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

Probiotics in septic acute kidney injury, a double blind, randomized control trial

INTRODUCTION

During acute kidney injury (AKI) due to sepsis, the intestinal microbiota changes to dysbiosis, which affects the kidney function recovery (KFR) and amplifies the injury. Therefore, the administration of probiotics could improve dysbiosis and thereby increase the probability of KFR.

METHODS

In this double-blind clinical trial, patients with AKI associated with sepsis were randomized (1:1) to receive probiotics or placebo for 7 consecutive days, with the objectives of evaluate the effect on KFR, mortality, kidney replacement therapy (KRT), urea, urine volume, serum electrolytes and adverse events at day 7.

RESULTS

From February 2019 to March 2022, a total of 92 patients were randomized, 48 to the Probiotic and 44 to Placebo group. When comparing with placebo, those in the Probiotics did not observe a higher KFR (HR 0.93, 0.52-1.68, p = 0.81), nor was there a benefit in mortality at 6 months (95% CI 0.32-1.04, p = 0.06). With probiotics, urea values decreased significantly, an event not observed with placebo (from 154 to 80 mg/dl, p = 0.04 and from 130 to 109 mg/dl, p = 0.09, respectively). Urinary volume, need for KRT, electrolyte abnormalities, and adverse events were similar between groups. (ClinicalTrial.gov NCT03877081) (registered 03/15/2019).

CONCLUSION

In AKI related to sepsis, probiotics for 7 consecutive days did not increase the probability of KFR, nor did other variables related to clinical improvement, although they were safe.

Gut Microbiota and Critically Ill Patients: Immunity and Its Modulation via Probiotics and Immunonutrition

Critically ill patients have a hyper-inflammatory response against various offending injuries that can result in tissue damage, organ failure, and fatal prognosis. The origin of this detrimental, uncontrolled inflammatory cascade can be found also within our gut. In detail, one of the main actors is our gut microbiota with its imbalance, namely gut dysbiosis: learning about the microbiota's dysfunction and pathophysiology in the frame of critical patients is of crucial and emerging importance in the management of the systemic inflammatory response syndrome (SIRS) and the multiple organ dysfunction syndrome (MODS). Multiple pieces of evidence indicate that the bacteria that populate our gut efficiently modulate the immune response. Treatment and pretreatment with probiotics have shown promising preliminary results to attenuate systemic inflammation, especially in postoperative infections and ventilation performance. Finally, it is emerging how immunonutrition may exert a possible impact on the health status of patients in intensive care. Thus, this manuscript reviews evidence from the literature on gut microbiota composition, its derangement in critically ill patients, its pathophysiological role, and the described and emerging opportunities arising from its modulation.

The Microbiome and Protein Carbamylation: Potential Targets for Protein-Restricted Diets Supplemented with Ketoanalogues in Predialysis Chronic Kidney Disease

In chronic kidney disease (CKD), metabolic derangements resulting from the interplay between decreasing renal excretory capacity and impaired gut function contribute to accelerating disease progression and enhancing the risk of complications. To protect residual kidney function and improve quality of life in conservatively managed predialysis CKD patients, current guidelines recommend protein-restricted diets supplemented with essential amino acids (EAAs) and their ketoanalogues (KAs). In clinical studies, such an approach improved nitrogen balance and other secondary metabolic disturbances, translating to clinical benefits, mainly the delayed initiation of dialysis. There is also increasing evidence that a protein-restricted diet supplemented with KAs slows down disease progression. In the present review article, recent insights into the role of KA/EAA-supplemented protein-restricted diets in delaying CKD progression are summarized, and possible mechanistic underpinnings, such as protein carbamylation and gut dysbiosis, are elucidated. Emerging evidence suggests that lowering urea levels may reduce protein carbamylation, which might contribute to decreased morbidity and mortality. Protein restriction, alone or in combination with KA/EAA supplementation, modulates gut dysbiosis and decreases the generation of gut-derived uremic toxins associated, e.g., with cardiovascular disease, inflammation, protein energy wasting, and disease progression. Future studies are warranted to assess the effects on the gut microbiome, the generation of uremic toxins, as well as markers of carbamylation.

Investigating the effect of oral synbiotic on enteral feeding tolerance in critically ill patients: A double-blinded controlled clinical trial of gut microbiota

BACKGROUND

Probiotics are beneficial live microorganisms that can modify the gut microbiota. It is assumed that they help improve enteral feeding intolerance (EFI) and nosocomial infections in critically ill patients. The present clinical trial aimed to investigate the efficacy of synbiotics in improving EFI and oropharyngeal aspiration in patients admitted to the intensive care unit (ICU).

METHODS

This randomized clinical trial was conducted on 105 critically ill patients admitted to the ICU of a tertiary referral hospital affiliated with a medical university. The patients were randomly assigned to either a synbiotic or control group and underwent 7 days of investigation. The primary end point was reduced gastric residual volume, which is suggestive of an improvement in EFI. The secondary end point included requirement for prokinetics, frequency of aspiration, duration of mechanical ventilation, length of ICU stay, and level of consciousness.

RESULTS

The present clinical trial showed that synbiotic intervention has resulted in a significantly diminished requirement for prokinetics (P = 0.019), fewer oropharyngeal aspirations (P = 0.01), improved volume of bolus administration, and decreased gastric residual volume during the 7-day follow-up period. The patients who received synbiotic had an improved level of consciousness (P = 0.01).

CONCLUSION

This clinical trial showed that the prescription of synbiotic from the initial days of enteral feeding has resulted in a significantly diminished requirement for prokinetics, less oropharyngeal aspiration, decreased gastric residual volume, improved volume of bolus administration, and hence, better tolerance of enteral feeding.

Synergistic effect of probiotic and postbiotic on attenuation of PM2.5-induced lung damage and allergic response

To date, few studies have been conducted on the relationship between postbiotics and air pollution, and there is limited knowledge if postbiotic and probiotic have synergistic effects. Therefore, we created a PM-induced lung inflammation mice model and demonstrated the effect of probiotic, postbiotic, and their combination treatment on attenuation of PM2.5-induced lung damage and allergic response. The mice were intratracheally given PM2.5 triggering conditions of acute lung damage and allergic response. Our results showed that individual treatment of probiotic and postbiotic reduced body weight loss by 47.1% and 48.9%, but the results did not show any effect on polarizing IFN-γ/IL-4 ratio. In addition, PM2.5-induced overactive expression of IgE treated by probiotic and postbiotic was reduced by 33.2% and 30.4%, respectively. While combination treatment of probiotic and postbiotic exerted a synergistic effect, especially considerably on improving IgE reduction by 57.1%, body weight loss by 78.3%, and IFN-γ/IL-4 ratio boost by 87.5%. To sum up the above functionality, these research findings may help establish a novel platform for postbiotic application, formulation, and mechanistic selection with regard to PM2.5-induced lung injury. PRACTICAL APPLICATION: Allergic inflammation caused by PM2.5 is not like common allergens (ex. Pollens, ovalbumin, dust mites), which simply skewing Th1/Th2 polarization to Th2. Thus using probiotics screened by Th1-skewing criteria might not be the best choice to treat on PM2.5-induced symptoms. This research proposed a combination of probiotics and postbiotics on modulating immunity homeostasis, and consequently attenuating complications of PM2.5-induced lung damage. These research findings may help establish a novel platform for postbiotic application, formulation and mechanistic selection with regard to PM2.5-induced lung injury.

The central and biodynamic role of gut microbiota in critically ill patients

Gut microbiota plays an essential role in health and disease. It is constantly evolving and in permanent communication with its host. The gut microbiota is increasingly seen as an organ, and its failure, reflected by dysbiosis, is seen as an organ failure associated with poor outcomes. Critically ill patients may have an altered gut microbiota, namely dysbiosis, with a severe reduction in “health-promoting” commensal intestinal bacteria (such as Firmicutes or Bacteroidetes) and an increase in potentially pathogenic bacteria (e.g. Proteobacteria). Many factors that occur in critically ill patients favour dysbiosis, such as medications or changes in nutrition patterns. Dysbiosis leads to several important effects, including changes in gut integrity and in the production of metabolites such as short-chain fatty acids and trimethylamine N-oxide. There is increasing evidence that gut microbiota and its alteration interact with other organs, highlighting the concept of the gut–organ axis. Thus, dysbiosis will affect other organs and could have an impact on the progression of critical diseases. Current knowledge is only a small part of what remains to be discovered. The precise role and contribution of the gut microbiota and its interactions with various organs is an intense and challenging research area that offers exciting opportunities for disease prevention, management and therapy, particularly in critical care where multi-organ failure is often the focus. This narrative review provides an overview of the normal composition of the gut microbiota, its functions, the mechanisms leading to dysbiosis, its consequences in an intensive care setting, and highlights the concept of the gut–organ axis.

Acute Kidney Injury and Intestinal Dysbiosis

Within the multiple communication pathways of the intestine-kidney axis, one of the most important pathways is the interaction between the commensals of the intestinal microbiome, through the production of short-chain fatty acids, and the segments of the nephron. These interactions maintain a perfect environmental balance. During AKI, there are negative repercussions in all organs, and the systemic interconnection is related in part to the intense inflammation and the uremic environment that this syndrome generates. For example, in the intestine, the microbiome is severely affected, with a decrease in benign bacteria that promote anti-inflammatory effects and an increase in negative, pro-inflammatory bacteria. This scenario of intestinal dysbiosis widens the inflammatory loop that favors worsening kidney function and the probability of dying. It is possible that the manipulation of the intestinal microbiome with probiotics, prebiotics and symbiotics is a reasonable therapeutic goal for AKI.

The role of bacterial translocation in sepsis: a new target for therapy

Sepsis is a leading cause of death in critically ill patients, primarily due to multiple organ failures. It is associated with a systemic inflammatory response that plays a role in the pathogenesis of the disease. Intestinal barrier dysfunction and bacterial translocation (BT) play pivotal roles in the pathogenesis of sepsis and associated organ failure. In this review, we describe recent advances in understanding the mechanisms by which the gut microbiome and BT contribute to the pathogenesis of sepsis. We also discuss several potential treatment modalities that target the microbiome as therapeutic tools for patients with sepsis.

Efficacy of probiotics or synbiotics for critically ill adult patients: a systematic review and meta-analysis of randomized controlled trials

Background

Microbial dysbiosis in critically ill patients is a leading cause of mortality and septic complications. Probiotics and synbiotics have emerged as novel therapy on gut microbiota to prevent septic complications. However, current evidence on their effects is conflicting. This work aims to systematically review the impact of probiotics or synbiotics in critically ill adult patients.

Methods

A comprehensive search of the PubMed, CBM, Embase, CENTRAL, ISI, and CNKI databases was performed to identify randomized controlled trials that evaluate probiotics or synbiotics in critically ill patients. The quality assessment was based on the modified Jadad's score scale and the Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.1. The major outcome measure was mortality. Secondary outcomes included incidence of septic complications, sepsis incidence, length of intensive care unit (ICU) stay, incidence of non-septic complication, and ventilator day. Data synthesis was conduct by Review Manager 5.4.

Results

A total of 25 randomized controlled trials reporting on 5049 critically ill patients were included. In the intervention group, 2520 participants received probiotics or synbiotics, whereas 2529 participants received standard care or placebo. Pooling data from randomized controlled trials demonstrated a significant reduction in the incidence of ventilator-associated pneumonia (VAP) in the treatment group [(risk ratio (RR) 0.86; 95% confidence interval (CI): 0.78–0.95; p < 0.003, I² = 85%)]. However, in the subgroup analysis, the reduction of incidence of VAP was only significant in patients receiving synbiotics (RR = 0.61, 95% CI: 0.47–0.80, p = 0.0004, I² = 40%) and not significant in those receiving only probiotics (RR = 0.91, 95% CI: 0.82–1.01, p = 0.07, I² = 65%). Moreover, sepsis incidence of critically ill patients was only significantly reduced by the addition of synbiotics (RR = 0.41; 95% CI: 0.22–0.72, p = 0.005, I² = 0%). The incidence of ICU-acquired infections was significantly reduced by the synbiotics therapy (RR = 0.72; 95% CI: 0.58–0.89, p = 0.0007, I² = 79%). There was no significant difference in mortality, diarrhea, or length of ICU stay between the treatment and control groups.

Conclusions

Synbiotics is an effective and safe nutrition therapy in reducing septic complications in critically ill patients. However, in such patients, administration of probiotics alone compared with placebo resulted in no difference in the septic complications.

Gut-Lung Axis: Microbial Crosstalk in Pediatric Respiratory Tract Infections

The gut microbiota is an important regulator for maintaining the organ microenvironment through effects on the gut-vital organs axis. Respiratory tract infections are one of the most widespread and harmful diseases, especially in the last 2 years. Many lines of evidence indicate that the gut microbiota and its metabolites can be considered in therapeutic strategies to effectively prevent and treat respiratory diseases. However, due to the different gut microbiota composition in children compared to adults and the dynamic development of the immature immune system, studies on the interaction between children's intestinal flora and respiratory infections are still lacking. Here, we describe the changes in the gut microbiota of children with respiratory tract infections and explain the relationship between the microbiota of children with their immune function and disease development. In addition, we will provide perspectives on the direct manipulation of intestinal microbes to prevent or treat pediatric respiratory infections.

Development of a rapid and sensitive analytical system for Pseudomonas aeruginosa based on reverse transcription quantitative PCR targeting of rRNA molecules

For Pseudomonas aeruginosa (PA), infection control and appropriate antimicrobial treatment have become important issues. Diagnosis is critical in managing PA infection, but conventional methods are not highly accurate or rapid. We developed a new PA quantification system based on 23S rRNA-targeted reverse transcription quantitative PCR (RT-qPCR). We confirmed that RT-qPCR can quantify PA directly from clinical samples quickly (within 6 h) and with high sensitivity (blood, 1 cell/mL; stool, 100 cells/g) and without cross-reaction. Also, under antibiotic treatment, PA viable counts detected by this system correlated well with the inflammatory response of infected Caco-2 cells compared to other methods such as culturing and qPCR. Next, we utilized this system on fecal samples collected from 65 septic ICU patients and 44 healthy volunteers to identify ICU infection status. We confirmed that the PA detection ratio in ICU patients was significantly higher than that in healthy volunteers (49.2% vs. 13.6%, P < 0.05). Additionally, we monitored drug-resistant PA in 4 ICU patients by this system. The trends in PA counts accurately reflected various treatment backgrounds such as antibiotic use and mechanical ventilator use. Our results suggest that this RT-qPCR system is beneficial for the early diagnosis and evaluation of appropriate antibacterial treatment and may be a useful tool in combating PA infection.

Gut Microbiota and Probiotics/Synbiotics for Modulation of Immunity in Critically Ill Patients

Patients suffering from critical illness have host inflammatory responses against injuries, such as infection and trauma, that can lead to tissue damage, organ failure, and death. Modulation of host immune response as well as infection and damage control are detrimental factors in the management of systemic inflammation. The gut is the motor of multiple organ failure following injury, and it is recognized that gut dysfunction is one of the causative factors of disease progression. The gut microbiota has a role in maintaining host immunity, and disruption of the gut microbiota might induce an immunosuppressive condition in critically ill patients. Treatment with probiotics and synbiotics has been reported to attenuate systemic inflammation by maintaining gut microbiota and to reduce postoperative infectious complications and ventilator-associated pneumonia. The administration of prophylactic probiotics/synbiotics could be an important treatment option for preventing infectious complications and modulating immunity. Further basic and clinical research is needed to promote intestinal therapies for critically ill patients.

Putative Probiotic Strains Isolated from Kefir Improve Gastrointestinal Health Parameters in Adults: a Randomized, Single-Blind, Placebo-Controlled Study

The dairy products remain as the largest reservoir for isolation of probiotic microorganisms. While probiotics have been immensely reported to exert various health benefits, it is also a common notion that these health potentials are strain and host dependent, leading to the need of more human evidence based on specific strains, health targets, and populations. This randomized, single-blind, and placebo-controlled human study aimed to evaluate the potential benefits of putative probiotic strains isolated from kefir on gastrointestinal parameters in fifty-six healthy adults. The consumption of AB-kefir (Bifidobacterium longum, Lactobacillus acidophilus, L. fermentum, L. helveticus, L. paracasei, L. rhamnosus, and Streptococcus thermophiles; total 10 log CFU/sachet) daily for 3 week reduced symptoms of abdominal pain, bloating (P = 0.014), and appetite (P = 0.041) in male subjects as compared to the control. Gut microbiota distribution profiles were shifted upon consumption of AB-kefir compared to baseline, where the abundance of bifidobacteria was increased in male subjects and maintained upon cessation of AB-kefir consumption. The consumption of AB-kefir also increased gastrointestinal abundance of total anaerobes (P = 0.038) and total bacterial (P = 0.049) in female subjects compared to the control after 3 weeks. Our results indicated that AB-kefir could potentially be developed as a natural strategy to improve gastrointestinal functions in adults.

Dynamic analysis of human small intestinal microbiota after an ingestion of fermented milk by small-intestinal fluid perfusion using an endoscopic retrograde bowel insertion technique

Probiotic products have been shown to have beneficial effects on human hosts, but what happens in the gastrointestinal tract after its ingestion remains unclear. Our aim was to investigate the changes within the small intestines after a single intake of a fermented milk product containing a probiotic. We have periodically collected the small-intestinal fluids from the terminal ileum of seven healthy subjects for up to 7 h after ingestion by small-intestinal fluid perfusion using an endoscopic retrograde bowel insertion technique. The bacterial composition of the terminal ileum clearly revealed that the ingested probiotics (Lactobacillus casei strain Shirota: LcS and Bifidobacterium breve strain Yakult: BbrY) occupied the ileal microbiota for several hours, temporarily representing over 90% of the ileal microbiota in several subjects. Cultivation of ileal fluids showed that under a dramatic pH changes before reaching the terminal ileum, a certain number of the ingested bacteria survived (8.2 ± 6.4% of LcS, 7.8 ± 11.0% of BbrY). This means that more than 1 billion LcS and BbrY cells reached the terminal ileum with their colony-forming ability intact. These results indicate that there is adequate opportunity for the ingested probiotics to continuously stimulate the host cells in the small intestines. Our data suggest that probiotic fermented milk intake affects intestinal microbes and the host, explaining part of the process from the intake of probiotics to the exertion of their beneficial effects on the host.

Impact of fecal short-chain fatty acids on prognosis in critically ill patients

Aim

This study aimed to evaluate the relationship between fecal organic acids and mortality in critically ill patients.

Methods

This retrospective study included 128 patients who fulfilled the criteria of systemic inflammatory response syndrome and had a serum C‐reactive protein level of greater than 10 mg/dL. Patients were treated in the intensive care unit for more than 2 days. Patients were divided into two groups: survivors and non‐survivors. We measured and compared eight kinds of fecal organic acids between the two groups. We focused on the minimum and maximum value of each fecal organic acid and evaluated prognostic factors by using classification and regression tree (CART) and multivariate logistic regression analyses.

Results

We included 90 patients as survivors and 38 as non‐survivors. The CART analysis revealed that the dominant factors for mortality were the minimum values of propionate and acetate and the maximum values of lactate and formic acid. In the evaluation of the minimum values of fecal organic acids, propionate was significantly associated with increased mortality (odds ratio, 0.11 [95% confidence interval, 0.024–0.51]; P = 0.005), acetate (0.047 [0.005–0.49]; P = 0.01), and age (1.048 [1.015–1.083]; P = 0.004). In the evaluation of the maximum values, lactate was significantly associated with increased mortality (5.21 [2.024–13.42], P = 0.001) and age (1.050 [1.017–1.084]; P = 0.003).

Conclusion

An altered balance of fecal organic acids was significantly associated with mortality in critically ill patients.

Human microbiome and homeostasis: insights into the key role of prebiotics, probiotics, and symbiotics

The interest in the study of the gut microbiome has grown exponentially. Indeed, its impact on health and disease has been increasingly reported, and the importance of keeping gut microbiome homeostasis clearly highlighted. However, and despite many advances, there are still some gaps, as well as the real discernment on the contribution of some species falls far short of what is needed. Anyway, it is already more than a solid fact of its importance in maintaining health and preventing disease, as well as in the treatment of some pathologies. In this sense, and given the existence of some ambiguous opinions, the present review aims to discuss the importance of gut microbiome in homeostasis maintenance, and even the role of probiotics, prebiotics, and symbiotics in both health promotion and disease prevention.

Stool Short-Chain Fatty Acids in Critically Ill Patients with Sepsis

Objective: To determine the concentration of stool short-chain fatty acids (SCFAs) in critically ill patients with sepsis and to compare the results between the critically ill patient and the control group.Methods: This descriptive, multicenter, observational study was conducted in five health institutions. Over a 6-month study period, critically ill patients with sepsis who were admitted to the intensive care unit (ICU) and met the inclusion criteria were enrolled, and a control, paired by age and sex, was recruited for each patient. A spontaneous stool sample was collected from each participant and a gas chromatograph coupled to a mass spectrometer (Agilent 7890/MSD 5975 C) was used to measure the concentrations SCFAs.Results: The final sample included 44 patients and 45 controls. There were no differences in the age and sex distributions between the groups (p > 0.05). According to body mass index (BMI), undernutrition was more prevalent among critically ill patients, and BMI in control subjects was most frequently classified as overweight (p = 0.024). Propionic acid, acetic acid, butyric acid, and isobutyric acid concentrations were significantly lower in the critically ill patient group than in the control group (p = 0.000). No association with outcome variables (complications, ICU stay, and discharge condition) was found in the patients, and patients diagnosed with infection on ICU admission showed significant decreases in butyric and isobutyric acid concentrations with respect to other diagnostic criteria (p < 0.05).Conclusions: The results confirm significantly lower concentrations of stool SCFAs in critically ill patients with sepsis than in control subjects. Due to its role in intestinal integrity, barrier function, and anti-inflammatory effect, maintaining the concentration of SCFAs may be important in the ICU care protocols of the critical patient.

Prophylactic Probiotics in Burn Patients: Risk versus Reward

Probiotics are often used in critically ill patients to prevent antibiotic-associated complications, including Clostridium difficile colitis. However, clinical evidence of their efficacy is lacking. The objective of this study is to assess the impact of prophylactic probiotic administration on bowel function, gut microbial diversity, and nutritional markers in adult burn patients. A retrospective cohort study was done on 108 burn patients aged 18 to 89. Patients were given >1 million colony-forming units per day of Lactobacillus acidophilus and Lactobacillus rhamnosus. Testing for C. difficile was used as a surrogate marker for the presence of diarrhea. Serum C-reactive protein and prealbumin values were measured. Additionally, the gut microbial diversity of eight patients was tracked via 16S quantitative PCR before and throughout the course of a standard probiotic regimen. Patients receiving oral probiotics had more reported diarrhea in the first and second weeks of treatment. In the second week, C-reactive protein levels were increased, while serum prealbumin levels were lower in patients receiving probiotics, suggesting potential malabsorption. Additionally, there was no difference in C. difficile infection, sepsis rates, emesis, or gastric residuals, indicating an absence of therapeutic benefit for probiotic administration in burn patients. Furthermore, it was determined that no discernible benefit to gut microbial diversity was conferred by probiotic therapy. Prophylactic probiotics in burn patients are not associated with improvements in patient outcomes and may in fact be associated with an increased incidence of diarrhea and malabsorption. Additional research is needed before routine use in burn patients.

Mechanisms and immunomodulatory properties of pre- and probiotics

The human body is exposed to many xenobiotic, potentially harmful compounds. The intestinal immune system is crucial in protecting the human body from these substances. Moreover, many microorganisms, residing in the gastrointestinal tract, play an important role in modulating immune responses. Pre- and probiotics may have beneficial effects on the microbial composition and activity within the human gut, subsequently affecting the immune system. Prebiotics can exert their effects via different mechanisms, like selectively stimulating the growth of bacteria by providing substrates or via direct immune stimulation. Probiotics may have beneficial health effects via competition with pathogens for substrates and binding intestinal sites, bioconversions of for example sugars into fermentation products with inhibitory properties, production of growth substrates like vitamins for the host, direct antagonism of pathogens via antimicrobial peptide production, reduction of inflammation and stimulation of immune cells. This review focuses on the different mechanisms via which the pre- and probiotics exert their beneficial effects on the host, addressing their immunomodulatory properties in particular.

Susceptibility to antibiotics in isolates of Lactobacillus plantarum RAPD-type Lp299v, harvested from antibiotic treated, critically ill patients after administration of probiotics

Recultured Lactobacillus plantarum 299v-like strains were tested regarding antibiotic susceptibility, and no decrease was detected. Antibiotics are frequently used to treat patients in intensive care units (ICUs) and are associated with a significant risk of selection of resistant bacterial strains. In particular, it is possible that genetic transfer of antibiotic resistance to the resident gastrointestinal flora, as well as to administered probiotics, may be increased in the ICU setting. The aim of the present investigation was to detect possible changes in antimicrobial susceptibility in reisolates of the probiotic strain Lactobacillus plantarum 299v (Lp299v) given to antibiotic treated, critically ill patients. Lp299v-like strains were identified in cultures of biopsies and fecal samples from 32 patients given the probiotic strain enterally in two previous ICU studies. The patients received a variety of antibiotics. Isolates with the same genomic RAPD profile (RAPD-type) as Lp299v were obtained to enable monitoring of antibiotic susceptibility by E-tests. Forty-two isolates, collected throughout the course of illness, were tested against 22 different antibiotics. No obvious decrease in susceptibility was found for 21 of the tested antibiotics. There was a tendency toward decreased susceptibility to ampicillin. The stable antibiotic susceptibility profiles of the Lp299v-like isolates studied here suggests this probiotic is less likely to acquire resistance when administered to critically ill patients treated with broad-spectrum antibiotics.

Synbiotics modulate gut microbiota and reduce enteritis and ventilator-associated pneumonia in patients with sepsis: a randomized controlled trial

BACKGROUND

Commensal microbiota deteriorate in critically ill patients. The preventive effects of probiotic/synbiotic therapy on microbiota and septic complications have not been thoroughly clarified in patients with sepsis. The objective of this study was to evaluate whether synbiotics have effects on gut microbiota and reduce complications in mechanically ventilated patients with sepsis.

METHODS

Sepsis patients who were mechanically ventilated in the intensive care unit (ICU) were included in this randomized controlled study. Patients receiving daily synbiotics (Bifidobacterium breve strain Yakult, Lactobacillus casei strain Shirota, and galactooligosaccharides) initiated within 3 days after admission (the Synbiotics group) were compared with patients who did not receive synbiotics (the No-Synbiotics group). The primary outcome was infectious complications including enteritis, ventilator-associated pneumonia (VAP), and bacteremia within 4 weeks from admission. The secondary outcomes included mortality within 4 weeks, fecal bacterial counts, and organic acid concentration. Enteritis was defined as the acute onset of continuous liquid stools for more than 12 h.

RESULTS

Seventy-two patients completed this trial; 35 patients received synbiotics and 37 patients did not receive synbiotics. The incidence of enteritis was significantly lower in the Synbiotics than the No-Synbiotics group (6.3% vs. 27.0%; p < 0.05). The incidence of VAP was also significantly lower in the Synbiotics than the No-Synbiotics group (14.3% vs. 48.6%; p < 0.05). The incidence of bacteremia and mortality did not differ significantly between the two groups. In the analysis of fecal bacteria, the number of Bifidobacterium and Lactobacillus in the Synbiotics group was significantly higher than that in the No-Synbiotics group. In the analysis of fecal organic acids, total organic acid concentration, especially the amounts of acetate, were significantly greater in the Synbiotics group than in the No-Synbiotics group at the first week (p < 0.05).

CONCLUSIONS

Prophylactic synbiotics could modulate the gut microbiota and environment and may have preventive effects on the incidence of enteritis and VAP in patients with sepsis.

TRIAL REGISTRATION

UMIN, R000007633 . Registered on 29 September 2011.

Association of prophylactic synbiotics with reduction in diarrhea and pneumonia in mechanically ventilated critically ill patients: A propensity score analysis

INTRODUCTION

The preventive association of synbiotics therapy has not been thoroughly clarified in mechanically ventilated patients. The purpose of this study was to evaluate whether synbiotics therapy has preventive association against septic complications in ventilated critically ill patients.

METHODS

Critically ill patients who were mechanically ventilated were included in this retrospective observational study. Patients who received synbiotics (Bifidobacterium breve, Lactobacillus casei, and galactooligosaccharides) within 3 days after admission (denoted as synbiotics group) were compared with patients who did not receive synbiotics. The incidences of enteritis, pneumonia, and bacteremia were evaluated as clinical outcome. Enteritis was defined as an acute onset of diarrhea consisting of continuous liquid watery stools for more than 12 h. The confounding factors include APACHE II on admission, gender, the cause of admission and antibiotics.

RESULTS

We included 179 patients in this study: 57 patients received synbiotics and 122 patients did not receive synbiotics. The incidences of enteritis were significantly lower in the synbiotics group compared with the control group (3.5% vs. 15.6%; p < 0.05). The odds ratios for diarrhea-free days during the first 28 days for the synbiotics group as compared with the controls were 4.354 (95% confidence interval (CI), 2.407 to 7.877; p < 0.001) in an ordinal logistic regression model with propensity scores. The odds ratios for pneumonia-free days during the first 28 days for the synbiotics group were 2.529 (95% CI, 1.715 to 3.731; p < 0.001). The incidences of bacteremia did not have significant differences.

CONCLUSION

Prophylactic synbiotics appeared to have preventive association on enteritis and pneumonia in mechanically ventilated critically ill patients.

Role of the microbiome, probiotics, and 'dysbiosis therapy' in critical illness

PURPOSE OF REVIEW

Loss of 'health-promoting' microbes and overgrowth of pathogenic bacteria (dysbiosis) in ICU is believed to contribute to nosocomial infections, sepsis, and organ failure (multiple organ dysfunction syndrome). This review discusses new understanding of ICU dysbiosis, new data for probiotics and fecal transplantation in ICU, and new data characterizing the ICU microbiome.

RECENT FINDINGS

ICU dysbiosis results from many factors, including ubiquitous antibiotic use and overuse. Despite advances in antibiotic therapy, infections and mortality from often multidrug-resistant organisms (i.e., Clostridium difficile) are increasing. This raises the question of whether restoration of a healthy microbiome via probiotics or other 'dysbiosis therapies' would be an optimal alternative, or parallel treatment option, to antibiotics. Recent clinical data demonstrate probiotics can reduce ICU infections and probiotics or fecal microbial transplant (FMT) can treat Clostridium difficile. This contributes to recommendations that probiotics should be considered to prevent infection in ICU. Unfortunately, significant clinical variability limits the strength of current recommendations and further large clinical trials of probiotics and FMT are needed. Before larger trials of 'dysbiosis therapy' can be thoughtfully undertaken, further characterization of ICU dysbiosis is needed. To addressing this, we conducted an initial analysis demonstrating a rapid and marked change from a 'healthy' microbiome to an often pathogen-dominant microbiota (dysbiosis) in a broad ICU population.

SUMMARY

A growing body of evidence suggests critical illness and ubiquitous antibiotic use leads to ICU dysbiosis that is associated with increased ICU infection, sepsis, and multiple organ dysfunction syndrome. Probiotics and FMT show promise as ICU therapies for infection. We hope future-targeted therapies using microbiome signatures can be developed to correct 'illness-promoting' dysbiosis to restore a healthy microbiome post-ICU to improve patient outcomes.

Gut-kidney crosstalk in septic acute kidney injury

Sepsis is the leading cause of acute kidney injury (AKI) in the intensive care unit (ICU). Septic AKI is a complex and multifactorial process that is incompletely understood. During sepsis, the disruption of the mucus membrane barrier, a shift in intestinal microbial flora, and microbial translocation may lead to systemic inflammation, which further alters host immune and metabolic homeostasis. This altered homeostasis may promote and potentiate the development of AKI. As part of this vicious cycle, when AKI develops, the clearance of inflammatory mediators and metabolic products is decreased. This will lead to further gut injury and breakdown in mucous membrane barriers. Thus, changes in the gut during sepsis can initiate and propagate septic AKI. This deleterious gut–kidney crosstalk may be a potential target for therapeutic maneuvers. This review analyses the underlying mechanisms in gut–kidney crosstalk in septic AKI.

The Pharmabiotic Approach to Treat Hyperammonemia

Ammonia is constantly produced as a metabolic waste from amino acid catabolism in mammals. Ammonia, the toxic waste metabolite, is resolved in the liver where the urea cycle converts free ammonia to urea. Liver malfunctions cause hyperammonemia that leads to central nervous system (CNS) dysfunctions, such as brain edema, convulsions, and coma. The current treatments for hyperammonemia, such as antibiotics or lactulose, are designed to decrease the intestinal production of ammonia and/or its absorption into the body and are not effective, besides being often accompanied by side effects. In recent years, increasing evidence has shown that modifications of the gut microbiota could be used to treat hyperammonemia. Considering the role of the gut microbiota and the physiological characteristics of the intestine, the removal of ammonia from the intestine by modulating the gut microbiota would be an ideal approach to treat hyperammonemia. In this review, we discuss the significance of hyperammonemia and its related diseases and the efficacy of the current management methods for hyperammonemia to understand the mechanism of ammonia transport in the human body. The possibility to use the gut microbiota as pharmabiotics to treat hyperammonemia and its related diseases is also explored.

Lactobacillus rhamnosus L34 Attenuates Gut Translocation-Induced Bacterial Sepsis in Murine Models of Leaky Gut

Gastrointestinal (GI) bacterial translocation in sepsis is well known, but the role of Lactobacillus species probiotics is still controversial. We evaluated the therapeutic effects of Lactobacillus rhamnosus L34 in a new sepsis model of oral administration of pathogenic bacteria with GI leakage induced by either an antibiotic cocktail (ATB) and/or dextran sulfate sodium (DSS). GI leakage with ATB, DSS, and DSS plus ATB (DSS+ATB) was demonstrated by fluorescein isothiocyanate (FITC)-dextran translocation to the circulation. The administration of pathogenic bacteria, either Klebsiella pneumoniae or Salmonella enterica serovar Typhimurium, enhanced translocation. Bacteremia was demonstrated within 24 h in 50 to 88% of mice with GI leakage plus the administration of pathogenic bacteria but not with GI leakage induction alone or bacterial gavage alone. Salmonella bacteremia was found in only 16 to 29% and 0% of mice with Salmonella and Klebsiella administrations, respectively. Klebsiella bacteremia was demonstrated in 25 to 33% and 10 to 16% of mice with Klebsiella and Salmonella administrations, respectively. Lactobacillus rhamnosus L34 attenuated GI leakage in these models, as shown by the reductions of FITC-dextran gut translocation, serum interleukin-6 (IL-6) levels, bacteremia, and sepsis mortality. The reduction in the amount of fecal Salmonella bacteria with Lactobacillus treatment was demonstrated. In addition, an anti-inflammatory effect of the conditioned medium from Lactobacillus rhamnosus L34 was also demonstrated by the attenuation of cytokine production in colonic epithelial cells in vitro In conclusion, Lactobacillus rhamnosus L34 attenuated the severity of symptoms in a murine sepsis model induced by GI leakage and the administration of pathogenic bacteria.

Characterizing the gut microbiome in trauma: significant changes in microbial diversity occur early after severe injury

Background

Recent studies have demonstrated the vital influence of commensal microbial communities on human health. The central role of the gut in the response to injury is well described; however, no prior studies have used culture-independent profiling techniques to characterize the gut microbiome after severe trauma. We hypothesized that in critically injured patients, the gut microbiome would undergo significant compositional changes in the first 72 hours after injury.

Methods

Trauma stool samples were prospectively collected via digital rectal examination at the time of presentation (0 hour). Patients admitted to the intensive care unit (n=12) had additional stool samples collected at 24 hours and/or 72 hours. Uninjured patients served as controls (n=10). DNA was extracted from stool samples and 16S rRNA-targeted PCR amplification was performed; amplicons were sequenced and binned into operational taxonomic units (OTUs; 97% sequence similarity). Diversity was analyzed using principle coordinates analyses, and negative binomial regression was used to determine significantly enriched OTUs.

Results

Critically injured patients had a median Injury Severity Score of 27 and suffered polytrauma. At baseline (0 hour), there were no detectable differences in gut microbial community diversity between injured and uninjured patients. Injured patients developed changes in gut microbiome composition within 72 hours, characterized by significant alterations in phylogenetic composition and taxon relative abundance. Members of the bacterial orders Bacteroidales, Fusobacteriales and Verrucomicrobiales were depleted during 72 hours, whereas Clostridiales and Enterococcus members enriched significantly.

Discussion

In this initial study of the gut microbiome after trauma, we demonstrate that significant changes in phylogenetic composition and relative abundance occur in the first 72 hours after injury. This rapid change in intestinal microbiota represents a critical phenomenon that may influence outcomes after severe trauma. A better understanding of the nature of these postinjury changes may lead to the ability to intervene in otherwise pathological clinical trajectories.

Level of evidence

III

Study type

Prognostic/epidemiological

Bacillus As Potential Probiotics: Status, Concerns, and Future Perspectives

Spore-forming bacilli are being explored for the production and preservation of food for many centuries. The inherent ability of production of large number of secretory proteins, enzymes, antimicrobial compounds, vitamins, and carotenoids specifies the importance of bacilli in food chain. Additionally, Bacillus spp. are gaining interest in human health related functional food research coupled with their enhanced tolerance and survivability under hostile environment of gastrointestinal tract. Besides, bacilli are more stable during processing and storage of food and pharmaceutical preparations, making them more suitable candidate for health promoting formulations. Further, Bacillus strains also possess biotherapeutic potential which is connected with their ability to interact with the internal milieu of the host by producing variety of antimicrobial peptides and small extracellular effector molecules. Nonetheless, with proposed scientific evidences, commercial probiotic supplements, and functional foods comprising of Bacillus spp. had not gained much credential in general population, since the debate over probiotic vs pathogen tag of Bacillus in the research and production terrains is confusing consumers. Hence, it’s important to clearly understand the phenotypic and genotypic characteristics of selective beneficial Bacillus spp. and their substantiation with those having GRAS status, to reach a consensus over the same. This review highlights the probiotic candidature of spore forming Bacillus spp. and presents an overview of the proposed health benefits, including application in food and pharmaceutical industry. Moreover, the growing need to evaluate the safety of individual Bacillus strains as well as species on a case by case basis and necessity of more profound analysis for the selection and identification of Bacillus probiotic candidates are also taken into consideration.

Microbial Endocrinology in the Pathogenesis of Infectious Disease

Microbial endocrinology represents the intersection of two seemingly disparate fields, microbiology and neurobiology, and is based on the shared presence of neurochemicals that are exactly the same in host as well as in the microorganism. The ability of microorganisms to not only respond to, but also produce, many of the same neurochemicals that are produced by the host, such as during periods of stress, has led to the introduction of this evolutionary-based mechanism which has a role in the pathogenesis of infectious disease. The consideration of microbial endocrinology-based mechanisms has demonstrated, for example, that the prevalent use of catecholamine-based synthetic drugs in the clinical setting contributes to the formation of biofilms in indwelling medical devices. Production of neurochemicals by microorganisms most often employs the same biosynthetic pathways as those utilized by the host, indicating that acquisition of host neurochemical-based signaling system in the host may have been acquired due to lateral gene transfer from microorganisms. That both host and microorganism produce and respond to the very same neurochemicals means that there is bidirectionality contained with the theoretical underpinnings of microbial endocrinology. This can be seen in the role of microbial endocrinology in the microbiota-gut-brain axis and its relevance to infectious disease. Such shared pathways argue for a role of microorganism-neurochemical interactions in infectious disease.

Head injury profoundly affects gut microbiota homeostasis: Results of a pilot study

OBJECTIVES

Head injury (HI) induces a hypercatabolic state, dysimmunity, and septic complications that increase morbidity and mortality. Although compromised immune function is usually incriminated in infection occurrence, gut dysbiosis could also be involved in this phenomenon and, to our knowledge, has never been considered. To assess if HI could affect microbiota, we explored the impact of HI on intestinal microbiota in a rodent model of fluid percussion.

METHODS

Nineteen rats were randomly assigned to two groups: Healthy rats fed ad libitum (n = 7) and HI rats (n = 12), which received standard enteral nutrition for 4 d. Four days after HI, rats were euthanized and cecal contents were sampled. Cecal microbiota was assessed using real-time quantitative polymerase chain reaction.

RESULTS

HI significantly decreased the cecal content of strict anaerobic groups, Bacteroides/Prevotella group (HI 8.9 versus healthy controls 9.3 median log₁₀ colony forming units [CFU]/g, P = 0.007), Clostridium cluster XIVab (HI 7.9 versus healthy controls 8.9 median log₁₀ CFU/g, P = 0.002), Lactobacillus/Leuconostoc group (HI 8.5 versus healthy controls 9.4 median log₁₀ CFU/g, P = 0.044), and Bifidobacterium sp. (HI 3.0 versus healthy controls 8.2 median log₁₀ CFU/g, P < 0.001). In contrast, colonization by Escherichia coli was dramatically increased (HI 10.5 versus healthy controls 7.0 median log₁₀ CFU/g, P < 0.001).

CONCLUSIONS

HI profoundly modified the gut microbiota homeostasis and thus could contribute to infection in head trauma patients. These preliminary results open a new field of research in the management of patients with HI.

Prebiotics: A Potential Treatment Strategy for the Chemotherapy-damaged Gut?

Mucositis, characterized by ulcerative lesions along the alimentary tract, is a common consequence of many chemotherapy regimens. Chemotherapy negatively disrupts the intestinal microbiota, resulting in increased numbers of potentially pathogenic bacteria, such as Clostridia and Enterobacteriaceae, and decreased numbers of "beneficial" bacteria, such as Lactobacilli and Bifidobacteria. Agents capable of restoring homeostasis in the bowel microbiota could, therefore, be applicable to mucositis. Prebiotics are indigestible compounds, commonly oligosaccharides, that seek to reverse chemotherapy-induced intestinal dysbiosis through selective colonization of the intestinal microbiota by probiotic bacteria. In addition, evidence is emerging that certain prebiotics contribute to nutrient digestibility and absorption, modulate intestinal barrier function through effects on mucin expression, and also modify mucosal immune responses, possibly via inflammasome-mediated processes. This review examines the known mechanisms of prebiotic action, and explores their potential for reducing the severity of chemotherapy-induced mucositis in the intestine.

Isolated exopolysaccharides from Lactobacillus rhamnosus GG alleviated adipogenesis mediated by TLR2 in mice

The fibroblast cell line of 3T3-L1 was used as a cell model for screening and evaluating the feasibility of probiotic components in improving animal lipid metabolisms. The extracts from 12 Lactobacillus strains caused significantly reduced triacylglycerol (TAG) accumulation but with severe inflammation induction in 3T3-L1 adipocytes. Interestingly, exopolysaccharides (EPS) from LGG (Lactobacillus rhamnosus GG) significantly decreased the TAG accumulation without any inflammation. The anti-obesity effect of EPS was confirmed in high-fat-diets feeding mice. Fat pads of mice injected with EPS (50 mg/kg) every two days for two weeks were significantly reduced with much smaller adipocytes, compared with the counterparts. The levels of TAG and cholesterol ester in liver, as well as serum TAG, were decreased in EPS injected mice. In addition, down-regulated inflammation was observed in adipose tissue and liver. Interestingly, the expression of TLR2 in adipose tissue and 3T3-L1 cells was significantly increased by EPS addition. Moreover, the reverse of TAG accumulation in TLR2 knockdown 3T3-L1 in the presence of EPS confirmed that the inhibition effect of EPS on adipogenesis was mediated by TLR2. EPS from LGG has the potential for therapeutic development to intervene lipid metabolic disorders in mammals.

Gut-lung axis: The microbial contributions and clinical implications

Gut microbiota interacts with host immune system in ways that influence the development of disease. Advances in respiratory immune system also broaden our knowledge of the interaction between host and microbiome in the lung. Increasing evidence indicated the intimate relationship between the gastrointestinal tract and respiratory tract. Exacerbations of chronic gut and lung disease have been shown to share key conceptual features with the disorder and dysregulation of the microbial ecosystem. In this review, we discuss the impact of gut and lung microbiota on disease exacerbation and progression, and the recent understanding of the immunological link between the gut and the lung, the gut-lung axis.

The Effect of Probiotic Plus Prebiotic Supplementation on the Tolerance and Efficacy of Helicobacter Pylori Eradication Quadruple Therapy: a Randomized Prospective Double Blind Controlled Trial

BACKGROUND

Standard anti-Helicobacter pylori (H. pylori) treatment fails in the eradication of the organism in almost 10-35% of the patients and has different side effects. Recent studies have proposed that probiotic supplementations with or without prebiotic may improve the eradication rate and diminish the side effects, although it is still a controversial issue. We aimed to investigate the effect of probiotic with prebiotic supplementation on the eradication rate and side effects of anti H. pylori quadruple therapy.

METHODS

76 patients with a positive biopsy specimen for H. pylori were enrolled. They were randomized to receive quadruple therapy of bismuth, clarithromycin, amoxicillin, and omeprazole for 14 days and also the synbiotic or the placebo. We asked them to answer study questionnaires at the beginning and during the treatment. Finally, urea breath test was done 8 weeks after the treatment.

RESULTS

The eradication rate was significantly better in the synbiotic group by intention-to-treat analysis (p<0.05). Treatment side effects such as diarrhea, nausea, vomiting, epigastric pain, flatulence, constipation, and taste abnormality were similar in both groups but anorexia was significantly better in the synbiotic group (p <0.05).

CONCLUSION

The eradication rate was significantly better in the synbiotic group by intention-to-treat analysis (p<0.05). Treatment side effects such as diarrhea, nausea, vomiting, epigastric pain, flatulence, but could improve the eradication by augmenting the treatment tolerance and compliance.

The Intestinal Microbiome and the Liver Transplant Recipient: What We Know and What We Need to Know

The intestinal microbiome and immune system are in close symbiotic relationship in health. Gut microbiota plays a role in many chronic liver diseases and cirrhosis. However, alterations in the gut microbiome after liver transplantation and the implications for liver transplant recipients are not well understood and rely mainly on experimental animal studies. Recent advances in molecular techniques have identified that increased intestinal permeability, decreased beneficial bacteria, and increased pathogenic species may play important roles in the early posttransplant period. The associations between microbiota perturbation and postliver transplant infections and acute rejection are evolving. The link with metabolic syndrome, obesity, and cardiac disease in the general population require translation into the transplant recipient. This review focuses on our current knowledge of the known and potential interaction of the microbiome in the liver transplant recipient. Future human studies focused on microbiota changes in liver transplant patients are warranted and expected.

Regulatory effect of paraprobiotic Lactobacillus gasseri CP2305 on gut environment and function

Background

Lactobacillus gasseri CP2305 (CP2305) is a strain of Lactobacillus isolated from a stool sample from a healthy adult that showed beneficial effects on health as a paraprobiotic. In a previous study, we demonstrated that CP2305-fermented heat-treated milk modified gut functions more than artificially acidified sour milk. Thus, the regulatory activity of the former beverage was attributed to the inactivated CP2305 cells.

Objective

The aim of this study was to elucidate the contribution of non-viable paraprobiotic CP2305 cells to regulating human gut functions. We thus conducted a randomized, placebo-controlled, double-blinded parallel group trial.

Design

The trial included 118 healthy participants with relatively low or high stool frequencies. The test beverage was prepared by adding 1×10¹⁰ washed, heat-treated, and dried CP2305 cells directly to the placebo beverage. The participants ingested a bottle of the assigned beverage daily for 3 weeks and answered daily questionnaires about defecation and quality of life. Fecal samples were collected and the fecal characteristics, microbial metabolite contents of the feces and composition of fecal microbiota were evaluated.

Results

The number of evacuations and the scores for fecal odors were significantly improved in the group that consumed the CP2305-containing beverage compared with those of the group that consumed the placebo (p=0.035 and p=0.040, respectively). Regarding the fecal contents of microbial metabolites, the level of fecal p-cresol was significantly decreased in the CP2305 group relative to that of the placebo group (p=0.013). The Bifidobacterium content of the intestinal microbiota was significantly increased in the CP2305 group relative to that of the placebo group (p<0.008), whereas the content of Clostridium cluster IV was significantly decreased (p<0.003). The parasympathetic nerve activity of the autonomic nervous system became dominant and the total power of autonomic activity was elevated in the CP2305 group (p=0.0401 and p=0.011, respectively).

Conclusions

The continuous ingestion of heat-treated CP2305 cells clearly affected intestinal functionality. This is the first report of sterilized Lactobacillus cells having a significant impact on the environment and functions of the intestinal tract. The observed effects might be due, at least in part, to the brain–gut interaction.

Allergic diseases among children: nutritional prevention and intervention

Allergic diseases comprise a genetically heterogeneous group of chronic, immunomediated diseases. It has been clearly reported that the prevalence of these diseases has been on the rise for the last few decades, but at different rates, in various areas of the world. This paper discusses the epidemiology of allergic diseases among children and their negative impact on affected patients, their families, and societies. These effects include the adverse effects on quality of life and economic costs. Medical interest has shifted from tertiary or secondary prevention to primary prevention of these chronic diseases among high-risk infants in early life. Being simple, practical, and cost-effective are mandatory features for any candidate methods delivering these strategies. Dietary therapy fits this model well, as it is simple, practical, and cost-effective, and involves diverse methods. The highest priority strategy is feeding these infants breast milk. For those who are not breast-fed, there should be a strategy to maintain beneficial gut flora that positively influences intestinal immunity. We review the current use of probiotics, prebiotics, and synbiotics, and safety and adverse effects. Other dietary modalities of possible potential in achieving this primary prevention, such as a Mediterranean diet, use of milk formula with modified (hydrolyzed) proteins, and the role of micronutrients, are also explored. Breast-feeding is effective in reducing the risk of asthma, allergic rhinitis, and atopic eczema among children. In addition, breast milk constitutes a major source of support for gut microbe colonization, due to its bifidobacteria and galactooligosaccharide content. The literature lacks consensus in recommending the addition of probiotics to foods for prevention and treatment of allergic diseases, while prebiotics may prove to be effective in reducing atopy in healthy children. There is insufficient evidence to support soy formulas or amino acid formulas for prevention of allergic disease. A healthy diet, such as the Mediterranean diet, may have a protective effect on the development of asthma and atopy in children. In children with asthma and allergic diseases, vitamin D deficiency correlates strongly with asthma, allergic rhinitis, and wheezing.

New aspects on the metabolic role of intestinal microbiota in the development of atherosclerosis

Gut microbiota remains a very interesting, yet largely unexplored ecosystem inside the human organism. The importance of this ecosystem for the physiology and the pathophysiology of the organism is being slowly unraveled. Recent studies reveal a connection between intestinal microbiota and atherosclerosis development. It seems that alterations in the function and composition of this bacterial population lead through complex mechanisms to a high risk for atherosclerosis. Although these mechanisms remain largely unknown, published studies show that microbiota can lead to atherosclerosis either by augmenting known risk factors or via other, more "direct" mechanisms. This review article summarizes the available literature regarding this matter.

When and how should sepsis patients be fed?

PURPOSE OF REVIEW

To provide an overview on the recent literature regarding metabolism during sepsis and outcome-related effects of nutrition therapy in septic patients. The question when and how these patients should be fed with respect to macronutrient intake is elaborated.

RECENT FINDINGS

Although the incidence of severe sepsis has steadily increased over the past years, still no strong evidence is available with respect to the role of energy and protein provision in these patients. On the basis of recent large randomized trials in mixed patient populations, the updated sepsis guidelines recommend early but limited nutrition via the enteral route rather than targeted feeding. Lately, the results of a large trial challenged the importance of the route of feeding on the clinical outcome of critically ill patients. Four post-hoc analyses of prospective randomized trials including a large number of severely septic patients yielded conflicting results. One reported significant mortality reduction with near-target calorie and protein intake by exclusive enteral nutrition, whereas the second showed an advantage of enteral compared to combined nutrition, albeit resulting in a lower calorie and protein provision. The other two analyses found no association at all of either lower or higher daily caloric or protein intake, respectively, with clinical outcomes.

SUMMARY

In the absence of strong clinical evidence, pathophysiological findings are discussed and nutritional strategies for septic patients derived. Future studies should explore the individual response to specific exogenous supply of macronutrients and micronutrients in the acute and persistent phase of severe systemic inflammation.

Effect of da-cheng-qi decoction on the repair of the injured enteric nerve-interstitial cells of cajal-smooth muscle cells network in multiple organ dysfunction syndrome

Wistar rats were randomly divided into control group, multiple organ dysfunction syndrome (MODS) group, and Da-Cheng-Qi decoction (DCQD) group. The network of enteric nerves-interstitial cells of Cajal- (ICC-) smooth muscle cells (SMC) in small intestine was observed using confocal laser scanning microscopy and transmission electron microscopy. The results showed that the numbers of cholinergic/nitriergic nerves, and the deep muscular plexus of ICC (ICC-DMP) and connexin43 (Cx43) in small intestine with MODS were significantly decreased. The network integrity of enteric nerves-ICC-SMC was disrupted. The ultrastructures of ICC-DMP, enteric nerves, and SMC were severely damaged. After treatment with DCQD, the damages were repaired and the network integrity of enteric nerves ICC-SMC was significantly recovered. In conclusion, the pathogenesis of gastrointestinal motility dysfunction in MODS in part may be due to the damages to enteric nerves-ICC-SMC network and gap junctions. The therapeutic mechanism of DCQD in part may be that it could repair the damages and maintain the integrity of enteric nerves ICC-SMC network.

The opposing forces of the intestinal microbiome and the emerging pathobiome

This article summarizes emerging concepts on the role of the intestinal microbiome in surgical patients. Revolutionary research over the past decade has shown that human beings live in close and constant contact with boundless communities of microbes. Recent innovations in the study of the human microbiome are reviewed. To demonstrate the applicability of these studies to surgical disease, the authors discuss what is known about the role of microbes in the pathogenesis of perioperative complications. Enhanced awareness of the human microbiome will empower clinicians to adopt novel practices in the prevention and treatment of a variety of surgical conditions.

VSL#3 probiotics provide protection against acute intestinal ischaemia/reperfusion injury

Acute intestinal ischaemia/reperfusion injury (AII/R) is an adaptive physiologic response during critical illness, involving mesenteric vasoconstriction and hypoperfusion. Prevention of AII/R in high risk patient populations would have a significant impact on morbidity and mortality. The purpose of this study was to investigate the protective effects of VSL#3 probiotic treatment in a murine model of AII/R. Adult 129/SvEv mice were subjected to an experimental AII/R model using superior mesenteric artery occlusion. Animals were pre-treated with either three days or two weeks of VSL#3 probiotics. Local tissue injury markers were assessed by levels of myeloperoxidase and activation of nuclear factor kappa B (NFкB). Systemic and local cytokines, including interleukin (IL)-1β, IL- 10, TNFα, and interferon gamma were measured by ELISA and multiplex fluorescent detection. VSL#3 probiotics reduced local tissue inflammation and injury due to AII/R. A two-week course of VSL#3 was more effective than a shorter three-day course. The reduction in local inflammation from the two-week course of VSL#3 is correlated to a significant reduction in levels of active IL-1β, and tissue levels of myeloperoxidase. Levels of active NFкB were significantly elevated in the vehicle-fed AII/R mice, corroborating with tissue inflammation, which were attenuated by VSL#3 administrations. VSL#3 did not cause any systemic inflammation or lung injury. VSL#3 probiotics are effective in reducing local tissue injury from AII/R by down-regulating pro-inflammatory mediators and immune cell recruitment. This study highlights a potential role for VSL#3 in management of patients at high risk for AII/R.