Safety of probiotics that contain lactobacilli or bifidobacteria

Probiotics (Lactobacillus acidophilus and Bifidobacterium infantis) prevent NEC in VLBW infants fed breast milk but not formula [corrected]

BACKGROUND

Specific probiotics prevent necrotizing enterocolitis (NEC). A mixture of lactobacilli and bifidobacteria (Infloran) was highly effective in Asian very-low-birth-weight (VLBW) infants. We analyzed the effect of Infloran on NEC, NEC severity, and the influence of enteral feedings (breast milk vs. formula) on NEC prevention in a cohort of European VLBW infants.

METHODS

Infloran was implemented for routine use at our department. VLBW infants receiving probiotics were prospectively followed (2010-2012) and compared with historic controls (2008-2009). Data on NEC, neonatal morbidity, feeding tolerance, and descriptive parameters on NEC cases were analyzed.

RESULTS

Infloran had no statistically significant impact on NEC (controls: 24/233 (10.3%); probiotics: 16/230 (7%); P = 0.2). However, NEC was significantly reduced in infants of the probiotics group who were fed any breast milk (20/179 (11.2%) vs. 10/183 (5.5%); P = 0.027), whereas it was ineffective in infants exclusively fed formula (4/54 (7.4%) vs. 6/44 (13.6%); P = 0.345). Occurrence of severe NEC (IIIb), time until full feeds, and gastric residuals were similar.

CONCLUSION

Infloran was of lower efficacy in a European VLBW cohort and showed a reduction of NEC only in infants fed breast milk. Future studies should investigate the influence of feeding formula or breast milk on the effect of probiotics.

Probiotics: an update

OBJECTIVE

Triggered by the growing knowledge on the link between the intestinal microbiome and human health, the interest in probiotics is ever increasing. The authors aimed to review the recent literature on probiotics, from definitions to clinical benefits, with emphasis on children.

SOURCES

Relevant literature from searches of PubMed, CINAHL, and recent consensus statements were reviewed.

SUMMARY OF THE FINDINGS

While a balanced microbiome is related to health, an imbalanced microbiome or dysbiosis is related to many health problems both within the gastro-intestinal tract, such as diarrhea and inflammatory bowel disease, and outside the gastro-intestinal tract such as obesity and allergy. In this context, a strict regulation of probiotics with health claims is urgent, because the vast majority of these products are commercialized as food (supplements), claiming health benefits that are often not substantiated with clinically relevant evidence. The major indications of probiotics are in the area of the prevention and treatment of gastro-intestinal related disorders, but more data has become available on extra-intestinal indications. At least two published randomized controlled trials with the commercialized probiotic product in the claimed indication are a minimal condition before a claim can be sustained. Today, Lactobacillus rhamnosus GG and Saccharomyces boulardii are the best-studied strains. Although adverse effects have sporadically been reported, these probiotics can be considered as safe.

CONCLUSIONS

Although regulation is improving, more stringent definitions are still required. Evidence of clinical benefit is accumulating, although still missing in many areas. Misuse and use of products that have not been validated constitute potential drawbacks.

Physiological Characteristics and Anti-obesity Effect of Lactobacillus plantarum Q180 Isolated from Feces

Obesity is strongly associated with several metabolic and chronic diseases and has become a major public health problem of worldwide concern. This study aimed to investigate the physiological characteristics and anti-obesity effects of Lactobacillus plantarum Q180. Lactobacillus plantarum Q180 was isolated from the faces of healthy adults and found to have a lipase inhibitory activity of 83.61±2.32% and inhibited adipocyte differentiation of 3T3-L1 cells (14.63±1.37%) at a concentration of 100 μg/mL. The strain was investigated for its physiological characteristics. The optimum growth temperature of L. plantarum Q180 was 37℃. Lactobacillus plantarum Q180 showed higher sensitivity to novobiocin in a comparison of fifteen different antibiotics and showed the highest resistance to rifampicin, polymyxin B and vancomycin. The strain showed higher β-galactosidase and N-acetyl-β-glucosaminidase activities. It also did not produce carcinogenic enzymes such as β-glucuronidase. The survival rate of L. plantarum Q180 in MRS broth containing 0.3% bile was 97.8%. Moreover, the strain showed a 97.2% survival rate after incubation for 3 h in pH 2.0. Lactobacillus plantarum Q180 was displayed resistance to Escherichia coli, Salmonella Typhimurium and Staphylococcus aureus with rates of 55.6%, 38.0% and 47.6%, respectively. These results demonstrate that L. plantarum Q180 has potential as a probiotic with anti-obesity effects.

Bifidobacterium--friend or foe? A case of urinary tract infection with Bifidobacterium species

Bifidobacterium-a commensal of the human intestine is considered non-pathogenic and has been advocated as a probiotic due to its potential beneficial effects. However, there have been case reports implicating bifidobacteria as pathogenic agents in a variety of different infectious conditions. We discuss here one such case of a complicated urinary tract infection associated with Bifidobacterium spp.

Immunomodulatory effect of non-viable components of probiotic culture stimulated with heat-inactivated Escherichia coli and Bacillus cereus on holoxenic mice

Background

Competition of probiotic bacteria with other species from the intestinal microbiota involves different mechanisms that occur regardless of probiotics’ viability. The objective of this paper was to assess the cytokine serum levels in holoxenic mice after oral administration of non-viable components (NVC) of Enterococcus faecium probiotic culture stimulated with heat-inactivated Escherichia coli and Bacillus cereus in comparison to NVC of unstimulated E. faecium probiotic culture.

Methods

Probiotic E. faecium CMGb 16 culture, grown in the presence of heat-inactivated cultures of E. coli and B. cereus CMGB 102, was subsequently separated into supernatant (SN) and heat-inactivated cellular sediment (CS) fractions by centrifugation. Each NVC was orally administered to holoxenic mice (balb C mouse strain), in three doses, given at 24 hours. Blood samples were collected from the retinal artery, at 7, 14, and 21 days after the first administration of the NVC. The serum concentrations of IL-12 and tumor necrosis factor-alpha (TNF-α) interleukins were assessed by ELISA method.

Results

After the oral administration of SN component obtained from the probiotic culture stimulated with heat-inactivated cultures of B. cereus CMGB 102 and E. coli O28, the serum concentrations of IL-12 were maintained higher in the samples collected at 7 and 14 days post-administration. No specific TNF-α profile could be established, depending on stimulated or non-stimulated probiotic culture, NVC fraction, or harvesting time.

Conclusion

The obtained results demonstrate that non-viable fractions of probiotic bacteria, stimulated by other bacterial species, could induce immunostimulatory effects mediated by cytokines and act, therefore, as immunological adjuvants.

Cold stress improves the ability of Lactobacillus plantarum L67 to survive freezing

The stress resistance of bacteria is affected by the physiological status of the bacterial cell and environmental factors such as pH, salts and temperature. In this study, we report on the stress response of Lactobacillus plantarum L67 after four consecutive freeze-thaw cycles. The cold stress response of the cold-shock protein genes (cspC, cspL and cspP) and ATPase activities were then evaluated. The cold stress was adjusted to 5 °C when the bacteria were growing at the mid-exponential phase. A comparative proteomic analysis was performed with two-dimensional gel electrophoresis (2D SDS-PAGE) and a matrix assisted laser desorption/ionization-mass spectrometer. Only 56% of the L. plantarum L67 cells without prior exposure to cold stress survived after four consecutive freeze-thaw cycles. However, 78% of the L. plantarum L67 cells that were treated with cold stress at 5 °C for 6 h survived after freeze-thaw conditions. After applying cold stress to the culture for 6h, the cells were then stored for 60 days at 5 °C, 25 °C and 35 °C separately. The cold-stressed culture of L. plantarum L67 showed an 8% higher viability than the control culture. After applying cold stress for 6h, the transcript levels of two genes (cspP and cspL) were up-regulated 1.4 (cspP) and 1.2 (cspL) times compared to the control. However, cspC was not up-regulated. A proteomic analysis showed that the proteins increased after a reduction of the incubation temperature to 5 °C. The importance of the expression of 13 other relevant proteins was also determined through the study. The exposure of L. plantarum cells to low temperatures aids their ability to survive through subsequent freeze-thaw processes and lyophilization.

Severe oral infection due to Lactobacillus rhamnosus during induction chemotherapy for acute myeloid leukemia

We report a case of severe oral infection with a high fever due to Lactobacillus rhamnosus during induction chemotherapy for acute myeloid leukemia. The patient did not improve on treatment with meropenem, clindamycin, or vancomycin until neutrophil recovery. Since L. rhamnosus GG is used in dairy products, and the patient ingested dairy products daily before starting chemotherapy, we suspected an association between the ingestion of dairy products and the development of infection. Pulsed-field gel electrophoresis using two different restriction enzymes showed that the strain isolated from the patient was identical to the L. rhamnosus GG strain isolated from dairy products and ATCC #53103. This was confirmed by a PCR assay with species-specific L. rhamnosus GG primers. Since Lactobacillus infection, particularly L. rhamnosus infection, can be fatal in immunocompromised hosts, we should consider Lactobacillus as a causative organism when Gram-positive rods are detected during treatment with broad-spectrum antibiotics and vancomycin. The causal association between the ingestion of dairy products containing Lactobacillus and Lactobacillus infection in immunocompromised hosts warrants further study.

Probiotics and prebiotics in dermatology

The rapid increase in the medical use of probiotics and prebiotics in recent years has confirmed their excellent safety profile. As immune modulators, they have been used in inflammatory skin conditions, such as atopic dermatitis. We review the literature regarding the use of probiotics and prebiotics in dermatology. Probiotics and prebiotics appear to be effective in reducing the incidence of atopic dermatitis in infants, but their role in atopic dermatitis treatment is controversial. Their role in acne, wound healing, and photoprotection is promising, but larger trials are needed before a final recommendation can be made.

Oral toxicity evaluation of kefir-isolated Lactobacillus kefiranofaciens M1 in Sprague-Dawley rats

Lactobacilli kefiranofaciens M1 has shown novel immunomodulation and anti-allergy probiotic attributes in cell and animal models. An acute oral toxicity assessment of L. kefiranofaciens M1 was evaluated in Sprague-Dawley rats. The rats were randomly assigned to four groups (12 rats/sex/group): the low dose group was orally gavaged with L. kefiranofaciens M1 at 3.0×10(8)cfu/kg bw while the medium dose and high dose groups received 9.0×10(9)cfu/kg bw and 1.8×10(10)cfu/kg bw, respectively, for 28days. The control group received phosphate buffer saline. The body weights were measured weekly while blood samples were collected for haematology and serum biochemistry tests. Histopathology of the organs (heart, liver, kidney, adrenal glands, spleen, ovary, testis), and urinalysis were conducted on study termination. The body weight gain of the L. kefiranofaciens M1 and control groups were comparable during the administration period. Overall, L. kefiranofaciens M1 did not induce adverse effects on haematology, serum biochemistry, and urinalysis parameters. Gross and microscopic histopathology of the organs revealed no toxicity effect of L. kefiranofaciens M1. In conclusion, 1.8×10(10)cfu/kg bw of L. kefiranofaciens M1 was considered as the no-observed-adverse-effect-level (NOAEL), which was the highest dose tested in the present study.

Functional analysis via standardized whole-blood stimulation systems defines the boundaries of a healthy immune response to complex stimuli

Standardization of immunophenotyping procedures has become a high priority. We have developed a suite of whole-blood, syringe-based assay systems that can be used to reproducibly assess induced innate or adaptive immune responses. By eliminating preanalytical errors associated with immune monitoring, we have defined the protein signatures induced by (1) medically relevant bacteria, fungi, and viruses; (2) agonists specific for defined host sensors; (3) clinically employed cytokines; and (4) activators of T cell immunity. Our results provide an initial assessment of healthy donor reference values for induced cytokines and chemokines and we report the failure to release interleukin-1α as a common immunological phenotype. The observed naturally occurring variation of the immune response may help to explain differential susceptibility to disease or response to therapeutic intervention. The implementation of a general solution for assessment of functional immune responses will help support harmonization of clinical studies and data sharing.

Antibiotic alternatives: the substitution of antibiotics in animal husbandry?

It is a common practice for decades to use of sub-therapeutic dose of antibiotics in food-animal feeds to prevent animals from diseases and to improve production performance in modern animal husbandry. In the meantime, concerns over the increasing emergence of antibiotic-resistant bacteria due to the unreasonable use of antibiotics and an appearance of less novelty antibiotics have prompted efforts to develop so-called alternatives to antibiotics. Whether or not the alternatives could really replace antibiotics remains a controversial issue. This review summarizes recent development and perspectives of alternatives to antibiotics. The mechanism of actions, applications, and prospectives of the alternatives such as immunity modulating agents, bacteriophages and their lysins, antimicrobial peptides, pro-, pre-, and synbiotics, plant extracts, inhibitors targeting pathogenicity (bacterial quorum sensing, biofilm, and virulence), and feeding enzymes are thoroughly discussed. Lastly, the feasibility of alternatives to antibiotics is deeply analyzed. It is hard to conclude that the alternatives might substitute antibiotics in veterinary medicine in the foreseeable future. At the present time, prudent use of antibiotics and the establishment of scientific monitoring systems are the best and fastest way to limit the adverse effects of the abuse of antibiotics and to ensure the safety of animal-derived food and environment.

Cohort study of probiotics in a North American neonatal intensive care unit

OBJECTIVE

To determine whether routine probiotic administration to very preterm infants would reduce the incidence of necrotizing enterocolitis (NEC) without adverse consequences.

STUDY DESIGN

Since the end of July 2011, we have administered a probiotic mixture to all admitted infants of <32 weeks' gestation. We give 0.5 g of a mixture of 4 bifidobacteria (Bifidobacterium breve, bifidum, infantis, and longum) and Lactobacillus rhamnosus HA-111 [corrected] (2 × 10(9) colony-forming units) per day, starting with the first feed, until the infant reaches 34 weeks. We compared complications among infants admitted during the first 17 months of routine use with those admitted during the previous 17 months.

RESULTS

Two hundred ninety-four infants received probiotics, and 317 infants formed the comparison group. Introduction of probiotics was associated with a reduction in NEC (from 9.8% to 5.4%, P < .02), a nonsignificant decrease in death (9.8% to 6.8%), and a significant reduction in the combined outcome of death or NEC (from 17% to 10.5%, P < .05). After adjustment for gestational age, intrauterine growth restriction, and sex, the improvements remained significant (OR for NEC, 0.51; 95% CI, 0.26-0.98; OR for death or NEC, 0.56; 95% CI, 0.33-0.93). There was no effect of probiotics on health care-associated infection.

DISCUSSION

A product that is readily available in North America, that has excellent quality control, and that contains strains similar to those that have been shown effective in randomized controlled trials substantially reduced the frequency of NEC in our neonatal intensive care unit.

Ventriculoperitoneal shunt infection caused by Bifidobacterium breve

Bifidobacterium breve is a rare cause of human infections. Previously, bacteremia and meningitis caused by this organism linked to probiotic use have been reported in a neonate. We report the first case of a ventriculoperitoneal shunt infection caused by B. breve in an adult without a history of probiotic use.

Physiological Characteristics and Production of Folic Acid of Lactobacillus plantarum JA71 Isolated from Jeotgal, a Traditional Korean Fermented Seafood

Folic acid, one of the B group of vitamins, is an essential substance for maintaining the functions of the nervous system, and is also known to decrease the level of homocysteine in plasma. Homocysteine influences the lowering of the cognitive function in humans, and especially in elderly people. In order to determine the strains with a strong capacity to produce folic acid, 190 bacteria were isolated from various kinds of jeotgal and chungkuk-jang. In our test experiment, JA71 was found to contain 9.03μg/mL of folic acid after 24 h of incubation in an MRS broth. This showed that JA71 has the highest folic acid production ability compared to the other lactic acid bacteria that were isolated. JA71 was identified as Lactobacillus plantarum by the result of API carbohydrate fermentation pattern and 16s rDNA sequence. JA71 was investigated for its physiological characteristics. The optimum growth temperature of JA71 was 37℃, and the cultures took 12 h to reach pH 4.4. JA71 proved more sensitive to bacitracin when compared with fifteen different antibiotics, and showed most resistance to neomycin and vancomycin. Moreover, it was comparatively tolerant of bile juice and acid, and displayed resistance to Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus with restraint rates of 60.4%, 96.7%, and 76.2%, respectively. These results demonstrate that JA71 could be an excellent strain for application to functional products.

Probiotic screening and safety evaluation of Lactobacillus strains from plants, artisanal goat cheese, human stools, and breast milk

The aim of this study was to select autochthonous strains of Lactobacillus from stools of healthy infants and adults, human milk, artisanal goat cheese, and fruits and vegetables according to their probiotic properties and safety. From 421 strains of Lactobacillus isolated, 102 (24.2%) were shown to be tolerant to gastric pH and bile salts; they were used to determine their anti-Helicobacter pylori (agar diffusion assay), antioxidant (oxygen radical absorption capacity), and anti-inflammatory (inhibition of interleukin-8 release by tumor necrosis factor-α-stimulated HT-29 cells) activities as well as their ability to adhere to intestinal (Caco-2) and gastric (AGS) epithelial cells. Results obtained were compared with three commercial probiotic Lactobacillus rhamnosus GG, L. plantarum 299v, and L. johnsonii NCC533. The five strains most efficient according to these activities were subsequently identified by sequencing their 16S rRNA gene, their susceptibility to antibiotics was determined, and their safety evaluated in mice. One strain of L. plantarum was discarded due to the higher prevalence of liver bacterial translocation observed in the animals fed this strain. In conclusion, four autochthonous strains of L. rhamnosus were finally selected with probiotic properties and safety allowing their eventual use in human studies. These results contribute to increase the diversity of probiotic strains available for the development of nutraceuticals and functional foods.

Antagonistic activity of Lactobacillus isolates against Salmonella typhi in vitro

Background. Enteric fever is a global health problem, and rapidly developing resistance to various drugs makes the situation more alarming. The potential use of Lactobacillus to control typhoid fever represents a promising approach, as it may exert protective actions through various mechanisms. Methods. In this study, the probiotic potential and antagonistic activities of 32 Lactobacillus isolates against Salmonella typhi were evaluated. The antimicrobial activity of cell free supernatants of Lactobacillus isolates, interference of Lactobacillus isolates with the Salmonella adherence and invasion, cytoprotective effect of Lactobacillus isolates, and possibility of concurrent use of tested Lactobacillus isolates and antibiotics were evaluated by testing their susceptibilities to antimicrobial agents, and their oxygen tolerance was also examined. Results. The results revealed that twelve Lactobacillus isolates could protect against Salmonella typhi infection through interference with both its growth and its virulence properties, such as adherence, invasion, and cytotoxicity. These Lactobacillus isolates exhibited MIC values for ciprofloxacin higher than those of Salmonella typhi and oxygen tolerance and were identified as Lactobacillus plantarum. Conclusion. The tested Lactobacillus plantarum isolates can be introduced as potential novel candidates that have to be subjected for in vivo and application studies for treatment and control of typhoid fever.

A potential role of probiotics in colorectal cancer prevention: review of possible mechanisms of action

A number of investigations, mainly using in vitro and animal models, have demonstrated a wide range of possible mechanisms, by which probiotics may play a role in colorectal cancer (CRC) prevention. In this context, the most well studied probiotics are certain strains from the genera of lactobacilli and bifidobacteria. The reported anti-CRC mechanisms of probiotics encompass intraluminal, systemic, and direct effects on intestinal mucosa. Intraluminal effects detailed in this review include competitive exclusion of pathogenic intestinal flora, alteration of intestinal microflora enzyme activity, reduction of carcinogenic secondary bile acids, binding of carcinogens and mutagens, and increasing short chain fatty acids production. Reduction of DNA damage and suppression of aberrant crypt foci formation have been well demonstrated as direct anti-CRC effects of probiotics on intestinal mucosa. Existing evidence clearly support a multifaceted immunomodulatory role of probiotics in CRC, particularly its ability to modulate intestinal inflammation, a well known risk factor for CRC. The effectiveness of probiotics in CRC prevention is dependent on the strain of the microorganism, while viability may not be a prerequisite for certain probiotic anticancer mechanisms, as indicated by several studies. Emerging data suggest synbiotic as a more effective approach than either prebiotics or probiotics alone. More in vivo especially human studies are warranted to further elucidate and confirm the potential role of probiotics (viable and non-viable), prebiotics and synbiotics in CRC chemoprevention.

In vitro and in vivo survival and colonic adhesion of Pediococcus acidilactici MTCC5101 in human gut

The present study aims to investigate the probiotic nature of Pediococcus acidilactici MTCC5101 by an in vitro assay of bacterial adherence to intestinal epithelial cells of human gastrointestinal (GI) tract using Caco-2 cell line. Further to assess the in vivo survival in the GI tract, oral feeding was carried out with the help of 10 healthy volunteers. The effect on wellness was assessed by studying blood biochemical parameters of the volunteers. The survival of the bacteria was assessed using PCR-based detection of P. acidilactici MTCC5101 in fecal samples. The probiotic nature of P. acidilactici MTCC 5101 was strengthened by its adherence to the intestinal epithelial Caco-2 cell line in the in vitro SEM observations. Oral feeding study for assessing the survival of bacteria in GI tract of volunteers showed the strain to be established in the GI tract which survived for about 2 weeks after feeding.

Lactobacillus: host-microbe relationships

Lactobacilli are a subdominant component of the human intestinal microbiota that are also found in other body sites, certain foods, and nutrient-rich niches in the free environment. They represent the types of microorganisms that mammalian immune systems have learned not to react to, which is recognized as a potential driving force in the evolution of the human immune system. Co-evolution of lactobacilli and animals provides a rational basis to postulate an association with health benefits. To further complicate a description of their host interactions, lactobacilli may rarely cause opportunistic infections in compromised subjects. In this review, we focus primarily on human-Lactobacillus interactions. We overview the microbiological complexity of this extraordinarily diverse genus, we describe where lactobacilli are found in or on humans, what responses their presence elicits, and what microbial interaction and effector molecules have been identified. The rare cases of Lactobacillus septicaemia are explained in terms of the host impairment required for such an outcome. We discuss possibilities for exploitation of lactobacilli for therapeutic delivery and mucosal vaccination.

Differential effect on cell-mediated immunity in human volunteers after intake of different lactobacilli

Probiotics are live microorganisms which have beneficial effects on the host when ingested in adequate amounts. Probiotic bacteria may stimulate immune effector functions in a strain-specific manner. In this blind placebo-controlled trial, we investigated the effects on the immune system following daily intake of six different strains of lactobacilli or the Gram-negative bacterium Pseudomonas lundensis for 2 or 5 weeks. Blood lymphocyte subsets were quantified by fluorescence activated cell sorter and the expression of activation and memory markers was determined. The bacterial strains were also examined for their capacity to adhere to human intestinal cells and to be phagocytosed by human peripheral blood mononuclear cells. Intake of Lactobacillus plantarum strain 299v increased the expression of the activation marker CD25 (P = 0·01) on CD8(+) T cells and the memory cell marker CD45RO on CD4(+) T cells (P = 0·03), whereas intake of L. paracasei tended to expand the natural killer T (NK T) cell population (P = 0·06). The phagocytic activity of granulocytes was increased following intake of L. plantarum 299v, L. plantarum HEAL, L. paracasei or L. fermentum. In contrast, ingestion of L. rhamnosus decreased the expression of CD25 and CD45RO significantly within the CD4(+) cell population. The observed immune effects after in-vivo administration of the probiotic bacteria could not be predicted by either their adherence capacity or the in-vitro-induced cytokine production. The stimulation of CD8(+) T cells and NK T cells suggests that intake of probiotic bacteria may enhance the immune defence against, e.g. viral infections or tumours.

Synergistic protection of combined probiotic conditioned media against neonatal necrotizing enterocolitis-like intestinal injury

Balance among the complex interactions of the gut microbial community is important for intestinal health. Probiotic bacteria can improve bacterial balance and have been used to treat gastrointestinal diseases. Neonatal necrotizing enterocolitis (NEC) is a life-threatening inflammatory bowel disorder primarily affecting premature infants. NEC is associated with extensive inflammatory NF-κB signaling activation as well as intestinal barrier disruption. Clinical studies have shown that probiotic administration may protect against NEC, however there are safety concerns associated with the ingestion of large bacterial loads in preterm infants. Bacteria-free conditioned media (CM) from certain probiotic organisms have been shown to retain bioactivity including anti-inflammatory and cytoprotective properties without the risks of live organisms. We hypothesized that the CM from Lactobacillus acidophilus (La), Bifidobacterium infantis (Bi), and Lactobacillus plantarum (Lp), used separately or together would protect against NEC. A rodent model with intestinal injury similar to NEC was used to study the effect of CM from Lp, La/Bi, and La/Bi/Lp on the pathophysiology of NEC. All the CM suppressed NF-κB activation via preserved IκBα expression and this protected IκBα was associated with decreased liver activity of the proteasome, which is the degrading machinery for IκBα. These CM effects also caused decreases in intestinal production of the pro-inflammatory cytokine TNF-α, a downstream target of the NF-κB pathway. Combined La/Bi and La/Bi/Lp CM in addition protected intestinal barrier function by maintaining tight junction protein ZO-1 levels and localization at the tight junction. Double combined La/Bi CM significantly reduced intestinal injury incidence from 43% to 28% and triple combined La/Bi/Lp CM further reduced intestinal injury incidence to 20%. Thus, this study demonstrates different protective mechanisms and synergistic bioactivity of the CM from different organisms in ameliorating NEC-like intestinal injury in an animal model.

Role of probiotics in short bowel syndrome in infants and children--a systematic review

Short bowel syndrome (SBS) is a cause of significant morbidity and mortality in children. Probiotics, due to their beneficial effects on the gastrointestinal tract (e.g., improving gut barrier function, motility, facilitation of intestinal adaptation and decreasing pathogen load and inflammation) may have a therapeutic role in the management of SBS. To conduct a systematic review of the current evidence for the effects of probiotic supplementation in children with SBS, the standard Cochrane methodology for systematic reviews was used. The databases, Pubmed, Embase, ACTR, CENTRAL, and the international trial registry, and reference lists of articles were searched for randomised (RCT) or quasi-randomised controlled trials reporting on the use of probiotics in SBS. Our search revealed no RCTs on the use of probiotics in children with SBS. We found one small cross-over RCT (placebo controlled crossover clinical trial), one case control study and nine case reports on the use of probiotics in children with SBS. In the crossover RCT, there was no consistent effect on intestinal permeability (primary outcome) after supplementation with Lactobacillus rhamnosus (LGG) in nine children with SBS. The case control study (four cases: four controls) reported a trend for increase in height and weight velocity and improvement in non-clinical outcomes, such as gut flora, lymphocyte count and serum prealbumin. Five of the nine case reports showed that children (n = 12) with SBS were benefited (e.g., cessation of diarrhoea, improved faecal flora, weight gain and weaning from parenteral nutrition) by probiotic supplementation. The remaining four reported on the adverse effects, such as Lactobacillus sepsis (n = 3) and D-lactic acidosis (n = 2). There is insufficient evidence on the effects of probiotics in children with SBS. The safety and efficacy of probiotic supplementation in this high-risk cohort needs to be evaluated in large definitive trials.

Probiotics: a new frontier for infection control

Probiotics are live micro-organisms administered to provide health benefits. Probiotics are being increasingly used in healthcare contexts both in research studies and routine practice, for example in neonatal intensive care. Currently there is a paucity of guidelines or regulations governing the mitigation of infection risks associated with the use of probiotics in clinical practice. We propose a number of recommendations to mitigate risks. These include the communication of probiotic use to appropriate stakeholders, ensuring that routine laboratories can identify and test the susceptibility of probiotic strains, assuring standards for preparation and administration, and ensuring surveillance designed to capture adverse events.

Probiotics and prebiotics in pediatric diarrheal disorders

INTRODUCTION

In pediatrics, prebiotics and/or probiotics are added to infant formula, mainly to prevent diseases such as diarrheal disorders. Probiotic food supplements and medication are frequently used in the treatment of diarrheal disorders. This paper reviews the recent published evidence on these topics.

AREAS COVERED

Relevant literature published using PubMed and CINAHL was collected and reviewed. Recent review papers were give special attention.

EXPERT OPINION

The addition of pre- and/or probiotics to infant formula seems not harmful, but the evidence for benefit is limited. Most probiotics are commercialized as food supplements, and therefore do not qualify for medication legislation. Worldwide, Saccharomyces boulardii is the only strain which is registered as "medication" in the majority of countries. Efficacy data can only be considered if performed with the commercialized product. Some products reduce the risk for antibiotic-associated diarrhea and reduced the duration of acute infectious diarrhea with about 24 h. Overall, data in the other indications (inflammatory bowel disease, irritable bowel syndrome) are disappointing, although there are some recent promising results. The use of food supplements as medication opens the discussion to create a category of "medical food."

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

OBJECTIVE

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

DESIGN

Systematic review.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSIONS

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

Effect of Lactobacillus rhamnosus LGG® and Bifidobacterium animalis ssp. lactis BB-12® on health-related quality of life in college students affected by upper respiratory infections

College students are susceptible to upper respiratory infections (URI) due to inadequate sleep, stress and close living quarters. Certain probiotic strains modulate immune function and may improve health-related quality of life (HRQL) during URI. The present study recruited apparently healthy college students and assessed the effect of probiotics on HRQL outcomes (i.e. self-reported duration, symptom severity and functional impairment of URI) in those who developed URI. Missed school and work days due to URI were also considered. Subjects (n 231) were apparently healthy college students living on campus in residence halls at the Framingham State University (Framingham, MA, USA), and were randomised to receive placebo (n 117) or probiotic-containing powder (daily dose of minimum 1 billion colony-forming units of each Lactobacillus rhamnosus LGG® (LGG®) and Bifidobacterium animalis ssp. lactis BB-12® (BB-12®); n 114) for 12 weeks. Subjects completed The Wisconsin Upper Respiratory Symptom Survey-21 to assess HRQL during URI. The final analyses included 198 subjects (placebo, n 97 and probiotics, n 101). The median duration of URI was significantly shorter by 2 d and median severity score was significantly lower by 34% with probiotics v. placebo (P,0·001), indicating a higher HRQL during URI. Number of missed work days was not different between groups (P=0·429); however, the probiotics group missed significantly fewer school days (mean difference = 0·2 d) compared to the placebo group (P=0·002). LGG® and BB-12® may be beneficial among college students with URI for mitigating decrements in HRQL. More research is warranted regarding mechanisms of action associated with these findings and the cost-benefit of prophylactic supplementation.

Worldwide consumption of functional foods: a systematic review

The present systematic review was performed to assess differences in the worldwide consumption of functional foods. The Medline and Scopus databases were used to search the existing literature. A total of 23 studies that examined functional food consumption and included information on the country, gender, and age of participants were identified for inclusion. The studies investigated a variety of functional foods, and analysis of the findings indicates it is not possible to reach generalized conclusions about consumer choices regarding functional food consumption. Gender, age, level of education, and personal health status may each predict consumption of one or more functional foods. Further studies aimed at gaining a better understanding of the factors that influence consumption of functional foods are needed.

The interplay between diet and emerging allergy: what can we learn from Indigenous Australians?

The pathophysiology of atopic diseases, including asthma and allergy, is the result of complex gene-environment interactions. Since European colonization the Indigenous population of Australia has undergone significant changes with respect to their lifestyle as hunter-gatherers. These changes have had a detrimental effect on Aboriginal health, in part due to immunological modification. This review provides a comparative look at both the traditional Aboriginal/Indigenous diet and modern Western diets, examines some common allergies increasingly reported in contemporary Indigenous populations, and reviews concepts such the effect of vitamin deficiencies and changes in gut microbiota on immune function.

Antilisterial activity of nisin-like bacteriocin-producing Lactococcus lactis subsp. lactis isolated from traditional Sardinian dairy products

With the aim of selecting LAB strains with antilisterial activity to be used as protective cultures to enhance the safety of dairy products, the antimicrobial properties of 117 Lactococcus lactis subsp. lactis isolated from artisanal Sardinian dairy products were evaluated, and six strains were found to produce bacteriocin-like substances. The capacity of these strains to antagonize Listeria monocytogenes during cocultivation in skimmed milk was evaluated, showing a reduction of L. monocytogenes counts of approximately 4 log units compared to the positive control after 24 h of incubation. In order for a strain to be used as bioprotective culture, it should be carefully evaluated for the presence of virulence factors, to determine what potential risks might be involved in its use. None of the strains tested was found to produce biogenic amines or to possess haemolytic activity. In addition, all strains were sensitive to clinically important antibiotics such as ampicillin, tetracycline, and vancomycin. Our results suggest that these bac+ strains could be potentially applied in cheese manufacturing to control the growth of L. monocytogenes.

Safety assessment of Bifidobacterium longum JDM301 based on complete genome sequences

AIM

To assess the safety of Bifidobacterium longum (B. longum) JDM301 based on complete genome sequences.

METHODS

The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence factors, putative antibiotic resistance genes and genes encoding enzymes responsible for harmful metabolites were identified by blast with virulence factors database, antibiotic resistance genes database and genes associated with harmful metabolites in previous reports. Minimum inhibitory concentration of 16 common antimicrobial agents was evaluated by E-test.

RESULTS

JDM301 was shown to contain 36 genes associated with antibiotic resistance, 5 enzymes related to harmful metabolites and 162 nonspecific virulence factors mainly associated with transcriptional regulation, adhesion, sugar and amino acid transport. B. longum JDM301 was intrinsically resistant to ciprofloxacin, amikacin, gentamicin and streptomycin and susceptible to vancomycin, amoxicillin, cephalothin, chloramphenicol, erythromycin, ampicillin, cefotaxime, rifampicin, imipenem and trimethoprim-sulphamethoxazol. JDM301 was moderately resistant to bacitracin, while an earlier study showed that bifidobacteria were susceptible to this antibiotic. A tetracycline resistance gene with the risk of transfer was found in JDM301, which needs to be experimentally validated.

CONCLUSION

The safety assessment of JDM301 using information derived from complete bacterial genome will contribute to a wider and deeper insight into the safety of probiotic bacteria.

Food fermentations: microorganisms with technological beneficial use

Microbial food cultures have directly or indirectly come under various regulatory frameworks in the course of the last decades. Several of those regulatory frameworks put emphasis on "the history of use", "traditional food", or "general recognition of safety". Authoritative lists of microorganisms with a documented use in food have therefore come into high demand. One such list was published in 2002 as a result of a joint project between the International Dairy Federation (IDF) and the European Food and Feed Cultures Association (EFFCA). The "2002 IDF inventory" has become a de facto reference for food cultures in practical use. However, as the focus mainly was on commercially available dairy cultures, there was an unmet need for a list with a wider scope. We present an updated inventory of microorganisms used in food fermentations covering a wide range of food matrices (dairy, meat, fish, vegetables, legumes, cereals, beverages, and vinegar). We have also reviewed and updated the taxonomy of the microorganisms used in food fermentations in order to bring the taxonomy in agreement with the current standing in nomenclature.

Structure of plantaricin locus of Lactobacillus plantarum 8P-A3

Lactobacillus plantarum 8P-A3 is a strain which is well known on the Russian pharmaceutical market and it is included in several probiotic products. The strain has been widely used since 1973 but the mechanisms of its antibacterial activity were unknown. L. plantarum 8P-A3 expressed high antagonistic activity against the wide range of bacterial pathogens including Streptococcus agalactiae, Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae strains. DNA sequence analysis of L. plantarum 8P-A3 genome revealed the presence of a complete plantaricin locus of about 20,000 bp encoding genes of at least two bacteriocins – plantaricins EF and NC8. The plantaricin locus found in L. plantarum 8P-A3 is homologous to the plantaricin cluster in L. plantarum J51.

Probiotics for the prevention of pediatric antibiotic-associated diarrhea

BACKGROUND

Antibiotics alter the microbial balance within the gastrointestinal tract. Probiotics may prevent antibiotic-associated diarrhea (AAD) via restoration of the gut microflora. Antibiotics are prescribed frequently in children and AAD is common in this population.

OBJECTIVES

The primary objectives were to assess the efficacy and safety of probiotics (any specified strain or dose) used for the prevention of AAD in children.

SEARCH METHODS

MEDLINE, EMBASE, CENTRAL, CINAHL, AMED, and the Web of Science (inception to May 2010) were searched along with specialized registers including the Cochrane IBD/FBD review group, CISCOM (Centralized Information Service for Complementary Medicine), NHS Evidence, the International Bibliographic Information on Dietary Supplements as well as trial registries. Letters were sent to authors of included trials, nutra/pharmaceutical companies, and experts in the field requesting additional information on ongoing or unpublished trials. Conference proceedings, dissertation abstracts, and reference lists from included and relevant articles were also searched.

SELECTION CRITERIA

Randomized, parallel, controlled trials in children (0 to 18 years) receiving antibiotics, that compare probiotics to placebo, active alternative prophylaxis, or no treatment and measure the incidence of diarrhea secondary to antibiotic use were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction as well as methodological quality assessment using the risk of bias instrument was conducted independently and in duplicate by two authors. Dichotomous data (incidence of diarrhea, adverse events) were combined using a pooled relative risk and risk difference (adverse events), and continuous data (mean duration of diarrhea, mean daily stool frequency) as weighted mean differences, along with their corresponding 95% confidence intervals. For overall pooled results on the incidence of diarrhea, sensitivity analyses included available case versus extreme-plausible analyses and random- versus fixed-effect models. To explore possible explanations for heterogeneity, a priori subgroup analysis were conducted on probiotic strain, dose, definition of antibiotic-associated diarrhea, antibiotic agent as well as risk of bias.

MAIN RESULTS

Sixteen studies (3432 participants) met the inclusion criteria. Trials included treatment with either Bacillus spp., Bifidobacterium spp., Lactobacilli spp., Lactococcus spp., Leuconostoc cremoris, Saccharomyces spp., or Streptococcus spp., alone or in combination. Nine studies used a single strain probiotic agent, four combined two probiotic strains, one combined three probiotic strains, one product included ten probiotic agents, and one study included two probiotic arms that used three and two strains respectively. The risk of bias was determined to be high in 8 studies and low in 8 studies. Available case (patients who did not complete the studies were not included in the analysis) results from 15/16 trials reporting on the incidence of diarrhea show a large, precise benefit from probiotics compared to active, placebo or no treatment control. The incidence of AAD in the probiotic group was 9% compared to 18% in the control group (2874 participants; RR 0.52; 95% CI 0.38 to 0.72; I(2) = 56%). This benefit was not statistically significant in an extreme plausible (60% of children loss to follow-up in probiotic group and 20% loss to follow-up in the control group had diarrhea) intention to treat (ITT) sensitivity analysis. The incidence of AAD in the probiotic group was 16% compared to 18% in the control group (3392 participants; RR 0.81; 95% CI 0.63 to 1.04; I(2) = 59%). An a priori available case subgroup analysis exploring heterogeneity indicated that high dose (≥5 billion CFUs/day) is more effective than low probiotic dose (< 5 billion CFUs/day), interaction P value = 0.010. For the high dose studies the incidence of AAD in the probiotic group was 8% compared to 22% in the control group (1474 participants; RR 0.40; 95% CI 0.29 to 0.55). For the low dose studies the incidence of AAD in the probiotic group was 8% compared to 11% in the control group (1382 participants; RR 0.80; 95% CI 0.53 to 1.21). An extreme plausible ITT subgroup analysis was marginally significant for high dose probiotics. For the high dose studies the incidence of AAD in the probiotic group was 17% compared to 22% in the control group (1776 participants; RR 0.72; 95% CI 0.53 to 0.99; I(2) = 58%). None of the 11 trials (n = 1583) that reported on adverse events documented any serious adverse events. Meta-analysis excluded all but an extremely small non-significant difference in adverse events between treatment and control (RD 0.00; 95% CI -0.01 to 0.02).

AUTHORS' CONCLUSIONS

Despite heterogeneity in probiotic strain, dose, and duration, as well as in study quality, the overall evidence suggests a protective effect of probiotics in preventing AAD. Using 11 criteria to evaluate the credibility of the subgroup analysis on probiotic dose, the results indicate that the subgroup effect based on dose (≥5 billion CFU/day) was credible. Based on high-dose probiotics, the number needed to treat (NNT) to prevent one case of diarrhea is seven (NNT 7; 95% CI 6 to 10). However, a GRADE analysis indicated that the overall quality of the evidence for the primary endpoint (incidence of diarrhea) was low due to issues with risk of bias (due to high loss to follow-up) and imprecision (sparse data, 225 events). The benefit for high dose probiotics (Lactobacillus rhamnosus or Saccharomyces boulardii) needs to be confirmed by a large well-designed randomized trial. More refined trials are also needed that test strain specific probiotics and evaluate the efficacy (e.g. incidence and duration of diarrhea) and safety of probiotics with limited losses to follow-up. It is premature to draw conclusions about the efficacy and safety of other probiotic agents for pediatric AAD. Future trials would benefit from a standard and valid outcomes to measure AAD.

Colonization of the Gastrointestinal Tract in Neonates

Bacterial colonization of the neonatal gastrointestinal tract has emerged as an issue involving nutrition, immunity, and overall mortality. Bacterial organisms colonizing the gastrointestinal tract play a vital role in maintaining intestinal homeostasis, including digestion, nutrient absorption, and immunological mechanisms. In neonates, these bacteria are essential in postnatal development of intestinal mucosa and gut-associated lymphoid tissue critical for immunological protection. Colonization of bacteria is thought to occur over the first 1 to 2 weeks of life. Delivery mode, feeding method, and environment affect the succession and establishment of the beneficial bacteria in the neonate. Neonates delivered vaginally are colonized by the bacteria from the mother, whereas neonates delivered via caesarean section initially colonize with bacteria from the environment. Feeding method is another factor; Bifidobacterium species are believed to dominate the microflora of breastfed infants by day of life 2 to 3 and are thought to be critical in postnatal immunology. Formula-fed infants often have a more diverse microflora and a less obvious presence of the Bifidobacterium. Compared with healthy, term neonates, preterm infants have a significant delay in bacterial colonization. The effects of an immature gastrointestinal track, lack of enteral feeding, and the frequent use of antibiotic therapy are believed to contribute to the delay and imbalance in the microflora of preterm infants. Prolonged exposure to hospital bacteria increases the risk of colonization with strains specific to hospital flora.

Impact of maternal supplementation with probiotics during pregnancy on atopic eczema in childhood--a meta-analysis

In the present study, we sought to conduct a literature review of randomised, double-blind, placebo-controlled trials, which assessed the impact of probiotics intake during pregnancy on the development of eczema in children. A meta-analysis was conducted for comparison of the development of atopic eczema in children whose mothers took probiotics during pregnancy v. placebo. Study selection, quality appraisal and data extraction were performed independently and in duplicate. The studies were rated according to their size in order to calculate the influence of individual studies on the meta-analysis. A total of seven randomised, double-blind, placebo-controlled trials, published between 2001 and 2009, were selected from the PubMed and Ovid databases for the meta-analysis. The meta-analysis was performed with statistical software Stata/SE11.0. The completed meta-analysis of the seven studies shows a significant risk reduction for atopic eczema in children aged 2-7 years by the administration of probiotics during pregnancy (reduction 5·7 %; P = 0·022). However, this effect was only significant for lactobacilli (reduction 10·6 %; P = 0·045), but not for a mixture of various bacterial strains as probiotics (difference 3·06 %, P = 0·204). In conclusion, the meta-analysis shows that the administration of lactobacilli during pregnancy prevents atopic eczema in children aged from 2 to 7 years. However, a mixture of various bacterial strains does not affect the development of atopic eczema, independent of whether they contain lactobacilli or not.