recently. Evidence to support considering strategies, such as probiotics, that modulate the gut microbiome, in IBS, has been provided by laboratory studies implicating the microbiome and the host response to the enteric microenvironment in IBS, as well as in vitro and in vivo studies demonstrating the ability of various commensal bacteria to influence such relevant functions as motility, visceral sensation, gut barrier integrity, and brain-gut interactions. Clinical studies supporting a role for probiotics in the management of IBS predated such experimental data, and randomized controlled trials of probiotics in IBS continue to be reported. Their interpretation is hampered by the less than optimal quality of many studies; nevertheless, it is apparent that probiotics, as a category, do exert significant effects in IBS. Defining the optimal strain, dose, formulation, and duration of therapy is more challenging given the limitations of available data. There is also an urgent need for appropriately powered and rigorously designed clinical trials of appropriate duration of probiotics in IBS; such studies should also help to define those who are most likely to respond to probiotics. Future laboratory and translational research should attempt to define the mechanism(s) of action of probiotics in IBS and explore the response to bacterial components or products in this common and oftentimes troublesome disorder.

The Influence of the Gut Microbiome on Obesity, Metabolic Syndrome and Gastrointestinal Disease

There is a fine balance in the mutual relationship between the intestinal microbiota and its mammalian host. It is thought that disruptions in this fine balance contribute/account for the pathogenesis of many diseases. Recently, the significance of the relationship between gut microbiota and its mammalian host in the pathogenesis of obesity and the metabolic syndrome has been demonstrated. Emerging data has linked intestinal dysbiosis to several gastrointestinal diseases including inflammatory bowel disease, irritable bowel syndrome, nonalcoholic fatty liver disease, and gastrointestinal malignancy. This article is intended to review the role of gut microbiota maintenance/alterations of gut microbiota as a significant factor as a significant factor discriminating between health and common diseases. Based on current available data, the role of microbial manipulation in disease management remains to be further defined and a focus for further clinical investigation.

Relationship between gastroesophageal reflux disease and psychological factors and autonomic nervous function

Gastroesophageal reflux disease (GERD) is a multifactorial disease. Psychological factors play an important role in the development and progression process and the treatment of GERD. Autonomic nervous dysfunction leads to changes of the digestive tract and high gastrointestinal sensitivity. Autonomic nerve function disorder is the intermediate link between psychological factors and gastroesophageal reflux symptoms in patients with GERD. Research on psychological factors and autonomic nervous function plays an important role in the clinical diagnosis and treatment of GERD in the future.

The future of probiotics for disorders of the brain-gut axis

Probiotics, or at the very least products that might have probiotic properties, have been with us for decades, if not centuries, but it has only been in recent years that they have been subjected to serious scientific study. This surge in interest in probiotics has coincided with the era of the microbiome; as more and more is understood about the gut microbiota in health and disease, the therapeutic option of modulating the microbiota through the administration of probiotics has gained a more secure foundation. Regrettably, while a vast literature attests to the beneficial impact of probiotics in a variety of animal models and the mechanisms underlying such positive effects have been dissected in great detail, the data base on probiotics in man remains pretty slender.To make progress, a number of basic issues need to be addressed: strain characterization and other aspects of quality control need to be rigorously applied and additional steps such as dose optimization, definition of desired site of effect and tailoring of formulation accordingly accomplished before large scale trials, based on appropriately selected study endpoints and employing a clinically meaningful study duration, are embarked upon. Meantime, it is to be hoped that the regulatory climate will have been clarified and appropriate guidelines for the evaluation of probiotics, whether as food or drug, developed. Ultimately, the current terminology may have to be abandoned as evidence for biological and clinical activity for dead bacteria, bacterial components and bacterial products accumulates.

Irritable bowel syndrome: A microbiome-gut-brain axis disorder?

Irritable bowel syndrome (IBS) is an extremely prevalent but poorly understood gastrointestinal disorder. Consequently, there are no clear diagnostic markers to help diagnose the disorder and treatment options are limited to management of the symptoms. The concept of a dysregulated gut-brain axis has been adopted as a suitable model for the disorder. The gut microbiome may play an important role in the onset and exacerbation of symptoms in the disorder and has been extensively studied in this context. Although a causal role cannot yet be inferred from the clinical studies which have attempted to characterise the gut microbiota in IBS, they do confirm alterations in both community stability and diversity. Moreover, it has been reliably demonstrated that manipulation of the microbiota can influence the key symptoms, including abdominal pain and bowel habit, and other prominent features of IBS. A variety of strategies have been taken to study these interactions, including probiotics, antibiotics, faecal transplantations and the use of germ-free animals. There are clear mechanisms through which the microbiota can produce these effects, both humoral and neural. Taken together, these findings firmly establish the microbiota as a critical node in the gut-brain axis and one which is amenable to therapeutic interventions.

Microbiota-host interactions in irritable bowel syndrome: Epithelial barrier, immune regulation and brain-gut interactions

Irritable bowel syndrome (IBS) is a common, sometimes debilitating, gastrointestinal disorder worldwide. While altered gut motility and sensation, as well as aberrant brain perception of visceral events, are thought to contribute to the genesis of symptoms in IBS, a search for an underlying aetiology has, to date, proven unsuccessful. Recently, attention has been focused on the microbiota as a possible factor in the pathogenesis of IBS. Prompted by a number of clinical observations, such as the recognition of the de novo development of IBS following enteric infections, as well as descriptions of changes in colonic bacterial populations in IBS and supported by clinical responses to interventions, such as antibiotics and probiotics, that modify the microbiota, various approaches have been taken to investigating the microbiota-host response in IBS, as well as in animal models thereof. From such studies a considerable body of evidence has accumulated to indicate the activation or upregulation of both factors involved in bacterial engagement with the host as well host defence mechanisms against bacteria. Alterations in gut barrier function, occurring in response, or in parallel, to changes in the microbiota, have also been widely described and can be seen to play a pivotal role in generating and sustaining host immune responses both within and beyond the gut. In this manner a plausible hypothesis, based on an altered microbiota and/or an aberrant host response, for the pathogenesis, of at least some instances of IBS, can be generated.

Manipulation of the microbiota for treatment of IBS and IBD-challenges and controversies

There is compelling rationale for manipulating the microbiota to treat inflammatory bowel diseases (IBDs). Although studies of animal models of intestinal inflammation produced promising results, trials in humans have been disappointing. In contrast to IBD, the role of the microbiota in the development of irritable bowel syndrome (IBS) only recently has been considered, but early stage results have been encouraging. As pharmaceutical companies develop fewer truly novel agents for treatment of these disorders, consumers seek safer, long-term strategies to deal with chronic symptoms. We assess the rationale for modulating the microbiota for treatment of IBD and IBS, and discuss whether current concepts are simplistic and overstated or simply under-researched. Are claims exaggerated and expectations unrealistic? Difficulties with microbiota terminology and technologies, as well as differences among patients and the heterogeneity of these diseases, pose additional challenges in developing microbiota-based therapies for IBD and IBS.

Socio-demographic characteristics of patients with diagnosed functional dyspepsia

INTRODUCTION

The term "dyspepsia" comes from the Greek words "dys' and 'peptin", which maen "ill digestion" or indigestion, although this set of symptoms in the adult clinic has little to do with the digestion or absorption process, and refers more to ailments related to the upper section of the gastrointestinal tract.

AIM

Assessment of the frequency of functional dyspepsia diagnosis, the characteristics of the group and an attempt to identify the accompanying symptoms, assessment of histological lesions and an attempt to answer question about the efficiency of anti-secretory and eradication therapy.

MATERIAL AND METHODS

The study involved patients reporting for gastrofiberscopic examination due to dyspeptic ailments. A total of 230 patients were examined, including 140 women and 90 men, above 18 years of age. They underwent endoscopic examination, and a selected group with functional dyspepsia (FD), analysed using the 'Gast' questionnaire, underwent eradication therapy or proton pump inhibitors. Statistical analysis involved χ(2) and Fischer's test.

RESULTS

The study involved 230 individuals with dyspeptic disorders. The largest age group was 46-60 years. These patients reported due to their ailments mostly in autumn and winter. The differentiated group with FD included 53 patients (23% of the clinical population). 69.8% of the FD group was infected with Helicobacter pylori (with 81.2% of the whole population, respectively). Individuals with FD reported improvement more often after being administered drugs to decrease gastric secretion, more often declared post-elementary education and suffered from non-gastric ailments yet still described their state of health as good. No positive therapeutic effect of eradication was noticed during the 6-month observation.

CONCLUSIONS

Due to the very high ratio of subjects with functional dyspepsia, also observed in the study sample, and the influence of civilization progress, we should expect increasing frequency of occurrence of this problem.