Expression of cytokines, inducible nitric oxide synthase, and matrix metalloproteinases in pouchitis: effects of probiotic treatment

Probiotics for the treatment of postoperative complications following intestinal surgery

Probiotics are living micro-organisms that belong to the normal enteric flora and exert a beneficial effect on health and well-being. The rationale for the therapeutic use of probiotics in pouchitis (the most frequent long-term complication following pouch surgery for ulcerative colitis) and postoperative recurrence in Crohn's disease is based on convincing evidence suggesting a crucial role for the endogenous intestinal microflora in the pathogenesis of these conditions. Positive results have been obtained with the administration of highly concentrated probiotic preparations in preventing the onset and relapses of pouchitis. Further controlled studies are needed to establish the efficacy of probiotics in the prophylaxis of postoperative recurrences of Crohn's disease and in the treatment of mild pouchitis.

Immunomodulatory effects of probiotic bacteria DNA: IL-1 and IL-10 response in human peripheral blood mononuclear cells

A new therapeutic approach for inflammatory bowel diseases is based on the administration of probiotic bacteria. Prokaryotic DNA contains unmethylated CpG motifs which can activate immune responses, but it is unknown whether bacterial DNA is involved in the beneficial effects obtained by probiotic treatment. Peripheral blood mononuclear cells (PBMC) from healthy donors were incubated with pure DNA of eight probiotic strains and with total bacterial DNA from human feces collected before and after probiotic ingestion. Cytokine production was analyzed in culture supernatants. Modification of human microflora after probiotic administration was proven by polymerase chain reaction analysis. Here we show that Bifidobacterium genomic DNA induced secretion of the antiinflammatory interleukin-10 by PBMC. Total bacterial DNA from feces collected after probiotic administration modulated the immune response by a decrease of interleukin-1 beta and an increase of interleukin-10.

Probiotics, Irritable Bowel Syndrome, and Inflammatory Bowel Disease

Probiotics are live, microbial food supplements that benefit the host animal by improving intestinal microbial balance. Their major role in preventing and treating gastrointestinal disease appears to be from their effect on the immune process, protection against abnormal invasive bacteria, and in the production of short-chain fatty acids from starch and non-starch polysaccharides. Probiotic microorganisms are administered in food supplements and yogurts. They are also now sold in the form of capsules and powders. There is great variation in the microorganisms in the various supplements. It is important to understand that all probiotic products are different. Some contain a single organism and others contain multiple organisms. Therapeutic results have been achieved with various probiotics in different diseases. In the treatment of inflammatory bowel diseases (IBD), success has been reported with Escherichia coli Nissle strain in ulcerative colitis, and with a multiple organism product, VSL#3 (VSL Pharmaceuticals, Fort Lauderdale, FL), in Crohn's disease and pouchitis. Initial reports in irritable bowel syndrome (IBS) have resulted in encouraging results with the use of E. coli Nissle strain, and recently with multiple organism probiotic supplements. However, caution must still apply to the use of probiotics in IBD and IBS because the reports and the number of patients treated are limited.

Targeting enteric bacteria in treatment of inflammatory bowel diseases: why, how, and when

PURPOSE

This review discusses the role of bacterial adjuvants and antigens in induction and reactivation of chronic intestinal inflammation in susceptible hosts; discusses the results of recent therapeutic trials of antibiotics, probiotics, and prebiotics; and suggests future treatment strategies.

RECENT FINDINGS

Bacterial adjuvants, including peptidoglycan, lipopolysaccharide, and DNA (CpG) bind to membrane-bound toll-like receptors (TLR-2, 4, and 9. respectively) or cytoplasmic (NOD1 and NOD2) receptors (pattern recognition receptors) that activate nuclear factor-kappaB and transcription of many proinflammatory cytokines and adhesion, costimulatory, and major histocompatibility complex class II molecules. Experimental enterocolitis does not occur in a sterile (germ-free) environment and is prevented and treated by broad-spectrum antibiotics. Individual nonpathogenic intestinal bacterial species selectively induce experimental colitis, with host specificity. Crohn disease and ulcerative colitis patients exhibit pathogenic immune responses (loss of immunologic tolerance) to multiple normal enteric bacterial species and serologic responses to Mycobacterium paratuberculosis. Metronidazole and ciprofloxacin selectively treat colonic Crohn disease, but not ulcerative colitis or ileal Crohn disease, and may prevent recurrence of postoperative Crohn disease. Certain probiotic species decrease relapse of ulcerative colitis and chronic pouchitis and delay onset of pouchitis.

SUMMARY

Normal, nonpathogenic enteric bacteria induce and perpetuate chronic intestinal inflammation in genetically susceptible hosts with defective immunoregulation, bacterial clearance, or mucosal barrier function. Altering the composition and decreasing mucosal adherence/invasion of commensal bacteria with antibiotics, probiotics, and prebiotics can potentially prevent and treat Crohn disease, pouchitis, and possibly ulcerative colitis, but optimal treatments have not yet been identified.

Prophylaxis of pouchitis onset with probiotic therapy: a double-blind, placebo-controlled trial

BACKGROUND & AIMS

We have recently documented the efficacy of a highly concentrated probiotic preparation (VSL#3) in the prevention of flare-up in patients with chronic pouchitis. The aim of this study was to compare probiotic therapy with VSL#3 versus placebo in the ability to prevent the onset of acute pouchitis during the first year after ileal pouch-anal anastomosis.

METHODS

Forty consecutive patients who underwent ileal pouch-anal anastomosis for ulcerative colitis were randomized to receive either VSL#3 (1 packet containing 900 billion bacteria/day) (n = 20) or an identical placebo (n = 20) immediately after ileostomy closure for 1 year. The patients were assessed clinically, endoscopically, and histologically after 1, 3, 6, 9, and 12 months. Health-related quality of life was assessed using the Inflammatory Bowel Disease Questionnaire.

RESULTS

Two of the 20 patients (10%) treated with VSL#3 had an episode of acute pouchitis compared with 8 of the 20 patients (40%) treated with placebo (log-rank test, z = 2.273; P < 0.05). Treatment with VSL#3 determined a significant improvement in Inflammatory Bowel Disease Questionnaire score, whereas this was not the case with placebo.

CONCLUSIONS

Treatment with VSL#3 is effective in the prevention of the onset of acute pouchitis and improves quality of life of patients with ileal pouch-anal anastomosis.

Maternal milk reduces severity of necrotizing enterocolitis and increases intestinal IL-10 in a neonatal rat model

Necrotizing enterocolitis (NEC) is a devastating intestinal disease of premature infants. Maternal milk has been suggested to be partially protective against NEC; however, the mechanisms of this protection are not defined. The aim of this study was to examine the effect(s) of artificial feeding of rat milk (RM)-versus cow milk-based rat milk substitute (RMS) on the development of NEC in a neonatal rat model and elucidate the role of inflammatory cytokines in NEC pathogenesis. Newborn rats were artificially fed with either collected RM or RMS. Experimental NEC was induced by exposure to asphyxia and cold stress and evaluated by histologic scoring of damage in ileum. Intestinal cytokine mRNA expression was determined by real-time PCR. Cytokine histologic localization was performed by confocal microscopy. Similar to human NEC, artificial feeding of RM reduces the incidence and severity of NEC injury in neonatal rats. Freezing and thawing of collected RM did not eliminate the protective effect of maternal milk. Ileal IL-10 expression was significantly increased in the RM group compared with RMS. Increased IL-10 peptide production was detected in the RM group with signal localized predominantly in the cytoplasm of villus epithelial cells. These results suggest that the protective effect of maternal milk is associated with increased production of anti-inflammatory IL-10 in the site of injury. Better understanding of the mechanisms underlying these protective effects could be beneficial either in the prevention of NEC or in the development of future therapeutic strategies to cure NEC.

Effect of Lactobacillus rhamnosus GG on ileal pouch inflammation and microbial flora

BACKGROUND

Preliminary trials of probiotics in preventing recurrent chronic pouchitis have been encouraging.

AIM

To investigate the efficacy of Lactobacillus GG supplementation as primary therapy for ileal pouch inflammation, and its effect on the microbial flora.

METHODS

Twenty patients, with a previous history of pouchitis and endoscopic inflammation, were recruited for a prospective, randomized, double-blind, placebo-controlled trial of Lactobacillus GG supplementation (10 LGG, 10 placebo) in two gelatine capsules [(0.5-1) x 10(10) colony-forming units/capsule] b.d. for 3 months. Quantitative bacterial culture of fresh faecal samples and biopsies taken from the pouch and afferent limb was performed before and after supplementation.

RESULTS

Lactobacillus GG supplementation changed the pouch intestinal flora by increasing the ratio of total faecal lactobacilli to total faecal anaerobes (P = 0.03) and enhancing the frequency of lactobacilli-positive cultures in the pouch and afferent limb mucosal biopsy samples. However, only 40% of patients were colonized with Lactobacillus GG. No differences were observed between the groups with regard to the mean pouchitis disease activity index or the total anaerobes or aerobes of faecal or tissue biopsy samples.

CONCLUSIONS

A single-strain probiotic bacterium supplement of Lactobacillus GG changed the pouch intestinal bacterial flora, but was ineffective as primary therapy for a clinical or endoscopic response. More clinical trials are needed to evaluate the right placement and dosage of probiotics within a treatment regimen for pouchitis.

Use of probiotics in the treatment of inflammatory bowel disease

The gut flora plays a fundamental role in maintaining normal intestinal function. A disturbance of this flora, or the host response to this flora, has been clearly demonstrated to play a role in the pathogenesis of inflammatory bowel disease (IBD). This has led to attempts to modify the bacterial flora with "live non-pathogenic organisms that confer health benefits by improving the microbial balance," otherwise known as probiotics. Recent attention has focused on this potential strategy to treat or prevent IBD. The potential therapeutic benefit is enhanced by the natural and apparently safe approach that probiotics offer. Animal models of colitis have provided the proof of principle that probiotics can prevent and treat established intestinal inflammation. Controlled clinical studies have demonstrated the efficacy of probiotics in the maintenance of remission of pouchitis, prophylaxis of pouchitis after the formation of an ileoanal reservoir, maintenance of remission of ulcerative colitis, and treatment of Crohn's disease. However, large controlled trials are needed to definitively establish the place for probiotics in the treatment of IBD and resolve issues such as the dose, duration, frequency of treatment, and use of single or multiple strains. Research is focusing on establishing the mechanism of action, so that treatments with individually tailored properties are developed and innovative approaches are explored.

Diagnosis and treatment of pouchitis

Total proctocolectomy with ileal pouch-anal anastomosis is the surgical procedure of choice for the management of ulcerative colitis. Pouchitis, a non-specific inflammation of the ileal reservoir, is the most frequent complication that patients experience in the long-term. Diagnosis should be made on the basis of clinical, endoscopic and histological aspects. The Pouchitis Disease Activity Index (PDAI) represents an objective and reproducible scoring system for pouchitis: active pouchitis is defined as a score > or = 7 and remission as a score < 7. About 15% of patients develop a chronic disease. Treatment of pouchitis is empirical, and very few controlled studies have been carried out. Antibiotics, particularly metronidazole and ciprofloxacin, are the treatment of choice. Chronic pouchitis may benefit from a prolonged course of a combination of antibiotics. Highly concentrated probiotics are effective for both prevention of relapses and prevention of pouchitis onset. There is no convincing evidence of the efficacy of other therapeutic agents.

Probiotics and health: new facts and ideas

Many trials on probiotics are now published that use established methods to demonstrate their clinical efficacy. Convincing progress has been made in the field of inflammatory bowel disease and allergy prevention in infants. Experimental studies show clear differences (and even sometimes opposite effects) between apparently closely related probiotics and suggest new mechanisms for the observed effects, such as immunostimulation by bacterial DNA and interaction with Toll-like receptors and dendritic cells in the gastrointestinal tract.

The potential role of probiotics in pediatric urology

PURPOSE

The application of select microbial strains to increase the host population of good bacteria is called probiotics, a term defined as "live microorganisms which when administered in adequate amounts confer a health benefit on the host." This review was done to evaluate the potential role that probiotic therapy may have in pediatric urology.

MATERIALS AND METHODS

Many children around the world die of diseases, such as gastrointestinal infection and HIV, while many have urinary tract infections that subsequently recur frequently in adulthood. Until recently the role of intestinal and urogenital (vaginal, urethral and perineal) microflora in health and disease has received scant attention. The data available in the literature on this topic were examined and a personal viewpoint is presented on how they may relate to urology.

RESULTS

There is mounting evidence that certain strains of lactobacilli and bifidobacteria have a major part in the maintenance and restoration of health in children and adults.

CONCLUSIONS

Implications for pediatric urology include a decreased risk of infection and stone disease as well as possible positive effects on preventing and managing inflammatory and some carcinogenic diseases.

Pouchitis in Children: Therapeutic Options

Pouchitis is an unfortunate common complication of the ileal pouch-anal anastomosis procedure, an otherwise very attractive surgical option in patients with ulcerative colitis (UC). The fact that the same pouch in familial polyposis is hardly complicated by pouchitis suggests that the basic inflammatory process in UC might participate in the pathophysiology. We review the clinical features of pouchitis, the diagnostic approach, and the many therapeutic considerations, including more recent data on prebiotics and probiotics.

New therapeutic approach in the management of intestinal disease: probiotics in intestinal disease in paediatric age

Current evidence supports the view that oral administration of probiotics may be of therapeutic usefulness in several clinical disorders by reestablishing normal flora in the gastrointestinal tract. These entities include inflammatory and infectious diseases of the gut as well as extraintestinal disorders (such as atopic eczema) in which a defective intestinal permeability plays a role. The probiotic effects are attributed to restoration to normal of increased intestinal permeability, unbalanced gut microecology, improved immunological gut barrier function, downregulation of the intestinal inflammatory responses with reduced generation of proinflammatory cytokines. Entities for which the impact of probiotic administration can be considered as proven are Rotavirus diarrhoea, Clostridium difficile diarrhoea, post-antibiotic diarrhoea, allergic diseases. On the other hand, entities for which administration of probiotics is considered under investigation are inflammatory bowel disease, necrotizing enterocolitis, cystic fibrosis, small bowel bacterial contamination, functional gastrointestinal disorders. The value of probiotics as therapy for a variety of gastrointestinal disorders in childhood still needs to be investigated in detail, through well controlled and rigorous studies, including a placebo group and strict criteria of randomisation. Much work needs to be done in this area by clearly defining indications, delivery system, costs, safety long-term effects.

Advances in the medical therapy of inflammatory bowel disease

The medical therapy of inflammatory bowel disease (IBD) has advanced significantly over the past year. Serologic markers of IBD have been further investigated and better defined, showing some discriminatory power with potential therapeutic implications. Studies of azathioprine and 6-mercaptopurine metabolites will make it easier and safer to use these effective drugs. Clinical data using other immunomodulators, including 6-thioguanine, mycophenolate mofetil, cyclosporine, and tacrolimus, continue to accrue with positive results. Infliximab has become even more firmly established as a reliable and effective therapy for active and fistulizing Crohn disease and may even be helpful in some patients with resistant ulcerative colitis. However, the recognition of potential complications of infliximab therapy has increased with the accumulated clinical experience. Results from trials of other biologic therapies directed at tumor necrosis factor alpha have been disappointing so far, although preliminary studies with biologics directed at adhesion molecules are encouraging. Growing appreciation of the importance of the enteric microflora in IBD has led to a considerable interest in manipulating intestinal bacteria for therapeutic benefit, and trials of both probiotics and prebiotics show promise.

Role of probiotics in food hypersensitivity

The definition of probiotics has evolved concomitant with a resurgence of research interest in host-microbe crosstalk. The original definition stated that the live active culture beneficially affects the host by improving its intestinal microbial balance, while current conceptions are based on target- and site- specific effects of clearly defined strains. The establishment of normal microbiota in the intestine represents a key process whereby the intestinal milieu is kept disease-free as it performs its dual function: mounting an inflammatory response to pathogens and maintaining hyporesponsiveness to innocuous antigens. Probiotic therapy is based on this concept of a healthy well-balanced gut microbiota. The probiotic performance of strains differs, however. Different bacteria have clearly defined adherence sites and immunological effects and divergent effects in the healthy versus inflamed mucosa. Hence, notwithstanding recent demonstrations of the important immunoregulatory potential of the healthy well-balanced gut microbiota, current probiotic research is directed towards identification of specific strains with anti-allergenic potential.

Anatomic and functional characteristics of the rat ileal pouch

BACKGROUND

The definitive operation for chronic ulcerative colitis (UC) and familial adenomatous polyposis is total proctocolectomy with ileal pouch-anal anastomosis (IPAA). Mild inflammation (pouchitis) is omnipresent in pouches and becomes severe in 50% of UC patients with IPAA. The etiology of pouchitis is likely due to combined genetic, microbial, and immunologic factors. Epithelial cell exposure to surgical trauma and/or to changes in intestinal bacterial composition may account for the inflammatory infiltrate. Progress in understanding pouchitis is restricted by the lack of suitable animal models.

METHODS

An ileal pouch-rectal anastomosis [IPRA] in rats was developed to reproduce a model of human IPAA and clinical, gross and histologic criteria were determined.

RESULTS

Many shared features with human ileal pouch were observed.

CONCLUSION

IPRA is an important in vivo model to study mechanisms of repair, defense and immunity that may contribute to pouchitis.

Probiotics in gastroenterology

Recent evidence has suggested the potential therapeutic role for probiotics in the prevention or treatment of gastrointestinal diseases. Several studies have shown that probiotics are of benefit in gastrointestinal infections, including viral diarrhea, Clostridium difficile-associated diarrhea, traveler's diarrhea, and antibiotic-associated diarrhea. Recent data support the potential beneficial therapeutic effect in inflammatory bowel disease as well. Other possible indications for probiotic treatment include Helicobacter pylori infection, irritable bowel syndrome, and radiotherapy-associated diarrhea. It is important to select well-characterized preparations; in fact, the viability and survival of many available preparations are unproven. More precise information on the mechanisms by which probiotic strains exert their beneficial effects in vivo is needed. This may provide the scientific rationale for the selection of the best probiotic strains to use in the performance of large, double-blind, controlled clinical trials.

Lactobacillus plantarum 299V in the treatment and prevention of spontaneous colitis in interleukin-10-deficient mice

Interleukin (IL)-10-deficient (IL-10-/-) mice develop colitis under specific pathogen-free (SPF) conditions and remain disease free if kept sterile (germ free [GF]). We used four different protocols that varied the time-points of oral administration of Lactobacillus plantarum 299v (L. plantarum) relative to colonization with SPF bacteria to determine whether L. plantarum could prevent and treat colitis induced by SPF bacteria in IL-10-/- mice and evaluated the effect of this probiotic organism on mucosal immune activation. Assessment of colitis included blinded histologic scores, measurements of secreted colonic immunoglobulin isotypes, IL-12 (p40 subunit), and interferon (IFN)-gamma production by anti-CD3-stimulated mesenteric lymph node cells. Treating SPF IL-10-/- mice with L. plantarum attenuated previously established colonic inflammation as manifested by decreased mucosal IL-12, IFN-gamma, and immunoglobulin G2a levels. Colonizing GF animals with L. plantarum and SPF flora simultaneously had no protective effects. Gnotobiotic IL-10-/- mice monoassociated with L. plantarum exhibited mild immune system activation but no colitis. Pretreatment of GF mice by colonization with L. plantarum, then exposure to SPF flora and continued probiotic therapy significantly decreased histologic colitis scores. These results demonstrate that L. plantarum can attenuate immune-mediated colitis and suggest a potential therapeutic role for this agent in clinical inflammatory bowel diseases.

Inflammatory bowel disease: is the intestine a Trojan horse?

Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory condition of the intestines that is clinically heterogenous. The cause(s) of IBD are currently unknown but the mechanisms of injury are immunological. Increasingly there is an emphasis on the study of the complex interactions at the interface of self and non-self--the gastrointestinal epithelial surface--in relationship to the pathogenesis of disease. There is mounting evidence that a lack of tolerance to the normal commensal flora of the intestine may underlie the disease pathogenesis. Several genetic loci that are markers of disease susceptibility have been identified. These loci map to areas of the genome that are concerned with antigen presentation or cytokine secretion and suggest a genetic heterogeneity that underlies the clinical differences. Overall a picture is emerging of defects in epithelial barrier function and, or immunoregulation leading to immune responses that are triggered or exaggerated by the antigenic components of the normal flora.