Probiotics as prevention and treatment for diarrhea

Hospital management of children with acute gastroenteritis

PURPOSE OF REVIEW

Acute gastroenteritis (AGE) is a major cause of ED visits, hospitalizations, and prescription of investigations, drugs, and changes in diet. Several guidelines on management have been produced.

RECENT FINDINGS

There is new information on different rehydration protocols, use of antiemetics, and antidiarrheal drugs that could reduce the burden of AGE. The need of intravenous (i.v.) rehydration is the main cause of hospital admission yet a standardized rehydration scheme is not available. Rehydration therapy through nasogastric tube is better than i.v. rehydration, in children with moderate-severe dehydration. Ultrarapid rehydration has been proposed by enteric or i.v. route to reduce the time in hospital and costs. However, reduced rehydration times are associated with high readmission rates and side effects. Antiemetics may reduce the need of i.v. rehydration because of vomiting and the number of hospital admissions. However, the main antiemetic, ondansetron, has been loaded with a warning for potentially severe side effects. Selected antidiarrheal drugs could reduce the length of stay, but data on their use in inpatients are still not conclusive.

SUMMARY

Inappropriate medical interventions are still common in the hospital setting and have a high impact on costs. A validated management is still needed in inpatients.

Probiotic cheese attenuates exercise-induced immune suppression in Wistar rats

Intense physical activity results in a substantial volume of stress and hence a significant probability of immunosuppression in athletes, with milk proteins being, perhaps, the most recommended protein supplements. Consumption of a probiotic cheese can attenuate immune suppression induced by exhausting exercise in rats. A popular Brazilian fresh cheese (Minas Frescal cheese) containing Lactobacillus acidophilus LA14 and Bifidobacterium longum BL05 was fed for 2wk to adult Wistar rats, which then were brought to exhaustion on the treadmill. Two hours after exhaustion, the rats were killed and material was collected for the determination of serum uric acid, total and high-density lipoprotein cholesterol fraction, total protein, triacylglycerols, aspartate aminotransferase, alanine aminotransferase, creatine kinase, and blood cell (monocyte, lymphocyte, neutrophil, and leukocyte) counts. Exercise was efficient in reducing lymphocyte counts, irrespective of the type of ingested cheese, but the decrease in the group fed the probiotic cheese was 22% compared with 48% in the animals fed regular cheese. Monocyte counts were unaltered in the rats fed probiotic cheese compared with a significant decrease in the rats fed the regular cheese. Most importantly, ingestion of the probiotic cheese resulted in a >100% increase in serum high-density lipoprotein cholesterol and a 50% decrease in triacylglycerols. We conclude that probiotic Minas Frescal cheese may be a viable alternative to enhance the immune system and could be used to prevent infections, particularly those related to the physical overexertion of athletes.

Comparison of the fecal microbiota of healthy horses and horses with colitis by high throughput sequencing of the V3-V5 region of the 16S rRNA gene

The intestinal tract houses one of the richest and most complex microbial populations on the planet, and plays a critical role in health and a wide range of diseases. Limited studies using new sequencing technologies in horses are available. The objective of this study was to characterize the fecal microbiome of healthy horses and to compare the fecal microbiome of healthy horses to that of horses with undifferentiated colitis. A total of 195,748 sequences obtained from 6 healthy horses and 10 horses affected by undifferentiated colitis were analyzed. Firmicutes predominated (68%) among healthy horses followed by Bacteroidetes (14%) and Proteobacteria (10%). In contrast, Bacteroidetes (40%) was the most abundant phylum among horses with colitis, followed by Firmicutes (30%) and Proteobacteria (18%). Healthy horses had a significantly higher relative abundance of Actinobacteria and Spirochaetes while horses with colitis had significantly more Fusobacteria. Members of the Clostridia class were more abundant in healthy horses. Members of the Lachnospiraceae family were the most frequently shared among healthy individuals. The species richness reported here indicates the complexity of the equine intestinal microbiome. The predominance of Clostridia demonstrates the importance of this group of bacteria in healthy horses. The marked differences in the microbiome between healthy horses and horses with colitis indicate that colitis may be a disease of gut dysbiosis, rather than one that occurs simply through overgrowth of an individual pathogen.

Microbial ecology and host-microbiota interactions during early life stages

The role of human microbiota has been redefined during recent years and its physiological role is now much more important than earlier understood. Intestinal microbial colonization is essential for the maturation of immune system and for the developmental regulation of the intestinal physiology. Alterations in this process of colonization have been shown to predispose and increase the risk to disease later in life. The first contact of neonates with microbes is provided by the maternal microbiota. Moreover, mode of delivery, type of infant feeding and other perinatal factors can influence the establishment of the infant microbiota. Taken into consideration all the available information it could be concluded that the exposure to the adequate microbes early in gestation and neonatal period seems to have a relevant role in health. Maternal microbial environment affects maternal and fetal immune physiology and, of relevance, this interaction with microbes at the fetal-maternal interface could be modulated by specific microbes administered to the pregnant mother. Indeed, probiotic interventions aiming to reduce the risk of immune-mediated diseases may appear effective during early life.

Nosocomial diarrhea: a review of pathophysiology, etiology, and treatment strategies

Diarrhea is a frequent complication among hospitalized patients. Nosocomial diarrhea is generally diagnosed as increased frequency and decreased consistency of stools developing after 72 hours of hospitalization. The causes of nosocomial diarrhea may be infectious or noninfectious. Noninfectious etiologies occur most commonly, and are often adverse effects of medications or enteral nutrition therapies. Infectious etiologies are most concerning and include Clostridium difficile and norovirus. Patients with nosocomial diarrhea should be placed in isolation with contact precautions in place until the presence of C difficile infection is determined. Irrespective of etiology, diarrhea can cause serious complications in hospitalized patients, including malnutrition, hemodynamic instability, metabolic acidosis, and potentially fatal pseudomembranous colitis. This article reviews nosocomial diarrhea, including its pathophysiology, infectious and noninfectious causes, and treatment strategies based on identified cause.

Randomized trial of probiotics and calcium on diarrhea and respiratory tract infections in Indonesian children

OBJECTIVE

To investigate the effects of calcium and probiotics on the incidence and duration of acute diarrhea and acute respiratory tract infections (ARTIs) in low-socioeconomic communities of Jakarta, Indonesia.

METHODS

We conducted a 6-month, double-blind, placebo-controlled study in 494 healthy children aged 1 to 6 years who received low-lactose milk with low calcium content (LC; ∼50 mg/day; n = 124), regular calcium content (RC; ∼440 mg/day; n = 126), RC with 5.10(8) colony-forming units per day of Lactobacillus casei CRL431 (casei; n = 120), or RC with 5.10(8) colony-forming units per day of Lactobacillus reuteri DSM17938 (reuteri; n = 124). Number and duration of diarrhea and ARTIs episodes were primary and secondary outcomes, respectively.

RESULTS

Incidence of World Health Organization-defined diarrhea (≥3 loose/liquid stools in 24 hours) was not significantly different between RC and LC (relative risk [RR]: 0.99 [95% confidence interval (CI): 0.62-1.58]), between casei and RC (RR: 1.21 [95% CI: 0.76-1.92]), or between reuteri and RC (RR: 0.76 [95% CI: 0.46-1.25]) groups. Incidence of all reported diarrhea (≥2 loose/liquid stools in 24 hours) was significantly lower in the reuteri versus RC group (RR: 0.68 [95% CI: 0.46-0.99]). Irrespective of the definition used, reuteri significantly reduced diarrhea incidence in children with lower nutritional status (below-median height-and-weight-for-age z score). None of the interventions affected ARTIs.

CONCLUSIONS

RC milk, alone or with L casei, did not reduce diarrhea or ARTIs in Indonesian children. L reuteri may prevent diarrhea, especially in children with lower nutritional status.

Randomised clinical trial: efficacy of a new synbiotic formulation containing Lactobacillus paracasei B21060 plus arabinogalactan and xilooligosaccharides in children with acute diarrhoea

BACKGROUND

Acute diarrhoea is a frequent problem in children with heavy economic burden for families and society.

AIM

To test the efficacy of a new synbiotic formulation containing Lactobacillus paracasei B21060, arabinogalactan and xilooligosaccharides in children with acute diarrhoea.

METHODS

Double-blind, randomised, placebo-controlled trial, including children (age 3-36 m) with acute diarrhoea who were allocated to placebo or synbiotic group. Major outcome was resolution rate of diarrhoea at 72 h. Total duration of diarrhoea, daily stool outputs, stool consistency, working days lost by parents, adjunctive medications, and hospitalisation were also assessed.

RESULTS

We enrolled 55 children in placebo group and 52 in synbiotic group. The two groups were similar for demographic and clinical characteristics. Resolution rate of diarrhoea at 72 h was significantly higher in synbiotic group (67%) compared to placebo group (40%, P = 0.005). Children in synbiotic group showed a significant reduction in the duration of diarrhoea (90.5 h, 78.1-102.9 vs. 109.8 h, 96.0-123.5, P = 0.040), daily stool outputs (3.3, 2.8-3.8 vs. 2.4, 1.9-2.8, P = 0.005) and stool consistency (1.3, 0.9-1.6 vs. 0.6, 0.4-0.9, P = 0.002) compared to placebo group (data expressed as mean, 95% CI). Rate of parents that missed at least one working day (41.8% vs. 15.4%, P = 0.003), rate of children that needed adjunctive medications (25.5% vs. 5.8%, P = 0.005) or hospitalisation (10.9% vs. 0%, P = 0.014) after the first 72 h of treatment, were reduced in synbiotic group.

CONCLUSION

The synbiotic formulation studied is effective in children with acute diarrhoea. Australian New Zealand Clinical Trials Registry (ACTRN12611000641998).

Invited review: Application of omics tools to understanding probiotic functionality

The human gut microbiota comprises autochthonous species that colonize and reside at high levels permanently and allochthonous species that originate from another source and are transient residents of the human gut. The interactions between bacteria and the human host can be classified as a continuum from symbiosis and commensalism (mutualism) to pathogenesis. Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Recent advances in omics tools and sequencing techniques have furthered our understanding of probiotic functionality and the specific interactions between probiotics and their human hosts. Although it is known that not all probiotics use the same mechanisms to confer benefits on hosts, some specific mechanisms of action have been revealed through omic investigations. These include competitive exclusion, bacteriocin-mediated protection against intestinal pathogens, intimate interactions with mucin and the intestinal epithelium, and modulation of the immune system. The ability to examine fully sequenced and annotated genomes has greatly accelerated the application of genetic approaches to elucidate many important functional roles of probiotic microbes.

Rotavirus infection: an update on management and prevention

Rotavirus infection is the most common cause of severe diarrhea disease in infants and young children worldwide and continues to have a major global impact on childhood morbidity and mortality. Vaccination is the only control measure likely to have a significant impact on the incidence of severe dehydrating rotavirus disease. Rotavirus vaccines have reduced the burden of rotavirus disease in the United States. Long-term monitoring will need to continue to assess the effects of rotavirus immunization programs and epidemiologic strain surveillance is necessary to determine whether changes in strain ecology will affect the rotavirus vaccine effectiveness and whether rotaviruses with the ability to evade vaccine immunity emerge.

Savings from the use of a probiotic formula in the prophylaxis of antibiotic-associated diarrhea

OBJECTIVE

Antibiotic-associated diarrhea (AAD) and particularly Clostridium difficile-associated diarrhea (CDAD) are the most common causes of healthcare associated infectious diarrhea. A double-blind, dose response, placebo-controlled trial of the probiotic formula (Bio-K+ Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R formula) for prophylaxis of AAD and CDAD was published in 2010. The Bio-K+ Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R formula is a registered trademark of Bio-K Plus International Inc. (Laval, Québec, Canada). Results indicated that the incidence of AAD and CDAD were lower for patients assigned to the probiotic formula compared with the placebo option. The present study aims to estimate the savings in direct medical costs that might result from the use of two different doses of the probiotic formula vs placebo.

METHODS

A cost-consequence analysis was conducted to compare the two doses of the probiotic formula compared to placebo. The analysis was based upon published data and adjusted to the North American context.

RESULTS

Economic analyses showed that the use of the probiotic formula would result in estimated mean per patients savings of US$1968 for the single dose and US$2661 for the double dose compared with the placebo option if used an average of 13 days by all patients at risk of developing AAD and CDAD.

LIMITATIONS

Several key parameters considered within the economic model were not captured within the Gao et al. study. Numerous sensitivity analyses were conducted to address this issue.

CONCLUSION

The use of the probiotic formula in prophylaxis of AAD and CDAD would lead to estimated savings in direct medical costs that would substantially offset its acquisition cost. Treating 1000 hospitalized patients on antibiotics with the double dose of the product compared to current practice would save a single payer system the sum of $2,661,218.

Small intestinal segment perfusion test in piglets: future applications in studying probiotics-gut crosstalk in infectious diarrhoea?

Worldwide infectious diarrhoea, mainly caused by rotavirus and enterotoxigenic Escherichia coli (ETEC), accounts for a large part of deaths in children. ETEC is also the main cause of traveller's diarrhoea. Probiotics are promising for prevention and treatment of diarrhoea, but there is insufficient evidence to support the use of any specific probiotic or probiotics in general. Because of the sensitivity of suckling and weaned piglets for ETEC, piglets are a good model for infectious diarrhoea in infants and traveller's diarrhoea. Just as in human the efficacy of probiotics in diminishing diarrhoea and improving growth in suckling and weaned piglets is not uniform. A piglet model of infectious diarrhoea provides access to intestinal compartments that are not easily accessible in infants. In an in situ piglet model of secretory diarrhoea, the functional physiological response to ETEC and the concomitant host genome response to ETEC and probiotics may be tested. This will provide new insights in the complex crosstalk between ETEC, probiotics and the gut in the future.

The management of acute diarrhea in children in developed and developing areas: from evidence base to clinical practice

INTRODUCTION

Acute diarrhea remains a major problem in children and is associated with substantial morbidity, mortality and costs. While vaccination against rotavirus could reduce the burden of the disease, the persistent impact of intestinal infections requires effective treatment in adjunct to oral rehydration solutions, to reduce the severity and duration of diarrhea. Several therapeutic options have been proposed for acute diarrhea, but proof of efficacy is available for few of them, including zinc, diosmectite, selected probiotics and racecadotril. However, at present there is no universal drug, and therapeutic efficacy has only been shown for selected drugs in selected settings, such as: outpatients/inpatients, developed/developing countries and viral/bacterial etiology.

AREAS COVERED

This narrative review reports the opinions of experts from different countries of the world who have discussed strategies to improve the management of diarrhea.

EXPERT OPINION

More data are needed to optimize the management of diarrhea and highlight the research priorities at a global level; such priorities include improved recommendations on oral rehydration solution composition, and the reevaluation of therapeutic options in the light of new trials. Therapeutic strategies need to be assessed in different settings, and pharmacoeconomic analyses based on country-specific data are needed. Transfer to clinical practice should result from the implementation of guidelines tailored at a local level, with an eye on costs.

Effect of herbal extract granules combined with probiotic mixture on irritable bowel syndrome with diarrhea: study protocol for a randomized controlled trial

Background

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder characterized by abdominal pain and change of bowel habits without organic disease. Many patients seek alternative IBS treatments because of the limitations of conventional treatments. Gwakhyangjeonggisan (GJS), a herbal formula, has long been used for alleviating diarrhea-predominant IBS (D-IBS) in traditional medicine. Duolac7S, which comprises 7 bacterial species as probiotics, has been frequently used for D-IBS. Although GJS and Duolac7S have been administered simultaneously in many D-IBS patients, no study has investigated the effects of GJS and Duolac7S combination therapy on D-IBS.

Methods/Design

The current trial is a randomized, double-blinded, placebo-controlled, 4-arm study. After a 2-week run-in period, 60 patients with D-IBS will be randomly assigned to one of the 4 combination groups consisting of GJS (water extract granules, 3 g/pack, 3 times a day) with Duolac7S (powder form, 1 capsule, 2 times a day) or their placebos and followed up for 2 weeks. The assigned treatments will last for 8 weeks. The primary outcomes are adequate relief of IBS pain and discomfort and the proportion of responders (on a weekly basis). The secondary outcomes are visual analog scale for IBS symptoms (on a daily basis), quality of life (at 0, 8, and 10 weeks), intestinal permeability, and composition of intestinal microbiota (at 0 and 8 weeks).

Discussion

The present study is designed to examine the safety and efficacy of GJS and Duolac7S combination therapy on D-IBS. Our study provides the clinical evidence of a new therapeutic strategy for D-IBS.

Trial registration

ClinicalTrials.gov NCT01342718 .

Probiotic, zinc and lactose-free formula in children with rotavirus diarrhea: are they effective?

BACKGROUND

The aim of the present study was to evaluate the effectiveness of zinc, probiotic bacteria, and lactose-free formula and their different combinations in the treatment of rotavirus diarrhea in young children.

METHODS

Eight different treatment groups were formed: group 1, 60 patients receiving Saccharomyces boulardii; group 2, 60 patients receiving zinc; group 3, 60 patients receiving lactose-free formula; group 4, 60 patients receiving S. boulardii plus zinc; group 5, 60 patients receiving S. boulardii plus lactose-free formula; group 6, 60 patients receiving zinc plus lactose-free formula; group 7, 60 patients receiving S. boulardii plus zinc plus lactose-free formula; group 8, 60 patients receiving only oral and/or parenteral rehydration solutions.

RESULTS

No statistically significant differences were found in the time to resolution of fever after intervention between the treatment groups and the control group. The time to resolution of vomiting was significantly lower in group 4 compared with groups 1 and 5. The duration of diarrhea was significantly reduced in groups 2 and 4 compared to control. A statistically significant difference in the duration of hospitalization was observed for the groups 2 and 4 in comparison to the control group.

CONCLUSIONS

A different combination of adjunct therapies did not seem to bring additional value to rehydration therapy in children with rotavirus diarrhea except for in those receiving only zinc and zinc plus S. boulardii. Further studies are required to determine the optimal protocol of adjunct therapy use in children with rotavirus diarrhea.

Growth phase-associated changes in the proteome and transcriptome of Lactobacillus rhamnosus GG in industrial-type whey medium

The growth phase during which probiotic bacteria are harvested and consumed can strongly influence their performance as health‐promoting agents. In this study, global transcriptomic and proteomic changes were studied in the widely used probiotic Lactobacillus rhamnosus GG during growth in industrial‐type whey medium under strictly defined bioreactor conditions. The expression of 636 genes (P ≤ 0.01) and 116 proteins (P < 0.05) changed significantly over time. Of the significantly differentially produced proteins, 61 were associated with alterations at the transcript level. The most remarkable growth phase‐dependent changes occurred during the transition from the exponential to the stationary growth phase and were associated with the shift from glucose fermentation to galactose utilization and the transition from homolactic to mixed acid fermentation. Furthermore, several genes encoding proteins proposed to promote the survival and persistence of L. rhamnosus GG in the host and proteins that directly contribute to human health showed temporal changes in expression. Our results suggest that L. rhamnosus GG has a highly flexible and adaptable metabolism and that the growth stage during which bacterial cells are harvested and consumed should be taken into consideration to gain the maximal benefit from probiotic bacteria.

Modulation of NF-κB signalling by microbial pathogens

The nuclear factor-κB (NF-κB) family of transcription factors plays a central part in the host response to infection by microbial pathogens, by orchestrating the innate and acquired host immune responses. The NF-κB proteins are activated by diverse signalling pathways that originate from many different cellular receptors and sensors. Many successful pathogens have acquired sophisticated mechanisms to regulate the NF-κB signalling pathways by deploying subversive proteins or hijacking the host signalling molecules. Here, we describe the mechanisms by which viruses and bacteria micromanage the host NF-κB signalling circuitry to favour the continued survival of the pathogen.

Successful treatment of asymptomatic or clinically terminal bovine Mycobacterium avium subspecies paratuberculosis infection (Johne's disease) with the bacterium Dietzia used as a probiotic alone or in combination with dexamethasone: Adaption to chronic human diarrheal diseases

A naturally occurring gastrointestinal disease, primarily of ruminants (Johne disease), is a chronic debilitating disease that is caused by Mycobacterium avium subspecies paratuberculosis (MAP). MAP infection occurs primarily in utero and in newborns. Outside our Dietzia probiotic treatment, there are no preventive/curative therapies for bovine paratuberculosis. Interestingly, MAP is at the center of controversy as to its role in (cause of) Crohn disease (CD) and more recently, its role in diabetes, ulcerative colitis, and irritable bowel syndrome (IBS); the latter two, like CD, are considered to be a result of chronic intestinal inflammation. Treatments, both conventional and biologic agents, which induce and maintain remission are directed at curtailing processes that are an intricate part of inflammation. Most possess side effects of varying severity, lose therapeutic value, and more importantly, none routinely result in prevention and/or cures. Based on (a) similarities of Johne disease and Crohn disease, (b) a report that Dietzia inhibited growth of MAP under specific culture conditions, and (c) findings that Dietzia when used as a probiotic, (i) was therapeutic for adult bovine paratuberculosis, and (ii) prevented development of disease in MAP-infected calves, the goal of the present investigations was to design protocols that have applicability for IBD patients. Dietzia was found safe for cattle of all ages and for normal and immunodeficient mice. The results strongly warrant clinical evaluation as a probiotic, in combination with/without dexamethasone.

Probiotic Lactobacillus rhamnosus downregulates FCER1 and HRH4 expression in human mast cells

AIM: To investigate the effects of four probiotic bacteria and their combination on human mast cell gene expression using microarray analysis.

METHODS: Human peripheral-blood-derived mast cells were stimulated with Lactobacillus rhamnosus (L. rhamnosus) GG (LGG^®), L. rhamnosus Lc705 (Lc705), Propionibacterium freudenreichii ssp. shermanii JS (PJS) and Bifidobacterium animalis ssp. lactis Bb12 (Bb12) and their combination for 3 or 24 h, and were subjected to global microarray analysis using an Affymetrix GeneChip^® Human Genome U133 Plus 2.0 Array. The gene expression differences between unstimulated and bacteria-stimulated samples were further analyzed with GOrilla Gene Enrichment Analysis and Visualization Tool and MeV Multiexperiment Viewer-tool.

RESULTS: LGG and Lc705 were observed to suppress genes that encoded allergy-related high-affinity IgE receptor subunits α and γ (FCER1A and FCER1G, respectively) and histamine H4 receptor. LGG, Lc705 and the combination of four probiotics had the strongest effect on the expression of genes involved in mast cell immune system regulation, and on several genes that encoded proteins with a pro-inflammatory impact, such as interleukin (IL)-8 and tumour necrosis factor alpha. Also genes that encoded proteins with anti-inflammatory functions, such as IL-10, were upregulated.

CONCLUSION: Certain probiotic bacteria might diminish mast cell allergy-related activation by downregulation of the expression of high-affinity IgE and histamine receptor genes, and by inducing a pro-inflammatory response.

An update on management of severe acute infectious gastroenteritis in children

This article focuses on clinical and diagnostic aspects relevant to severe acute infectious gastroenteritis in children and will update treatment strategies focused on, although not limited to, anti-infective therapy. For the purposes of this article we will consider severe acute infectious gastroenteritis as follows: watery diarrhea accompanied by, or at high risk for, moderate to severe dehydration due to abrupt onset of vomiting that reduces oral intake, and/or frequent emission of liquid stools, or moderate to severe dysenteric/bloody diarrhea with moderate to high-grade fever. The article will not include food poisoning associated with bacterial toxins and will only briefly discuss oral rehydration strategies and intravenous solutions. The article will also briefly discuss current preventive measures against rotavirus gastroenteritis through vaccination, a topic that has been extensively discussed elsewhere.

Dose-response efficacy of a proprietary probiotic formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for antibiotic-associated diarrhea and Clostridium difficile-associated diarrhea prophylaxis in adult patients

OBJECTIVES

Standard therapies for antibiotic-associated diarrhea (AAD) and Clostridium difficile-associated diarrhea (CDAD) have limited efficacy. Probiotic prophylaxis is a promising alternative for reduction of AAD and CDAD incidence.

METHODS

In this single-center, randomized, double-blind, placebo-controlled dose-ranging study, we randomized 255 adult inpatients to one of three groups: two probiotic capsules per day (Pro-2, n=86), one probiotic capsule and one placebo capsule per day (Pro-1, n=85), or two placebo capsules per day (n=84). Each probiotic capsule contained 50 billion c.f.u. of live organisms (Lactobacillus acidophilus CL1285 +Lactobacillus casei LBC80R Bio-K+ CL1285). Probiotic prophylaxis began within 36 h of initial antibiotic administration, continued for 5 days after the last antibiotic dose, and patients were followed for an additional 21 days.

RESULTS

Pro-2 (15.5%) had a lower AAD incidence vs. Pro-1 (28.2%). Each probiotic group had a lower AAD incidence vs. placebo (44.1%). In patients who acquired AAD, Pro-2 (2.8 days) and Pro-1 (4.1 days) had shorter symptom duration vs. placebo (6.4 days). Similarly, Pro-2 (1.2%) had a lower CDAD incidence vs. Pro-1 (9.4%). Each treatment group had a lower CDAD incidence vs. placebo (23.8%). Gastrointestinal symptoms were less common in the treatment groups vs. placebo and in Pro-2 vs. Pro-1.

CONCLUSIONS

The proprietary probiotic blend used in this study was well tolerated and effective for reducing risk of AAD and, in particular, CDAD in hospitalized patients on antibiotics. A dose-ranging effect was shown with 100 billion c.f.u., yielding superior outcomes and fewer gastrointestinal events compared to 50 billion c.f.u. (ClinicalTrials.gov number NCT00958308).

Toxin-specific antibodies for the treatment of Clostridium difficile: current status and future perspectives

Therapeutic agents targeting bacterial virulence factors are gaining interest as non-antibiotic alternatives for the treatment of infectious diseases. Clostridium difficile is a Gram-positive pathogen that produces two primary virulence factors, enterotoxins A and B (TcdA and TcdB), which are responsible for Clostridium difficile-associated disease (CDAD) and are targets for CDAD therapy. Antibodies specific for TcdA and TcdB have been shown to effectively treat CDAD and prevent disease relapse in animal models and in humans. This review summarizes the various toxin-specific antibody formats and strategies under development, and discusses future directions for CDAD immunotherapy, including the use of engineered antibody fragments with robust biophysical properties for systemic and oral delivery.

Effects of probiotics on acquisition and spread of multiresistant enterococci

Ampicillin-resistant Enterococcus faecium (ARE) and vancomycin-resistant E. faecium (VRE) are important nosocomial pathogens. We quantified effects of probiotics and antibiotics on intestinal acquisition of ARE colonization in patients hospitalized in two non-intensive care unit (non-ICU) wards with high ARE prevalence. In a prospective cohort study with crossover design, all patients with a length of stay of >48 h were offered a multispecies probiotic product twice daily until discharge (4.5 months, intervention period) or not (4.5 months, control period). Perianal ARE carriage was determined <48 h after admission, twice weekly, and <48 h before discharge. The first isolates were genotyped by multiple-locus variable-number tandem repeat analysis (MLVA). Risk factors for acquisition were determined by Cox proportional hazards modeling, with special emphasis on ecological postantibiotic effects and delays between actual acquisition and culture positivity. Of 530 patients included, 94 (18%) were ARE colonized on admission. Of the remaining 436 noncolonized patients, 92 acquired ARE colonization: 28 (25%) of 110 probiotic users and 64 (20%) of 326 control patients (chi(2) test, P = 0.325). In all, 661 ARE strains were isolated from 186 patients, of which 186 were genotyped. In both wards, two MLVA types (MTs; MT1 and MT159) were responsible for >80% of acquisitions. Both MTs were genetically different from the probiotic E. faecium strain. Antibiotics to which ARE is resistant (hazard ratio [HR], 7.73 [95% confidence interval (CI), 4.52 to 13.22]), an ecological postantibiotic effect (HR, 7.11 [95% CI, 3.10 to 16.30]), and age (HR, 1.01 [95% CI, 0.99 to 1.02]) were associated with ARE acquisition. The HR of probiotics was 1.43 (95% CI, 0.88 to 2.34). In a setting with high selective antibiotic pressure, probiotics failed to prevent acquisition of multiresistant enterococci.

Host interactions of probiotic bacterial surface molecules: comparison with commensals and pathogens

How can probiotic bacteria transduce their health benefits to the host? Bacterial cell surface macromolecules are key factors in this beneficial microorganism-host crosstalk, as they can interact with host pattern recognition receptors (PRRs) of the gastrointestinal mucosa. In this Review, we highlight the documented signalling interactions of the surface molecules of probiotic bacteria (such as long surface appendages, polysaccharides and lipoteichoic acids) with PRRs. Research on host-probiotic interactions can benefit from well-documented host-microorganism studies that span the spectrum from pathogenicity to mutualism. Distinctions and parallels are therefore drawn with the interactions of similar molecules that are presented by gastrointestinal commensals and pathogens.

Clinical role of diosmectite in the management of diarrhea

BACKGROUND

Diosmectite (DS), an antidiarrheal absorbent natural clay, was proposed for treatment of acute gastroenteritis and more recently considered for diarrhea within the functional bowel disorder syndrome.

OBJECTIVE

To review pharmacology efficacy, mechanisms of action and safety of DS.

METHODS

We consulted PubMed/Medline using the keywords of smectite and diarrhea or gastroenteritis, and reviewed most recent recommendations by scientific societies.

CONCLUSIONS

Solid data show that DS is effective in infectious diarrhea, mainly as an ion antisecretory agent and in preventing intestinal damage. Despite clinical data being consistent and convincing, DS is not considered as first-line treatment because of the presence of alternative therapeutic options. However, it definitely may play a role in infectious colitis, where treatment options are less convincing. Some available evidences demonstrate a role of DS in functional diarrhea.

Comparative genomic analysis of Lactobacillus rhamnosus GG reveals pili containing a human- mucus binding protein

To unravel the biological function of the widely used probiotic bacterium Lactobacillus rhamnosus GG, we compared its 3.0-Mbp genome sequence with the similarly sized genome of L. rhamnosus LC705, an adjunct starter culture exhibiting reduced binding to mucus. Both genomes demonstrated high sequence identity and synteny. However, for both strains, genomic islands, 5 in GG and 4 in LC705, punctuated the colinearity. A significant number of strain-specific genes were predicted in these islands (80 in GG and 72 in LC705). The GG-specific islands included genes coding for bacteriophage components, sugar metabolism and transport, and exopolysaccharide biosynthesis. One island only found in L. rhamnosus GG contained genes for 3 secreted LPXTG-like pilins (spaCBA) and a pilin-dedicated sortase. Using anti-SpaC antibodies, the physical presence of cell wall-bound pili was confirmed by immunoblotting. Immunogold electron microscopy showed that the SpaC pilin is located at the pilus tip but also sporadically throughout the structure. Moreover, the adherence of strain GG to human intestinal mucus was blocked by SpaC antiserum and abolished in a mutant carrying an inactivated spaC gene. Similarly, binding to mucus was demonstrated for the purified SpaC protein. We conclude that the presence of SpaC is essential for the mucus interaction of L. rhamnosus GG and likely explains its ability to persist in the human intestinal tract longer than LC705 during an intervention trial. The presence of mucus-binding pili on the surface of a nonpathogenic Gram-positive bacterial strain reveals a previously undescribed mechanism for the interaction of selected probiotic lactobacilli with host tissues.

Acute infectious diarrhea in children

BACKGROUND

Acute infectious enteritis is one of the more common childhood diseases worldwide, especially in the first three years of life. Every year, in Germany, one in six children under age 5 is taken to a physician at least once because of infectious diarrheal disease. 10% of the children presenting with rotavirus infection are admitted to hospital. The existing national and international recommendations for the treatment of acute infectious diarrheal disease are inadequately followed, despite the high level of evidence on which they are based.

METHODS

Selective literature search based on national and international guidelines.

RESULTS AND CONCLUSIONS

The therapeutic goal is to replace the fluid and electrolyte losses resulting from diarrhea and vomiting. The administration of a hypotonic oral rehydration solution (ORS) is indicated to treat impending dehydration (infants aged up to 6 months with diarrhea and/or more than 8 watery stools in the last 24 hours and/or more than 4 episodes of vomiting in the last 24 hours), or when mild or moderate dehydration is already present. Oral rehydration with ORS given in frequent, small amounts over 3-4 hours is successful in more than 90% of cases. Regular feeding can be begun immediately afterward. Laboratory testing of blood or stool is usually unnecessary. Children who can be rehydrated orally or through a nasogastric tube should not be given intravenous fluids.

Identification of a Gene Cluster for the Biosynthesis of a Long, Galactose-Rich Exopolysaccharide in Lactobacillus rhamnosus GG and Functional Analysis of the Priming Glycosyltransferase

Cell surface polysaccharides have an established role as virulence factors in human bacterial pathogens. Less documented are the biosynthesis and biological functions of surface polysaccharides in beneficial bacteria. We identified a gene cluster that encodes the enzymes and regulatory and transporter proteins for the different steps in the biosynthesis of extracellular polysaccharides (EPS) of the well-documented probiotic strain Lactobacillus rhamnosus GG. Subsequent mutation of the welE gene, encoding the priming glycosyltransferase within this cluster, and comparative phenotypic analyses of wild-type versus mutant strains confirmed the specific function of this gene cluster in the biosynthesis of high-molecular-weight, galactose-rich heteropolymeric EPS molecules. The phenotypic analyses included monomer composition determination, estimation of the polymer length of the isolated EPS molecules, and single-molecule force spectroscopy of the surface polysaccharides. Further characterization of the welE mutant also showed that deprivation of these long, galactose-rich EPS molecules results in an increased adherence and biofilm formation capacity of L. rhamnosus GG, possibly because of less shielding of adhesins such as fimbria-like structures.

Colon in acute intestinal infection

The colon is actively implicated in intestinal infections not only as a target of enteric pathogens and their products but also as a target organ for treatment. In the presence of diarrhea, both of osmotic and secretory nature, the colon reacts with homeostatic mechanisms to increase ion absorption. These mechanisms can be effectively exploited to decrease fluid discharge. A model of intestinal infections using rotavirus (RV) in colonic cells was set up and used to define a dual model of secretory and osmotic diarrhea in sequence. Using this model, antidiarrheal drugs were tested, namely zinc and the enkephalinase inhibitor racecadotril. Zinc was able to decrease the enterotoxic activity responsible for secretory diarrhea. It also inhibited the cytotoxic effect of RV. The mechanism of zinc was related at least in part to the activation of MAPK activity, but also a direct antiviral effect was observed. Racecadotril showed a potent and selective inhibition of active secretion, being particularly effective in the first phase of RV diarrhea. The use of drugs active at the colonic level, therefore, offers effective options to treat intestinal infections in childhood. In addition, the colon is the natural site of colonic microflora, a target of probiotic therapy, which is the first line of approach recommended by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition to treat infectious diarrhea.