Benefits of a synbiotic formula (Synbiotic 2000Forte) in critically Ill trauma patients: early results of a randomized controlled trial

The role of probiotics in the prevention of severe infections following abdominal surgery

Administration of probiotics has been proposed for various medical and surgical conditions. Their effect has been largely attributed to their ability to maintain the integrity of the intestinal mucosal barrier as well as to modulate the innate immune response. Multiple studies have demonstrated their effect in reducing infectious complications in critically ill patients, minimising bacterial translocation and increasing the secretion of anti-inflammatory cytokines. Furthermore, they have been shown to be effective in reducing infections following colorectal surgery, while at the same time preventing overgrowth of bacterial species such as Pseudomonas aeruginosa that has been implicated in the pathogenesis of anastomotic leak. Recent experimental studies have demonstrated that probiotics may decrease expression of the SOCS3 gene, which encodes the protein SOCS3 that suppresses cytokine production, implying a direct interaction of probiotics with the innate immune system. These results hold high promises for the development of new therapeutic strategies.

Gut microbiome, surgical complications and probiotics

The trigger for infectious complications in patients following major abdominal operations is classically attributed to endogenous enteral bacterial translocation, due to the critical condition of the gut. Today, extensive gut microbiome analysis has enabled us to understand that almost all "evidence-based" surgical or medical intervention (antibiotics, bowel preparation, opioids, deprivation of nutrition), in addition to stress-released hormones, could affect the relative abundance and diversity of the enteral microbiome, allowing harmful bacteria to proliferate in the place of depressed beneficial species. Furthermore, these bacteria, after tight sensing of host stress and its consequent humoral alterations, can and do switch their virulence accordingly, towards invasion of the host. Probiotics are the exogenously given, beneficial clusters of live bacteria that, upon digestion, seem to succeed in partially restoring the distorted microbial diversity, thus reducing the infectious complications occurring in surgical and critically ill patients. This review presents the latest data on the interrelationship between the gut microbiome and the occurrence of complications after colon surgery, and the efficacy of probiotics as therapeutic instruments for changing the bacterial imbalance.

Probiotic and synbiotic therapy in critical illness: a systematic review and meta-analysis

Background

Critical illness is characterized by a loss of commensal flora and an overgrowth of potentially pathogenic bacteria, leading to a high susceptibility to nosocomial infections. Probiotics are living non-pathogenic microorganisms, which may protect the gut barrier, attenuate pathogen overgrowth, decrease bacterial translocation and prevent infection. The purpose of this updated systematic review is to evaluate the overall efficacy of probiotics and synbiotic mixtures on clinical outcomes in critical illness.

Methods

Computerized databases from 1980 to 2016 were searched. Randomized controlled trials (RCT) evaluating clinical outcomes associated with probiotic therapy as a single strategy or in combination with prebiotic fiber (synbiotics). Overall number of new infections was the primary outcome; secondary outcomes included mortality, ICU and hospital length of stay (LOS), and diarrhea. Subgroup analyses were performed to elucidate the role of other key factors such as probiotic type and patient mortality risk on the effect of probiotics on outcomes.

Results

Thirty trials that enrolled 2972 patients were identified for analysis. Probiotics were associated with a significant reduction in infections (risk ratio 0.80, 95 % confidence interval (CI) 0.68, 0.95, P = 0.009; heterogeneity I² = 36 %, P = 0.09). Further, a significant reduction in the incidence of ventilator-associated pneumonia (VAP) was found (risk ratio 0.74, 95 % CI 0.61, 0. 90, P = 0.002; I² = 19 %). No effect on mortality, LOS or diarrhea was observed. Subgroup analysis indicated that the greatest improvement in the outcome of infections was in critically ill patients receiving probiotics alone versus synbiotic mixtures, although limited synbiotic trial data currently exists.

Conclusion

Probiotics show promise in reducing infections, including VAP in critical illness. Currently, clinical heterogeneity and potential publication bias reduce strong clinical recommendations and indicate further high quality clinical trials are needed to conclusively prove these benefits.

Effect of probiotics on the incidence of ventilator-associated pneumonia in critically ill patients: a randomized controlled multicenter trial

PURPOSE

To evaluate the potential preventive effect of probiotics on ventilator-associated pneumonia (VAP).

METHODS

This was an open-label, randomized, controlled multicenter trial involving 235 critically ill adult patients who were expected to receive mechanical ventilation for ≥48 h. The patients were randomized to receive (1) a probiotics capsule containing live Bacillus subtilis and Enterococcus faecalis (Medilac-S) 0.5 g three times daily through a nasogastric feeding tube plus standard preventive strategies or (2) standard preventive strategies alone, for a maximum of 14 days. The development of VAP was evaluated daily, and throat swabs and gastric aspirate were cultured at baseline and once or twice weekly thereafter.

RESULTS

The incidence of microbiologically confirmed VAP in the probiotics group was significantly lower than that in the control patients (36.4 vs. 50.4 %, respectively; P = 0.031). The mean time to develop VAP was significantly longer in the probiotics group than in the control group (10.4 vs. 7.5 days, respectively; P = 0.022). The proportion of patients with acquisition of gastric colonization of potentially pathogenic microorganisms (PPMOs) was lower in the probiotics group (24 %) than the control group (44 %) (P = 0.004). However, the proportion of patients with eradication PPMO colonization on both sites of the oropharynx and stomach were not significantly different between the two groups. The administration of probiotics did not result in any improvement in the incidence of clinically suspected VAP, antimicrobial consumption, duration of mechanical ventilation, mortality and length of hospital stay.

CONCLUSION

Therapy with the probiotic bacteria B. Subtilis and E. faecalis are an effective and safe means for preventing VAP and the acquisition of PPMO colonization in the stomach.

Probiotics in critically ill children

Gut microflora contribute greatly to immune and nutritive functions and act as a physical barrier against pathogenic organisms across the gut mucosa. Critical illness disrupts the balance between host and gut microflora, facilitating colonization, overgrowth, and translocation of pathogens and microbial products across intestinal mucosal barrier and causing systemic inflammatory response syndrome and sepsis. Commonly used probiotics, which have been developed from organisms that form gut microbiota, singly or in combination, can restore gut microflora and offer the benefits similar to those offered by normal gut flora, namely immune enhancement, improved barrier function of the gastrointestinal tract (GIT), and prevention of bacterial translocation. Enteral supplementation of probiotic strains containing either Lactobacillus alone or in combination with Bifidobacterium reduced the incidence and severity of necrotizing enterocolitis and all-cause mortality in preterm infants. Orally administered Lactobacillus casei subspecies rhamnosus, Lactobacillus reuteri, and Lactobacillus rhamnosus were effective in the prevention of late-onset sepsis and GIT colonization by Candida in preterm very low birth weight infants. In critically ill children, probiotics are effective in the prevention and treatment of antibiotic-associated diarrhea. Oral administration of a mix of probiotics for 1 week to children on broad-spectrum antibiotics in a pediatric intensive care unit decreased GIT colonization by Candida, led to a 50% reduction in candiduria, and showed a trend toward decreased incidence of candidemia. However, routine use of probiotics cannot be supported on the basis of current scientific evidence. Safety of probiotics is also a concern; rarely, probiotics may cause bacteremia, fungemia, and sepsis in immunocompromised critically ill children. More studies are needed to answer questions on the effectiveness of a mix versus single-strain probiotics, optimum dosage regimens and duration of treatment, cost effectiveness, and risk-benefit potential for the prevention and treatment of various critical illnesses.

Gut Microbiome: What We Do and Don't Know

Within the last decade, research regarding the human gut microbiome has exploded. While the gastrointestinal tract was once regarded simply as a digestive organ, new technologies have led the science world to wonder about the impact that the gut microbiota may have on human health and disease. The gut microbiome is now becoming known for its role in metabolism, immune defense, and behavior. From in utero variations to those that rapidly occur post partum, our gut microbiome changes with age, environment, stress, diet, and health status as well as medication exposure. This article reviews what is currently known regarding various influences on the gut microbiome and is meant to encourage the reader to further explore the unknown.

Synbiotics in Surgery for Chronic Pancreatitis: Are They Truly Effective? A Single-blind Prospective Randomized Control Trial

BACKGROUND

Postoperative infectious complications in patients undergoing pancreatic surgery are a significant cause for morbidity and mortality. Although synbiotics have beneficial effects on human health, their clinical value in surgical patients remains unclear given a paucity of applicable clinical studies.

AIM

To determine the impact of perioperative synbiotic therapy on postoperative infectious complications, morbidity and mortality in patients undergoing pancreatic surgery for chronic pancreatitis.

METHODS

A trial was conducted in patients with chronic calcific pancreatitis undergoing Frey's procedure. Group A received a specific synbiotic composition, 5 days prior and 10 days after the surgery. Group B received a placebo. Primary study endpoint was the occurrence of postoperative infection during the first 30 days. Secondary outcome measures were mortality, length of hospital stay, days in intensive care unit, and duration of antibiotic therapy. Using previously accrued data, with α of 0.05 and power 80%, the sample size was calculated as 35 patients for each group with a dropout rate of 10%.

RESULTS

Of the 79 patients enrolled, 75 completed the trial [group A (n = 39) and group B (n = 36)]. The incidence of postoperative infectious complications (12.8% vs 39%; P < 0.05), duration of antibiotics therapy (P < 0.05), and length of hospital stay (P < 0.05) were significantly lower in the synbiotic group.

CONCLUSIONS

Synbiotics significantly reduce septic complications, hospital stay, and antibiotic requirement in patients undergoing pancreatic surgery for chronic pancreatitis. Furthermore, basic and clinical research would clarify the underlying mechanisms of their therapeutic effect and define the appropriate conditions for use.

Modeling the impact of interventions against Acinetobacter baumannii transmission in intensive care units

The efficacy of infection control interventions against Acinetobacter baumannii remains unclear, despite such information being critical for effective prevention of the transmission of this pathogen. Mathematical modeling offers an alternative to clinical trials, which may be prohibitively expensive, unfeasible or unethical, in predicting the impact of interventions. Furthermore, it allows the ability to ask key “what if” questions to evaluate which interventions have the most impact. We constructed a transmission dynamic model to quantify the effects of interventions on reducing A. baumannii prevalence and the basic reproduction ratio (R₀) in intensive care units (ICUs). We distinguished between colonization and infection, and incorporated antibiotic exposure and transmission from free-living bacteria in the environment. Under the assumptions and parameterization in our model, 25% and 18% of patients are colonized and infected with A. baumannii, respectively; and R₀ is 1.4. Improved compliance with hand hygiene (≥87%), enhanced environmental cleaning, reduced length of ICU stay of colonized patients (≤ 10 days), shorter durations of antibiotic treatment of A. baumannii (≤6 days), and isolation of infected patients combined with cleaning of isolation rooms are effective, reducing R₀ to below unity. In contrast, expediting the recovery of the intestinal microbiota (e.g. use of probiotics) is not effective. This study represents a biologically realistic model of the transmission dynamics of A. baumannii, and the most comprehensive analysis of the effectiveness of interventions against this pathogen. Our study provides important data for designing effective infection control interventions.

Perioperative synbiotics decrease postoperative complications in periampullary neoplasms: a randomized, double-blind clinical trial

Periampullary neoplasms are rapidly progressive tumors with a poor prognosis and high morbidity and mortality rates, which have a negative influence on patient outcomes. Some probiotics and prebiotics have the ability to protect the intestinal barrier and prevent bacterial translocation, infection, and postoperative complications. We evaluated the use of synbiotics in a prospective, double-blind study of patients undergoing surgery for periampullary neoplasms (PNs) and assessed the effect of these agents on nutritional status, postoperative complications, antibiotic use, length of hospital stay, and mortality. Patients were randomized to receive probiotics and prebiotics-synbiotics--group S [Lactobacillus acidophilus 10, 1 × 10(9)CFU, Lactobacillus rhamnosus HS 111, 1 × 10(9) CFU, Lactobacillus casei 10, 1 × 10(9) CFU, Bifidobacterium bifidum, 1 × 10(9)CFU, and fructooligosaccharides (FOS) 100 mg]--or placebo-controls--group C, twice daily, for a total of 14 days. Risk, clinical status, and postoperative complication rates were assessed. Twenty-three patients were allocated to each group. The incidence of postoperative infection was significantly lower in group S (6 of 23 patients, 26.1%) than in group C (16 of 23 patients, 69.6%) (P = 0.00). Duration of antibiotic therapy was also shorter in group S (mean = 9 days vs. 15 days in group C; P = 0.01). Noninfectious complications were less common in group S (6 of 23 vs. 14 of 23 patients in group C; P = 0.03). Mean length of hospital stay was 12 ± 5 days in group S vs. 23 ± 14 days in group C (P = 0.00). No deaths occurred in group S, whereas 6 deaths occurred in group C (P = 0.02). Perioperative administration of synbiotics reduces postoperative mortality and complication rates in patients undergoing surgery for PNs.

Pre-treatment with probiotics prolongs survival after experimental infection by multidrug-resistant Pseudomonas aeruginosa in rodents: an effect on sepsis-induced immunosuppression

Based on several randomised clinical studies indicating benefit from oral probiotic intake for the prevention of hospital-acquired infections in critically ill patients, this study aimed to explain the mechanism of action of probiotics for the prevention of lethal experimental infection by multidrug-resistant (MDR) Pseudomonas aeruginosa. Experiments using an Escherichia coli strain susceptible to all antimicrobials were also conducted. C57BL/6 mice were pre-treated intraperitoneally with sterile water for injection or Lactobacillus plantarum. Survival was recorded and mice were sacrificed for measurement of apoptosis and tissue bacterial overgrowth and for isolation and culture of splenocytes for cytokine production. Experiments were repeated after pre-treatment with a commercial preparation of four probiotics (L. plantarum, Lactobacillus acidophilus, Saccharomyces boulardii and Bifidobacterium lactis; LactoLevure(®)). Peripheral blood mononuclear cells (PBMCs) of healthy volunteers were stimulated by heat-killed P. aeruginosa following pre-treatment with medium or probiotics. Pre-treatment with L. plantarum significantly prolonged survival after challenge by either MDR P. aeruginosa (66.7% vs. 31.3%; P=0.026) or E. coli (56.0% vs. 12.0%, P=0.003). Survival benefit was even more pronounced when mice were pre-treated with LactoLevure(®). Tissue bacterial outgrowth and apoptosis of white blood cells and splenocytes were not altered. TNFα and IL-10 production by splenocytes of mice pre-treated with probiotic was increased and IFNγ production was decreased. Pre-treatment with LactoLevure(®) restored production of IL-17. Stimulation of human PBMCs after probiotic pre-treatment was accompanied by reduced gene expression of SOCS3. The results suggest that the protective effect of probiotics is mediated through prevention of sepsis-induced immunosuppression.

Probiotics for preventing ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is common in intensive care units (ICUs). Some evidence indicates that probiotics may reduce the incidence of VAP. Several additional published studies have demonstrated that probiotics are safe and efficacious in preventing VAP in ICUs. We aimed to systematically summarise the results of all available data to generate the best evidence for the prevention of VAP.

OBJECTIVES

To evaluate the effectiveness and safety of probiotics for preventing VAP.

SEARCH METHODS

We searched CENTRAL (2014, Issue 8), MEDLINE (1948 to September week 1, 2014) and EMBASE (2010 to September 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing probiotics with placebo or another control (excluding RCTs that use probiotics in both study groups) to prevent VAP.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and the quality of trials, and extracted data.

MAIN RESULTS

We included eight RCTs, with 1083 participants. All studies compared a form of probiotic (Lactobacillus casei rhamnosus; Lactobacillus plantarum; Synbiotic 2000FORTE; Ergyphilus; combination Bifidobacterium longum + Lactobacillus bulgaricus + Streptococcus thermophilus) versus a control group (placebo; glutamine; fermentable fibre; peptide; chlorhexidine). The analysis of all RCTs showed that the use of probiotics decreased the incidence of VAP (odds ratio (OR) 0.70, 95% confidence interval (CI) 0.52 to 0.95, low quality evidence). However, the aggregated results were uncertain for ICU mortality (OR 0.84, 95% CI 0.58 to 1.22 very low quality evidence), in-hospital mortality (OR 0.78, 95% CI 0.54 to 1.14, very low quality evidence), incidence of diarrhoea (OR 0.72, 95% CI 0.47 to 1.09, very low quality evidence), length of ICU stay (mean difference (MD) -1.60, 95% CI -6.53 to 3.33, very low quality evidence), duration of mechanical ventilation (MD -6.15, 95% CI -18.77 to 6.47, very low quality evidence) and antibiotic use (OR 1.23, 95% CI 0.51 to 2.96, low quality evidence). Antibiotics for VAP were used for a shorter duration (in days) when participants received probiotics in one small study (MD -3.00, 95% CI -6.04 to 0.04). However, the CI of the estimated effect was too wide to exclude no difference with probiotics. There were no reported events of nosocomial probiotic infections in any included study.The overall methodological quality of the included studies, based on our 'Risk of bias' assessments, was moderate with half of the included studies rated as a 'low' risk of bias; however, we rated four included studies as a 'high' risk of bias across one or more of the domains. The study limitations, differences in probiotics administered and participants, and small sample sizes across the included studies mean that the power to detect a trend of overall effect may be limited and chance findings cannot be excluded.To explore the influence of some potential confounding factors in the studies, we conducted an intention-to-treat (ITT) analysis, which did not change the inference of per-protocol analysis. However, our sensitivity analysis did not indicate a significant difference between groups for instances of VAP.

AUTHORS' CONCLUSIONS

Evidence suggests that use of probiotics is associated with a reduction in the incidence of VAP. However, the quality of the evidence is low and the exclusion of the one study that did not provide a robust definition of VAP increased the uncertainty in this finding. The available evidence is not clear regarding a decrease in ICU or hospital mortality with probiotic use. Three trials reported on the incidence of diarrhoea and the pooled results indicate no clear evidence of a difference. The results of this meta-analysis do not provide sufficient evidence to draw conclusions on the efficacy and safety of probiotics for the prevention of VAP in ICU patients.

Lactobacillus rhamnosus GG and Bifidobacterium longum attenuate lung injury and inflammatory response in experimental sepsis

Introduction

Probiotic use to prevent nosocomial gastrointestinal and potentially respiratory tract infections in critical care has shown great promise in recent clinical trials of adult and pediatric patients. Despite well-documented benefits of probiotic use in intestinal disorders, the potential for probiotic treatment to reduce lung injury following infection and shock has not been well explored.

Objective

Evaluate if Lactobacillus rhamnosus GG (LGG) or Bifidobacterium longum (BL) treatment in a weanling mouse model of cecal ligation and puncture (CLP) peritonitis will protect against lung injury.

Methods

3 week-old FVB/N mice were orally gavaged with 200 µl of either LGG, BL or sterile water (vehicle) immediately prior to CLP. Mice were euthanized at 24 h. Lung injury was evaluated via histology and lung neutrophil infiltration was evaluated by myeloperoxidase (MPO) staining. mRNA levels of IL-6, TNF-α, MyD88, TLR-4, TLR-2, NFΚB (p50/p105) and Cox-2 in the lung analyzed via real-time PCR. TNF-α and IL-6 in lung was analyzed via ELISA.

Results

LGG and BL treatment significantly improved lung injury following experimental infection and sepsis and lung neutrophil infiltration was significantly lower than in untreated septic mice. Lung mRNA and protein levels of IL-6 and TNF-α and gene expression of Cox-2 were also significantly reduced in mice receiving LGG or BL treatment. Gene expression of TLR-2, MyD88 and NFΚB (p50/p105) was significantly increased in septic mice compared to shams and decreased in the lung of mice receiving LGG or BL while TLR-4 levels remained unchanged.

Conclusions

Treatment with LGG and BL can reduce lung injury following experimental infection and sepsis and is associated with reduced lung inflammatory cell infiltrate and decreased markers of lung inflammatory response. Probiotic therapy may be a promising intervention to improve clinical lung injury following systemic infection and sepsis.

Use of probiotics in the treatment of severe acute pancreatitis: a systematic review and meta-analysis of randomized controlled trials

Introduction

Necrotic tissue infection can worsen the prognosis of severe acute pancreatitis (SAP), and probiotics have been shown to be beneficial in reducing the infection rate in animal experiments and primary clinical trials. However, the results of multicenter randomized clinical trials have been contradictory. Our aim in this study was to systematically review and quantitatively analyze all randomized controlled trials with regard to important outcomes in patients with predicted SAP who received probiotics.

Methods

A systematic literature search of the PubMed, Embase and Cochrane Library databases was conducted using specific search terms. Eligible studies were randomized controlled trials that compared the effects of probiotic with placebo treatment in patients with predicted SAP. Mean difference (MD), risk ratio (RR) and 95% confidence interval (95% CI) were calculated using the Mantel-Haenszel fixed- and random-effects models. A meta-analysis on the use of probiotics in the treatment of critically ill patients was also performed to serve as a reference.

Results

In this study, 6 trials comprising an aggregate total of 536 patients were analyzed. Significant heterogeneities were observed in the type, dose, treatment duration and clinical effects of probiotics in these trials. Systematic analysis showed that probiotics did not significantly affect the pancreatic infection rate (RR = 1.19, 95% CI = 0.74 to 1.93; P = 0.47), total infections (RR = 1.09, 95% CI = 0.80 to 1.48; P = 0.57), operation rate (RR = 1.42, 95% CI = 0.43 to 3.47; P = 0.71), length of hospital stay (MD = 2.45, 95% CI = −2.71 to 7.60; P = 0.35) or mortality (RR = 0.72, 95% CI = 0.42 to 1.45; P = 0.25).

Conclusions

Probiotics showed neither beneficial nor adverse effects on the clinical outcomes of patients with predicted SAP. However, significant heterogeneity was noted between the trials reviewed with regard to the type, dose and treatment duration of probiotics, which may have contributed to the heterogeneity of the clinical outcomes. The current data are not sufficient to draw a conclusion regarding the effects of probiotics on patients with predicted SAP. Carefully designed clinical trials are needed to validate the effects of particular probiotics given at specific dosages and for specific treatment durations.

Bugs or drugs: are probiotics safe for use in the critically ill?

Probiotics are living microorganisms which have demonstrated many benefits in prevention, mitigation, and treatment of various disease states in critically ill populations. These diseases include antibiotic-associated diarrhea, Clostridium difficile diarrhea, ventilator-associated pneumonia, clearance of vancomycin-resistant enterococci from the GI tract, pancreatitis, liver transplant, major abdominal surgery, and trauma. However, their use has been severely limited due to a variety of factors including a general naïveté within the physician community, lack of regulation, and safety concerns. This article focuses on uses for probiotics in prevention and treatment, addresses current concerns regarding their use as well as proposing a protocol for safe use of probiotics in the critically ill patient.

Effect of a probiotic preparation (VSL#3) in critically ill patients: A randomized, double-blind, placebo-controlled trial (Pilot Study)

Objective: Reactive oxygen species (ROS) are a major contributing factor in diseases pathophysiology in critically ill patients. Oxidative stress usually occurs in critical illnesses, specifically during sepsis, and organ dysfunction. The anti-oxidative properties of probiotics may serve as a defense in intestine and overcome various oxidative stresses. The aim of this trial was to determine the effect of probiotics on inflammation, antioxidant capacity and lipid peroxidation in critically ill patients.

Methodology: Forty patients admitted to the intensive care unit were enrolled in this double-blind, randomized controlled trial. They were randomized to receive placebo or probiotic for 7 days. Serum levels of Total Antioxidant Capacity (TAC), Malodialdehyde (MDA), C-Reactive Protein (CRP) and Acute Physiology and Chronic Health Evaluation (APACHE II) score were measured before initiation of the study and on the 7^th day.

Results: There was a significant difference in CRP levels and APACHE II score between two groups at the end of the study (P= 0.003 and 0.001, respectively). There was not a significant difference in levels of TAC and MDA between two groups.

Conclusions: Administration of probiotics to critically ill patients caused reduction in inflammation and improvement of clinical outcome. However, there were not significant changes in markers of oxidative stress.

Probiotics for preventing ventilator-associated pneumonia: a systematic review and meta-analysis of high-quality randomized controlled trials

Background

Ventilator-associated pneumonia (VAP) is considered to be a worldwide issue along with the development of supportive ventilation. The preventing strategy is of great importance for its poor prognostic and difficulties in treatment. Probiotics have been advocated as one of the possible preventive measures. We conducted a systematic review and meta-analysis to explore the potential benefits of probiotics.

Methods

The databases, Web of science, PubMed, Ovid and Cochrane lib were searched for randomized controlled trials (RCTs) publications that compared the effectiveness of probiotics with placebo in the prevention of VAP. The incidence of VAP was considered as the primary endpoint, mortality, length of stay in intensive care units (ICUs), etiology of the infections were considered as secondary endpoints.

Results

A total of 844 patients from 5 trials were subjected to meta-analysis. Probiotics did not significantly decrease the incidence of VAP (RR 0.94, 95%CI 0.85-1.04, p=0.22), however, the administration of probiotics reduced the risk of VAP caused by Pseudomonas aeruginosa (P. aeruginosa) (RR 0.30, 95%CI 0.11-0.91, P=0.03). It failed to affect any other endpoints.

Conclusion

Probiotic prophylaxis of ventilator-associated pneumonia remained inconclusive and it failed to improve the prognosis of general mechanically ventilated patients. It was noteworthy that infections caused by P. aeruginosa was reduced by administration of probiotics. In further, it is recommended that advanced studies should exploit transformation in pathogenic microorganisms owing to administration of probiotics as well as the specific population.

The gut microbiome, kidney disease, and targeted interventions

The human gut harbors >100 trillion microbial cells, which influence the nutrition, metabolism, physiology, and immune function of the host. Here, we review the quantitative and qualitative changes in gut microbiota of patients with CKD that lead to disturbance of this symbiotic relationship, how this may contribute to the progression of CKD, and targeted interventions to re-establish symbiosis. Endotoxin derived from gut bacteria incites a powerful inflammatory response in the host organism. Furthermore, protein fermentation by gut microbiota generates myriad toxic metabolites, including p-cresol and indoxyl sulfate. Disruption of gut barrier function in CKD allows translocation of endotoxin and bacterial metabolites to the systemic circulation, which contributes to uremic toxicity, inflammation, progression of CKD, and associated cardiovascular disease. Several targeted interventions that aim to re-establish intestinal symbiosis, neutralize bacterial endotoxins, or adsorb gut-derived uremic toxins have been developed. Indeed, animal and human studies suggest that prebiotics and probiotics may have therapeutic roles in maintaining a metabolically-balanced gut microbiota and reducing progression of CKD and uremia-associated complications. We propose that further research should focus on using this highly efficient metabolic machinery to alleviate uremic symptoms.

Probiotic administration reduces mortality and improves intestinal epithelial homeostasis in experimental sepsis

BACKGROUND

Recent clinical trials indicate that probiotic administration in critical illness has potential to reduce nosocomial infections and improve clinical outcome. However, the mechanism(s) of probiotic-mediated protection against infection and sepsis remain elusive. The authors evaluated the effects of Lactobacillus rhamnosus GG (LGG) and Bifidobacterium longum (BL) on mortality, bacterial translocation, intestinal epithelial homeostasis, and inflammatory response in experimental model of septic peritonitis.

METHODS

Cecal ligation and puncture (n=14 per group) or sham laparotomy (n=8 per group) were performed on 3-week-old FVB/N weanling mice treated concomitantly with LGG, BL, or vehicle (orally gavaged). At 24 h, blood and colonic tissue were collected. In survival studies, mice were given probiotics every 24 h for 7 days (LGG, n=14; BL, n=10; or vehicle, n=13; shams, n=3 per group).

RESULTS

Probiotics significantly improved mortality after sepsis (92 vs. 57% mortality for LGG and 92 vs. 50% mortality for BL; P=0.003). Bacteremia was markedly reduced in septic mice treated with either probiotic compared with vehicle treatment (4.39±0.56 vs. 1.07±1.54; P=0.0001 for LGG; vs. 2.70±1.89; P=0.016 for BL; data are expressed as mean±SD). Sepsis in untreated mice increased colonic apoptosis and reduced colonic proliferation. Probiotics significantly reduced markers of colonic apoptosis and returned colonic proliferation to sham levels. Probiotics led to significant reductions in systemic and colonic inflammatory cytokine expression versus septic animals. Our data suggest that involvement of the protein kinase B pathway (via AKT) and down-regulation of Toll-like receptor 2/Toll-like receptor 4 via MyD88 in the colon may play mechanistic roles in the observed probiotic benefits.

CONCLUSIONS

Our data demonstrate that probiotic administration at initiation of sepsis can improve survival in pediatric experimental sepsis. The mechanism of this protection involves prevention of systemic bacteremia, perhaps via improved intestinal epithelial homeostasis, and attenuation of the local and systemic inflammatory responses.

Use of pro-/synbiotics as prophylaxis in patients undergoing colorectal resection for cancer: a meta-analysis of randomized controlled trials

AIMS

To estimate the efficacy of pro-/synbiotics treatment in patients undergoing colorectal resection, a meta-analysis of randomized controlled trials was conducted.

METHODS

An electronic search of PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Academic Search Premier, and China National Knowledge Infrastructure was performed, and RevMan 5.0 was used for statistical analysis.

RESULTS

Six studies including 361 patients undergoing elective colorectal surgery were retrieved. The combined analysis revealed that perioperative pro-/synbiotics administration had a positive effect on the incidence of diarrhea (OR 0.29, 95% CI 0.14 to 0.62, P=0.001), the incidence of symptomatic intestinal obstructions (OR 0.39, 95% CI 0.19 to 0.78, P=0.008), the incidence of operative total infections (OR 0.39, 95% CI: 0.22 to 0.68, P=0.0010), and pneumonia infection (OR 0.32, 95% CI 0.11 to 0.93, P=0.04). The regimen increased the numbers of Lactobacillus (MD 2.66, 95% CI: 2.13 to 3.18; P<0.00001), and decreased the counts of Enterobacteriaceae (MD -1.52, 95% CI: -1.93 to -1.11, P<0.00001). No significant differences were found between the two groups in septic morbidity, incision infection, perineal infection, intraabdominal infection, anastomotic leak, the first defecation time, length of hospital stay, mesenteric lymph nodes for bacterial translocation. No mortality related to pro-/synbiotics treatment was revealed in all studies.

CONCLUSIONS

Based on the meta-analysis, perioperatively use pro-/synbiotics as prophylaxis in patients undergoing colorectal resection improved clinical outcomes. The best preventive strategy (including species and the optimal dose) of pro-/synbiotics should be considered in future meta-analyses.

Lack of efficacy of probiotics in preventing ventilator-associated pneumonia probiotics for ventilator-associated pneumonia: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Ventilator-associated pneumonia (VAP) remains a common hazardous complication in patients who are mechanically ventilated and is associated with increased morbidity and mortality.We undertook a systematic review and meta-analysis of randomized controlled trials to evaluate the efficacy and safety of probiotics for the prevention of VAP.

METHODS

The PubMed and EMBASE databases were searched to identify randomized controlled trials comparing probiotics with control for VAP in adult patients undergoing mechanical ventilation.The primary outcome was the incidence of VAP. Secondary outcomes included ICU mortality,hospital mortality, urinary tract infection, catheter-related bloodstream infection, diarrhea, length of ICU stay, length of hospital stay, and duration of mechanical ventilation.

RESULTS

A total of 1,142 patients from seven trials were subjected to meta-analysis. Probiotics did not significantly decrease the incidence of VAP (OR, 0.82; 95% CI, 0.55-1.24; P 5 .35), with low heterogeneity among the studies ( I 2 5 36.5%, P 5 .15). Probiotics also did not appear to significantly alter any of the other meta-analysis end points.

CONCLUSIONS

The limited evidence suggests that probiotics show no beneficial effect in patients who are mechanically ventilated; thus, probiotics should not be recommended for routine clinical application. However, the results of this meta-analysis should be interpreted with caution because of the heterogeneity among study designs. Future studies should focus on the safety of probiotics.

Impact of the administration of probiotics on mortality in critically ill adult patients: a meta-analysis of randomized controlled trials

BACKGROUND

The objective of this study was to systematically review and quantitatively synthesize all randomized controlled trials (RCTs) that have compared important outcomes in critically ill patients who received an administration of probiotics.

METHODS

A systematic literature search of PubMed, Scopus, and the Cochrane Central Register of Controlled Trials was conducted using specific search terms. Eligible studies were RCTs that compared the effect of prebiotics, probiotics, or synbiotics administration with control on ICU and hospital mortality rates in critically ill adult patients. Weighted mean differences (WMDs), pooled ORs, and 95% CIs were calculated using the Mantel-Haenszel fixed- and random-effects models.

RESULTS

Thirteen trials with 1,439 patients were analyzed. Probiotics did not significantly reduce ICU (OR, 0.85; 95% CI, 0.63-1.15) or hospital (OR, 0.90; 95% CI, 0.65-1.23) mortality. By contrast, probiotics administration reduced the incidence of ICU-acquired pneumonia (OR, 0.58; 95% CI, 0.42-0.79) and was associated with a shorter stay in the ICU (WMD, -1.49 days; 95% CI, -2.12 to -0.87 days). Finally, probiotics use was not associated with a shorter duration of mechanical ventilation (WMD, -0.18 days; 95% CI, -1.72-1.36 days) or a shorter hospital length of stay (WMD, -0.45 days; 95% CI, -1.41-0.52 days).

CONCLUSIONS

The present meta-analysis suggests that the administration of probiotics did not significantly reduce ICU or hospital mortality rates but did reduce the incidence of ICU-acquired pneumonia and ICU length of stay.

Probiotics: a new way to fight bacterial pulmonary infections?

Antibiotics, of which Fleming has identified the first representative, penicillin, in 1928, allowed dramatical improvement of the treatment of patients presenting with infectious diseases. However, once an antibiotic is used, resistance may develop more or less rapidly in some bacteria. It is thus necessary to develop therapeutic alternatives, such as the use of probiotics, defined by the World Health Organization (WHO) as "micro-organisms which, administered live and in adequate amounts, confer a benefit to the health of the host". The scope of these micro-organisms is broad, concerning many areas including that of infectious diseases, especially respiratory infections. We describe the rational use of probiotics in respiratory tract infections and detail the results of various clinical studies describing the use of probiotics in the management of respiratory infections such as nosocomial or community acquired pneumonia, or on specific grounds such as cystic fibrosis. The results are sometimes contradictory, but the therapeutic potential of probiotics seems promising. Implementing research to understand their mechanisms of action is critical to conduct therapeutic tests based on a specific rational for the strains to be used, the dose, as well as the chosen mode and rhythm of administration.

Controversies in the management of the critically ill: the role of probiotics

Probiotics are commercially available, viable, non-pathogenic micro-organisms that, when ingested in sufficient quantities, exert a health benefit to the host derived through modification of the gut flora, local release of antimicrobial factors, maintenance of integrity of the gut barrier, competition for epithelial adherence, prevention of bacterial translocation, and modulation of the local immune response. In critically ill patients, probiotics appear to lead to decreased susceptibility to antibiotic-associated diarrhoea, Clostridium difficile infections, ventilator-associated pneumonia, necrotising enterocolitis, acute severe pancreatitis, sepsis and multiple organ dysfunction syndrome as well as a shortened duration of infections. Current scientific evidence supporting the use of probiotics is not conclusive and is mainly derived from single-centre, not very well designed trials that are limited by many factors including small sample sizes, heterogeneity in the probiotic strains used, effectiveness of the combined strains, optimum dose regimens, frequency and duration of administration, and certainly incomplete knowledge of the mechanism of action of each strain. Probiotics appear to be well tolerated, whilst adverse events are very rare. The most commonly reported adverse events include bacteraemia, fungaemia and sepsis. At present, based on the available evidence and although helpful and relatively safe for certain disease conditions, routine use of probiotics in the critically ill is not recommended.

Disease-specific nutrition therapy: one size does not fit all

INTRODUCTION

The delivery of adequate nutrition is an integral part of the care of the critically ill surgical patient, and the provision of nutrition may have a greater impact on outcome than many other therapies commonly employed in the treatment of certain disease states.

METHODS

A review of the existing literature was performed to summarize the evidence for utilizing disease-specific nutrition in critically ill surgical patients.

RESULTS

Enteral nutrition, unless specifically contraindicated, is always preferable to parenteral nutrition. Methodological heterogeneity and conflicting results plague research in immunonutrition, and routine use is not currently recommended in critically ill patients.

CONCLUSION

There is currently insufficient evidence to recommend the routine initial use of most disease-specific formulas, as most patients with the disease in question will tolerate standard enteral formulas. However, the clinician should closely monitor for signs of intolerance and utilize disease-specific formulas when appropriate.

Probiotics in the critically ill: a systematic review of the randomized trial evidence

OBJECTIVE

Critical illness results in changes to the microbiology of the gastrointestinal tract, leading to a loss of commensal flora and an overgrowth of potentially pathogenic bacteria. Administering certain strains of live bacteria (probiotics) to critically ill patients may restore balance to the microbiota and have positive effects on immune function and gastrointestinal structure and function. The purpose of this systematic review was to evaluate the effect of probiotics in critically ill patients on clinical outcomes.

DESIGN

Systematic review.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We searched computerized databases, reference lists of pertinent articles, and personal files from 1980 to 2011. We included randomized controlled trials enrolling critically ill adults, which evaluated probiotics compared to a placebo and reported clinically important outcomes (infections, mortality, and length of stay). A total of 23 randomized controlled trials met inclusion criteria. Probiotics were associated with reduced infectious complications as documented in 11 trials (risk ratio 0.82; 95% confidence interval 0.69-0.99; p = .03; test for heterogeneity p = .05; I 44%). When data from the seven trials reporting ventilator-associated pneumonia were pooled, ventilator-associated pneumonia rates were also significantly reduced with probiotics (risk ratio 0.75; 95% confidence interval 0.59-0.97; p = .03; test for heterogeneity p = .16; I 35%). Probiotics were associated with a trend toward reduced intensive care unit mortality (risk ratio 0.80; 95% confidence interval 0.59-1.09; p = .16; test for heterogeneity p = .89; I 0%) but did not influence hospital mortality. Probiotics had no effect on intensive care unit or hospital length of stay. Compared to trials of higher methodological quality, greater treatment effects were observed in trials of a lower methodological quality.

CONCLUSIONS

Probiotics appear to reduce infectious complications including ventilator-associated pneumonia and may influence intensive care unit mortality. However, clinical and statistical heterogeneity and imprecise estimates preclude strong clinical recommendations. Further research on probiotics in the critically ill is warranted.

Nutrition of the critically ill &#8212; a 21st-century perspective

Health care-induced diseases constitute a fast-increasing problem. Just one type of these health care-associated infections (HCAI) constitutes the fourth leading cause of death in Western countries. About 25 million individuals worldwide are estimated each year to undergo major surgery, of which approximately 3 million will never return home from the hospital. Furthermore, the quality of life is reported to be significantly impaired for the rest of the lives of those who, during their hospital stay, suffered life-threatening infections/sepsis. Severe infections are strongly associated with a high degree of systemic inflammation in the body, and intimately associated with significantly reduced and malfunctioning GI microbiota, a condition called dysbiosis. Deranged composition and function of the gastrointestinal microbiota, occurring from the mouth to the anus, has been found to cause impaired ability to maintain intact mucosal membrane functions and prevent leakage of toxins - bacterial endotoxins, as well as whole bacteria or debris of bacteria, the DNA of which are commonly found in most cells of the body, often in adipocytes of obese individuals or in arteriosclerotic plaques. Foods rich in proteotoxins such as gluten, casein and zein, and proteins, have been observed to have endotoxin-like effects that can contribute to dysbiosis. About 75% of the food in the Western diet is of limited or no benefit to the microbiota in the lower gut. Most of it, comprised specifically of refined carbohydrates, is already absorbed in the upper part of the GI tract, and what eventually reaches the large intestine is of limited value, as it contains only small amounts of the minerals, vitamins and other nutrients necessary for maintenance of the microbiota. The consequence is that the microbiota of modern humans is greatly reduced, both in terms of numbers and diversity when compared to the diets of our paleolithic forebears and the individuals living a rural lifestyle today. It is the artificial treatment provided in modern medical care - unfortunately often the only alternative provided - which constitute the main contributors to a poor outcome. These treatments include artificial ventilation, artificial nutrition, hygienic measures, use of skin-penetrating devices, tubes and catheters, frequent use of pharmaceuticals; they are all known to severely impair the microbiomes in various locations of the body, which, to a large extent, are ultimately responsible for a poor outcome. Attempts to reconstitute a normal microbiome by supply of probiotics have often failed as they are almost always undertaken as a complement to - and not as an alternative to - existing treatment schemes, especially those based on antibiotics, but also other pharmaceuticals.

Probiotic/synbiotic therapy for treating critically ill patients from a gut microbiota perspective

The gut is an important target organ for stress caused by severe insults such as sepsis, trauma, burn, shock, bleeding and infection. Severe insult to the gut is considered to have an important role in promoting infectious complications and multiple organ dysfunction syndrome. These are sequelae of interactions between deteriorated intestinal epithelium, the immune system and commensal bacteria. The gut is the "motor" of multiple organ failure, and now it is recognized that gut dysfunction is a causative factor in disease progression. The gut flora and environment are significantly altered in critically ill patients, and the number of obligate anaerobes is associated with prognosis. Synbiotic therapy is a combination of probiotics and prebiotics. Probiotic, prebiotic and synbiotic treatment has been shown to be a promising therapy to maintain and repair the gut microbiota and gut environment. In the critically ill, such as major abdominal surgery, trauma and ICU patients, synbiotic therapy has been shown to significantly reduce septic complications. Further basic and clinical research would clarify the underlying mechanisms of the therapeutic effect of probiotic/synbiotic treatment and define the appropriate conditions for use.

Probiotics, prebiotics, synbiotics: is there enough evidence to support their use in colorectal cancer surgery?

BACKGROUND/AIMS

Pro-/pre-/synbiotics supplementation seems to provide beneficial effects in various aspects of abdominal pathology. Skepticism exists with respect to their effects on colorectal cancer (CRC) patients. This review presents the potential clinical applications of pro-/pre-/synbiotics in CRC surgery.

METHODS

A literature search of electronic databases was conducted and all studies published on 'probiotics', 'prebiotics' and 'synbiotics' were collected. Among them, the ones referring to CRC and which had any clinical relevance offering information on perioperative parameters were used.

RESULTS

Incorporation of pre-/pro-/synbiotic formulations in the preoperative mechanical bowel preparation cannot be supported by the current evidence. Limited clinical studies may be promising in supporting their potentially protective role against postoperative infectious complications. Encouraging are the results on their protective role against adjuvant (chemo)radiation-induced diarrhea. Such supplementation may also hold promise to improve postcolectomy gastrointestinal related quality of life.

CONCLUSIONS

Despite the positive results and plethora of agents, bacterial combinations and concentrations, the inconsistency in administration, the inhomogeneity of comparison groups and lack of stringent clinical endpoints remain obstacles in the effort to establish a definitive clinical strategy at this time. Further work is warranted to gain a keen understanding of their clinical value in CRC patients.

Nutrition of the critically ill - emphasis on liver and pancreas

About 25 million individuals undergo high risk surgery each year. Of these about 3 million will never return home from hospital, and the quality of life for many of those who return is often significantly impaired. Furthermore, many of those who manage to leave hospital have undergone severe life-threatening complications, mostly infections/sepsis. The development is strongly associated with the level of systemic inflammation in the body, which again is entirely a result of malfunctioning GI microbiota, a condition called dysbiosis, with deranged composition and function of the gastrointestinal microbiota from the mouth to the anus and impaired ability to maintain intact mucosal membrane functions and prevent leakage of toxins-bacterial endotoxins and whole or debris of bacteria, but also foods containing proteotoxins gluten, casein and zein and heat-induced molecules such as advanced glycation end products (AGEs) and advanced lipoxidation end products (ALEs). Markedly lower total anaerobic bacterial counts, particularly of the beneficial Bifidobacterium and Lactobacillus and higher counts of total facultative anaerobes such as Staphylococcus and Pseudomonas are often observed when analyzing the colonic microbiota. In addition Gram-negative facultative anaerobes are commonly identified microbial organisms in mesenteric lymph nodes and at serosal "scrapings" at laparotomy in patients suffering what is called "Systemic inflammation response system" (SIRS). Clearly the outcome is influenced by preexisting conditions in those undergoing surgery, but not to the extent as one could expect. Several studies have for example been unable to find significant influence of pre-existing obesity. The outcome seems much more to be related to the life-style of the individual and her/his "maintenance" of the microbiota e.g., size and diversity of microbiota, normal microbiota, eubiosis, being highly preventive. About 75% of the food Westerners consume does not benefit microbiota in the lower gut. Most of it, refined carbohydrates, is already absorbed in the upper part of the GI tract, and of what reaches the large intestine is of limited value containing less minerals, less vitamins and other nutrients important for maintenance of the microbiota. The consequence is that the microbiota of modern man has a much reduced size and diversity in comparison to what our Palelithic forefathers had, and individuals living a rural life have today. It is the artificial treatment provided by modern care, unfortunately often the only alternative, which belongs to the main contributor to poor outcome, among them; artificial ventilation, artificial nutrition, hygienic measures, use of skin penetrating devices, tubes and catheters, frequent use of pharmaceuticals, all known to significantly impair the total microbiome of the body and dramatically contribute to poor outcome. Attempts to reconstitute a normal microbiome have often failed as they have always been undertaken as a complement to and not an alternative to existing treatment schemes, especially treatments with antibiotics. Modern nutrition formulas are clearly too artificial as they are based on mixture of a variety of chemicals, which alone or together induce inflammation. Alternative formulas, based on regular food ingredients, especially rich in raw fresh greens, vegetables and fruits and with them healthy bacteria are suggested to be developed and tried.

Synbiotic therapy reduces the pathological gram-negative rods caused by an increased acetic acid concentration in the gut

BACKGROUND

The mechanisms for the improvement of the gut flora and the intestinal environment by synbiotic therapy are unclear.

AIMS

This study evaluated the changes in the gut flora and the intestinal environment after synbiotic therapy, and tried to clarify the mechanisms by which synbiotic therapy reduces pathological bacteria in the gut.

METHODS

A total of 47 enteral feeding patients with long-term mechanical ventilation support were enrolled in the study. Patients were randomly assigned to synbiotic and control groups, at a two to one ratio. Patients in the synbiotic group were administrated Lactobacillus, Bifidobacterium, and galactooligosaccharides as synbiotics for 8 weeks.

RESULTS

The characteristics of the patients were not significantly different between the control (n = 16) and synbiotic (n = 31) groups. In the synbiotic group, the counts of Bifidobacterium and Lactobacillus in the gut increased significantly to 100 times the initial level following synbiotic treatment. The acetic acid concentration increased (71.1 ± 15.9 vs. 46.8 ± 24.1 μmol/g) and pH decreased in the gut in comparison with the control group. The concentration of acetic acid in the gut increased in proportion to the Bifidobacterium counts. The counts of pathological gram-negative rod decreased significantly to one-tenth of the initial level in inverse proportion to the Bifidobacterium counts. Furthermore, the amount of Pseudomonas aeruginosa in the lower respiratory tract decreased significantly after synbiotic therapy compared to the controls.

CONCLUSION

Synbiotic therapy reduces the pathological Gram-negative rods by increasing the acetic acid concentration in association with an increased counts of Bifidobacterium.

Gut microbiota, immune development and function

The microbiota of Westerners is significantly reduced in comparison to rural individuals living a similar lifestyle to our Paleolithic forefathers but also to that of other free-living primates such as the chimpanzee. The great majority of ingredients in the industrially produced foods consumed in the West are absorbed in the upper part of small intestine and thus of limited benefit to the microbiota. Lack of proper nutrition for microbiota is a major factor under-pinning dysfunctional microbiota, dysbiosis, chronically elevated inflammation, and the production and leakage of endotoxins through the various tissue barriers. Furthermore, the over-comsumption of insulinogenic foods and proteotoxins, such as advanced glycation and lipoxidation molecules, gluten and zein, and a reduced intake of fruit and vegetables, are key factors behind the commonly observed elevated inflammation and the endemic of obesity and chronic diseases, factors which are also likely to be detrimental to microbiota. As a consequence of this lifestyle and the associated eating habits, most barriers, including the gut, the airways, the skin, the oral cavity, the vagina, the placenta, the blood-brain barrier, etc., are increasingly permeable. Attempts to recondition these barriers through the use of so called 'probiotics', normally applied to the gut, are rarely successful, and sometimes fail, as they are usually applied as adjunctive treatments, e.g. in parallel with heavy pharmaceutical treatment, not rarely consisting in antibiotics and chemotherapy. It is increasingly observed that the majority of pharmaceutical drugs, even those believed to have minimal adverse effects, such as proton pump inhibitors and anti-hypertensives, in fact adversely affect immune development and functions and are most likely also deleterious to microbiota. Equally, it appears that probiotic treatment is not compatible with pharmacological treatments. Eco-biological treatments, with plant-derived substances, or phytochemicals, e.g. curcumin and resveratrol, and pre-, pro- and syn-biotics offers similar effects as use of biologicals, although milder but also free from adverse effects. Such treatments should be tried as alternative therapies; mainly, to begin with, for disease prevention but also in early cases of chronic diseases. Pharmaceutical treatment has, thus far, failed to inhibit the tsunami of endemic diseases spreading around the world, and no new tools are in sight. Dramatic alterations, in direction of a paleolithic-like lifestyle and food habits, seem to be the only alternatives with the potential to control the present escalating crisis. The present review focuses on human studies, especially those of clinical relevance.

Probiotics for infectious diseases: more drugs, less dietary supplementation

According to current definitions, probiotics are live microorganisms that, when ingested in adequate quantities, exert a health benefit to the host. The action of probiotics in the host is exerted by three mechanisms: modulation of the content of gut microbiota; maintenance of the integrity of the gut barrier and prevention of bacterial translocation; and modulation of the local immune response by the gut-associated immune system. Regarding their role for the prevention and treatment of infectious diseases, adequate evidence coming from randomised clinical trials (RCTs) is available for antibiotic-associated diarrhoea (AAD), Clostridium difficile infection (CDI), acute gastroenteritis and infectious complications following admission to the Intensive Care Unit (ICU). Existing evidence supports their role for decreasing the incidence of AAD and CDI when administered in parallel with antimicrobials. They also shorten the duration of symptoms when administered in paediatric populations with acute gastroenteritis, particularly of rotavirus aetiology. Available evidence is not sufficient to support administration for the management of CDI. Regarding populations of critically ill patients, data from many RCTs suggest a decrease of infectious complications by starting feeding with probiotics following ICU admission, with the exception of patients suffering from severe pancreatitis. However, it should be underscored that all analysed RCTs are characterised by marked heterogeneity regarding the type of administered probiotic species, precluding robust recommendations.

Randomized pilot trial of a synbiotic dietary supplement in chronic HIV-1 infection

Background

Infection with HIV-1 results in marked immunologic insults and structural damage to the intestinal mucosa, including compromised barrier function. While the development of highly active antiretroviral therapy (HAART) has been a major advancement in the treatment of HIV-1 infection, the need for novel complementary interventions to help restore intestinal structural and functional integrity remains unmet. Known properties of pre-, pro-, and synbiotics suggest that they may be useful tools in achieving this goal.

Methods

This was a 4-week parallel, placebo-controlled, randomized pilot trial in HIV-infected women on antiretroviral therapy. A synbiotic formulation (Synbiotic 2000®) containing 4 strains of probiotic bacteria (10¹⁰ each) plus 4 nondigestible, fermentable dietary fibers (2.5 g each) was provided each day, versus a fiber-only placebo formulation. The primary outcome was bacterial translocation. Secondary outcomes included the levels of supplemented bacteria in stool, the activation phenotype of peripheral T-cells and monocytes, and plasma levels of C-reactive protein and soluble CD14.

Results

Microbial translocation, as measured by plasma bacterial 16S ribosomal DNA concentration, was not altered by synbiotic treatment. In contrast, the synbiotic formulation resulted in significantly elevated levels of supplemented probiotic bacterial strains in stool, including L. plantarum and P. pentosaceus, with the colonization of these two species being positively correlated with each other. T-cell activation phenotype of peripheral blood lymphocytes showed modest changes in response to synbiotic exposure, with HLA-DR expression slightly elevated on a minor population of CD4+ T-cells which lack expression of HLA-DR or PD-1. In addition, CD38 expression on CD8+ T-cells was slightly lower in the fiber-only group. Plasma levels of soluble CD14 and C-reactive protein were unaffected by synbiotic treatment in this study.

Conclusions

Synbiotic treatment for 4 weeks can successfully augment the levels of probiotic species in the gut during chronic HIV-1 infection. Associated changes in microbial translocation appear to be absent, and markers of systemic immune activation appear largely unchanged. These findings may help inform future studies aimed at testing pre- and probiotic approaches to improve gut function and mucosal immunity in chronic HIV-1 infection.

Trial registration

Clinical Trials.gov: NCT00688311

Probiotics' effects on the incidence of nosocomial pneumonia in critically ill patients: a systematic review and meta-analysis

Introduction

To evaluate the efficacy of probiotics in preventing nosocomial pneumonia in critically ill patients.

Methods

We searched PubMed, EMBASE, and the Web of Science for relevant studies. Two reviewers extracted data and reviewed the quality of the studies independently. The primary outcome was the incidence of nosocomial pneumonia. Study-level data were pooled using a random-effects model when I² was > 50% or a fixed-effects model when I² was < 50%.

Results

Twelve randomized controlled studies with a total of 1,546 patients were considered. Pooled analysis showed a statistically significant reduction in nosocomial pneumonia rates due to probiotics (odd ratio [OR]= 0.75, 95% CI 0.57 to 0.97, P = 0.03, I² = 46%). However, no statistically significant difference was found between groups regarding in-hospital mortality (OR = 0.93, 95% CI 0.50 to 1.74, P = 0.82, I² = 51%), intensive care unit mortality (OR = 0.84, 95% CI 0.55 to 1.29, P = 0.43, I² = 0%), duration of stay in the hospital (mean difference [MD] in days = -0.13, 95% CI -0.93 to 0.67, P = 0.75, I² = 46%), or duration of stay in the intensive care units (MD = -0.72, 95% CI -1.73 to 0.29, P = 0.16, I² = 68%).

Conclusions

The use of probiotics was associated with a statistically significant reduction in the incidence of nosocomial pneumonia in critically ill patients. However, large, well-designed, randomized, multi-center trials are needed to confirm any effects of probiotics clinical endpoints such as mortality and length of ICU and hospital stay.

Integrative medicine and human health - the role of pre-, pro- and synbiotics

Western lifestyle is associated with a sustained low grade increase in inflammation -increased levels of endotoxin in the body and increased activation of Toll-like receptors and neutrophils, which leads to impaired immunity and reduced resistance to disease, changes which might explain the epidemic of chronic diseases spreading around the globe. The immune system cannot function properly without access to bacteria and raw plants, rich not only in bacteria but also in plant fibre, antioxidants, healthy fats and numerous other nutrients. Modern food technology with plant breeding, separation, condensation of food ingredients, heating, freezing, drying, irradiation, microwaving, are effective tool to counteract optimal immune function, and suspected to be a leading cause of so called Western diseases. Supply of pre-, pro-, and synbiotics have sometimes proved to be effective tools to counteract, especially acute diseases, but have often failed, especially in chronic diseases. Thousands of factors contribute to unhealth and numerous alterations in life style and food habits are often needed, in order to prevent and cure “treatment-resistant” chronic diseases. Such alterations include avoiding processed foods rich in pro-inflammatory molecules, but also a focus on consuming substantial amounts of foods with documented anti-inflammatory effects, often raw and fresh green vegetables and tubers such as turmeric/curcumin.

Probiotics for prevention of nosocomial infections: efficacy and adverse effects

PURPOSE OF REVIEW

In this era of increasing antimicrobial resistance, use of probiotics in infection prevention has brought new perspective. However, in 2008 the, until then considered, safe use of probiotics became an important topic after publication of a trial showing excess mortality in patients on probiotic prophylaxis. In this article, we review the concept of infection prevention by probiotics and the present knowledge of the efficacy of probiotics in prevention of infections among patients with abdominal diseases and in intensive care. Safety issues of probiotics will be discussed extensively.

RECENT FINDINGS

Over 30 clinical trials with probiotics to prevent infections have been published, some of which were prematurely stopped recently. Studies with critically ill patients and patients with abdominal diseases showed conflicting results regarding the effects of probiotics on infection rates, as did meta-analyses. These studies are difficult to compare because different probiotics were used which all have different efficacy and safety profiles.

SUMMARY

The efficacy of probiotics in infection prevention among critically ill patients is still not unequivocally determined. The safety profile differs per probiotic strain and should not be generalized towards other strains and patient populations. A well designed and well powered clinical trial with clear endpoints to demonstrate efficacy is warranted.