Evaluation of probiotic treatment in a neonatal animal model

Bifidobacterium bifidum CCFM1163 Alleviated Cathartic Colon by Regulating the Intestinal Barrier and Restoring Enteric Nerves

Cathartic colon (CC), a type of slow-transit constipation caused by the long-term use of stimulant laxatives, does not have a precise and effective treatment. This study aimed to evaluate the ability of Bifidobacterium bifidum CCFM1163 to relieve CC and to investigate its underlying mechanism. Male C57BL/6J mice were treated with senna extract for 8 weeks, followed by a 2-week treatment with B. bifidum CCFM1163. The results revealed that B. bifidum CCFM1163 effectively alleviated CC symptoms. The possible mechanism of B. bifidum CCFM1163 in relieving CC was analyzed by measuring the intestinal barrier and enteric nervous system (ENS)-related indices and establishing a correlation between each index and gut microbiota. The results indicated that B. bifidum CCFM1163 changed the gut microbiota by significantly increasing the relative abundance of Bifidobacterium, Faecalibaculum, Romboutsia, and Turicibacter as well as the content of short-chain fatty acids, especially propionic acid, in the feces. This increased the expression of tight junction proteins and aquaporin 8, decreased intestinal transit time, increased fecal water content, and relieved CC. In addition, B. bifidum CCFM1163 also increased the relative abundance of Faecalibaculum in feces and the expression of enteric nerve marker proteins to repair the ENS, promote intestinal motility, and relieve constipation.

Evidence-Based Perioperative Nutrition Recommendations: Optimizing Results and Minimizing Risks

Plastic surgery patients span the nutritional spectrum from generally healthy, nutritionally competent patients to inherently catabolic, nutritionally deficient, and chronic wound patients. Therefore, plastic and reconstructive surgery affords the opportunity to investigate the impact of nutrition across a heterogeneous patient population following a wide variety of procedures. Although patients may be nutritionally deficient in certain vitamins warranting perioperative repletion, other supplements have the potential to benefit all patients, regardless of nutritional status. Despite these putative benefits, there is a dearth of information regarding nutritional optimization, with the limited, available literature focusing mostly on herbal supplements and their potential side effects. A significant barrier to supplement use is the lack of education and available supporting information regarding the indications, contraindications, and physiology of these adjuncts. The goal of this article is to provide a comprehensive, evidence-based review of available nutritional supplements that can be considered for the plastic surgery patient in the perioperative period to optimize surgical outcomes while minimizing risk. Prospective, well-designed studies using validated, high-quality supplements will be critical in determining the significance that perioperative supplementation can have for surgical outcomes. Until well-done prospective studies are performed, the supplement, dose, and duration should be determined on an individual, patient-per-patient basis at the discretion of the operating surgeon.

The role of thermal injury on intestinal bacterial translocation and the mitigating role of probiotics: A review of animal and human studies

INTRODUCTION

Burn patients represent a combination of nutritionally deplete and calorically demanding individuals who are susceptible to morbidity and mortality. A source of sepsis in thermal injury patients is the gastrointestinal tract with its interaction of normal and potentially pathogenic bacteria. The normal flora of the intestines maintains the equilibrium of the gut and prevents bacterial translocation (BT) through numerous mechanisms, all of which are disrupted as a consequence of thermal injury. Probiotic supplements with varying strains of bacteria have the potential to stabilize the integrity of the gut lining and decrease the incidence of BT after thermal injury.

METHODS

A literature review was conducted for animal and human studies in English addressing probiotic therapy in thermal injury. Keywords, "probiotics," "thermal injury" and "burn" were utilized. Reference lists for each analyzed article were also examined to ensure completeness of literature search. Each article was reviewed for methodology, results and conclusions.

RESULTS

Eleven and six unique articles were identified addressing probiotics in thermal injury in animal and human studies, respectively. Heterogeneity between studies and limited demographic and outcome reporting prevented meta-analysis and comprehensive recommendations to be formalized.

CONCLUSION

While heterogeneity did not allow for meta-analysis, the results overall suggest a preventative, if not therapeutic, potential for probiotics in patients after thermal injury. Despite initial concern that probiotic therapy could lead to systemic infection in immune compromised individuals, this was not observed in the analyzed studies. Numerous unanswered questions exist in regards to optimizing probiotic therapy in patients after thermal injury.

Can probiotics modulate human disease by impacting intestinal barrier function?

Intestinal barrier integrity is a prerequisite for homeostasis of mucosal function, which is balanced to maximise absorptive capacity, while maintaining efficient defensive reactions against chemical and microbial challenges. Evidence is mounting that disruption of epithelial barrier integrity is one of the major aetiological factors associated with several gastrointestinal diseases, including infection by pathogens, obesity and diabetes, necrotising enterocolitis, irritable bowel syndrome and inflammatory bowel disease. The notion that specific probiotic bacterial strains can affect barrier integrity fuelled research in which in vitro cell lines, animal models and clinical trials are used to assess whether probiotics can revert the diseased state back to homeostasis and health. This review catalogues and categorises the lines of evidence available in literature for the role of probiotics in epithelial integrity and, consequently, their beneficial effect for the reduction of gastrointestinal disease symptoms.

Anticoccidial effect of mananoligosacharide against experimentally induced coccidiosis in broiler

The aim of this study was to find the effect of mananoligosacharide (MOS) in comparison with amprolium hydrochloride on performance and integrity of gut in experimentally induced coccidiosis in broiler. A total of 300, day-old male broiler chickens (Ross 308) was randomly allocated to four treatments. Each group was further divided into five replicates of 15 birds each. Group A was kept as control; group B was contaminated with Eimeria tenella, while groups C and D were infected with E. tenella and treated with MOS (0.8 g/kg feed) and anticoccidial drug, amprolium hydrochloride (12 g/100 l water), respectively. The results showed that weight gain, feed intake, and feed conversion ratio (FCR) were significantly higher (P < 0.05) in infected + MOS-treated group compared to the other groups. The result of oocyte per gram (OPG) was significantly higher (P < 0.05) in the group infected with coccidiosis during 5th, 7th, 10th, and 12th day post infection (dpi). Furthermore, the OPG was significantly lower (P < 0.05) in infected groups treated with MOS and amprolium at the studied periods (5, 7, and 10 dpi). At 12 dpi, the infected group treated with MOS showed significantly lower OPG compared to the other groups suggesting the effectiveness of MOS in comparison to amprolium. The result of pinpoint hemorrhages, thickness of cecal wall, bloody fecal contents, and mucoid contents in the cecum were significant highly (P < 0.05) in birds fed with infected oocytes. It was also noted that the differences were not significant in these parameters between amprolium and MOS-treated birds showing the effectiveness of the prebiotic agent. It was concluded from the results of the present study that MOS improved growth performance and reversed the lesions of E. tenella.

Isolation and characterization of lactobacilli from human faeces and indigenous fermented foods for their potential application as probiotics

This study was conducted to select Lactobacillus strains from various sources on the basis of their probiotic attributes, such as acid and bile tolerance, binding to intestinal cells, and antimicrobial activity. Twelve isolates were obtained from human and food sources and were evaluated against standard probiotic Lactobacillus rhamnosus GG (LGG). Isolates were also studied for their antibiotic susceptibility. Isolate Lactobacillus fermentum GPI-6 showed the best survival profile at 0.3% and 1% bile salt, as compared with LGG. Isolates Lactobacillus plantarum GRI-2 and Lactobacillus salivarius GPI-4 showed no reduction in survival rate at pH 2.5. As expected, isolates showed strain-specific differences when comparing various attributes. Isolates GPI-4, GPI-7, and FA-5 showed better adhesion to HT-29, while isolate GPI-4 adhered better to Caco-2 cells than did LGG. However, when studying their ability to compete with Escherichia coli O26:H11, isolates GPI-6 and GPI-7 significantly inhibited E. coli adhesion to both HT-29 and Caco-2 cells compared with LGG. In conclusion, isolates GPI-4, GPI-7, and FA-5 showed excellent binding ability and antagonistic activity and better tolerance to acidic pH (pH 2.5) and to different bile salt concentrations in comparison with LGG, and hence, they could be considered as potential probiotic candidates.

Microbiome-Gut-Brain Axis: A Pathway for Improving Brainstem Serotonin Homeostasis and Successful Autoresuscitation in SIDS-A Novel Hypothesis

Sudden infant death syndrome (SIDS) continues to be a major public health issue. Following its major decline since the "Back to Sleep" campaign, the incidence of SIDS has plateaued, with an annual incidence of about 1,500 SIDS-related deaths in the United States and thousands more throughout the world. The etiology of SIDS, the major cause of postneonatal mortality in the western world, is still poorly understood. Although sleeping in prone position is a major risk factor, SIDS continues to occur even in the supine sleeping position. The triple-risk model of Filiano and Kinney emphasizes the interaction between a susceptible infant during a critical developmental period and stressor/s in the pathogenesis of SIDS. Recent evidence ranges from dysregulated autonomic control to findings of altered neurochemistry, especially the serotonergic system that plays an important role in brainstem cardiorespiratory/thermoregulatory centers. Brainstem serotonin (5-HT) and tryptophan hydroxylase-2 (TPH-2) levels have been shown to be lower in SIDS, supporting the evidence that defects in the medullary serotonergic system play a significant role in SIDS. Pathogenic bacteria and their enterotoxins have been associated with SIDS, although no direct evidence has been established. We present a new hypothesis that the infant's gut microbiome, and/or its metabolites, by its direct effects on the gut enterochromaffin cells, stimulates the afferent gut vagal endings by releasing serotonin (paracrine effect), optimizing autoresuscitation by modulating brainstem 5-HT levels through the microbiome-gut-brain axis, thus playing a significant role in SIDS during the critical period of gut flora development and vulnerability to SIDS. The shared similarities between various risk factors for SIDS and their relationship with the infant gut microbiome support our hypothesis. Comprehensive gut-microbiome studies are required to test our hypothesis.

In vitro and in vivo screening of native lactic acid bacteria toward their selection as a probiotic in broiler chickens

Among 360 isolates from the gastrointestinal tract (GIT) of broilers, eleven isolates which showed in vitro probiotic properties were identified and selected for further tests. After the in vitro screening, three strains were chosen for the in vivo study of persistence of fresh cultures and then one strain was selected for the in vivo study of persistence of lyophilized culture. Lyophilized Lactobacillus salivarius DSPV 001P was capable of persisting in broilers during a complete rearing, even 28 days following cessation of administration. L. salivarius DSPV 001P administered to broilers and recovered from GIT was compared by pulsed-field gel electrophoresis (PFGE) to ensure that the same genotype was persistently identified. A combination of in vitro and in vivo screening of native lactic acid bacteria (LAB) described in this study may offer a method for selecting the most suitable strain for potential application as a broiler probiotic supplement.

The evolving role of infectomics in drug discovery

Signatures of infectomes, which are encoded by both host and microbial genomes, and mirror the interplay between pathogens and their hosts, provide invaluable knowledge in the search for novel antimicrobial drugs. Infectomics is the study of infectomes by using systems biology and high-throughput omic approaches. There are three types of infectomic approaches that can be used for drug discovery: ecological infectomics, immunoinfectomics and chemical infectomics. Ecological infectomics, which is the ecological study of infectomes, explores symbiotic solutions to microbial infections. Research on drug discovery using infectomic signatures and immunomic approaches falls within the field of immunoinfectomics. Advances in chemical infectomics will lead to the development of a new generation of chemical drugs for therapeutics for microbial infections.

Pathogen translocation and histopathological lesions in an experimental model of Salmonella Dublin infection in calves receiving lactic acid bacteria and lactose supplements

The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 10⁹ CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 × 10¹⁰ CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection.

Impact of probiotic administration on the health and fecal microbiota of young calves: a meta-analysis of randomized controlled trials of lactic acid bacteria

Before weaning, dairy calves are susceptible to many pathogens which can affect their subsequent performance. The use of lactic acid bacteria (LAB) has been identified as a tool to maintain the intestinal microbial balance and to prevent the establishment of opportunistic pathogenic bacterial populations. However, a consensus has not been reached as to whether probiotics may be effective in reducing the prevalence of gastrointestinal diseases in young calves. The aim of this meta-analysis was to assess the effect of probiotics on diarrhea incidence and the intestinal microbial balance. LAB supplementation has been shown to exert a protective effect and to reduce the incidence of diarrhea (relative risk, RR=0.437, 95% confidence interval (CI) 0.251-0.761). In the subanalysis, this protective effect of the probiotics against diarrhea was observed only in trials that used whole milk (RR=0.154, 95% CI 0.079-0.301) and trials that used multistrain inocula (RR=0.415, 95% CI 0.227-0.759). Probiotics did not improve the fecal characteristics (standardized mean difference, SMD=-0.4904, 95% CI -1.011-0.035) and were unable to change the LAB:coliforms ratio (SMD=0.016, 95% CI -0.701-0.733). Probiotics showed a beneficial impact on the LAB:coliforms ratio in the subanalysis that included trials that used whole milk (SMD=0.780, 95% CI 0.141-1.418) and monostrain inocula (SMD=0.990, 95% CI 0.340-1.641). The probability of significant effects (probiotic positive effect) in a new study was >0.70 for diarrhea and fecal consistency. Whole milk feeding improved the action of the probiotic effect on the incidence of diarrhea and LAB:coliforms ratio. The probability to find significant effects in the diarrhea frequency and LAB:coliforms ratio was higher (P>0.85) if the new studies were conducted using whole milk to feed calves. This paper defines the guidelines to standardize the experimental designs of future trials. LAB can be used as growth promoters in calves instead of antibiotics to counteract the negative effects of their widespread use.

Effect of mannanoligosaccharides and/or enzymes on antibody titers against infectious bursal and Newcastle disease viruses

The effect of including mannanoligosaccharides (MOS) and/or enzymes in broiler diets on antibody titers against infectious bursal disease virus (IBDV) and Newcastle disease virus (NDV) was evaluated. A total of 750 broilers were distributed into a completely randomized experimental design in a factorial arrangement 2 x 2 + 1 with two levels of MOS (0 and 0.1% until 21 days and 0.05% from 22 to 42 days of age), two levels of enzymes (0 and 0.05%) and a positive control diet containing antibiotic, totaling five treatments with five replicates each. For antibody analyses, blood samples were weekly collected by jugular vein puncture in the same two birds per replicate. The first and last collections were done at 7 and 42 days of age, respectively. The inclusion of MOS resulted in increased antibody titers against IBDV in the fourth (P<0.03) and fifth (P<0.02) weeks, and against NDV in the third (P<0.01), fourth (P<0.03) and fifth (P<0.03) weeks of age. MOS was effective in stimulating the humoral immune responses against IBDV and NDV vaccine viruses.

Probiotics and prebiotics in inflammatory bowel disease: microflora 'on the scope'

The intestinal microflora is a large bacterial community that colonizes the gut, with a metabolic activity equal to an organ and various functions that affect the physiology and pathology of the host's mucosal immune system. Intestinal bacteria are useful in promotion of human health, but certain components of microflora, in genetically susceptible individuals, contribute to various pathological disorders, including inflammatory bowel disease. Clinical and experimental observations indicate an imbalance in protective and harmful microflora components in these disorders. Manipulation of gut flora to enhance its protective and beneficial role represents a promising field of new therapeutic strategies of inflammatory bowel disease. In this review, we discuss the implication of gut flora in the intestinal inflammation that justifies the role of probiotics and prebiotics in the prevention and treatment of inflammatory bowel disease and we address the evidence for therapeutic benefits from their use in experimental models of colitis and clinical trials.

Probiotic bacteria prevent hepatic damage and maintain colonic barrier function in a mouse model of sepsis

A breakdown in intestinal barrier function and increased bacterial translocation are key events in the pathogenesis of sepsis and liver disease. Altering gut microflora with noninvasive and immunomodulatory probiotic organisms has been proposed as an adjunctive therapy to reduce the level of bacterial translocation and prevent the onset of sepsis. The purpose of this study was to determine the efficacy of a probiotic compound in attenuating hepatic and intestinal injury in a mouse model of sepsis. Wild-type and interleukin-10 (IL-10) gene-deficient 129 Sv/Ev mice were fed the probiotic compound VSL#3 for 7 days. To induce sepsis, the mice were injected with lipopolysaccharide (LPS) and D-galactosamine (GalN) in the presence and absence of the peroxisome proliferator-activated receptor gamma (PPARgamma) inhibitor GW9662. The mice were killed after 6 hours, and their colons were removed for the measurement of the cytokine production and epithelial function. The functional permeability was assessed by the mannitol movement and cyclic adenosine monophosphate-dependent chloride secretion in tissue mounted in Ussing chambers. The livers were analyzed for bacterial translocation, cytokine production, histological injury, and PPARgamma levels. The tissue levels of tumor necrosis factor alpha, interferon gamma, IL-6, and IL-12p35 ribonucleic acid were measured by semiquantitative reverse transcription polymerase chain reaction. Mice injected with LPS/GalN demonstrated a breakdown in colonic barrier function, which correlated with enhanced proinflammatory cytokine secretion, bacterial translocation, and significant hepatic injury. A pretreatment with oral probiotics prevented the breakdown in intestinal barrier function, reduced bacterial translocation, and significantly attenuated liver injury. The inhibition of PPARgamma with GW9662 abrogated the protection induced by probiotics.

CONCLUSION

Orally administered probiotics prevented liver and intestinal damage in a mouse model of sepsis through a PPARgamma-dependent mechanism.

Probiotic administration and the incidence of nosocomial infection in pediatric intensive care: a randomized placebo-controlled trial

OBJECTIVE

To evaluate the efficacy of probiotics in reducing the rates of nosocomial infection in pediatric intensive care.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

A 16-bed pediatric intensive care unit in a university-affiliated children's hospital.

PATIENTS

Sixty-one pediatric patients were enrolled from April 2004 until December 2004. Screening of all patients admitted occurred on a daily basis. Patients were excluded if they had the following: evidence/suspicion of intestinal perforation, evidence/suspicion of mechanical gastrointestinal obstruction, absolute neutrophil count <or =0.5 x 10(9) cells/L, judgment by the attending physician that unable to tolerate the enteral volume necessary for administration, use of a probiotic preparation at any time in the week before study entry, participation in another clinical trial, lack of parental presence, or lack of parental consent.

INTERVENTIONS

Patients were randomized to receive either one capsule of Lactobacillus rhamnosus strain GG (Culturelle, ConAgra Foods, Omaha, NE) or placebo capsule of insulin once a day until discharge from the hospital.

RESULTS

Sixty-one patients were randomized: 31 in the treatment group and 30 on the placebo group. Three patients in the control group developed four infections. Six patients in the treatment group developed 11 infections. The relative risk of developing infection in the treatment group was 1.94 (confidence interval [CI], 0.53 to 7.04; p = .31). The mean number of infections in the treatment and control groups was 1.83 and 1.33, respectively, with a difference of 0.5 (p = .52). No serious adverse effects in the study population were noted. However, due to recent safety concerns regarding the administration of L. rhamnosus strain GG and a lack of benefit in this interim analysis, the study was terminated by the study investigators.

CONCLUSIONS

The results of this preliminary investigation were unexpected but important in view of the increased use of probiotic preparations in medically fragile pediatric patients. In this randomized, placebo-controlled trial, L. rhamnosus strain GG was not shown to be effective in reducing the incidence of nosocomial infections. In fact, a statistically nonsignificant trend toward an increase in infection was seen (four vs. 11). Further studies with a larger patient population are needed to establish both safety and efficacy of probiotics in pediatric critical care.

Non–digestible oligosaccharides and defense functions: lessons learned from animal models

Animals are constantly exposed to a diversity of health challenges and the gastrointestinal tract (GIT) is a major, if not the principal, site of exposure. Animal models and a limited number of human clinical studies have shown that the assemblages and metabolic activities of the resident bacteria are important determinants of the effectiveness of the various host defense mechanisms and thereby influence the ability of animals to respond to health challenges. The assemblages of bacteria resident in the GIT provide a first line of defense that can exclude invading pathogens, reduce the proliferation of opportunistic pathogens already resident in the GIT, and reduce the availability, carcinogenicity, or toxicity of noxious chemicals. The mucosa of the GIT is a second, multilayered line of defense that includes the mucous and other secretions, the epithelial cells, and immune-associated cells scattered within and under the epithelium. The final line of defense contends with pathogens or noxious chemicals that transcend the mucosal barrier and enter the host and consists of the innate and acquired components of the systemic immune system and the xenobiotic metabolizing enzymes. The lactic acid producing bacteria (LAB) are considered to be immunomodulatory and directly or indirectly influence the GIT and systemic defense functions. Corresponding with this, supplementing the diet with inulin, oligofructose, or other nondigestible oligosaccharides that increase the densities and metabolic capacities of the LAB enhances defense mechanisms of the host, increases resistance to various health challenges, and accelerates recovery of the GIT after disturbances.

Probiotics: their role in the treatment and prevention of disease

A probiotic is a "live microbial food ingredients that, when ingested in sufficient quantities, exerts health benefits on the consumer". Probiotics exert their benefits through several mechanisms; they prevent colonization, cellular adhesion and invasion by pathogenic organisms, they have direct antimicrobial activity and they modulate the host immune response. The strongest evidence for the clinical effectiveness of probiotics has been in their use for the prevention of symptoms of lactose intolerance, treatment of acute diarrhea, attenuation of antibiotic-associated gastrointestinal side effects and the prevention and treatment of allergy manifestations. More research needs to be carried out to clarify conflicting findings on the use of probiotics for prevention of travelers' diarrhea, infections in children in daycare and dental caries, and elimination of nasal colonization with potentially pathogenic bacteria. Promising ongoing research is being conducted on the use of probiotics for the treatment of Clostridium difficile colitis, treatment of Helicobacter pylori infection, treatment of inflammatory bowel disease and prevention of relapse, treatment of irritable bowel syndrome, treatment of intestinal inflammation in cystic fibrosis patients, and prevention of necrotizing enterocolitis in premature infants. Finally, areas of future research include the use of probiotics for the treatment of rheumatoid arthritis, prevention of cancer and the treatment of graft-versus-host disease in bone marrow transplant recipients.

Evaluation of Lactobacillus pentosus WE7 for prevention of diarrhea in neonatal foals

OBJECTIVE

To evaluate the efficacy of Lactobacillus pentosus WE7, an equine-origin organism with potentially beneficial in vitro properties, as a probiotic for prevention of neonatal diarrhea in foals.

DESIGN

Randomized controlled clinical trial.

ANIMALS

153 foals.

PROCEDURE

Foals were enrolled at 24 to 48 hours of age and randomly assigned to treatment or control groups. The treatment group received approximately 2 x 10(11) CFU of freeze-dried L. pentosus WE7 orally once daily for 7 days, whereas the control group received a placebo. Clinical monitoring was performed for 14 days.

RESULTS

Probiotic administration was significantly associated with development of signs of depression, anorexia, and colic and the need for veterinary examination and treatment. Probiotic-treated foals also had more days of diarrhea, compared with the control group, although not significantly. In a multivariate model, probiotic administration was significantly associated with development of diarrhea and diarrhea plus additional clinical abnormalities.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of L. pentosus WE7 did not prevent diarrhea; rather, it was associated with development of diarrhea and, most importantly, development of diarrhea plus additional clinical abnormalities and the need for veterinary intervention. The promising in vitro properties of L. pentosus WE7 were not evident in vivo. Results raise concern about the variety of untested probiotic products that are commercially available. Safety and efficacy testing needs to be performed for all potential equine probiotics.

Effect of Probiotic Supplementation on Bacterial Translocation in Thermal Injury

PURPOSE

To examine the effects of probiotic supplementation and enteral solutions containing glutamine and arginine on bacterial translocation (BT) and intestinal villous atrophy in thermal injury.

METHODS

Forty male Sprague-Dawley rats weighing 200-250 g were divided into four groups of ten. Group 1 served as control group without thermal injury and was fed standard chow. Thermal injury was inflicted as a 30% scald burn in the other three groups. Group 2 was fed standard chow and group 3 was fed standard chow supplemented with a probiotic (Acidophilus plus) containing Bifidobacterium bifidum, Lactobacillus acidophilus, and Lactobacillus bulgaricus (2 x 10(9) CFU/day) via an orogastric tube. Group 4 was fed only an enteral diet (Stresson multifiber) containing glutamine, arginine, and medium chain triglyceride, at 1 g/kg per day amino acid and 230 kcal/kg, for 7 days before thermal injury. All the animals were killed 24 h after thermal injury, and ileal segments were resected and examined histopathologically. To evaluate BT, samples from blood, mesenteric lymph nodes, and cecal content were cultured under aerobic and anaerobic conditions. Terminal ileum specimens were histologically examined to evaluate mucosal integrity.

RESULTS

Significantly less BT was seen in groups 3 and 4 than in group 2 (P < 0.001). No significant difference was found between groups 3 and 4. Histological evaluation showed significant reduction in villous atrophy in groups 3 and 4.

CONCLUSION

Probiotic supplementation seems to reduce bacterial translocation and decrease intestinal mucosal atrophy in rats with thermal injury, as do enteral solutions with arginine and glutamine.

Probiotic and other functional microbes: from markets to mechanisms

Insight into the diversity and function of the human intestinal microbiota has been stimulated by clinical studies with bacteria that exhibit specific functions and which are marketed as probiotics to positively affect our health. Initial efforts concentrated on establishing sound scientific support for the efficacy of these probiotic bacteria, which mainly include Lactobacillus and Bifidobacterium species. Following these evidence-based functional approaches, considerable research is now focused on the mechanisms of action of probiotic bacteria. The mechanisms identified to date mainly relate to the stimulation of host defence systems, immune modulation and the competitive exclusion of pathogens. Recent efficacy, molecular and genomics-based studies have also been reported for some probiotic strains that have found their position in the market place.

Germ warfare: probiotics in defense of the premature gut

The potential benefits of a predominantly lactic acid bacterial flora include an improved balance of gut microbial ecology and decreased susceptibility of the gut mucosa to bacterial translocation via adherence to the intestinal mucosa, strengthening mucosal barrier function. These properties should be especially beneficial to the premature neonate with (1) delayed establishment of nor-mal flora, increasing the potential for proliferation of pathogenic bacteria and (2) immature development of the intestinal mucosa, rendering it more susceptible to the translocation of these pathogenic bacteria and leading to extra-intestinal spread and systemic disease. Early probiotic supplementation in preterm infants is theoretically sound and associated with minimal risk. Clinical data remain preliminary but are supportive of a reduction in feeding intolerance and NEC in this high-risk group.

Use of mouse models to evaluate the persistence, safety, and immune modulation capacities of lactic acid bacteria

Recent clinical and experimental observations showed that specific probiotic microorganisms may provide therapeutic benefits in inflammatory bowel disease. However, a rigorous screening for new candidate probiotic strains with optimized therapeutic properties necessitates also determining possible adverse interactions with the host, particularly in individuals who are not healthy. We have evaluated the persistence of strains of lactic acid bacteria (LAB) in the digestive tracts of mice, their immunomodulation capacity, and their safety in healthy animals and in a colitis model. Following daily administration of 10(9) CFU of viable LAB orally, intragastrically, or intrarectally, the animals' feces were examined for bacterial excretion and cytokines were quantified in intestinal samples by quantitative reverse transcription-PCR. The level of bacterial translocation was assessed in healthy mice and in mice suffering from colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). Irrespective of the route of administration, the potential probiotic strain Lactobacillus plantarum NCIMB8826 was found to persist for up to 10 days in the digestive tracts of mice. This strain did not induce detrimental effects in healthy or in TNBS-treated animals, as was reflected by the absence of weight loss, intestinal inflammation, modification of cytokine levels in the ileum and colon (healthy mice), and bacterial dissemination (healthy and colitic animals). Moreover, the translocation of endogenous microflora to the mesenteric lymph nodes and spleen was greatly reduced in the TNBS-treated mice after administration of LAB. This property, together with the strain's persistence capacity and innocuousness renders L. plantarum NCIMB8826 an attractive candidate as a probiotic to be used in the prevention or treatment of chronic inflammation.

Probiotic supplementation reduces the risk of bacterial translocation in experimental short bowel syndrome

BACKGROUND/PURPOSE

Probiotics are live organisms that survive passage through the gastrointestinal tract and have beneficial effects on the host. Lactobacillus and Bifidobacterium have been recommended for cholesterol lowering, acute diarrhea, prevention of cancer, or inflammatory bowel disease. On the other hand, after massive bowel resection, bacterial overgrowth is frequent and favors bacterial translocation (BT). The possible beneficial effects of Bifidobacterium lactis (BL) administration on BT in experimental short bowel syndrome (SBS), have not been investigated. The aim of this study was to test the hypothesis that BL administration decreases BT in SBS in animals fed orally.

METHODS

One hundred twenty-eight adult Wistar rats fed orally with standard rat chow and tap water "ad libitum" were maintained in individual metabolic cages for 10 days and divided into 3 groups: control group (n = 71): nonmanipulated animals; RES group (n = 39): 80% gut resection from 10 cm beyond the angle of Treitz to 10 cm above the cecum; RES-PRO group (n = 18): same resection and daily 7.8 x 10(8) CFU B Lactis administration, after orogastric intubation. At the end of the experiment they were killed, and mesenteric lymph nodes (MLN) and peripheral and portal blood specimens were recovered and cultured. Bacterial identification in blood was made by conventional methods, and MLN culture was considered positive with a growth over 100 CFU/g.

RESULTS

Bacterial translocation was detected in 6% of control group rats. The incidence of BT in the RES group was 87% (34 of 39), whereas only 50% (9 of 18) of RES-PRO animals had BT (P <.05). The relative risk reduction (RRR) was 0.43 (95% Cl 0.14 to 0.72), and the number needed to treat (NNT) was 3 (95% Cl 2 to 8). In other words, animals that received BL had the risk of BT reduced by 43% (RRR of 0.43), and of every 3 animals treated, 1 is expected to be free of BT (NNT of 3).

CONCLUSION

Administration of B Lactis reduces the incidence of BT in adult Wistar rats after 80% gut resection.