Randomized, placebo-controlled trial of Lactobacillus rhamnosus GG as treatment of atopic dermatitis in infancy

Oral administration of Lactobacillus casei variety rhamnosus partially alleviates TMA-induced atopic dermatitis in mice through improving intestinal microbiota

AIMS

The purpose of this study was to investigate the effect of Lactobacillus casei variety rhamnosus (LCR35) on Atopic dermatitis (AD)-like symptoms in mice.

METHODS AND RESULTS

AD-like skin lesions in BALB/C mice were induced by sensitization and subsequent repeated challenges with trimellitic anhydride (TMA) for 10 days. LCR35 was orally administered to the mice once daily throughout the study. In the TMA-induced AD model, orally administered LCR35 suppressed significantly irritant-related scratching behaviour and skin dehydration as well as apparent severity of AD. LCR35 also significantly decreased serum levels of IgE and IL-4, but not IFN-γ, implying the restoration of TMA-induced disruption of Th1/Th2 balance. Quantitative real-time PCR targeting hypervariable regions of 16S rDNA gene of faecal microbiota indicated that the LCR35 treatment increased the population of Bifidobacterium, Lactobacilli, Enterococcus and Bacteroides fragilis group, but decreased those of Clostridium coccoides group.

CONCLUSIONS

LCR35 has the ability to suppress the development of AD in mice, possibly through the modulation of Th1/Th2 balance and gut microbiota.

SIGNIFICANCE AND IMPACT OF THE STUDY

LCR35 has a strong potential as a probiotic for preventing AD.

Children with atopic dermatitis show clinical improvement after Lactobacillus exposure

BACKGROUND

The role of probiotics in the treatment of atopic dermatitis (AD) is not clearly established. Further clinical trials with new probiotic formulations are warranted.

OBJECTIVES

To assess the effects of Lactobacillus paracasei (LP) and Lactobacillus fermentum (LF), and their mixture on the disease severity, quality of life, and immune biomarkers of children with AD.

METHOD

A double-blind, prospective, randomized placebo-controlled study was conducted on 220 children aged 1-18 years with moderate-to-severe AD (Trial number: NCT01635738). The children were randomized to receive LP, LF, LP + LF mixture, and placebo for 3 months. Changes in severity scoring of atopic dermatitis (SCORAD), Family Dermatology Life Quality Index (FDLQI), and Children's Dermatology Life Quality Index (CDLQI) scores in the different groups and at different visits were evaluated. Skin prick tests, levels of IgE, IFN-γ, IL-4, TGF-β, and TNF-α, and urine biomarkers were also evaluated.

RESULTS

Children who received LP, LF, and LP + LF mixture showed lower SCORAD scores than the placebo group (P < 0.001), and this difference remained even at 4 months after discontinuing the probiotics. The FDLQI and CDLQI scores were lower in the LP, LF, and LP + LF mixture group than in the placebo group (P = 0.02 and 0.03). IgE, TNF-α, urine eosinophilic protein X, and 8-OHdG levels decreased, whereas IFN-γ and TGF-β increased in the probiotic groups, but these did not reach statistical significance except for IL-4 (P = 0.04). In subgroup analyses, SCORAD scores significantly decreased after probiotic treatment especially in children younger than age 12, with breastfeeding > 6 months, and with mite sensitization (P < 0.001).

CONCLUSION

Supplementation of a probiotic mixture of LP and LF is associated with clinical improvement in children with AD.

Inclusion of fermented foods in food guides around the world

Fermented foods have been a well-established part of the human diet for thousands of years, without much of an appreciation for, or an understanding of, their underlying microbial functionality, until recently. The use of many organisms derived from these foods, and their applications in probiotics, have further illustrated their impact on gastrointestinal wellbeing and diseases affecting other sites in the body. However, despite the many benefits of fermented foods, their recommended consumption has not been widely translated to global inclusion in food guides. Here, we present the case for such inclusion, and challenge health authorities around the world to consider advocating for the many benefits of these foods.

Towards a better understanding of Lactobacillus rhamnosus GG--host interactions

Lactobacillus rhamnosus GG (LGG) is one of the most widely used probiotic strains. Various health effects are well documented including the prevention and treatment of gastro-intestinal infections and diarrhea, and stimulation of immune responses that promote vaccination or even prevent certain allergic symptoms. However, not all intervention studies could show a clinical benefit and even for the same conditions, the results are not univocal. Clearly, the host phenotype governed by age, genetics and environmental factors such as the endogenous microbiota, plays a role in whether individuals are responders or non-responders. However, we believe that a detailed knowledge of the bacterial physiology and the LGG molecules that play a key role in its host-interaction capacity is crucial for a better understanding of its potential health benefits. Molecules that were yet identified as important factors governing host interactions include its adhesive pili or fimbriae, its lipoteichoic acid molecules, its major secreted proteins and its galactose-rich exopolysaccharides, as well as specific DNA motifs. Nevertheless, future studies are needed to correlate specific health effects to these molecular effectors in LGG, and also in other probiotic strains.

Effects of probiotics for the treatment of atopic dermatitis: a meta-analysis of randomized controlled trials

BACKGROUND

The effects of probiotics on the treatment of atopic dermatitis (AD) are inconclusive.

OBJECTIVE

To determine the clinical effect of probiotics in the management of AD overall and in different age groups.

METHODS

A comprehensive search of databases through December 2013 was performed. For this meta-analysis, randomized controlled trials measuring the treatment effects of probiotics or synbiotics in patients diagnosed with AD were included. The primary outcome was a difference in Scoring of Atopic Dermatitis (SCORAD) values between the treatment and placebo groups overall and in different age populations.

RESULTS

Twenty-five randomized controlled trials (n = 1,599) were available for this meta-analysis. Significant differences in SCORAD values favoring probiotics over the control were observed overall (mean -4.51, 95% confidence interval -6.78 to -2.24), in children 1 to 18 years old (-5.74, 95% confidence interval -7.27 to -4.20), and in adults (-8.26, 95% confidence interval -13.28 to -3.25). However, the effectiveness of probiotics in infants (<1 year old) with AD was not proved. The effect of synbiotic use was not significantly different from that of probiotic use. Treatment with a mixture of different bacterial species or of Lactobacillus species showed greater benefit than did treatment with Bifidobacterium species alone.

CONCLUSION

The overall result of this meta-analysis suggests that probiotics could be an option for the treatment of AD, especially for moderate to severe AD in children and adults. However, no evidence was found supporting the beneficial role of probiotics in infants.

Is there a role for probiotics in the prevention or treatment of food allergy?

A balanced gut microbiota is crucial for the development of healthy immunoregulation and gut barrier function to allow brisk immune responses to pathogens and systemic hyporesponsiveness to harmless antigens such as food. Although the first allergic disease to manifest itself, atopic eczema, is not equivalent to food allergy, pre- and postnatal administration of specific probiotic strains has emerged as a promising tool for the prevention of this condition, with potential implications for food allergy development. For food allergy proper, however, we lack markers and risk factors and mechanisms, i.e., targets for preventive measures. The focus here is therefore on the treatment. Indeed, the potential of specific probiotic strains to alleviate food allergy resides in their ability to modify antigens, repair gut barrier functions, balance altered microbiota, and restore local and systemic immune regulation. In patients with multiple food allergies, induction of oral tolerance by specific probiotics continues to attract research interest.

Probiotic supplementation during pregnancy or infancy for the prevention of asthma and wheeze: systematic review and meta-analysis

OBJECTIVE

To evaluate the association of probiotic supplementation during pregnancy or infancy with childhood asthma and wheeze.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase, and Central (Cochrane Library) databases from inception to August 2013, plus the World Health Organization's international clinical trials registry platform and relevant conference proceedings for the preceding five years. Included trials and relevant reviews were forward searched in Web of Science.

REVIEW METHODS

Two reviewers independently identified randomised controlled trials evaluating probiotics administered to mothers during pregnancy or to infants during the first year of life. The primary outcome was doctor diagnosed asthma; secondary outcomes included wheeze and lower respiratory tract infection.

RESULTS

We identified 20 eligible trials including 4866 children. Trials were heterogeneous in the type and duration of probiotic supplementation, and duration of follow-up. Only five trials conducted follow-up beyond participants' age of 6 years (median 24 months), and none were powered to detect asthma as the primary outcome. The overall rate of doctor diagnosed asthma was 10.7%; overall rates of incident wheeze and lower respiratory tract infection were 33.3% and 13.9%, respectively. Among 3257 infants enrolled in nine trials contributing asthma data, the risk ratio of doctor diagnosed asthma in participants randomised to receive probiotics was 0.99 (95% confidence interval 0.81 to 1.21, I(2)=0%). The risk ratio of incident wheeze was 0.97 (0.87 to 1.09, I(2)=0%, 9 trials, 1949 infants). Among 1364 infants enrolled in six trials, the risk ratio of lower respiratory tract infection after probiotic supplementation was 1.26 (0.99 to 1.61, I(2)=0%). We adjudicated most trials to be of high (ten trials) or unclear (nine trials) risk of bias, mainly due to attrition.

CONCLUSIONS

We found no evidence to support a protective association between perinatal use of probiotics and doctor diagnosed asthma or childhood wheeze. Randomised controlled trials to date have not yielded sufficient evidence to recommend probiotics for the primary prevention of these disorders. Extended follow-up of existing trials, along with further clinical and basic research, are needed to accurately define the role of probiotics in the prevention of childhood asthma.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (CRD42013004385).

Preventative and therapeutic probiotic use in allergic skin conditions: experimental and clinical findings

Probiotics are ingested live microbes that can modify intestinal microbial populations in a way that benefits the host. The interest in probiotic preventative/therapeutic potential in allergic diseases stemmed from the fact that probiotics have been shown to improve intestinal dysbiosis and permeability and to reduce inflammatory cytokines in human and murine experimental models. Enhanced presence of probiotic bacteria in the intestinal microbiota is found to correlate with protection against allergy. Therefore, many studies have been recently designed to examine the efficacy of probiotics, but the literature on the allergic skin disorders is still very scarce. Here, our objective is to summarize and evaluate the available knowledge from randomized or nonrandomized controlled trials of probiotic use in allergic skin conditions. Clinical improvement especially in IgE-sensitized eczema and experimental models such as atopic dermatitis-like lesions (trinitrochlorobenzene and picryl chloride sensitizations) and allergic contact dermatitis (dinitrofluorobenzene sensitization) has been reported. Although there is a very promising evidence to recommend the addition of probiotics into foods, probiotics do not have a proven role in the prevention or the therapy of allergic skin disorders. Thus, being aware of possible measures, such as probiotics use, to prevent/heal atopic diseases is essential for the practicing allergy specialist.

Probiotic effects in allergic disease

The increasing prevalence of allergic disease has been linked to reduced microbial exposure in early life. Probiotics have recently been advocated for the prevention and treatment of allergic disease. This article summarises recent publications on probiotics in allergic disease, focusing on clinical studies of prevention or treatment of allergic disease. Studies employing the combined administration of pre-natal and post-natal probiotics suggest a role for certain probiotics (alone or with prebiotics) in the prevention of eczema in early childhood, with the pre-natal component of treatment appearing to be important for beneficial effects. On the other hand, current data are insufficient to support the use of probiotics for the treatment of established allergic disease, although recent studies have highlighted new hope in this area. Probiotic bacteria continue to represent the most promising intervention for primary prevention of allergic disease, and well-designed definitive intervention studies should now be a research priority.

Challenges in translational research on probiotic lactobacilli: from in vitro assays to clinical trials

Beneficial effects of certain probiotic strains have been established in the treatment and prevention of various immune and intestinal disorders in humans, including allergic diseases, chronic inflammatory diseases and diarrhoea. The proposed mechanisms underlying the immunomodulatory effects of probiotics in humans are not understood in precise detail but include enhancement of intestinal barrier function, altered epithelial signalling, competition with pathogens and effects on immune cells and immunity depending on the probiotic strain. The publication of controversial or inconclusive probiotic studies in humans highlights the need for a better understanding of the mechanisms and improved strain selection criteria. This review focuses on the immunomodulatory properties of lactobacilli and bifidobacteria in vitro and in vivo, current knowledge concerning the mechanisms in vivo and challenges in translational research on probiotics. A better understanding of the molecular mechanisms of probiotics, the effect of probiotic mixtures versus single strains, the effect of formulation of probiotics and the fate of ingested probiotics should help to clarify the value of immune assays as selection criteria for probiotics.

Probiotics in the treatment and prevention of allergy in children

Several fold increase in allergic diseases in developed, high-income countries during recent decades is attributed to environmental changes such as urbanization with improved hygiene. This, together with conquering severe bacterial infections during childhood, has reduced the microbial stimulation of the developing immune system of infants. Studies on the pathogenesis of allergy both in man and experimental animal have shown the importance of commensal bacteria in the gastrointestinal tract in stimulating and directing the immune system. The interest in modulating commensal bacterial flora with probiotics to prevent and treat allergy has multiplied in recent years.

In the present review we report results on randomized, controlled studies in which childhood atopic eczema was treated or which aimed to prevent development of allergy during childhood.

Nine studies with 639 patients have looked at the effect of probiotics in treatment of eczema. While 3 studied showed no effect, other studies suggested a moderate benefit of the use of probiotics on the severity of eczema. Studies suggested that the effect may be seen particularly in patients with food allergy and/or sensitization.

Nine studies have reported on the prevention of allergy on 6 study population with altogether 1989 high risk infants. While the early study reporting the development of allergy at ages 2, 4 and 7 years showed a marked reduction of eczema in 77 treated infants, later studies have failed to show similar success. Two studies showed no effect. In the largest study with more than 900 children at age 2 atopic eczema was reduced by 20%, but at age 5 positive effect was present in only the subgroup of children who had born by cesarean section. None of studies has reported adverse effects of probiotics in infants.

Result in both treatment and prevention studies are quite variable, the major reason being the use of different strains of probiotic bacteria and varying types of intervention. Even if the results are encouraging, we need a stronger effect. This may be reached by finding new strains of probiotics affecting stronger stimulation of immune system, together with longer lasting and varying treatment schedules. However, safety issues have to be observed.

Prenatal and postnatal probiotics reduces maternal but not childhood allergic diseases: a randomized, double-blind, placebo-controlled trial

BACKGROUND

The prevalence of atopic diseases has increased rapidly in recent decades globally. The administration of probiotics to reduce gastrointestinal inflammation has been popular, but its role in the prevention or treatment of allergic disease remains controversial. This study evaluated the effectiveness of prenatal and postnatal probiotics in the prevention of early childhood and maternal allergic diseases.

METHODS

In a prospective, double-blind, placebo-controlled clinical trial, pregnant women with atopic diseases determined by history, total immunoglobulin (Ig)E > 100 kU/L, and/or positive specific IgE were assigned to receive either probiotics (Lactobacillus GG; ATCC 53103; 1 × 10(10) colony-forming units daily) or placebo from the second trimester of pregnancy. Both of clinical evaluation performed by questionnaires concerning any allergic symptoms and plasma total IgE, and allergen-specific IgE were obtained in high-risk parents and children at 0, 6, 18, and 36 months of age. The primary and secondary outcomes were the point and cumulative prevalence of sensitization and developing of allergic diseases, and improvement of maternal allergic symptom score and plasma immune parameters before and after intervention, respectively.

RESULTS

In total, 191 pregnant women (LGG group, n = 95; control group, n = 96) were enrolled. No significant effects of prenatal and postnatal probiotics supplementation on sensitization, development of allergic diseases, and maternal IgE levels between placebo and LGG groups. Symptoms of maternal allergic scores improved significantly in the LGG group (P = 0.002). Maternal allergic diseases improvement was more prominent in pregnant women with IgE > 100 kU/L (P = 0.01) and significantly associated with higher interleukin-12p70 levels (P = 0.013).

CONCLUSIONS

LGG administration beginning at the second trimester of pregnancy reduced the severity of maternal allergic disease through increment of Th1 response, but not the incidence of childhood allergic sensitization or allergic diseases (ClinicalTrials.govnumber, IDNCT00325273).

Probiotics in the development and treatment of allergic disease

Gut microbiota composition can discriminate between allergic and healthy children, and the distinction may precede clinical manifestations of disease. The mother provides the first inoculum of bacteria, which influences the risk of becoming allergic later in life. Bifidobacterium species are major determinants of disease risk. Specific probiotics may modulate early microbial colonization, which represents the first intervention target in allergic disease, together with their ability to reverse the increased intestinal permeability characteristic of children with atopic eczema and food allergy. Probiotics also enhance gut-specific IgA responses, which are frequently defective in children with food allergy. In addition, probiotics have the potential to alleviate allergic inflammation locally and systemically.

A randomized trial of Lactobacillus plantarum CJLP133 for the treatment of atopic dermatitis

BACKGROUND

There have been considerable disagreements regarding the therapeutic effects of probiotics in atopic dermatitis (AD). We performed this study to examine whether the oral administration of Lactobacillus plantarum CJLP133 improves pediatric AD.

METHODS

In a randomized, double-blind, placebo-controlled study, either L. plantarum CJLP133 at a dosage of 0.5 × 10(10) colony-forming units or placebo in children aged 12 months to 13 yr was given twice a day for 12 wk. SCOring of Atopic Dermatitis (SCORAD) scores, eosinophil counts, serum total IgE, and cytokines were evaluated.

RESULTS

Forty-four of 58 patients in the probiotic group and 39 of 60 patients in the placebo group completed the study. The SCORAD score at week 14 was lower in the probiotic group than in the placebo group (p = 0.044). The mean change in the SCORAD score from weeks 2 to 14 was 9.1 in the probiotic group, which was greater than the mean change of 1.8 in the placebo group (p = 0.004). No statistical differences in the total use of topical corticosteroids were found between two groups (p = 0.815). In the probiotic group, the total eosinophil count was significantly lower at the end of the intervention compared to the baseline measurements (p = 0.023). Logarithmic IFN-γ and IL-4 were significantly decreased by the end of the intervention compared to baseline measurements in the probiotic group (p < 0.001 and 0.049).

CONCLUSIONS

Our results suggest that supplementation with probiotic L. plantarum CJLP133 is beneficial in the treatment of pediatric AD.

Clinical Use of Probiotics in Pediatric Allergy (CUPPA): A World Allergy Organization Position Paper

BACKGROUND

: Probiotic administration has been proposed for the prevention and treatment of specific allergic manifestations such as eczema, rhinitis, gastrointestinal allergy, food allergy, and asthma. However, published statements and scientific opinions disagree about the clinical usefulness.

OBJECTIVE

: A World Allergy Organization Special Committee on Food Allergy and Nutrition review of the evidence regarding the use of probiotics for the prevention and treatment of allergy.

METHODS

: A qualitative and narrative review of the literature on probiotic treatment of allergic disease was carried out to address the diversity and variable quality of relevant studies. This variability precluded systematization, and an expert panel group discussion method was used to evaluate the literature. In the absence of systematic reviews of treatment, meta-analyses of prevention studies were used to provide data in support of probiotic applications.

RESULTS

: Despite the plethora of literature, probiotic research is still in its infancy. There is a need for basic microbiology research on the resident human microbiota. Mechanistic studies from biology, immunology, and genetics are needed before we can claim to harness the potential of immune modulatory effects of microbiota. Meanwhile, clinicians must take a step back and try to link disease state with alterations of the microbiota through well-controlled long-term studies to identify clinical indications.

CONCLUSIONS

: Probiotics do not have an established role in the prevention or treatment of allergy. No single probiotic supplement or class of supplements has been demonstrated to efficiently influence the course of any allergic manifestation or long-term disease or to be sufficient to do so. Further epidemiologic, immunologic, microbiologic, genetic, and clinical studies are necessary to determine whether probiotic supplements will be useful in preventing allergy. Until then, supplementation with probiotics remains empirical in allergy medicine. In the future, basic research should focus on homoeostatic studies, and clinical research should focus on preventive medicine applications, not only in allergy. Collaborations between allergo-immunologists and microbiologists in basic research and a multidisciplinary approach in clinical research are likely to be the most fruitful.

Probiotic therapy as a novel approach for allergic disease

The prevalence of allergic disease has increased dramatically in Western countries over the past few decades. The hygiene hypothesis, whereby reduced exposure to microbial stimuli in early life programs the immune system toward a Th2-type allergic response, is suggested to be a major mechanism to explain this phenomenon in developed populations. Such microbial exposures are recognized to be critical regulators of intestinal microbiota development. Furthermore, intestinal microbiota has an important role in signaling to the developing mucosal immune system. Intestinal dysbiosis has been shown to precede the onset of clinical allergy, possibly through altered immune regulation. Existing treatments for allergic diseases such as eczema, asthma, and food allergy are limited and so the focus has been to identify alternative treatment or preventive strategies. Over the past 10 years, a number of clinical studies have investigated the potential of probiotic bacteria to ameliorate the pathological features of allergic disease. This novel approach has stemmed from numerous data reporting the pleiotropic effects of probiotics that include immunomodulation, restoration of intestinal dysbiosis as well as maintaining epithelial barrier integrity. In this mini-review, the emerging role of probiotics in the prevention and/or treatment of allergic disease are discussed with a focus on the evidence from animal and human studies.

Recent advances in the role of probiotics in human inflammation and gut health

The gastrointestinal (GI) tract provides residence to an astounding number of bacterial species, which have profound effects on host biology, function, physiology, and immune response. Discovery of "symbiosis factors" from symbionts that facilitate the peaceful coexistence of microbiota and the host immune system are of interest. Symbionts synthesize immunomodulatory molecules that guide maturation of the immune system and have pivotal roles in many biological processes; however, individuals differ in the makeup of their GI microbiota, which is influenced by many external and internal factors such as diet, antibiotic use, and host genetics, which in turn influences health and disease outcomes. Various endogenous, genetic, and environmental factors influence GI development including species composition and health status of neonates, resulting in interactions that occur between the bacteria and the host. Mechanisms of probiotics involved in homeostasis of a balanced immune system have been inconclusive. The probable mechanism of action may be postulated as direct competition between pathogenic bacteria in the gut and/or immune modulation. This review focuses on probiotics in health and disease prevention, especially the biological importance of intestinal regulation of inflammatory processes that may be beneficial in a multitude of disorders both inside and outside the GI tract.

Probiotics and atopic dermatitis in children

There is increasing interest in the potential beneficial role of probiotic supplementation in the prevention and treatment of atopic diseases in children. Probiotics are defined as ingested live microorganisms that, when administered in an adequate amount, confer a health benefit to the host. They are mainly represented by Lactobacilli and Bifidobacteria. Several epidemiological data demonstrate that intestinal microflora of atopic children is different from the one of healthy children. Many literature data show that probiotics may modulate the intestinal microflora composition and may have immunomodulatory effect. Based on this hypothesis, probiotics are supposed to confer benefits to allergic diseases. Administration of probiotics when a natural population of indigenous intestinal bacteria is still developing could theoretically influence immune development by favoring the balance between Th1 and Th2 inflammatory responses. For this reason, some studies have evaluated the potential impact of probiotics supplementation in the prevention of atopic dermatitis, with contrasting results. Clinical improvement in immunoglobulin (Ig)E-sensitized (atopic) eczema following probiotic supplementation has been reported in some published studies and the therapeutic effects of probiotics on atopic dermatitis seemed to be encouraging. However, as far as the usefulness of probiotics as a prevention strategy is concerned, results are still inconclusive. In fact, the clinical benefits of probiotic therapy depend upon numerous factors, such as the type of bacteria, dosing regimen, delivery method and other underlying host factors, such as age and diet. More studies are still needed to definitively prove the role of probiotics in the treatment of allergic eczema.

Effects of probiotics, probiotic DNA and the CpG oligodeoxynucleotides on ovalbumin-sensitized Brown-Norway rats via TLR9/NF-κB pathway

The aim of the study was to investigate the effect of living probiotics, probiotic DNA and the synthetic oligodeoxynucleotides containing CpG motifs (CpG-ODN) on both immune response and intestinal barrier function in ovalbumin-sensitized rat and the underlying mechanisms. Brown-Norway rats were orally sensitized with ovalbumin, and living probiotics, probiotic DNA extraction, synthetic CpG-ODN or non-CpG ODN control was administered. In the living probiotics, probiotic DNA and CpG-ODN groups, the allergic response was significantly inhibited, the Th1/Th2 cytokine balance was shifted away from Th2 side, the percentage of CD4(+) CD25(+high) Treg cells was increased, and the intestinal barrier function was improved. The levels of toll-like receptor (TLR) 9 mRNA and nuclear factor (NF)-κB activity, as well as the IκB-α phosphorylation (p-IκB-α) was significantly increased in these three intervention groups compared with the OVA-positive group, whereas no such effects were found in the non-CpG ODN control group. These data show that the probiotic genomic DNA and the synthetic CpG-ODN was comparable with living probiotics in preventing food allergic response by immune modulation and intestinal barrier function enhancement, and the activation of TLR9/NF-κB signal pathway might be involved in this process.

Empirical evaluation of age groups and age-subgroup analyses in pediatric randomized trials and pediatric meta-analyses

BACKGROUND

An important step toward improvement of the conduct of pediatric clinical research is the standardization of the ages of children to be included in pediatric trials and the optimal age-subgroups to be analyzed.

METHODS

We set out to evaluate empirically the age ranges of children, and age-subgroup analyses thereof, reported in recent pediatric randomized clinical trials (RCTs) and meta-analyses. First, we screened 24 RCTs published in Pediatrics during the first 6 months of 2011; second, we screened 188 pediatric RCTs published in 2007 in the Cochrane Central Register of Controlled Trials; third, we screened 48 pediatric meta-analyses published in the Cochrane Database of Systematic Reviews in 2011. We extracted information on age ranges and age-subgroups considered and age-subgroup differences reported.

RESULTS

The age range of children in RCTs published in Pediatrics varied from 0.1 to 17.5 years (median age: 5; interquartile range: 1.8-10.2) and only 25% of those presented age-subgroup analyses. Large variability was also detected for age ranges in 188 RCTs from the Cochrane Central Register of Controlled Trials, and only 28 of those analyzed age-subgroups. Moreover, only 11 of 48 meta-analyses had age-subgroup analyses, and in 6 of those, only different studies were included. Furthermore, most of these observed differences were not beyond chance.

CONCLUSIONS

We observed large variability in the age ranges and age-subgroups of children included in recent pediatric trials and meta-analyses. Despite the limited available data, some age-subgroup differences were noted. The rationale for the selection of particular age-subgroups deserves further study.

Immunomodulatory effects of potential probiotics in a mouse peanut sensitization model

Peanut allergy accounts for the majority of severe food-related allergic reactions and there is a need for new prevention and treatment strategies. Probiotics may be considered for treatment on the basis of their immunomodulating properties. Cytokine profiles of probiotic strains were determined by in vitro co-culture with human PBMCs. Three strains were selected to investigate their prophylactic potential in a peanut sensitization model by analysing peanut-specific antibodies, mast cell degranulation and ex vivo cytokine production by splenocytes. The probiotic strains induced highly variable cytokine profiles in PBMCs. L. salivarius HMI001, L. casei Shirota (LCS) and L. plantarum WCFS1 were selected for further investigation owing to their distinct cytokine patterns. Prophylactic treatment with both HMI001 and LCS attenuated the Th2 phenotype (reduced mast cell responses and ex vivo IL-4 and/or IL-5 production). In contrast, WCFS1 augmented the Th2 phenotype (increased mast cell and antibody responses and ex vivo IL-4 production). In vitro PBMC screening was useful in selecting strains with anti-inflammatory and Th1 skewing properties. In case of HMI001 (high IL-10/IL-12 ratio) and LCS (high interferon-γ and IL-12), partial protection was seen in a mouse peanut allergy model. Strikingly, certain strains may worsen the allergic reaction as shown in the case of WCFS1.

Designing probiotics with respect to the native microbiome

It is now well known that genetic and environmental factors affect the intestinal microbiome in an individual’s lifetime and thus, different individuals possess different intestinal microbiomes and microbial metabolomes. The intestinal microbiome has been shown to differ among individuals from the same sex, between sexes and between individuals of different ages. Different families and, from a larger perspective, different communities, possess different microbiomes, and thus corresponding metagenomes. Therefore, it can be deduced that each individual human being can be characterized by his/her own intestinal microbial fingerprint. This understanding may prove helpful in future individualized medicine. These microorganisms are natural beneficial symbionts of the GI tract, have adapted to their human host over million years of coevolution and are now regarded as the second human genome. The difference in intestinal microbiome of different populations may explain why the results from different clinical trials on probiotic efficacy do not match with each other. People pay much, but they benefit little. In this article, it is recommended to isolate probiotics from natives’ microbiomes and in the interest of efficacy, to use them in the same population. This line of thought can be considered in future guidelines from the Food and Agriculture Organization and the WHO on evaluation of probiotics in foods.

Gut matters: microbe-host interactions in allergic diseases

The human body can be considered a metaorganism made up of its own eukaryotic cells and trillions of microbes that colonize superficial body sites, such as the skin, airways, and gastrointestinal tract. The coevolution of host and microbes brought about a variety of molecular mechanisms, which ensure a peaceful relationship. The mammalian barrier and immune functions warrant simultaneous protection of the host against deleterious infections, as well as tolerance toward harmless commensals. Because these pivotal host functions evolved under high microbial pressure, they obviously depend on a complex network of microbe-host interactions. The rapid spread of immune-mediated disorders, such as autoimmune diseases, inflammatory bowel diseases, and allergies, in westernized countries is thus thought to be due to environmentally mediated disturbances of this microbe-host interaction network. The aim of the present review is to highlight the importance of the intestinal microbiota in shaping host immune mechanisms, with particular emphasis on allergic diseases and possible intervention strategies.

Probiotics in the management of children with allergy and other disorders of intestinal inflammation

Soon after birth, the human gastrointestinal tract quickly becomes colonised by a variety of bacterial species. Throughout life the gastrointestinal tract continues to serve as host to a complex society of nonpathological bacteria. Microorganisms, such as probiotics, have the potential to modulate mucosal immune response and reduce gastrointestinal inflammation caused by a variety of infectious and allergic events. The most widely studied genera of probiotics are lactobacilli and bifidobacteria. Lactobacillus rhamnosis strain ATC53103 (LGG) can replenish gut flora during infectious diarrhoeal episodes. This beneficial effect is carried over to traveller's diarrhoea and children experiencing antibiotic-associated diarrhoea. Furthermore, LGG can reduce the risk of respiratory tract infections in children attending daycares and hospitals. With allergic disease on the rise, probiotics have the potential to positively impact atopic dermatitis, asthma, and allergic rhinitis. LGG has been shown to decrease the severity and delay the onset of atopic dermatitis. Additionally, LGG is beneficial in the treatment of allergic colitis and necrotising entercolitis. Some strains of probiotics appear to be useful in the treatment and/or prevention of allergic disease, however, caution must be used when generalising the effectiveness of a specific strain of organism to other organisms and other disease states.

Treatment and secondary prevention effects of the probiotics Lactobacillus paracasei or Bifidobacterium lactis on early infant eczema: randomized controlled trial with follow-up until age 3 years

BACKGROUND

Allergic disease has been associated with altered intestinal microbiota. Therefore, probiotics have been suggested as a potential treatment for eczema.

OBJECTIVE

We investigated whether dietary supplementation of infants with eczema at age 3-6 months with Lactobacillus paracasei CNCM I-2116 or Bifidobacterium lactis CNCM I-3446 had a treatment effect or altered allergic disease progression.

METHODS

Primary outcome included eczema severity (SCORing Atopic Dermatitis, SCORAD) 3 months post-randomization. Secondary: SCORAD (other visits); infant dermatitis quality of life (IDQoL); gastrointestinal permeability; urinary eosinophilic protein X; allergen-sensitization; allergic symptoms (age 12, 18, 36 months). A total of 208 infants aged 3-6 months with physician-diagnosed eczema were recruited; 137/208 (SCORAD ≥ 10, consuming ≥ 200 mL standard formula/day) were randomized to daily supplements containing L. paracasei or B. lactis or placebo for a 3-month period, while receiving extensively hydrolysed whey-formula (dairy-free diet). There were two open observational groups, one group exclusively breastfed (n = 22) and the other, standard formula-fed (n = 49).

TRIAL NUMBER

ISRCTN41490500.

RESULTS

Eczema severity decreased significantly over time in all groups. No significant difference was observed between randomized groups after 12-week treatment-period (SCORAD-score pre-/post-intervention: B. lactis 25.9 [95% CI: 22.8-29.2] to 12.8 [9.4-16.6]; L. paracasei 25.4 [22.1-29] to 12.5 [9.2-16.4]; placebo 26.9 [23.4-30.6] to 11.8 [9.6-14.3]; P = 0.7). Results were similar when analysis was controlled for allergen-sensitization, or when only sensitized infants were analysed. No differences were found for secondary outcomes. No difference was observed in SCORAD-score between randomized and observational groups.

CONCLUSION AND CLINICAL RELEVANCE

We found no benefit from supplementation with B. lactis or L. paracasei in the treatment of eczema, when given as an adjunct to basic topical treatment, and no effect on the progression of allergic disease from age 1 to 3 years.

Immunomodulatory mechanisms of lactobacilli

Over the past decade it has become clear that lactobacilli and other probiotic and commensal organisms can interact with mucosal immune cells or epithelial cells lining the mucosa to modulate specific functions of the mucosal immune system. The most well understood signalling mechanisms involve the innate pattern recognition receptors such as Toll-like receptors, nucleotide oligomerization domain-like receptors and C-type lectin receptors. Binding of microbe-associated molecular patterns with these receptors can activate antigen presenting cells and modulate their function through the expression of surface receptors, secreted cytokines and chemokines. In vitro the cytokine response of human peripheral blood mononuclear cells and dendritic cells to lactobacilli can be strikingly different depending on both the bacterial species and the strain. Several factors have been identified in lactobacilli that influence the immune response in vitro and in vivo including cell surface carbohydrates, enzymes modifying the structure of lipoteichoic acids and metabolites. In mice mechanistic studies point to a role for the homeostatic control of inducible T regulatory cells in the mucosal tissues as one possible immunomodulatory mechanism. Increasing evidence also suggests that induction of epithelial signalling by intestinal lactobacilli can modulate barrier functions, defensin production and regulate inflammatory signalling. Other probiotic mechanisms include modulation of the T cell effector subsets, enhancement of humoral immunity and interactions with the epithelial-associated dendritic cells and macrophages. A major challenge for the future will be to gain more knowledge about the interactions occurring between lactobacilli and the host in vivo and to understand the molecular basis of innate signalling in response to whole bacteria which trigger multiple signalling pathways.

Probiotic supplement reduces atopic dermatitis in preschool children: a randomized, double-blind, placebo-controlled, clinical trial

BACKGROUND

The role of probiotics in the treatment of atopic dermatitis (AD) remains controversial. A recent systematic review of the available evidence called for further clinical trials with new probiotic formulations.

OBJECTIVE

To assess the clinical efficacy and impact of Lactobacillus acidophilus DDS-1, Bifidobacterium lactis UABLA-12 with fructo-oligosaccharide on peripheral blood lymphocyte subsets in preschool children with moderate-to-severe AD.

METHOD

Randomized, double-blind, placebo-controlled, prospective trial of 90 children aged 1-3 years with moderate-to-severe AD who were treated with a mixture of L. acidophilus DDS-1, B. lactis UABLA-12 with fructo-oligosaccharide at a dosage of 5 billion colony-forming units twice daily for 8 weeks versus placebo. The primary outcome measure was the percentage change in Scoring of Atopic Dermatitis (SCORAD) value. Other outcome measures were changes in Infant Dermatitis Quality Of Life (IDQOL) and Dermatitis Family Impact (DFI) scores, frequency and amount of topical corticosteroid used, and lymphocyte subsets in peripheral blood measured by laser flow cytometry.

RESULTS

At the final visit, the percentage decrease in SCORAD was 33.7% in the probiotic group compared with 19.4% in the placebo group (p = 0.001). Children receiving probiotic showed a greater decrease in the mean [SD] SCORAD score than did children from the placebo group at week 8 (-14.2 [9.9] vs -7.8 [7.7], respectively; p = 0.001). IDQOL and DFI scores decreased significantly from baseline by 33.0% and 35.2% in the probiotic group and by 19.0% and 23.8% in the placebo group, respectively (p = 0.013, p = 0.010). Use of topical corticosteroids during the 8-week trial period averaged 7.7 g less in probiotic patients (p = 0.006). CD3, CD16, and CD22 lymphocyte subsets remained unchanged, whereas the percentage of CD4, and the percentage and absolute count of CD25 decreased, and the percentage and absolute count of CD8 increased in the probiotic group at week 8 (p < 0.007 vs placebo). There was a significant correlation between CD4 percentage, CD25 percentage, CD25 absolute count, and SCORAD values (r = 0.642, r = 0.746, r = 0.733, respectively; p < 0.05) in the probiotic group at week 8.

CONCLUSION

The administration of a probiotic mixture containing L. acidophilus DDS-1, B. lactis UABLA-12, and fructo-oligosaccharide was associated with significant clinical improvement in children with AD, with corresponding lymphocyte subset changes in peripheral blood. The efficacy of probiotic therapy in adults with AD requires further investigation.

Probiotics and prebiotics: clinical effects in allergic disease

PURPOSE OF REVIEW

This paper summarizes recent publications on probiotics and prebiotics in allergic disease. It focuses on clinical studies of prevention or treatment of allergic disease.

RECENT FINDINGS

Studies suggest a role for certain probiotics (alone or with prebiotics) in the prevention of atopic eczema. Treatment during the prenatal period appears to be important for beneficial effects. The use of probiotics for the treatment of established allergic disease is less promising, despite some positive results. A Cochrane systematic review concluded that, when the results for the different probiotic strains used in clinical trials are pooled, probiotics are not effective for the treatment of eczema. There are fewer studies of prebiotics for the treatment or prevention of allergic disease, but data suggest that prebiotic-supplemented formulas may be effective for preventing eczema in infants at high risk of developing allergic disease when breast-feeding is not possible.

SUMMARY

Allergic diseases continue to increase in prevalence worldwide, and primary prevention of allergic disease has proved an elusive goal. Probiotic bacteria represent the most promising intervention for primary prevention that has been studied to date, and definitive intervention studies should now be a research priority.

The effects of probiotics supplementation timing on an ovalbumin-sensitized rat model

The aim of the present study was to investigate the effect of oral probiotic bacteria administration at different times on ovalbumin-sensitized rats. Brown-Norway (BN) rats were orally sensitized with ovalbumin for 6 weeks. Probiotics were administered before the initial sensitization (prevention group) or at the end of sensitization period (treatment group). In whole-course intervention group, probiotics were administered 2 weeks before the initial sensitization until 1 week after the end of sensitization period. Ovalbumin-immunoglobulin E (IgE) level, intestinal barrier function and immune responses were analyzed. The positive control group had a significantly increased ovalbumin-IgE level (P<0.05), impaired intestinal barrier function and skewed T-helper 1 (Th1)/Th2 cytokine balance compared with the negative control group. In probiotics prevention and whole-course intervention groups, the infiltration of inflammatory cells (eosinophil and mast cells) in small intestinal mucosa was significantly lower (P<0.05), and the ratio of cytokine interferon-γ/interleukin-4 produced by spleen and mesenteric lymph nodes significantly higher (P<0.05) than in the positive control group, which suggested a cytokine profile inclined to Th1. Both probiotics prevention and prebiotics treatment could attenuate food allergic response. Probiotics prevention tends to modulate the immune response, whereas probiotics treatment has a more obvious effect in enhancing intestinal integrity.

Probiotics for allergic diseases: realities and myths

The prevalence of allergic diseases such as asthma, allergic rhinitis, and atopic dermatitis has increased sharply over the past two to three decades in many countries, and allergies are now the most common chronic disease among children throughout the world. In the past few years, probiotics have been advocated for the management of allergic diseases in many parts of the world. Physicians have a responsibility to ensure the efficacy and safety of any products they prescribe or recommend. This article provides a comprehensive overview and a critical interpretation of currently available evidence regarding the role of probiotics in the prevention and treatment of allergic diseases in humans and also discusses several major myths and potential risks associated with the use of probiotics. In the current era of evidence-based medicine, there is still insufficient evidence to recommend probiotics for the prevention of allergic diseases or as part of standard management for any allergic conditions in children.

Probiotics and allergy in children--an update review

The hygiene hypothesis suggests that the increased prevalence of allergic diseases has resulted from a relative lack of microbial stimuli during infancy and early childhood. Children with atopic diseases have different commensal bacterial groups in the gut compared to non-atopic children, and differences are also found between countries with high and low incidence of atopic diseases. Probiotics are defined as live microorganisms that provide benefits to the health of a host by altering the host's microflora when they are administered in adequate amounts. They are being investigated for possible roles in managing allergic diseases. To date, the evidence that probiotics can be used to treat or prevent allergic diseases of children remains controversial. We reviewed recent randomized, double-blinded, placebo-controlled clinical trials using probiotics for allergic diseases of children and evaluated their clinical efficacy, possible mechanisms, dosage, and safety for managing allergic diseases of children. The current data are insufficient to strongly recommend probiotics as a standard treatment or preventative measure for pediatric allergic disease. More studies are needed to standardize study designs, bacterial strains, dosages, and durations for different allergic diseases of children.

Effect of Lactobacillus sakei supplementation in children with atopic eczema-dermatitis syndrome

BACKGROUND

Probiotics have been suggested to be useful in children with atopic eczema-dermatitis syndrome (AEDS).

OBJECTIVE

To assess the clinical effect of Lactobacillus sakei supplementation in children with AEDS.

METHODS

In a double-blind, placebo-controlled trial, children aged 2 to 10 years with AEDS with a minimum SCORing of Atopic Dermatitis (SCORAD) score of 25 were randomized to receive either daily L sakei KCTC 10755BP or daily placebo supplementation for 12 weeks. Changes in SCORAD scores and serum chemokine levels from baseline were evaluated.

RESULTS

Eighty-eight children were enrolled, and 45 were allocated to probiotic treatment. Seventy-five children completed the study, with 4 dropouts in the probiotic group and 9 in the placebo group. At week 12, SCORAD total scores adjusted by pretreatment values were lower after probiotic treatment than after placebo treatment (P = .01). There was a 31% (13.1-point) improvement in mean disease activity with probiotic use compared with a 13% (5.2-point) improvement with placebo use (P = .008). Significant differences in favor of probiotic treatment were also observed in proportions of patients achieving improvement of at least 30% and 50%. Compared with placebo, probiotic administration was associated with lower pretreatment-adjusted serum levels of CCL17 and CCL27 (P =.03 for both), which were significantly correlated with SCORAD total score (r = 0.59 and 0.63, respectively; P < .001).

CONCLUSIONS

Supplementation of L sakei in children with AEDS was associated with a substantial clinical improvement and a significant decrease in chemokine levels, reflecting the severity of AEDS.

Practical prebiotics, probiotics and synbiotics for allergists: how useful are they?

With the advent of the hygiene hypothesis, probiotics have provided an avenue of hope in curbing the allergic epidemic. The initial enthusiasm has been tempered by recognition of the inherent complexities of this approach. This review examines the current clinical evidence and practical issues in using probiotics and related products, for the prevention and treatment of allergic disease. So far, probiotics have shown more promise, albeit limited, in the primary prevention of allergic disease rather than in the treatment of established disease. These effects have largely been limited to the prevention of early childhood conditions such as eczema, with no consistent effects on other allergic outcomes. There is emerging evidence that clinical effects may be strain specific, but again these findings have been inconsistent. While there have been several meta-analyses to examine probiotics in both the prevention and the treatment of allergic disease, these have been hampered by significant heterogeneity between studies, including wide variations in the strains used, the methods and timing of administration and the age and assessment of allergic outcomes. In any case, these have also become outdated by a series of new studies published in the last year. Although it is not yet clear exactly how the growing number of new studies will modify the results of meta-analyses, it is likely that these will add yet further heterogeneity that will continue to make interpretation of pooled data difficult. At this stage, the effects of prebiotics, synbiotics and postbiotics are even less clear. Thus, while there is little doubt that microbiota modulate immune development and can prevent the allergic phenotype, the optimal way of achieving this is far from clear. Given the current level of evidence, it is not appropriate to recommend prebiotics/probiotics/synbiotics or postbiotics as a part of standard therapy or for the prevention of any allergic conditions. Further studies are needed to address the growing speculation that supplementation with a single probiotic strain may be oversimplistic and that approaches that have a more global effect on colonization may be warranted.

What dose metaphor?

The concept of hormesis, or low-dose U-shaped responses, is now well established in toxicology and pharmacology but requires development in medicine and therapeutics. In doing so, care must be taken to not confuse metaphorical and chemical uses of the term hormesis. Low dose, continuous adaptive responses are fundamentally different than conventional pharmacology, and they may improve the scientific underpinning for complementary medicine, nutrition and lifestyle therapies.

Guidance for substantiating the evidence for beneficial effects of probiotics: prevention and management of allergic diseases by probiotics

Allergy is a hypersensitivity reaction mediated by specific antibody-mediated or cell-mediated immunologic mechanisms and clinically manifested as atopic eczema, allergic rhinoconjunctivitis, or asthma. During the recent decades there has been an increase in allergy prevalence, which is attributed to changes in environmental factors. The so-called "hygiene hypothesis" suggests that a lack of exposure to microbial stimulus early in childhood is a major factor involved in this trend. This provides a rationale for using probiotics to modify the gut microbiota and thereby shaping the immune response of the host, especially in infancy. Most success has been obtained in primary prevention of atopic eczema. A limited number of studies also provided evidence for a beneficial effect of different probiotics in the management of allergic diseases (atopic eczema, allergic rhinitis). However, choice of probiotic strains as well as timing of the intervention are important variables. The exact in vivo mechanism of probiotics in shaping the immune response still needs to be determined. Future studies should use uniform criteria for diagnosis and symptom scoring of atopic diseases and may identify the genes predisposing to allergic disease. There is encouraging evidence that specific probiotics can become valuable tools in the prevention and management of allergic diseases.

Probiotics and prebiotics in atopic dermatitis: review of the theoretical background and clinical evidence

The prevalence of atopic dermatitis (AD) has risen over the past decades, especially in western societies. According to the revised hygiene hypothesis this increase is caused by a changed intestinal colonization pattern during infancy, which has an impact on the immune system. Manipulating the intestinal microflora with pro-, pre- or synbiotics is an innovative way to prevent or treat AD. This review provides an overview of the theoretical basis for using probiotics and prebiotics in AD and presents the current evidence from randomized controlled trials (RCTs) regarding prevention and treatment of AD and food allergy in children with pro-, pre- and synbiotics. Seven RCTs on prevention and 12 RCTs on treatment were found by searching the Pubmed, Embase and Cochrane databases. Results of these trials are conflicting. In conclusion, at this moment there is not enough evidence to support the use of pro-, pre- or synbiotics for prevention or treatment of AD in children in clinical practice.

Prebióticos, probióticos e simbióticos na prevenção e tratamento das doenças alérgicas

OBJETIVO: Avaliar o papel dos probióticos, prebióticos e simbióticos no equilíbrio do sistema imunológico do lactente, bem como seu efeito preventivo no desenvolvimento de doenças alérgicas na criança. FONTE DE DADOS: A partir do levantamento de todos os ensaios clínicos duplo-cegos e randômicos em seres humanos, publicados nos últimos cinco anos na base de dados Medline e que contivessem unitermos relacionados a prebióticos (oligossacarídeos), probióticos e simbióticos versus hipersensibilidade, analisou-se seu papel quanto à utilização em doenças alérgicas. SÍNTESE DE DADOS: Foram incluídos nesta revisão três trabalhos com prebióticos, os quais utilizaram a mistura GOS:FOS (9:1) em fórmulas infantis em lactentes nos primeiros meses de vida; 24 trabalhos com probióticos, sendo os micro-organismos utilizados na suplementação L. rhamnosus GG, B. lactis, L. casei, L. paracasei, L. reuteri, L. acidophilus, B. longum, B. breve e P. freudenreichii sp., e dois estudos com simbióticos. CONCLUSÕES: Apesar das evidências de benefícios da suplementação precoce de probióticos com algumas cepas específicas, prebióticos e simbióticos na prevenção da dermatite atópica, em crianças de alto risco para alergias, e do uso de probióticos no tratamento das dermatites atópicas moderadas e graves mediadas por IgE, há necessidade de ampliar os estudos quanto ao tempo de observação dos indivíduos suplementados, quanto à segurança e aos efeitos em longo prazo

Effect of a new synbiotic mixture on atopic dermatitis in infants: a randomized-controlled trial

BACKGROUND

Clinical trials investigating the therapeutic effect of probiotics on atopic dermatitis (AD) show inconsistent results. Better results can possibly be achieved by combining probiotics with prebiotics, i.e. synbiotics.

OBJECTIVE

To investigate the therapeutic effect of a synbiotic mixture on the severity of AD in infants.

METHODS

In a double-blind, placebo-controlled multi-centre trial, 90 infants with AD [SCORing Atopic Dermatitis (SCORAD) score > or =15], aged < 7 months and exclusively formula fed, were randomly assigned to receive either an extensively hydrolysed formula with Bifidobacterium breve M-16V and a galacto-/fructooligosaccharide mixture (Immunofortis), or the same formula without synbiotics for 12 weeks. The primary outcome was severity of AD, assessed using the SCORAD index. A secondary outcome measure was intestinal microbiota composition.

RESULTS

There was no difference in SCORAD score improvement between the synbiotic and the placebo group. The synbiotic group did have a significantly higher percentage of bifidobacteria (54.7% vs. 30.1%, P<0.001) and significantly lower percentages of Clostridium lituseburense/Clostridium histolyticum (0.5 vs. 1.8, P=0.02) and Eubacterium rectale/Clostridium coccoides (7.5 vs. 38.1, P<0.001) after intervention than the placebo group. In the subgroup of infants with IgE-associated AD (n=48), SCORAD score improvement was significantly greater in the synbiotic than in the placebo group at week 12 (-18.1 vs. -13.5 points, P=0.04).

CONCLUSIONS

This synbiotic mixture does not have a beneficial effect on AD severity in infants, although it does successfully modulate their intestinal microbiota. Further randomized-controlled trials should explore a possible beneficial effect in IgE-associated AD.

Pro- and prebiotic supplementation induces a transient reduction in hemoglobin concentration in infants

OBJECTIVES

: Regarding safety, we investigated the effect of prenatal probiotic and 6 months of pro- and prebiotic supplementation of infants on their hematologic values at 6 months and 2 years and factors affecting these values.

PATIENTS AND METHODS

: In a prospective randomized controlled probiotic intervention trial in infants at high risk for allergy, we obtained blood samples consecutively from 98 infants at 6 months and from 658 children at 2 years to measure hematologic values. We collected fecal samples at 3 and 6 months to measure immunologic development by calprotectin, alpha-1-antitrypsin, tumor necrosis factor-alpha, and immunoglobulin A.

RESULTS

: At 6 months, infants in the probiotic group had significantly lower hemoglobin (Hb) values than did the placebo group, mean (SD): 119.8 g/L (6.3) versus 123.3 g/L (8.4), P = 0.025. Adjustment for factors that might affect Hb values (breast-feeding duration, solid-food introduction, and sex), revealed no need for adjustment. A significant negative correlation emerged between Hb values at 6 months and fecal calprotectin at age 3 months r = -0.301, P = 0.009, which was affected neither by breast-feeding, sex, nor study group. At 2 years, hematologic values in both groups became similar.

CONCLUSIONS

: Probiotics cause a gut mucosal inflammation with decreased Hb values during intervention, corrected after halting the supplementation.