Probiotics and prebiotics in chronic inflammatory bowel diseases

INTRODUCTION At birth, the gastrointestinal tract is a sterile environment. Initial exposure of the gut to microbes occurs during the birthing process from the maternal fecal and vaginal ? ora. Within a few months after birth, a relatively stable microbia…     

Probiotics and gastrointestinal diseases

There is increasing evidence indicating health benefits by consumption of foods containing microorganisms, i.e. probiotics. A number of clinical trials have been performed to evaluate the effects in the prevention and treatment of gastrointestinal diseases caused by pathogenic microorganisms or by disturbances in the normal microflora. Gastrointestinal infections caused by Helicobacter pylori, traveller's diarrhoea, rotavirus diarrhoea, antibiotic-associated diarrhoea (AAD) and Clostridium difficile-induced diarrhoea are conditions that have been studied. There are also studies performed on the preventive effect of probiotics on radiation-induced diarrhoea and diarrhoea in tube-fed patients. Inflammatory bowel disease and irritable bowel syndrome, two idiopathic conditions where alterations in the normal microflora have been implicated as responsible for initiation, are two further areas where the use of probiotics has been regarded as promising. The results from clinical studies have not been conclusive in that the effects of probiotics have been strain-dependent and different study designs have been used. Treatment of acute diarrhoea in children and prevention of AAD are the two most justified areas for the application of probiotics.     

肠道微生态与肠易激综合征

微生物群与宿主、环境之间的相互作用、相互协调对于维持宿主正常的生理功能起着十分重要的作用,三者关系失衡则直接或间接参与了众多疾病的发生、发展。肠易激综合征(IBS)是一种复杂的多因素功能性疾病,流行病学研究表明IBS患者多存在肠道菌群失调,益生菌的治疗也取得部分疗效,通过对正常人和IBS患者肠道菌群的比较,从小肠细菌过度生长、感染、抗生素、应激、肠道酵解异常五个方面,将近年肠道微生态与IBS关系做一综述。     

Probiotics: history,definition, requirements and possible therapeutic applications

The ingestion of probiotics is associated with various beneficial effects on human health and modifies the physiological homeostasis of the intestinal flora. Probiotics are microorganisms with some particular characteristics: human origin, safety in human use, bile and acid resistance, survival in the intestine, at least temporary colonization of the human gut, adhesion to the mucosa and bacteriocine production. Thanks to these characteristics, probiotics block the invasion of human intestinal cells by the enteroinvasive bacteria. Furthermore, they should be able to stimulate and modulate the intestinal immune response, and to protect and stabilize the mucosal barrier. Finally, the efficacy of probiotics should be evident and documented with valid studies. All their properties should be maintained during processing and storage. Probiotics are usually used to protect the host from pathogens. With regard to this, they are useful in the prevention of antibiotic and traveler's diarrhea and they may play a role in the management of gastric Helicobacter pylori infection. Furthermore, their efficacy in the treatment of infectious diarrhea, in inflammatory bowel diseases, in pouchitis and in food allergy has been shown. Probiotics can improve the symptoms of irritable bowel syndrome and of lactose malabsorption. Finally, it has been suggested that such microorganisms may play a role in the prevention of carcinogenesis and of tumor growth.     

A Gastroenterologist's Guide to Probiotics

The enteric microbiota contribute to gastrointestinal health, and their disruption has been associated with many disease states. Some patients consume probiotic products in attempts to manipulate the intestinal microbiota for health benefit. It is important for gastroenterologists to improve their understanding of the mechanisms of probiotics and the evidence that support their use in practice. Clinical trials have assessed the therapeutic effects of probiotic agents for several disorders, including antibiotic- or Clostridium difficile-associated diarrhea, irritable bowel syndrome, and the inflammatory bowel diseases. Although probiotic research is a rapidly evolving field, there are sufficient data to justify a trial of probiotics for treatment or prevention of some of these conditions. However, the capacity of probiotics to modify disease symptoms is likely to be modest and varies among probiotic strains-not all probiotics are right for all diseases. The current review provides condition-specific rationale for using probiotic therapy and literature-based recommendations.     

Intestinal microbiota in health and disease: Role of bifidobacteria in gut homeostasis

The pool of microbes inhabiting our body is known as “microbiota” and their collective genomes as “microbiome”. The colon is the most densely populated organ in the human body, although other parts, such as the skin, vaginal mucosa, or respiratory tract, also harbour specific microbiota. This microbial community regulates some important metabolic and physiological functions of the host, and drives the maturation of the immune system in early life, contributing to its homeostasis during life. Alterations of the intestinal microbiota can occur by changes in composition (dysbiosis), function, or microbiota-host interactions and they can be directly correlated with several diseases. The only disease in which a clear causal role of a dysbiotic microbiota has been demonstrated is the case of Clostridium difficile infections. Nonetheless, alterations in composition and function of the microbiota have been associated with several gastrointestinal diseases (inflammatory bowel disease, colorectal cancer, or irritable bowel syndrome), as well as extra-intestinal pathologies, such as those affecting the liver, or the respiratory tract (e.g., allergy, bronchial asthma, and cystic fibrosis), among others. Species of Bifidobacterium genus are the normal inhabitants of a healthy human gut and alterations in number and composition of their populations is one of the most frequent features present in these diseases. The use of probiotics, including bifidobacteria strains, in preventive medicine to maintain a healthy intestinal function is well documented. Probiotics are also proposed as therapeutic agents for gastrointestinal disorders and other pathologies. The World Gastroenterology Organization recently published potential clinical applications for several probiotic formulations, in which species of lactobacilli are predominant. This review is focused on probiotic preparations containing Bifidobacterium strains, alone or in combination with other bacteria, which have been tested in human clinical studies. In spite of extensive literature on and research into this topic, the degree of scientific evidence of the effectiveness of probiotics is still insufficient in most cases. More effort need to be made to design and conduct accurate human studies demonstrating the efficacy of probiotics in the prevention, alleviation, or treatment of different pathologies.     

Role of prebiotics,probiotics, and synbiotics in management of inflammatory bowel disease: Current perspectives

Experimental evidence supports the fact that changes in the bowel microflora due to environmental or dietary factors have been investigated as implicating factors in the etiopathogenesis of inflammatory bowel disease(IBD). The amassing knowledge that the inhabited microbiome regulates the gut physiology and immune functions in IBD, has led researchers to explore the effectiveness of prebiotics, probiotics, and synbiotics in treating IBD. This therapeutic approach focuses on restoring the dynamic...     

Antibiotics and probiotics in treatment of inflammatory bowel disease

Many experimental and clinical observations suggest that intestinal microflora plays a potential role in the pathogenesis of inflammatory bowel disease (IBD). Manipulation of the luminal content using antibiotics or probiotics represents a potentially effective therapeutic option. The available studies do not support the use of antibiotics in ulcerative colitis (UC). Antibiotics are effective in treating septic complications of Crohn's disease (CD) but their use as a primary therapy is more controversial, although this approach is frequently and successfully adopted in clinical practice. There is evidence that probiotic therapy may be effective in the prevention and treatment of mild to moderate UC. In contrast, a lack of successful study data at present precludes the widespread use of probiotics in the treatment of CD. Both antibiotics and probiotics appear to play a beneficial role in the treatment and prevention of pouchitis and further trials are warranted to fully quantify their clinical efficacy.     

Bacteriotherapy using fecal flora: toying with human motions

The intestinal flora may play a key role in the pathogenesis of certain gastrointestinal (GI) diseases. Components of bowel flora such as Lactobacillus acidophilus and Bifidobacterium bifidus have long been used empirically as therapeutic agents for GI disorders. More complex combinations of probiotics for therapeutic bacteriotherapy have also recently become available, however the most elaborate mix of human-derived probiotic bacteria is, by definition, the entire fecal flora. Fecal bacteriotherapy uses the complete normal human flora as a therapeutic probiotic mixture of living organisms. This type of bacteriotherapy has a longstanding history in animal health and has been used sporadically against chronic infections of the bowel, especially as a treatment of last resort for patients with severe Clostridium difficile syndromes including recurrent diarrhea, colitis, and pseudomembranous colitis. Encouraging results have also been observed following infusions of human fecal flora in patients with inflammatory bowel disease, irritable bowel syndrome, and chronic constipation. The therapeutic use of fecal bacteriotherapy is reviewed here and possible mechanisms of action and potential applications explored. Published reports on fecal bacteriotherapy are few in number, and detail the results of small uncontrolled open studies and case reports. Nevertheless, given the promising clinical responses, formal research into fecal bacteriotherapy is now warranted.     

肠道菌群失调与心血管疾病及其中医药调控研究进展

心血管疾病的发病率和死亡率正随着人口老龄化及城镇化的推进而呈持续升高之势,严重威胁人类的生命健康安全。心血管疾病的起病及病程进展受多种因素影响,肠道菌群失调作为其中之一吸引了众多目光。肠道菌群是存在于胃肠道内与人体互利共生的微生物群,越来越多的研究表明,肠道菌群与心血管疾病相互影响,二者互为因果,通过调节肠道菌群靶向干预心血管疾病可成为新的治疗思路。现代研究发现中药复方、中药单体及针灸可有效纠正肠道菌群紊乱,上调益生菌数量,恢复肠道屏障功能,减轻炎症反应。基于上述研究,该文总结了肠道菌群及其代谢产物与心血管疾病之间的相互作用,还对部分中医药调控肠道菌群,恢复肠道菌群动态平衡,从肠治心,干预心血管疾病的治疗作用进行了归纳,以期为心血管疾病的防治提供新的思路和可行性方案。     

肠道菌群与疾病关系的研究进展

多种疾病与肠道菌群失衡有关。肠道微生物参与宿主新陈代谢和免疫系统的调节,并与环境因子相互作用决定机体的健康和疾病状态。本文就肠道菌群与代谢综合征、炎症性肠病和结直肠癌等疾病关系的研究进展作一综述,进一步揭示了肠道微生物在人类健康中起到的重要作用,并通过介绍益生菌和粪菌移植等方法,为探索治疗诸多疾病提供新的方向。     

Role of bacteria in experimental colitis

Epidemiology suggests some relationship between the establishment of the gut flora and the risk of developing inflammatory bowel disease. Unrestrained activation of the immune system against commensal bacteria appears to be responsible for the chronicity of these diseases. In animal models, broad-spectrum antibiotics reduce the bacterial load and militate against intestinal inflammation. Several bacterial species found in of the common microflora, including anaerobes, are able to invade the colonic wall when there is dysfunction of the colonic mucosal barrier. Most aerobes provoke focal areas of acute inflammation, but some anaerobes in the predominant flora induce diffuse a fibrogenic transmural response. Current research aims to identify the probiotics that might act against these bacteria. Colonization with specific probiotic strains, including a bacterium genetically engineered to secrete interleukin-10, prevents spontaneous colitis in susceptible mice. Certain lactobacilli exhibit anti-inflammatory properties naturally, i.e. without previous genetic manipulation. Prebiotics may increase colonization by lactobacilli and can prevent mucosal inflammation. Modulation of the gut flora with probiotics may prove useful in the prevention and control of inflammatory bowel diseases.     

Effect of probiotic administration on the intestinal microbiota,current knowledge and potential applications

Although it is now known that the human body is colonized by a wide variety of microbial populations in different parts(such as the mouth, pharynx and respiratory system, the skin, the gastro- and urogenital tracts), many effects of the complex interactions between the human host and microbial symbionts are still not completely understood. The dysbiosis of the gastrointestinal tract microbiota is considered to be one of the most important contributing factors in the development of many gastrointestinal diseases such as inflammatory bowel disease, irritable bowel syndrome and colorectal cancer, as well as systemic diseases like obesity, diabetes, atherosclerosis and non-alcoholic fatty liver disease. Fecal microbial transplantations appear to be promising therapies for dysbiosis-associated diseases; however, probiotic microorganisms have been growing in popularity due to increasing numbers of studies proving that certain strains present health promoting properties, among them the beneficial balance of the intestinal microbiota. Inflammatory bowel diseases andobesity are the pathologies in which there are more studies showing this beneficial association using animal models and even in human clinical trials.In this review,the association of the human gut microbiota and human health will be discussed along with the benefits that probiotics can confer on this symbiotic activity and on the prevention or treatment of associated diseases.     

Modulation of microbiota as treatment for intestinal inflammatory disorders: An uptodate

Alterations of intestinal microflora may significantly contribute to the pathogenesis of different inflammatory and autoimmune disorders. There is emerging interest on the role of selective modulation of microflora in inducing benefits in inflammatory intestinal disorders, by as probiotics, prebiotics, synbiotics, antibiotics, and fecal microbiota transplantation(FMT). To summarize recent evidences on microflora modulation in main intestinal inflammatory disorders, Pub Med was searched using terms microbiota, intestinal flora, probiotics, prebiotics, fecal transplantation. More than three hundred articles published up to 2015 were selected and reviewed. Randomized placebo-controlled trials and meta-analysis were firstly included, mainly for probiotics. A meta-analysis was not performed because of the heterogeneity of these studies. Most of relevant data derived from studies on probiotics, reporting some efficacy in ulcerative colitis and in pouchitis, while disappointing results are available for Crohn's disease. Probiotic supplementation may significantly reduce rates of rotavirus diarrhea. Efficacy of probiotics in NSAID enteropathy and irritable bowel syndrome is still controversial. Finally, FMT has been recently recognized as an efficacious treatment for recurrent Clostridium difficile infection. Modulation of intestinal flora represents a very interesting therapeutic target, although it still deserves some doubts and limitations. Future studies should be encouraged to provide new understanding about its therapeutical role.     

益生菌制剂在肠病治疗中的应用进展

目前:益生菌在医疗、保健和食品等领域备受欢迎,这得益于其调节人体微生态平衡的独特之处.随着肠道疾病研究的逐步深入,益生菌的治疗效用越发引起关注.本文主要综述了益生菌的功能和作用机制,在肠病治疗中的应用及其展望.     

Bacterial flora as a cause or treatment of chronic diarrhea

Intestinal microflora can be considered an organ of the body. It has several functions in the human gut, mostly metabolic and immunologic, and constantly interacts with the intestinal mucosa in a delicate equilibrium. Chronic diarrhea is associated with an alteration of gut microbiota when a pathogen invades the gut and also in several conditions associated with intestinal mucosal damage or bowel dysfunction, as in inflammatory bowel disease, irritable bowel syndrome, or small bowel bacterial overgrowth. This article discusses the basis of gut microbiota modulation. Evidence for the efficacy of gut microbiota modulation in chronic conditions is also discussed.     

World Gastroenterology Organisation practice guideline: Probiotics and prebiotics

The human gut harbors dense and diverse microbial communities which have an impact on host’s health. The symbiotic relationship between gut microbial communities and host can be optimized by pharmacological or nutritional intervention on the intestinal ecosystem using probiotics or prebiotics. Worldwide research on the use of prebiotics and probiotics in human and animal health has accelerated in recent years. However, there is lack of information about the practical use of probiotics and prebiotics in Medicine. A major area for medical applications has been the prevention or treatment of gastrointestinal diseases. Recently, a group of international experts appointed by the World Gastroenterology Organization prepared a practical guideline on the current indications of probiotics and prebiotics in Gastroenterology. The full text of the guideline is published in the current issue of our Journal. The document underscores strain-specificity of the clinical effects, and provides precise information on which specific probiotic strains or prebiotic compounds are useful for what particular clinical indications (see Table 3).     

Nutritional modulation of the inflammatory bowel response

Crohn's disease and ulcerative colitis represent distinct phenotypic forms of inflammatory bowel disease and continue to be a common cause of morbidity. The corticosteroids and the immunomodulatory drugs, which are the basis of treatment for the inflammatory bowel diseases, do not assure always satisfactory outcomes. Nutrition has been used in order to modify the inflammatory response of various chronic inflammatory diseases, including Crohn's disease and ulcerative colitis. In the pathogenesis of inflammatory bowel diseases, the intestinal microflora and the intestinal mucosal disorders play a crucial role. Also, the release of reactive oxygen species is a significant factor of initiation and preservation of the inflammatory reaction in these diseases. The advantages of the nutritional treatment derive from the sequestration of intraluminal agents which may promote the inflammatory bowel response or, alternatively, nutrition is able to modify the immune response, reducing the uncontrolled inflammatory reaction. Furthermore, nutrition can enhance the mucosal barrier function and consists a significant source of antioxidants. This review focuses on certain nutritional components that modulate the inflammatory response of the bowel and aims to present a rational thesis regarding the use of nutritional agents in the management of inflammatory bowel diseases.     

Fecal Microbiota Transplantation in Inflammatory Bowel Disease: A Primer for Internists

Inflammatory bowel disease consists of disorders characterized by chronic idiopathic bowel inflammation. The concept of host–gut–microbiome interaction in the pathogenesis of various complex immune-mediated chronic diseases, including inflammatory bowel disease, has recently generated immense interest. Mounting evidence confirms alteration of intestinal microflora in patients with inflammatory bowel disease. Thus, restoration of normal gut microbiota has become a focus of basic and clinical research in recent years. Fecal microbiota transplantation is being explored as one such therapeutic strategy and has shown encouraging results in the management of patients with inflammatory bowel disease.     

Akkermansia muciniphila对肠道疾病的作用以及菌群治疗的展望

Akkermansia muciniphila作为定植于肠道黏液层的细菌,影响着人体肠道环境。Akkermansia muciniphila在肥胖症、糖尿病等代谢性疾病中的丰度下降,而在肠易激综合征、炎症性肠病、肠道肿瘤等肠道疾病中的丰度存在差异。本文就Akkermansia muciniphila对肠道疾病的作用以及菌群治疗的展望作一综述。