Probiotics and their use in diverticulitis

Probiotics are live microorganisms that when ingested affect the intestinal microbial flora and benefit the health of the host. Probiotics have been shown to have a positive effect on various gastrointestinal and other conditions; however, the beneficial effect of probiotics on treating diverticulitis and diverticular disease has not yet been clearly demonstrated. In this paper, the theoretical framework for using probiotics to prevent or treat diverticular disease is reviewed, and two preliminary studies on the use of probiotics for maintenance of remission of uncomplicated diverticular disease are briefly summarized.     

Probiotics and mechanisms of their curative action.

Information about probiotics used for the correction of resident normal colon microflora and mechanism of their positive therapeutic actions are presented. Probiotics are drugs containing live microbes or substances of microbial origin that, when introduced by natural methods, are expected to confer beneficial physiologic, biochemical and immune effects to the host through the stabilization and optimization of functions of normal microflora. Probiotics containing the Bifidobacterium, Lactobacillus, Escherichia, Enterococcus, Asporogenic aerobe Bacillus and Saccharomyces boulardii microorganisms are characterized.     

Probiotics in luminal gastroenterology: the current state of play

In recent years, there has been a growing interest in the use of probiotics in various areas of gastrointestinal (GI) health. Probiotics are defined as live microorganisms that provide beneficial health effects on the host when administered in adequate amounts. Various probiotics have been shown to suppress bacterial growth, modulate the immune system and improve intestinal barrier function. However, despite several studies with promising results, most trials are small and many have substantial methodological limitations. However, with better targeting and appropriate randomised controlled trials, this area may soon yield important therapeutic strategies to optimise GI health. Here, we review the current knowledge of probiotics of relevance to luminal GI health.     

Mechanisms of probiotic action: Implications for therapeutic applications in inflammatory bowel diseases

Probiotics are defined as nonpathogenic living microorganisms, including some commensal bacterial flora, which have beneficial effects on host health and disease prevention and/or treatment. Clinical trials have shown beneficial effects of probiotics on several human diseases, such as inflammatory bowel diseases (IBDs), which are among the most-studied diseases testing probiotics as a potential therapy. However, a significant question regarding clinical use of probiotics is the mechanism underlying the wide range of actions. Studies discussed in this review suggest 3 distinct cellular and molecular mechanisms for probiotic regulation in IBD therapy: 1) Probiotics block pathogenic bacterial effects by producing bactericidal substances and competing with pathogens and toxins for adherence to the intestinal epithelium; 2) Probiotics regulate immune responses by enhancing the innate immunity and modulating pathogen-induced inflammation via toll-like receptor-regulated signaling pathways; and 3) Probiotics regulate intestinal epithelial homeostasis by promoting intestinal epithelial cell survival, enhancing barrier function, and stimulating protective responses. Probiotics modulate host cell signaling pathways, including Akt, mitogen-activated protein kinases, and nuclear factor-kappaB to mediate these intestinal epithelial functions. It is hoped that developing a mechanistic understanding of probiotic action will provide the rationale to support the development of new hypothesis-driven studies to define the clinical efficacy in preventive, adjunctive, or alternative treatments for IBD.     

Probiotics in infective diarrhoea and inflammatory bowel diseases

Bacteria are present throughout the gastrointestinal tract, but their pattern and concentration vary greatly. Probiotics are living organisms that supply beneficial health effects to the host. So far the beneficial effects of probiotics have been shown, almost exclusively, under poorly defined experimental conditions. There are little convincing data from well-designed, double-blind controlled trials supporting health-promoting effects. The use of probiotics to treat gastrointestinal infections has produced contrasting results. Apart from information on rotavirus infection in children, there is no convincing evidence from controlled studies on the efficacy of probiotics in the prevention or treatment of infective diarrhoea. However, experimental and clinical studies suggest that there are potential therapeutic roles for probiotics in the treatment of inflammatory bowel diseases. This review focuses on the available data concerning the mechanisms of action of probiotics, and on the results from clinical studies using probiotics to treat infective diarrhoea and inflammatory bowel disease.     

Probiotics in gastroenterology

Probiotics are defined as live microorganisms of human origin. Their use may favorably influence human health and ameliorate or prevent certain diseases. Prebiotics are non-digestible foodstuffs (fiber, oligofructans - "colonic foods"), which enter the colon and are metabolized by the probiotics. Probiotics should fulfill the following criteria: Phenotypic and genotypic classification, no pathogenic properties, human origin, application in the living state, resistance to gastric acid and bile, ability to adhere to colonocytes, ability to colonize the gut, clinically proved favorable health-effect, and safety. Experimental and clinical studies supplied evidence of the possible use of probiotics in the following diseases: Traveler's diarrhea, antibiotic-associated diarrhea, relapsing Clostridium difficile colitis, infantile diarrhea, rotavirus enteritis, inflammatory bowel disease, irritable bowel syndrome, colon cancer, peritonitis, acute pancreatitis, and diarrhea associated with HIV infection. Probiotics displayed the following effects in these studies: Involvement in production of essential nutrients of the colonic mucosa, beneficial effect on intestinal immunity, recovery of the disturbed gut mucosal barrier and prevention of microbial translocation, elimination of toxins and eradication of microbial pathogens, production of steroids from cholesterol and reduction of its pool in circulation, participation in regulation of intestinal functions, reduced incidence of chemically induced colon tumors in rodents. Probiotics open new therapeutic modalities in a number of diseases and it may be expected that their importance will increase with growing knowledge and experience.     

Probiotics for the Treatment of Inflammatory Bowel Disease

Probiotics are organisms which provide a desired and beneficial effect on human health. With recent evidence implicating a disruption in the balance of the gastrointestinal microbiome and intestinal immunity as a potential trigger for inflammatory bowel disease (IBD), there has been growing interest in using probiotics as an adjunct to standard anti-inflammatory and immune suppressing therapy. Animal models describe potential and plausible mechanisms of action for probiotics to counter inflammation of colonic mucosa. Although there are insufficient data to recommend probiotics in ulcerative colitis or Crohn's disease, good evidence supports the use of specific probiotics for maintenance of remission in pouchitis. Although there are limited regulatory standards for the agents, probiotics are relatively safe with minimal reported side effects or contraindications. More rigorous studies need to be published supporting efficacy and safety of these agents before they become a mainstay of IBD medical treatment.     

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.     

Indications for the use of probiotics in gastrointestinal diseases

Probiotics are live microbial organisms that are present in foods or dietary supplements and that confer health benefits to the host when ingested in sufficient quantities. Probiotics can be bacterial (e.g. Bifidobacteria spp. and Lactobacillus spp.) or yeasts (e.g. Saccharomyces boulardii). The administration of probiotics is often believed to be by and large beneficial for individuals with inflammatory or infectious diseases of the gastrointestinal tract. These positive effects are generally attributed to the ability of probiotics to regulate intestinal permeability, normalize host intestinal flora, improve gut immune barrier function, and equilibrate the balance between proinflammatory and anti-inflammatory cytokines. Of note, however, these claims are not always substantiated by findings from properly conducted clinical trials. Of particular importance, even when results from randomized controlled trials support the beneficial effects of a particular probiotic for a specific indication, the benefits achieved by the probiotic are generally not translatable to other probiotic formulations. This review discusses the gastrointestinal indications for probiotic use and describes the level of evidence that supports the use of specific probiotics for these indications. Several indications are addressed, including enteric infections, gastritis caused by Helicobacter pylori infection, necrotizing enterocolitis, inflammatory bowel diseases, and irritable bowel syndrome.     

Probiotics and immunity

Probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host, including the gastrointestinal tract. While this beneficial effect was originally thought to stem from improvements in the intestinal microbial balance, there is now substantial evidence that probiotics can also provide benefits by modulating immune functions. In animal models, probiotic supplementation is able to provide protection from spontaneous and chemically induced colitis by downregulating inflammatory cytokines or inducing regulatory mechanisms in a strain-specific manner. In animal models of allergen sensitization and murine models of asthma and allergic rhinitis, orally administered probiotics can strain-dependently decrease allergen-specific IgE production, in part by modulating systemic cytokine production. Certain probiotics have been shown to decrease airway hyperresponsiveness and inflammation by inducing regulatory mechanisms. Promising results have been obtained with probiotics in the treatment of human inflammatory diseases of the intestine and in the prevention and treatment of atopic eczema in neonates and infants. However, the findings are too variable to allow firm conclusions as to the effectiveness of specific probiotics in these conditions.     

益生菌在抗肠道寄生虫病感染中的作用

益生菌是一类对宿主有益的活性微生物,可以有效治疗胃肠道、呼吸道感染和过敏性疾病。虽然目前主要用于治疗细菌和病毒感染,但也有研究表明益生菌对寄生虫感染有抑制作用。因此,以益生菌制成的微生态制剂将为寄生虫防治提供一种新的途径。     

Prebiotics as gut microflora management tools

Functional foods is an often-used term applied to dietary ingredients that serve to improve consumer health. Over the last few decades, these foods have gained in popularity with sales continuing to increase rapidly. Recent scientific, and some lay, reports have shown the popularity of both probiotics and prebiotics. These serve to elicit changes in the gut microbiota composition that increase populations of purported beneficial gut bacterial genera, for example, lactobacilli or bifidobacteria. Probiotics use live microbial feed additions, whereas prebiotics target indigenous flora components. As gastrointestinal disorders are prevalent in terms of human health, both probiotics and prebiotics serve an important role in the prophylactic management of various acute and chronic gut derived conditions. Examples include protection from gastroenteritis and some inflammatory conditions.     

Treating critically ill patients with probiotics: Beneficial or dangerous?

Probiotic bacteria are live microorganisms which confer to health benefits of the host. They help to maintain the integrity of the intestinal barrier function by modulating the mucosal and systemic immune response of the host. These bacteria have proven their beneficial effect in several conditions of ulcerative colitis. More recently probiotics/synbiotics have been included in the treatment of critically ill patients. However to date it remains uncertain whether probiotics/synbiotics are beneficial or even dangerous to the clinical outcome of this patient group. This article reviews the current evidence of the use of bacteria in critically ill patients in intensive care settings.     

Current level of consensus on probiotic science--report of an expert meeting--London, 23 November 2009

The present paper summarizes the consensus views of a group of 9 European clinicians and scientists on the current state of scientific knowledge on probiotics, covering those areas where there is substantial evidence for beneficial effects and those where the evidence base is poor or inconsistent. There was general agreement that probiotic effects were species and often strain specific. The experts agreed that some probiotics were effective in reducing the incidence and duration of rotavirus diarrhoea in infants, antibiotic-associated diarrhoea in adults and, for certain probiotics, Clostridium difficile infections. Some probiotics are associated with symptomatic improvements in irritable bowel syndrome and alleviation of digestive discomfort. Probiotics can reduce the frequency and severity of necrotizing enterocolitis in premature infants and have been shown to regulate intestinal immunity. Several other clinical effects of probiotics, including their role in inflammatory bowel disease, atopic dermatitis, respiratory or genito-urinary infections or H.pylori adjuvant treatment were thought promising but inconsistent.     

Current level of consensus on probiotic science-Report of an expert meeting- London, 23 November 2009

The present paper summarizes the consensus views of a group of 9 European clinicians and scientists on the current state of scientific knowledge on probiotics, covering those areas where there is substantial evidence for beneficial effects and those where the evidence base is poor or inconsistent. There was general agreement that probiotic effects were species and often strain specific. The experts agreed that some probiotics were effective in reducing the incidence and duration of rotavirus diarrhoea in infants, antibiotic-associated diarrhoea in adults and, for certain probiotics, Clostridium difficile infections. Some probiotics are associated with symptomatic improvements in irritable bowel syndrome and alleviation of digestive discomfort. Probiotics can reduce the frequency and severity of necrotizing enterocolitis in premature infants and have been shown to regulate intestinal immunity. Several other clinical effects of probiotics, including their role in inflammatory bowel disease, atopic dermatitis, respiratory or genito-urinary infections or H.pylori adjuvant treatment were thought promising but inconsistent.     

Novel perspectives in probiotic treatment: the efficacy and unveiled mechanisms of the physiological functions

Probiotics are defined as “live microorganisms which confer a health benefit on the host” when administered in adequate amounts, and have potential effects for maintaining intestinal development, nutrition, and treating intestinal inflammations, functional disorders, and other extra-intestinal diseases. Although the benefits of probiotics for human health were first noted over 100 years ago, the analysis of probiotic functions began in earnest only 20 years ago. Probiotics, such as some strains of Lactobacillus, Bifidobacterium, Escherichia coli, and Bacillus subtilis, inhibit the growth of pathogenic bacteria, induce competitive effects for the adherent of pathogenic bacteria and their toxins to intestinal epithelia, induce cytoprotective heat shock proteins, enhance the intestinal barrier function, and modulate the host immune responses. The crosstalk between the host and the probiotics appears to be mediated by bacteria-derived effectors, which can be sensed with multiple systems, including the Toll-like receptors and cell membrane transporters. Future analyses will identify more probiotic-derived effectors, the recognition mechanisms of these effectors, and the subsequent changes of the intestinal epithelia and immune cells for each probiotic treatment. For clinical use, a procedure that objectively evaluates the ability of each probiotic effect will help establish a standard for choosing the most valuable strain and its proper dose for each individual patient.     

Helicobacter pylori treatment: a role for probiotics?

Many new therapeutic strategies are studied to improve Helicobacter pylori eradication rate. Probiotics are live microorganisms which, upon administration, may interact with the human microflora and positively affect the health status. The use of probiotics in the field of H. pylori infection has been proposed for improving eradication rate and tolerability and for compliance of multiple antibiotic regimens used for the infection. Results from laboratory studies and from clinical trials seem to confirm the expectancies, but there is lack of standardization in terms of type of probiotic strain used, dosage and timing of supplementation. Before further ongoing trials and future studies will clarify these points, probiotics could remain a useful adjunct to standard anti-H. pylori therapies, but cannot take the place of other validated options.     

Developmental biology of gut-probiotic interaction

While our current knowledge of probiotic interaction in the developing gut remains poorly understood, emerging science is providing greater biological insight into their mechanism of action and therapeutic potential for human disease. Given their beneficial effects, probiotics remain promising agents in neonatal gastrointestinal disorders. Probiotics may restore or supply essential bacterial strains needed for gut maturation and homeostasis, particularly in hosts where this process has been disrupted. Here we highlight the unique characteristics of developing intestinal epithelia with a focus on gut development and colonization as well as the inflammatory propensity of immature epithelia. Additionally, we review potential mechanisms of beneficial probiotic interaction with immature intestinal epithelia including immunomodulation, upregulation of cytoprotective genes, prevention and regulation of apoptosis, and maintenance of barrier function. Improved knowledge of gut-probiotic interaction in developing epithelia will allow for a better understanding of how probiotics exert their beneficial effects and help guide their therapeutic use.     

Developmental biology of gut-probiotic interaction

While our current knowledge of probiotic interaction in the developing gut remains poorly understood, emerging science is providing greater biological insight into their mechanism of action and therapeutic potential for human disease. Given their beneficial effects, probiotics remain promising agents in neonatal gastrointestinal disorders. Probiotics may restore or supply essential bacterial strains needed for gut maturation and homeostasis, particularly in hosts where this process has been disrupted. Here we highlight the unique characteristics of developing intestinal epithelia with a focus on gut development and colonization as well as the inflammatory propensity of immature epithelia. Additionally, we review potential mechanisms of beneficial probiotic interaction with immature intestinal epithelia including immunomodulation, upregulation of cytoprotective genes, prevention and regulation of apoptosis and maintenance of barrier function. Improved knowledge of gut-probiotic interaction in developing epithelia will allow for a better understanding of how probiotics exert their beneficial effects and help guide their therapeutic use.     

Use of probiotics in abdominal surgery

Several clinical trials have demonstrated that the use of probiotics and synbiotics in patients undergoing abdominal surgery might be beneficial in preventing postoperative infectious complications. However, other investigators report that there is no evidence supporting any benefits from preoperative use of pre- and probiotics (synbiotics) in patients undergoing elective abdominal surgery, and that in some cases there is even an increased risk of mortality. Possible explanations behind these controversies may be found in the postoperative period of administration (median time of 4 days), the oral (instead of jejunal) route of administration with the accompanying unclear survival rate of the probiotics in the stomach due to low pH, and the high-risk operations such as complicated colectomies resulting in a high overall rate of bacterial translocation and infections. In recent years, three important randomized studies on the effects of probiotics in patients undergoing colorectal surgery have reported that the use of probiotics markedly improved intestinal microbial populations and significantly decreased the incidence of further infectious complications. Furthermore, the patients' quality of life was also improved by shortening the duration of postoperative hospital stay and the period needed for antibiotics administration. Improvements in infection-related complications and gut defecation function have also been reported in patients receiving perioperative oral probiotics treatment, suggesting that the use of probiotics could reduce the extent of damage to colon mucosa after surgery. Probiotics can improve the integrity of the gut mucosal barrier as well as the balance of the gut microbiota, and they play a role in decreasing the rate of infection. This area, however, requires more research before preoperative oral intake of probiotics combined with postoperative treatment can be recommended for patients in need of gastrointestinal surgery.