Probiotics in the prevention of eczema: a randomised controlled trial

Probiotics supplementation during pregnancy or infancy on multiple food allergies and gut microbiota: a systematic review and meta-analysis

CONTEXT

Probiotics show promise in preventing and managing food allergies, but the impact of supplementation during pregnancy or infancy on children's allergies and gut microbiota remains unclear.

OBJECTIVE

This study aimed to assess the effects of maternal or infant probiotic supplementation on food allergy risk and explore the role of gut microbiota.

DATA SOURCES

A systematic search of databases (PubMed, Cochrane Library, Embase, and Medline) identified 37 relevant studies until May 20, 2023.

DATA EXTRACTION

Two independent reviewers extracted data, including probiotics intervention details, gut microbiota analysis, and food allergy information.

DATA ANALYSIS

Probiotics supplementation during pregnancy and infancy reduced the risk of total food allergy (relative risk [RR], 0.79; 95% CI, 0.63-0.99), cow-milk allergy (RR, 0.51; 95% CI, 0.29-0.88), and egg allergy (RR, 0.57; 95% CI, 0.39-0.84). Infancy-only supplementation lowered cow-milk allergy risk (RR, 0.69; 95% CI, 0.49-0.96), while pregnancy-only had no discernible effect. Benefits were observed with over 2 probiotic species, and a daily increase of 1.8 × 109 colony-forming units during pregnancy and infancy correlated with a 4% reduction in food allergy risk. Children with food allergies had distinct gut microbiota profiles, evolving with age.

CONCLUSIONS

Probiotics supplementation during pregnancy and infancy reduces food allergy risk and correlates with age-related changes in gut microbial composition in children.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023425988.

Dietary Interventions in Atopic Dermatitis: A Comprehensive Scoping Review and Analysis

BACKGROUND

This scoping review aims to critically assess gaps in the current literature on atopic dermatitis (AD) by evaluating the overall effectiveness of dietary interventions. Through a comprehensive analysis that follows the Preferred Reporting Item for Systematic Review and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines, we conducted a thorough search on the Web of Science database in May 2023 using specific search strategies to identify all relevant studies on the research topic.

SUMMARY

A total of 104 full-text articles were included for review. Our synthesis identified seven notable categories of dietary interventions for AD, showcasing the diversity of interventions utilized. This includes vitamin supplementation, probiotic and prebiotic supplementation, dietary fat, biological compounds, foods from natural sources, major nutrients, and diet-related approaches. Further analyses stratified by targeted populations revealed a predominant focus on pediatrics, particularly in probiotic supplementation, and on adults, with an emphasis on vitamin D and E supplementation.

KEY MESSAGES

Despite most dietary interventions demonstrating overall effectiveness in improving AD severity and its subjective symptoms, several significant gaps were identified. There was a scarcity of studies on adults and whole-diet interventions, a prevalence of short-term interventions, heterogeneity in study outcomes, designs, and population, occasional disparity between statistical significance and clinical relevance, and a lack of a comprehensive multidisciplinary approach. Nonetheless, these findings offer valuable insights for future AD research, guiding additional evidence-driven dietary interventions and informing healthcare professionals, researchers, and individuals, advancing both understanding and management of AD.

Modulation of gut-microbiota through probiotics and dietary interventions to improve host health

Dietary patterns play an important role in regards to the modulation and control of the gut microbiome composition and function. The interaction between diet and microbiota plays an important role in order to maintain intestinal homeostasis, which ultimately affect the host's health. Diet directly impacts the microbes that inhabit the gastrointestinal tract (GIT), which then contributes to the production of secondary metabolites, such as short-chain fatty acids, neurotransmitters, and antimicrobial peptides. Dietary consumption with genetically modified probiotics can be the best vaccine delivery vector and protect cells from various illnesses. A holistic approach to disease prevention, treatment, and management takes these intrinsically linked diet-microbes, microbe-microbe interactions, and microbe-host interactions into account. Dietary components, such as fiber can modulate beneficial gut microbiota, and they have resulting ameliorative effects against metabolic disorders. Medical interventions, such as antibiotic drugs can conversely have detrimental effects on gut microbiota by disputing the balance between Bacteroides and firmicute, which contribute to continuing disease states. We summarize the known effects of various dietary components, such as fibers, carbohydrates, fatty acids, vitamins, minerals, proteins, phenolic acids, and antibiotics on the composition of the gut microbiota in this article in addition to the beneficial effect of genetically modified probiotics and consequentially their role in regards to shaping human health. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Maternal fish oil and/or probiotics intervention: Allergic diseases in children up to two years old

BACKGROUND

As n-3 long-chain polyunsaturated fatty acids and probiotics possess immunomodulatory properties, theoretically they could lower the risk of allergic diseases. But their effects remain controversial. We aimed to study the effects of fish oil and probiotics separately or in combination from early pregnancy onwards to lower the risk of allergic diseases in the infants.

METHODS

In this double-blind trial, women (n = 439) in early pregnancies were randomized into four intervention groups: fish oil + placebo, probiotics + placebo, fish oil + probiotics, and placebo + placebo. Fish oil (1.9 g docosahexaenoic acid and 0.22 g eicosapentaenoic acid) and probiotic (Lacticaseibacillus rhamnosus HN001 and Bifidobacterium animalis ssp. lactis 420, 1010 colony-forming units each) supplements were provided for daily consumption from randomization up to 6 months postpartum. All analyses were adjusted with pet ownership.

RESULTS

No difference between the infants in the four intervention groups were found regarding physician-diagnosed food allergy, atopic eczema, or atopy at the age of 12 or 24 months (all p > .05). The probiotic intervention was associated with lower odds of recurrent wheezing at 24 months (OR 0.39, 95% CI 0.18-0.84, p = .017), but not at 12 months.

CONCLUSIONS

The use of fish oil and/or probiotics from early pregnancy onwards did not lower the odds of childhood allergic diseases or atopy, with the exception of the probiotic intervention which decreased the risk of recurrent wheezing when the infants were two years old. This suggests that the incidence of asthma could also decrease later in childhood and thus these outcomes need to be clarified in further investigations.

The Role of Probiotics in Skin Health and Related Gut-Skin Axis: A Review

Aging skin, wrinkles, pigmentation, and dryness are problems that plague people, and researchers are working to solve them. Recent studies have shown that intestinal microbiota homeostasis can influence skin health, demonstrating the existence of a gut-skin axis. Recently, improving skin health through probiotic interventions has been proposed, and micro-ecological skin care is becoming a popular concept. By regulating skin health and gut-skin axis interactions, probiotics can be used as potential management tools to suppress and improve skin diseases in multiple ways, including decreasing oxidative stress, suppressing inflammatory responses, and keeping immune effects. The purpose of this paper is to provide a comprehensive review of the application and mechanisms of probiotic-mediated gut microbiota homeostasis in skin care and to offer a theoretical basis for the application of probiotics in skin care.

Anti-Atherogenic Actions of the Lab4b Consortium of Probiotics In Vitro

Probiotic bacteria have many protective effects against inflammatory disorders, though the mechanisms underlying their actions are poorly understood. The Lab4b consortium of probiotics contains four strains of lactic acid bacteria and bifidobacteria that are reflective of the gut of newborn babies and infants. The effect of Lab4b on atherosclerosis, an inflammatory disorder of the vasculature, has not yet been determined and was investigated on key processes associated with this disease in human monocytes/macrophages and vascular smooth muscle cells in vitro. The Lab4b conditioned medium (CM) attenuated chemokine-driven monocytic migration, monocyte/macrophage proliferation, uptake of modified LDL and macropinocytosis in macrophages together with the proliferation and platelet-derived growth factor-induced migration of vascular smooth muscle cells. The Lab4b CM also induced phagocytosis in macrophages and cholesterol efflux from macrophage-derived foam cells. The effect of Lab4b CM on macrophage foam cell formation was associated with a decrease in the expression of several key genes implicated in the uptake of modified LDL and induced expression of those involved in cholesterol efflux. These studies reveal, for the first time, several anti-atherogenic actions of Lab4b and strongly implicate further studies in mouse models of the disease in vivo and in clinical trials.

Shedding light on key pharmacological knowledge and strategies for pediatric atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is an inflammatory disease affecting over 20% of the pediatric population, with 85% of cases presenting before the age of five. Recently, therapeutic options in pediatric patients have evolved rapidly, following extensive development in adult treatments.

AREAS COVERED

This review will encompass relevant molecular drivers, along with an overlook on treatment modalities in pediatric AD, as well as a summary of pipeline treatments in clinical trials for pediatric patients from PubMed, Google Scholar, and Clinicaltrials.gov up to July 2022. Topical corticosteroids are the mainstay for AD flares in adults and children. Topical approved agents in pediatric AD are calcineurin inhibitors, crisaborolecrisaborole, and ruxolitinib. Dupilumab is the only FDA approved biologic for patients with AD from six months of age. A Janus kinase inhibitor, upadacitinib, is a systemic treatment approved for pediatric AD patients (age >12 years). Systemic immunosuppressants used in pediatric AD include methotrexate, azathioprine, cyclosporinecyclosporine, and mycophenolate mofetil.

EXPERT OPINION

Data regarding disease prevention are conflicting, however, an abundance of research has transpired regarding amelioration of symptoms and induction of disease clearance by targeting numerous pathological mechanisms. Understanding the pediatric AD phenotype will further advance the field and the development of improved therapeutics.

The Baseline Gut Microbiota Enterotype Directs Lifestyle-Induced Amelioration of Pollen Allergy Severity: A Self Controlled Case-Series Study

Deciphering the key factors underlying individual responses to a habitual diet is important in implementing personalized nutrition strategies to treat allergic diseases. This prospective randomized cohort study aimed to identify key factors determining individual pollen allergy (PA) trajectories in a natural setting. Baseline data on fecal microbiota composition, lifestyle activities, and diet habits of 190 participants with PA and 92 healthy controls were collected, followed by a SOMPO-guided intestinal activity program. Three enterotypes enriched in Bacteroides, Prevotella, and Ruminococcus and four subenterotypes for enterotypes Bacteroides and Prevotella enriched with Faecalibacterium, Megamonas, and Fusobacterium were identified at baseline. PA severity was significantly negatively correlated with the daily intake of fermented plants and no weekly intake of meat, but positively correlated with poor sleep quality. Interactions between enterotype and lifestyle factors affected PA severity, and intestinal activity intervention based on the baseline enterotype reduced the PA severity score. In conclusion, the findings of this study demonstrated that the baseline gut enterotype plays a crucial role in PA. This study suggests combining enterotype data with habitual diet can improve PA severity.

Exploring the Potential of Human Milk and Formula Milk on Infants’ Gut and Health

Early-life gut microbiota plays a role in determining the health and risk of developing diseases in later life. Various perinatal factors have been shown to contribute to the development and establishment of infant gut microbiota. One of the important factors influencing the infant gut microbial colonization and composition is the mode of infant feeding. While infant formula milk has been designed to resemble human milk as much as possible, the gut microbiome of infants who receive formula milk differs from that of infants who are fed human milk. A diverse microbial population in human milk and the microbes seed the infant gut microbiome. Human milk contains nutritional components that promote infant growth and bioactive components, such as human milk oligosaccharides, lactoferrin, and immunoglobulins, which contribute to immunological development. In an attempt to encourage the formation of a healthy gut microbiome comparable to that of a breastfed infant, manufacturers often supplement infant formula with prebiotics or probiotics, which are known to have a bifidogenic effect and can modulate the immune system. This review aims to elucidate the roles of human milk and formula milk on infants’ gut and health.

Probiotics for the prevention of atopic dermatitis in infants from different geographic regions: a systematic review and meta-analysis

BackgroundAtopic dermatitis (AD) is a common skin disease during infancy, but the preventive effect of probiotics on AD remains unclear.AimTo evaluate the efficacy of probiotic supplementation for the prevention of AD in infants.MethodsPubMed, Cochrane Library, and Embase databases were reviewed for relevant randomized controlled trials (RCTs). Two authors independently extracted the data. The primary endpoint was the risk of AD in infants. Risk ratio (RR) and 95% confidence interval (CI) were calculated.ResultsA total of 20 related articles including 22 studies were included. A significant reduction in AD risk was revealed for the probiotic group compared to the control group (RR 0.76; 95% CI 0.67-0.87). Subgroup analyses by participant receiving intervention revealed that not only probiotics given to mother (RR 0.70; 95% CI 0.57-0.85) or given to mother and infant (RR 0.76; 95% CI 0.61-0.95) were effective in preventing AD in infants, and probiotics given to infants alone (RR 0.76; 95% CI 0.60-0.96) still effectively decreased the risk of AD.ConclusionProbiotic supplementation reduced the risk of developing AD in infants. Furthermore, probiotic supplementation given to mother or to mother and infant could effectively prevent AD in infants.

Association of Probiotics with Atopic Dermatitis among Infant: A Meta-analysis of Randomized Controlled Trials

Background. Previous studies have explored the relationship between probiotics and risk of atopic dermatitis among infant; however, the results are still inconclusive. We aimed to assess the abovementioned association. Methods. PubMed, Web of Science, Embase, and China National Knowledge Infrastructure were retrieved for association between probiotics and atopic dermatitis with randomized controlled trials (RCTs) until Nov 20, 2021. The effect size was pooled by using random or fixed effect models according to the heterogeneity. Stata 12.0 was used for meta-analysis, sensitivity analysis, and bias analysis. Results. At the end of the screening article, 2575 infants were extracted from 8 trials and finally met the qualification criteria. In comparison to placebo, probiotics dramatically reduced incidence of childhood atopic dermatitis ( $\text{RR}=0.86$ , 95% $\text{CI}=0.78$ -0.95). However, probiotics did not exhibit benefit over placebo in preventing the development of either IgE-associated infant AD ( $\text{RR}=0.98$ , 95% $\text{CI}=0.79$ -1.22) or sensitive constitution ( $\text{RR}=0.93$ , 95% $\text{CI}=0.81$ -1.08). From the results of sensitivity and publication bias, we found that these results were robust with little publication bias. Conclusion. During the late stages of pregnancy, women taking probiotics could lower the risk of infantile atopic dermatitis, but not for IgE-associated infant AD or sensitive constitution. The results could provide evidence for the fibrosis. Future studies are needed to confirm the results.

Probiotics Function in Preventing Atopic Dermatitis in Children

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by relapsing eczematous injuries and severe pruritus. In the last few years, the AD prevalence has been increasing, reaching 20% in children and 10% in adults in high-income countries. Recently, the potential role of probiotics in AD prevention has generated considerable interest. As many clinical studies show, the gut microbiota is able to modulate systemic inflammatory and immune responses influencing the development of sensitization and allergy. Probiotics are used increasingly against AD. However, the molecular mechanisms underlying the probiotics mediated anti-allergic effect remain unclear and there is controversy about their efficacy. In this narrative review, we examine the actual evidence on the effect of probiotic supplementation for AD prevention in the pediatric population, discussing also the potential biological mechanisms of action in this regard.

Microbiome Modulation as a Therapeutic Approach in Chronic Skin Diseases

There is a growing quantity of evidence on how skin and gut microbiome composition impacts the course of various dermatological diseases. The strategies involving the modulation of bacterial composition are increasingly in the focus of research attention. The aim of the present review was to analyze the literature available in PubMed (MEDLINE) and EMBASE databases on the topic of microbiome modulation in skin diseases. The effects and possible mechanisms of action of probiotics, prebiotics and synbiotics in dermatological conditions including atopic dermatitis (AD), psoriasis, chronic ulcers, seborrheic dermatitis, burns and acne were analyzed. Due to the very limited number of studies available regarding the topic of microbiome modulation in all skin diseases except for AD, the authors decided to also include case reports and original studies concerning oral administration and topical application of the pro-, pre- and synbiotics in the final analysis. The evaluated studies mostly reported significant health benefits to the patients or show promising results in animal or ex vivo studies. However, due to a limited amount of research and unambiguous results, the topic of microbiome modulation as a therapeutic approach in skin diseases still warrants further investigation.

Mechanisms of microbe-immune system dialogue within the skin

The prevalence and severity of dermatological conditions such as atopic dermatitis have increased dramatically during recent decades. Many of the factors associated with an altered risk of developing inflammatory skin disorders have also been shown to alter the composition and diversity of non-pathogenic microbial communities that inhabit the human host. While the most densely microbial populated organ is the gut, culture and non-culture-based technologies have revealed a dynamic community of bacteria, fungi, viruses and mites that exist on healthy human skin, which change during disease. In this review, we highlight some of the recent findings on the mechanisms through which microbes interact with each other on the skin and the signalling systems that mediate communication between the immune system and skin-associated microbes. In addition, we summarize the ongoing clinical studies that are targeting the microbiome in patients with skin disorders. While significant efforts are still required to decipher the mechanisms underpinning host-microbe communication relevant to skin health, it is likely that disease-related microbial communities, or Dermatypes, will help identify personalized treatments and appropriate microbial reconstitution strategies.

Topical Probiotics Do Not Satisfy New Criteria for Effective Use Due to Insufficient Skin Microbiome Knowledge

We propose a set of criteria for topical probiotics to adhere to for safe and effective use for the skin microbiome. To form the basis of the criteria, we redefine the term “probiotics” and discuss successful and unsuccessful high-profile examples of the artificial addition of organisms to ecosystems in nature to understand what worked and what did not. Probiotics are often immediately assumed to have health benefits. However, as ecologists are aware, interfering with ecosystems is potentially catastrophic. The addition or removal of just one organism can significantly upset the delicate ecosystem balance. If our criteria are not met, we argue that topical probiotics could also cause damage and will not be beneficial. Due to the large intra- and inter-personal variation of the skin microbiome, our current knowledge of a healthy skin microbiome composition is not complete enough to fully satisfy the criteria. In follow-up work, we will investigate whether current topical probiotics research and commercial products meet our new criteria. We will also discuss problems with how to measure their effectiveness and suggest alternative solutions to replacing the lost biodiversity of the skin microbiome that was stripped away by environmental factors in the Western world.

Comparative effectiveness of probiotic strains on the prevention of pediatric atopic dermatitis: A systematic review and network meta-analysis

BACKGROUND

Atopic dermatitis is the most common chronic skin disease affecting the pediatric population. Probiotics have been proposed to be effective in preventing the development of pediatric atopic dermatitis. Although studies show promise for the use of probiotics, the evidence is still inconclusive due to significant heterogeneity and imprecision.

OBJECTIVE

To determine the comparative effectiveness of the different types of probiotic strains in preventing the development of atopic dermatitis among pediatric patients.

METHODOLOGY

A systematic search of Cochrane Library, MEDLINE, TRIP Database, and Centre for Research and Dissemination was conducted. Manual search of the reference lists and search for unpublished articles were also done. All randomized controlled trials available from inception until April 12, 2020, on the use of probiotics in the prevention of atopic dermatitis among children were included. The comparator groups considered are other probiotic strains and placebo. The primary outcome of interest was the development of atopic dermatitis. Two authors independently searched for articles, screened the articles for inclusion, appraised the articles using the Cochrane risk of bias tool version 2, and extracted the data. In case of disagreement, the two authors discussed the source of disagreement until consensus was reached. If consensus was not reached, an independent third party reviewer was consulted. Frequentist network meta-analysis was conducted using STATA 14 software. The ranking probabilities and surface under the cumulative ranking curve (SUCRA) values were obtained to determine ranking of the different probiotic strains based on efficacy and safety data.

RESULTS

We included 21 original studies represented by 35 records and a total of 5406 children with atopic dermatitis as diagnosed by clinicians or fulfillment of validated diagnostic criteria. All studies were randomized placebo-controlled trials. The top 3 probiotic preparations in terms of efficacy in reducing the risk of atopic dermatitis are Mix8 (Lactobacillus paracasei ST11, Bifidobacterium longum BL999), LP (Lactobacillus paracasei ssp paracasei F19) and Mix3 (Lactobacillus rhamnosus GG, Bifidobacterium animalis ssp lactis Bb-12). Mix8 compared with placebo probably reduces the risk of atopic dermatitis based on low-quality evidence (RR = 0.46, 95% CI 0.25-0.85). Mix3 compared with placebo also probably reduces the risk of atopic dermatitis based on low-quality evidence (RR = 0.50, 95% CI 0.27-0.94). It is uncertain whether LP compared with placebo reduces the risk of atopic dermatitis due to very-low-quality certainty of evidence (RR = 0.49, 95% CI 0.20-1.19). In terms of adverse events, LGG may slightly lead to less adverse events compared with placebo based on low-quality evidence (RR = 0.70, 95% CI 0.32-1.52). Mix4 may slightly lead to more adverse events compared with placebo based on low-quality evidence (RR = 1.06, 95% CI 0.02-51.88). Based on subgroup analysis of studies involving infants, Mix3 compared with placebo probably reduces the risk of atopic dermatitis based on low-quality evidence (RR = 0.46, 95% CI 0.22-0.97). In the subgroup analysis of studies where probiotics were administered to pregnant women and to infants, LRH compared with placebo probably reduces the risk of atopic dermatitis based on moderate-quality evidence (RR = 0.54, 95% CI 0.26-1.11).

CONCLUSION

Certain probiotic preparations demonstrate efficacy in reducing the risk of developing atopic dermatitis when administered to pregnant women, infants, or both.

The prevention effect of probiotics against eczema in children: an update systematic review and meta-analysis

Accumulated evidences support the fetus's intestinal flora unbalance is associated with the development of allergic diseases. Probiotic supplements in pregnancy and childhood might prevent atopic diseases. The aim of this systematic review and meta-analysis was to evaluate the effect of probiotic supplementation during pregnancy and early infancy in preventing eczema, atopic eczema, and other allergic diseases. We also explored whether different probiotic strains or intervention objects affected the antiallergic effect of probiotics and the prevention atopy effect of the long-term period. Fixed-effect models were used, and random-effects models where significant heterogeneity was present. Results were expressed as odds ratios (ORs) with a 95% confidence interval (CI). Twenty-one studies were included in the meta-analysis. The probiotics group had a significantly lower risk of eczema and atopic eczema compared to controls, especially those treated with probiotic combinations. Mothers' probiotics intake significantly contributed to reducing the risk of eczema as well as atopic eczema. What's more, probiotics seemed effective on eczema prevention ≤2 years of age, but against atopic eczema after 1 of age year. No significant difference in terms of prevention of asthma, rhinitis, wheeze, allergic diseases and sensation. In brief, a probiotic supplement is expected to become a novel potential strategy for infant eczema and atopic eczema.

Gut microbiota restoration through fecal microbiota transplantation: a new atopic dermatitis therapy

The pathogenesis of atopic dermatitis (AD) involves complex factors, including gut microbiota and immune modulation, which remain poorly understood. The aim of this study was to restore gut microbiota via fecal microbiota transplantation (FMT) to ameliorate AD in mice. FMT was performed using stool from donor mice. The gut microbiota was characterized via 16S rRNA sequencing and analyzed using Quantitative Insights into Microbial Ecology 2 with the DADA2 plugin. Gut metabolite levels were determined by measuring fecal short-chain fatty acid (SCFA) contents. AD-induced allergic responses were evaluated by analyzing blood parameters (IgE levels and eosinophil percentage, eosinophil count, basophil percentage, and monocyte percentage), the levels of Th1 and Th2 cytokines, dermatitis score, and the number of mast cells in the ileum and skin tissues. Calprotectin level was measured to assess gut inflammation after FMT. FMT resulted in the restoration of gut microbiota to the donor state and increases in the levels of SCFAs as gut metabolites. In addition, FMT restored the Th1/Th2 balance, modulated Tregs through gut microbiota, and reduced IgE levels and the numbers of mast cells, eosinophils, and basophils. FMT is associated with restoration of gut microbiota and immunologic balance (Th1/Th2) along with suppression of AD-induced allergic responses and is thus a potential new therapy for AD.

Can Mixed Strains of Lactobacillus and Bifidobacterium Reduce Eczema in Infants under Three Years of Age? A Meta-Analysis

(1) Background: Whether early supplementation of probiotics to improve intestinal flora can effectively prevent eczema remains a controversial issue. We aimed to investigate the effect of a mixed strain of Lactobacillus and Bifidobacterium on eczema in infants under three years old at present; (2) Methods: We searched the databases of PubMed, Web of Science, and Cochrane Library, as well as National Knowledge Infrastructure (CNKI), WeiPu (VIP), and WanFang Data (WanFang) for randomized controlled trials (RCTs) of probiotics in the prevention of eczema in infants without language restriction. The main outcome was eczema incidence, while adverse events during the intervention constituted the secondary outcome. The random-/fixed-effects model was utilized to calculate the combined relative risk (RR) and 95% confidence interval (CI). The methodological quality of the study was evaluated using the Cochrane "bias risk" tool. According to the initial intervention time, subgroup analysis was carried out, follow-up time, family history, etc.; (3) Results: Nine articles were selected (2093 infants). The Lactobacillus and Bifidobacterium mixed strain could prevent eczema in infants under three years of age compared to the placebo (RR = 0.60; I² = 67%; p < 0.001). Subgroup analysis revealed that the mixture of two probiotic strains had preventive effects on both infants with positive (RR = 0.53; I² = 52%; p < 0.001) and negative (RR = 0.69; I² = 62%; p = 0.02) family history; The follow-up time for ≤12 months (RR = 0.65; I² = 12%; p = 0.01) and 12-24 months (RR = 0.60; I² = 79%; p = 0.003), daily dose of probiotics ≤ 1 × 10⁹ and > 1 × 10⁹ colony forming units all can be effective (p < 0.01); Compared with the intervention of infants alone (RR = 0.63; I² = 63%; p = 0.29), the effect of probiotics mixture at the beginning of pregnancy was more significant (RR = 0.59; I² = 71%; p < 0.001); Except for the mixture of Lactobacillus rhamnosusGG (LGG) and Bifidobacterium longum (B. longum) (p = 0.18), other subgroups of intervention group can play a preventive effect (p < 0.05); (4) Conclusions: The mixed strain of Lactobacillus and Bifidobacterium can effectively reduce the incidence of eczema in infants under three years old. However, further research is needed to fully understand the exact mechanism of their effect on infant eczema.

The Role of Bifidobacteria in Predictive and Preventive Medicine: A Focus on Eczema and Hypercholesterolemia

Bifidobacteria colonize the human gastrointestinal tract early on in life, their interaction with the host starting soon after birth. The health benefits are strain specific and could be due to the produced polysaccharides. The consumption of probiotics may prevent obesity, irritable bowel syndrome, eczema or atopic dermatitis, and asthma. Non-replicative strains of Bifidobacterium longum (NCC3001 and NCC2705) promote the differentiation of normal human epidermal keratinocytes (NHEKs), inducing a high expression of differentiation markers (keratin —KRT1—, and transglutaminase —TGM1—) and pro-regeneration markers (cathepsins), including β-defensin-1, which plays an important role in modulating the cutaneous immune response. Strains belonging to the genera Bifidobacterium and Lactobacillus can increase tight-junction proteins in NHEKs and enhance barrier function. Bifidobacteria and lactobacilli may be used as prophylactic or therapeutic agents towards enteric pathogens, antibiotic-associated diarrhea, lactose intolerance, ulcerative colitis, irritable bowel syndrome, colorectal cancer, cholesterol reduction, and control of obesity and metabolic disorders. Bifidobacterium bifidum showed an in vitro capability of lowering cholesterol levels thanks to its absorption into the bacterial membrane. Several strains of the species Lactobacillus acidophilus, L. delbrueckii subsp. bulgaricus, L. casei, and L. gasseri led to a reduced amount of serum cholesterol due to their ability to assimilate cholesterol (in vitro). Lactococcus lactis KF147 and Lactobacillus plantarum Lp81 have also been shown to reduce cholesterol levels by 12%. Clarifying the specific health mechanisms of Bifidobacterium and Lactobacillus strains in preventing high-cost pathologies could be useful for delineating effective guidelines for the treatment of infants and adults.

Multi-Strain Probiotics: Synergy among Isolates Enhances Biological Activities

The use of probiotics for health benefits is becoming popular because of the quest for safer products with protective and therapeutic effects against diseases and infectious agents. The emergence and spread of antimicrobial resistance among pathogens had prompted restrictions over the non-therapeutic use of antibiotics for prophylaxis and growth promotion, especially in animal husbandry. While single-strain probiotics are beneficial to health, multi-strain probiotics might be more helpful because of synergy and additive effects among the individual isolates. This article documents the mechanisms by which multi-strain probiotics exert their effects in managing infectious and non-infectious diseases, inhibiting antibiotic-resistant pathogens and health improvement. The administration of multi-strain probiotics was revealed to effectively alleviate bowel tract conditions, such as irritable bowel syndrome, inhibition of pathogens and modulation of the immune system and gut microbiota. Finally, while most of the current research focuses on comparing the effects of multi-strain and single-strain probiotics, there is a dearth of information on the molecular mechanisms of synergy among multi-strain probiotics isolates. This forms a basis for future research in the development of multi-strain probiotics for enhanced health benefits.

Effects of therapeutic probiotics on modulation of microRNAs

Probiotics are beneficial bacteria that exist within the human gut, and which are also present in different food products and supplements. They have been investigated for some decades, due to their potential beneficial impact on human health. Probiotics compete with pathogenic microorganisms for adhesion sites within the gut, to antagonize them or to regulate the host immune response resulting in preventive and therapeutic effects. Therefore, dysbiosis, defined as an impairment in the gut microbiota, could play a role in various pathological conditions, such as lactose intolerance, gastrointestinal and urogenital infections, various cancers, cystic fibrosis, allergies, inflammatory bowel disease, and can also be caused by antibiotic side effects. MicroRNAs (miRNAs) are short non-coding RNAs that can regulate gene expression in a post-transcriptional manner. miRNAs are biochemical biomarkers that play an important role in almost all cellular signaling pathways in many healthy and disease states. For the first time, the present review summarizes current evidence suggesting that the beneficial properties of probiotics could be explained based on the pivotal role of miRNAs.

Probiotics and Gut Health in Athletes

PURPOSE OF REVIEW

To provide a focused analysis of the challenges to gut health in athletes and examine recent research aimed at determining the impact of probiotics on preventing gastrointestinal (GI) symptoms and loss of barrier function in athletes.

RECENT FINDINGS

Frequency and severity of GI symptoms during training or competition were reduced by approximately one-third in studies demonstrating efficacy. Improvement of GI symptoms with probiotic supplementation was measured in both single-strain Lactobacillus and multi-strain Lactobacillus and Bifidobacterim probiotics, while improvement in gut barrier function was only measured for multi-strain probiotics. Likelihood of efficacy increased with duration of supplementation. The greatest efficacy for reducing GI symptom frequency and severity, as well as improving or preserving gut barrier function during exercise training and competition, appears to be for multi-strain Lactobacillus and Bifidobacterium probiotic cocktails supplemented for at least 11 weeks.

Allergy Prevention: An Overview of Current Evidence

Background: There has been a rapid rise in allergic disorders across the globe. This has increased research into the determinants of allergy development, to identify factors that may be manipulated to mitigate risk. An opportune window in immunological development appears to exist in early life whereby certain exposures may promote or prevent the development of an allergic disposition. Furthermore, factors that affect the composition and diversity of the microbiome in early life have been explored. In this review, we discuss current literature and recommendations relating to exposures that may prevent allergy development or promote tolerance. Risk factors and recommendations: Delivery by caesarean section, omission of breastfeeding, vitamin D insufficiency, and environmental exposures, such as cigarette smoke exposure, all increase the risk of an allergic predisposition. Dietary diversity during pregnancy, lactation, and in infancy is protective. Breastfeeding for at least 4 months reduces the risk of eczema. Recommendations for food-allergen exposure has shifted from delayed introduction to early introduction as a tolerance-inducing strategy. Supplements such as probiotics and vitamins during pregnancy and infancy have yet to produce conclusive results for allergy prevention. Emollient use in infancy has not been shown to be protective against eczema or food allergy.

Microbiome and Graves' Orbitopathy

BACKGROUND

Studies from animal models of autoimmunity have highlighted the potential importance of microorganisms and their metabolic products in shaping the immune system.

SUMMARY

This review provides an introduction to the current state-of-the-art in microbiome research both from the perspective of "what is known" and of methodologies for its investigation. It then summarises the evidence for a role for the microbiome in the pathogenesis of Graves' disease and Graves' orbitopathy with reference to animal models and studies in human cohorts, from both published and ongoing sources.

KEY MESSAGE

Microbiome research is in its infancy but has already provided novel insights into disease pathogenesis across the spectrum from cancer to mental health and autoimmunity.

The Role of Probiotics in the Prevention and Treatment of Atopic Dermatitis in Children: An Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease common among infants and children. It is associated with a high risk of allergies, asthma, and mental health problems. Attempts have been made to use probiotics in clinical interventions for AD.

OBJECTIVE

Our objective was to perform an updated meta-analysis of recently published studies to evaluate the effect of probiotics in the prevention and treatment of AD in children and to further understand the role of probiotics in AD interventions in the clinic.

METHOD

We searched the PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, and Wanfang databases with prespecified selection criteria from inception of each database to 11 January 2020. No language restrictions were applied.

RESULTS

A total of 25 studies were included in our meta-analysis. Of these, 14 were prevention studies (with 3049 children enrolled) and 11 were treatment studies (with 816 children enrolled). One treatment study was excluded after the sensitivity analysis. From the 14 prevention studies included, the pooled relative risk ratio of AD in those treated with probiotics versus placebo was 0.70 [95% confidence interval (CI) 0.57-0.84; P = 0.0002]. Subgroup analyses showed that only mixed strains of probiotics had a significant effect on lowering the incidence of AD. Probiotics administered solely to infants did not prevent the development of AD, but effects were significant when probiotics were administered to both pregnant mothers and their infants or solely to pregnant mothers. In studies with treatment durations > 6 months, the incidence of AD decreased significantly; a similar effect was achieved when the treatment duration was < 6 months. Meta-analysis of the ten treatment studies showed a significant decrease in the weighted mean difference (WMD) in Scoring Atopic Dermatitis (SCORAD) index values in the probiotics group compared with the control group (WMD, - 7.23; 95% CI - 10.59 to - 3.88; P < 0.0001). Subgroup analyses showed that both single-strain and mixed-strain probiotics had a significant effect on improving SCORAD values. Studies with participants aged < 1 year (P = 0.07) reported no significant results. In studies with treatment periods > 8 weeks, SCORAD values seemed to decrease more than in studies with treatment periods < 8 weeks. However, the subgroup difference was only statistically significant when the analysis was performed according to participant age in prevention studies.

CONCLUSION

Our updated meta-analysis demonstrates that interventions with probiotics potentially lower the incidence of AD and relieve AD symptoms in children, particularly when treating infants and children aged ≥ 1 year with AD. Interventions with mixed-strain probiotics tended to have better preventive and curative effects. Probiotics administered solely to infants appeared to produce negative preventive effects. Different intervention durations might also affect clinical outcomes. However, given the insignificant subgroup differences, except for treatment by participant age, and the moderate heterogeneity among the studies, these conclusions should be interpreted with caution, and more powerful randomized controlled trials using standardized measurements should be conducted to assess the long-term effects of probiotics.

Probiotic Supplementation During the Perinatal and Infant Period: Effects on Gut Dysbiosis and Disease

The perinatal period is crucial to the establishment of lifelong gut microbiota. The abundance and composition of microbiota can be altered by several factors such as preterm delivery, formula feeding, infections, antibiotic treatment, and lifestyle during pregnancy. Gut dysbiosis affects the development of innate and adaptive immune responses and resistance to pathogens, promoting atopic diseases, food sensitization, and infections such as necrotizing enterocolitis (NEC). Recent studies have indicated that the gut microbiota imbalance can be restored after a single or multi-strain probiotic supplementation, especially mixtures of Lactobacillus and Bifidobacterium strains. Following the systematic search methodology, the current review addresses the importance of probiotics as a preventive or therapeutic tool for dysbiosis produced during the perinatal and infant period. We also discuss the safety of the use of probiotics in pregnant women, preterm neonates, or infants for the treatment of atopic diseases and infections.

Immune modulatory capacity of probiotic lactic acid bacteria and applications in vaccine development

Vaccination is one of the most important prevention tools providing protection against infectious diseases especially in children below the age of five. According to estimates, more than 5 million lives are saved annually by the implementation of six standard vaccines, including diphtheria, hepatitis B, Haemophilus influenza type b, polio, tetanus and yellow fever. Despite these efforts, we are faced with challenges in developing countries where increasing population and increasing disease burden and difficulties in vaccine coverage and delivery cause significant morbidity and mortality. Additionally, the high cost of these vaccines is also one of the causes for inappropriate and inadequate vaccinations in these regions. Thus, developing cost-effective vaccine strategies that could provide a stronger immune response with reduced vaccination schedules and maximum coverage is of critical importance. In last decade, different approaches have been investigated; among which live bacterial vaccines have been the focus of attention. In this regard, probiotic lactic acid bacteria have been extensively studied as safe and effective vaccine candidates. These microorganisms represent the largest group of probiotic bacteria in the intestine and are generally recognised as safe (GRAS) bacteria. They have also attracted attention due to their immunomodulatory actions and their effective role as novel vaccine adjuvants. A significant property of these bacteria is their ability to mimic natural infections, while intrinsically possessing mucosal adjuvant properties. Additionally, as live bacterial vaccines are administered orally or nasally, they have higher acceptance and better safety, but also avoid the risk of contamination due to needles and syringes. In this review, we emphasise the role of probiotic Lactobacillus strains as putative oral vaccine carriers and novel vaccine adjuvants.

Supporting a Healthy Microbiome for the Primary Prevention of Eczema

Eczema is increasing worldwide with associated increases in health costs and decreases in quality of life. There are many factors that are speculated to interact in the development of eczema including genetics and environmental exposures. Prevention of the development of eczema may prevent the further development of food allergies and asthma. This concept has prompted a variety of research into the area of primary prevention of eczema in infants. This exploration includes a growing body of research examining infants supplemented with probiotics, prebiotics, or both (synbiotics) often compared with their breastfed counterparts. The goal of this paper is to examine the evidence for manipulating the microbiome in the prevention of eczema. Several strains of probiotics, compositions of prebiotics, and varied combinations of both are commercially available. Evidence supports altering the microbiome in infants at high risk of atopy who are not able to breastfeed with Lactobacillus strains when given both prenatally followed by prolonged use (greater than 6 months) postnatally for the primary prevention of eczema. Prebiotics have also been shown beneficial for primary prevention of eczema in formula-fed infants with prolonged use greater than 6 months. These findings are in keeping with the World Allergy Organization (WAO) recommendations that support interventions to manipulate the microbiome with both probiotics and prebiotics.

Postnatal probiotics and allergic disease in very preterm infants: Sub-study to the ProPrems randomized trial

BACKGROUND

Probiotic supplementation to mothers and/or their term-born infants has been suggested to prevent allergic disease, in particular eczema; however, no studies have investigated probiotics for prevention of allergic diseases in very preterm infants. We evaluated the effect of a postnatal probiotic combination on development of allergic diseases in very preterm infants.

METHODS

This sub-study was an a priori secondary outcome of the ProPrems multi-center, double-blind, placebo-controlled randomized trial (ANZCTR:12607000144415). ProPrems randomized 1099 very preterm infants to receive a probiotic combination or placebo from soon after birth until discharge from hospital or term corrected age (CA), whichever was earlier. Allergic disease (eczema, atopic eczema, food allergy, wheeze, atopic sensitization) was assessed in a subgroup of ProPrems infants (n = 281) as close to 12 months CA as possible by questionnaire, clinical examination, and skin prick tests to common allergens.

RESULTS

There was no difference in eczema incidence between the probiotic and placebo groups (35[30%] of 118 infants vs 37[27%] of 137 infants, respectively, absolute difference 2.65%, 95% CI -8.45 to 13.75). Similarly, the incidence of atopic eczema (6[5%] of 118 vs 3[2%] of 137), food allergy (4[3%] of 124 vs 2[1%] of 154), wheeze (39[31%] of 127 vs 45[29%] of 154), and atopic sensitization (14[13%] of 106 vs 13[11%] of 123) were similar between the probiotic and placebo groups.

CONCLUSION

This study found no effect of postnatal administration of a probiotic combination on the incidence of allergic diseases or atopic sensitization in the first 2 years of life in children born very preterm. Evidence that probiotics are effective for prevention of allergic disease in premature infants remains lacking; adequately powered randomized controlled trials evaluating probiotic supplementation for allergy prevention in very preterm infants are needed.

The Role of Prebiotics and Probiotics in Prevention of Allergic Diseases in Infants

Allergic diseases have been linked to genetic and/or environmental factors, such as antibiotic use, westernized high fat and low fiber diet, which lead to early intestinal dysbiosis, and account for the rise in allergy prevalence, especially in western countries. Allergic diseases have shown reduced microbial diversity, including fewer lactobacilli and bifidobacteria, within the neonatal microbiota, before the onset of atopic diseases. Raised interest in microbiota manipulating strategies to restore the microbial balance for atopic disease prevention, through prebiotics, probiotics, or synbiotics supplementation, has been reported. We reviewed and discussed the role of prebiotics and/or probiotics supplementation for allergy prevention in infants. We searched PubMed and the Cochrane Database using keywords relating to "allergy" OR "allergic disorders," "prevention" AND "prebiotics" OR "probiotics" OR "synbiotics." We limited our evaluation to papers of English language including children aged 0-2 years old. Different products or strains used, different period of intervention, duration of supplementation, has hampered the draw of definitive conclusions on the clinical impact of probiotics and/or prebiotics for prevention of allergic diseases in infants, except for atopic dermatitis in infants at high-risk. This preventive effect on eczema in high-risk infants is supported by clear evidence for probiotics but only moderate evidence for prebiotic supplementation. However, the optimal prebiotic or strain of probiotic, dose, duration, and timing of intervention remains uncertain. Particularly, a combined pre- and post-natal intervention appeared of stronger benefit, although the definition of the optimal intervention starting time during gestation, the timing, and duration in the post-natal period, as well as the best target population, are still an unmet need.

Early Probiotic Supplementation and the Risk of Celiac Disease in Children at Genetic Risk

Probiotics are linked to positive regulatory effects on the immune system. The aim of the study was to examine the association between the exposure of probiotics via dietary supplements or via infant formula by the age of 1 year and the development of celiac disease autoimmunity (CDA) and celiac disease among a cohort of 6520 genetically susceptible children. Use of probiotics during the first year of life was reported by 1460 children. Time-to-event analysis was used to examine the associations. Overall exposure of probiotics during the first year of life was not associated with either CDA (n = 1212) (HR 1.15; 95%CI 0.99, 1.35; p = 0.07) or celiac disease (n = 455) (HR 1.11; 95%CI 0.86, 1.43; p = 0.43) when adjusting for known risk factors. Intake of probiotic dietary supplements, however, was associated with a slightly increased risk of CDA (HR 1.18; 95%CI 1.00, 1.40; p = 0.043) compared to children who did not get probiotics. It was concluded that the overall exposure of probiotics during the first year of life was not associated with CDA or celiac disease in children at genetic risk.

Probiotic Supplementation for Prevention of Atopic Dermatitis in Infants and Children: A Systematic Review and Meta-analysis

BACKGROUND

Probiotic supplementation in early life may be effective in preventing atopic dermatitis (AD); however, results regarding efficacy have been controversial.

OBJECTIVE

The aim of our study was to investigate the effect of probiotic supplementation on the risk of AD.

METHODS

We systematically searched PubMed, EBSCO, Embase and Web of Science databases up to 8 March 2018 for potentially relevant studies regarding probiotic supplementation and AD. Included infants and children were those with probiotic exposure in utero and/or after birth who were not previously diagnosed with AD. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) and used the Jadad and Newcastle-Ottawa scales to assess methodologic quality.

RESULTS

A total of 28 studies met the inclusion criteria. Compared with controls, probiotic treatment was associated with a reduced risk of AD (OR 0.69; 95% CI 0.58-0.82, P < 0.0001). The use of probiotics during both the prenatal and the postnatal period significantly reduced the incidence of AD (OR 0.67; 95% CI 0.54-0.82); however, analysis of studies of probiotics given prenatally only or postnatally only did not reach statistical significance.

CONCLUSIONS

Our meta-analysis showed that probiotic supplementation during both the prenatal and the postnatal period reduced the incidence of AD in infants and children. Our findings suggest that starting probiotic treatment during gestation and continuing through the first 6 months of the infant's life may be of benefit in the prevention of AD.

In vitro neuroprotective activities of two distinct probiotic consortia

Neurodegeneration has been linked to changes in the gut microbiota and this study compares the neuroprotective capability of two bacterial consortia, known as Lab4 and Lab4b, using the established SH-SY5Y neuronal cell model. Firstly, varying total antioxidant capacities (TAC) were identified in the intact cells from each consortia and their secreted metabolites, referred to as conditioned media (CM). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Crystal Violet (CV) assays of cell viability revealed that Lab4 CM and Lab4b CM could induce similar levels of proliferation in SH-SY5Y cells and, despite divergent TAC, possessed a comparable ability to protect undifferentiated and retinoic acid-differentiated cells from the cytotoxic actions of rotenone and undifferentiated cells from the cytotoxic actions of 1-methyl-4-phenylpyridinium iodide (MPP+). Lab4 CM and Lab4b CM also had the ability to attenuate rotenone-induced apoptosis and necrosis with Lab4b inducing the greater effect. Both consortia showed an analogous ability to attenuate intracellular reactive oxygen species accumulation in SH-SY5Y cells although the differential upregulation of genes encoding glutathione reductase and superoxide dismutase by Lab4 CM and Lab4b CM, respectively, implicates the involvement of consortia-specific antioxidative mechanisms of action. This study implicates Lab4 and Lab4b as potential neuroprotective agents and justifies their inclusion in further in vivo studies.

Mapping the microbial interactome: Statistical and experimental approaches for microbiome network inference

IMPACT STATEMENT

This review provides a comprehensive description of experimental and statistical tools used for network analyses of the human gut microbiome. Understanding the system dynamics of microbial interactions may lead to the improvement of therapeutic approaches for managing microbiome-associated diseases. Microbiome network inference tools have been developed and applied to both cross-sectional and longitudinal experimental designs, as well as to multi-omic datasets, with the goal of untangling the complex web of microbe-host, microbe-environmental, and metabolism-mediated microbial interactions. The characterization of these interaction networks may lead to a better understanding of the systems dynamics of the human gut microbiome, augmenting our knowledge of the microbiome's role in human health, and guiding the optimization of effective, precise, and rational therapeutic strategies for managing microbiome-associated disease.

Use of probiotics in atopic dermatitis

OBJECTIVE

Atopic dermatitis is a common skin disease. Its increased incidence has changed the focus of research on atopic dermatitis toward epidemiology, prevention, and treatment.

METHODS

Evidence suggests that intestinal microbiota plays an important role in the pathogenesis of atopic dermatitis inducing immunosuppression, but its exact mechanism is still unclear. Probiotics have been widely reported to act on the immune system. They are living microorganisms with immunomodulatory effects that stimulate Th1 cytokines and suppress the Th2 response, which are being researched for the treatment of several diseases. Probiotics most commonly used are part of the intestinal microflora like lactobacilli, bifidobacteria, and enterococci.

RESULTS

We describe here a case of evident response to the use of probiotics in a girl with severe atopic dermatitis, with a significant change in severity scores of atopic dermatitis (BSA/SCORAD/FDLQI).

CONCLUSIONS

Modulation of the intestinal microbiota with probiotics may offer a way to prevent or treat allergic diseases, including atopic dermatitis.

Cream Cheese-Derived Lactococcus chungangensis CAU 28 Modulates the Gut Microbiota and Alleviates Atopic Dermatitis in BALB/c Mice

Atopic dermatitis (AD) has a drastic impact on human health owing to complex skin, gut microbiota, and immune responses. Some lactic acid bacteria (LAB) are effective in ameliorating AD; however, the alleviative effects of dairy products derived from these LAB remain unclear. In this study, the efficacies of Lactococcus chungangensis CAU 28 (CAU 28) cream cheese and L. chungangensis CAU 28 dry cells were evaluated for treating AD in an AD mouse model. Overall, CAU 28 cream cheese administration was more effective against AD than L. chungangensis CAU 28 dry cells. Faeces from CAU 28 cream cheese-administered mice had increased short chain fatty acid, butyrate, acetate, and lactic acid levels, as well as butyrate-producing bacteria, including Akkermansia, Bacteroides, Lactobacillus, and Ruminococcus. Furthermore, oral CAU 28 cream cheese administration resulted in regulatory T cell (Treg)-mediated suppression of T helper type 2 (Th2) immune responses in serum and mRNA expression levels in the ileum. Oral CAU 28 cream cheese further reduced IgE levels, in addition to eosinophil and mast cell numbers. Therefore, CAU 28 cream cheese administration induced a coordinated immune response involving short-chain fatty acids and gut microbiota, indicating its potential for use as a supplement for AD mitigation.

[Effect of probiotic supplementation during pregnancy and infancy in preventing atopic dermatitis in children: a Meta analysis]

OBJECTIVE

To systematically review the effect of probiotic supplementation during pregnancy and infancy in preventing atopic dermatitis in children.

METHODS

RevMan5.3 was used to perform a Meta analysis of randomized controlled trials on the effect of probiotic supplementation during pregnancy and infancy in preventing atopic dermatitis in children published between January 2008 and May 2018 across the world. A subgroup analysis was conducted according to the type of probiotics for intervention, follow-up time, time of probiotic supplementation, and study areas.

RESULTS

A total of 22 articles were selected, with 3 280 cases in the intervention group and 3 281 cases in the control group. The results of pooled effect size showed that probiotic supplementation during pregnancy and/or infancy significantly reduced the incidence rate of atopic dermatitis (RR=0.81, 95%CI: 0.70-0.93, P<0.05). According to the subgroup analysis, the intervention with Lactobacillus and Bifidobacterium had a significant effect (RR=0.68, 95%CI: 0.52-0.90, P<0.05); probiotic supplementation during both pregnancy and infancy also had a significant effect (RR=0.77, 95%CI: 0.66-0.90, P<0.05); probiotic supplementation during pregnancy and/or infancy had a better effect in preventing atopic dermatitis in children aged ≤2 years than in those aged >2 years (RR=0.74, 95%CI: 0.61-0.90, P<0.05); probiotic supplementation had a significant effect in Australia (RR=0.83, 95%CI: 0.73-0.96, P<0.05) and Europe/the United States (RR=0.74, 95%CI: 0.61-0.91, P<0.05). Heterogeneity was mainly due to follow-up time (I²=62.7%) and time of probiotic supplementation (I²=53.5%).

CONCLUSIONS

Probiotic supplementation during pregnancy and infancy helps to prevent atopic dermatitis in children, and mixed Lactobacillus-Bifidobacterium intervention has a better effect.

[Effect of probiotic supplementation during pregnancy and infancy in preventing atopic dermatitis in children: a Meta analysis]

OBJECTIVE

To systematically review the effect of probiotic supplementation during pregnancy and infancy in preventing atopic dermatitis in children.

METHODS

RevMan5.3 was used to perform a Meta analysis of randomized controlled trials on the effect of probiotic supplementation during pregnancy and infancy in preventing atopic dermatitis in children published between January 2008 and May 2018 across the world. A subgroup analysis was conducted according to the type of probiotics for intervention, follow-up time, time of probiotic supplementation, and study areas.

RESULTS

A total of 22 articles were selected, with 3 280 cases in the intervention group and 3 281 cases in the control group. The results of pooled effect size showed that probiotic supplementation during pregnancy and/or infancy significantly reduced the incidence rate of atopic dermatitis (RR=0.81, 95%CI: 0.70-0.93, P<0.05). According to the subgroup analysis, the intervention with Lactobacillus and Bifidobacterium had a significant effect (RR=0.68, 95%CI: 0.52-0.90, P<0.05); probiotic supplementation during both pregnancy and infancy also had a significant effect (RR=0.77, 95%CI: 0.66-0.90, P<0.05); probiotic supplementation during pregnancy and/or infancy had a better effect in preventing atopic dermatitis in children aged ≤2 years than in those aged >2 years (RR=0.74, 95%CI: 0.61-0.90, P<0.05); probiotic supplementation had a significant effect in Australia (RR=0.83, 95%CI: 0.73-0.96, P<0.05) and Europe/the United States (RR=0.74, 95%CI: 0.61-0.91, P<0.05). Heterogeneity was mainly due to follow-up time (I2=62.7%) and time of probiotic supplementation (I2=53.5%).

CONCLUSIONS

Probiotic supplementation during pregnancy and infancy helps to prevent atopic dermatitis in children, and mixed Lactobacillus-Bifidobacterium intervention has a better effect.

Guidance on the use of probiotics in clinical practice in children with selected clinical conditions and in specific vulnerable groups

AIM

The use of probiotics has been covered by many guidelines, position papers and evidence-based recommendations, but few have referred to specific patient groups or clinical indications. This review summarises recommendations and scientifically credited guidelines on the use of probiotics for children with selected clinical conditions and provides practice points.

METHODS

An expert panel was convened by the European Paediatric Association in June 2017 to define the relevant clinical questions for using probiotics in paediatric health care and review and summarise the guidelines, recommendations, position papers and high-quality evidence.

RESULTS

The panel found that specific probiotic strains were effective in preventing antibiotic-associated and nosocomial diarrhoea, treating acute gastroenteritis and treating infantile colic in breastfed infants. However, special caution is indicated for premature infants, immunocompromised and critically ill patients and those with central venous catheters, cardiac valvular disease and short-gut syndrome. This review discusses the safety of using probiotics in selected groups of paediatric patients and the quality of the available products providing practice points based on proved findings.

CONCLUSION

Efficacy of probiotics is strain specific. Their benefits are currently scientifically proven for their use in selected clinical conditions in children and not recommended for certain patient groups.

Long term extension of a randomised controlled trial of probiotics using electronic health records

Most randomised controlled trials (RCTs) are relatively short term and, due to costs and available resources, have limited opportunity to be re-visited or extended. There is no guarantee that effects of treatments remain unchanged beyond the study. Here, we illustrate the feasibility, benefits and cost-effectiveness of enriching standard trial design with electronic follow up. We completed a 5-year electronic follow up of a RCT investigating the impact of probiotics on asthma and eczema in children born 2005–2007, with traditional fieldwork follow up to two years. Participants and trial outcomes were identified and analysed after five years using secure, routine, anonymised, person-based electronic health service databanks. At two years, we identified 93% of participants and compared fieldwork with electronic health records, highlighting areas of agreement and disagreement. Retention of children from lower socio-economic groups was improved, reducing volunteer bias. At 5 years we identified a reduced 82% of participants. These data allowed the trial’s first robust analysis of asthma endpoints. We found no indication that probiotic supplementation to pregnant mothers and infants protected against asthma or eczema at 5 years. Continued longer-term follow up is technically straightforward.

The nutrition-gut microbiome-physiology axis and allergic diseases

Dietary and bacterial metabolites influence immune responses. This raises the question whether the increased incidence of allergies, asthma, some autoimmune diseases, cardiovascular disease, and others might relate to intake of unhealthy foods, and the decreased intake of dietary fiber. In recent years, new knowledge on the molecular mechanisms underpinning a 'diet-gut microbiota-physiology axis' has emerged to substantiate this idea. Fiber is fermented to short chain fatty acids (SCFAs), particularly acetate, butyrate, and propionate. These metabolites bind 'metabolite-sensing' G-protein-coupled receptors such as GPR43, GPR41, and GPR109A. These receptors play fundamental roles in the promotion of gut homeostasis and the regulation of inflammatory responses. For instance, these receptors and their metabolites influence Treg biology, epithelial integrity, gut homeostasis, DC biology, and IgA antibody responses. The SCFAs also influence gene transcription in many cells and tissues, through their inhibition of histone deacetylase expression or function. Contained in this mix is the gut microbiome, as commensal bacteria in the gut have the necessary enzymes to digest dietary fiber to SCFAs, and dysbiosis in the gut may affect the production of SCFAs and their distribution to tissues throughout the body. SCFAs can epigenetically modify DNA, and so may be one mechanism to account for diseases with a 'developmental origin', whereby in utero or post-natal exposure to environmental factors (such as nutrition of the mother) may account for disease later in life. If the nutrition-gut microbiome-physiology axis does underpin at least some of the Western lifestyle influence on asthma and allergies, then there is tremendous scope to correct this with healthy foodstuffs, probiotics, and prebiotics.

Lactobacillus salivarius LA307 and Lactobacillus rhamnosus LA305 attenuate skin inflammation in mice

Oral probiotics potential for the management of dermatological diseases is vast. However, results of available studies in skin diseases, such as atopic dermatitis (AD), are inconsistent, partly because probiotic effects are strain specific. Careful selection of probiotic strains is therefore indispensable to ensure efficacy of treatment. In this study, Lactobacillus salivarius LA307, Lactobacillus rhamnosus LA305 and Bifidobacterium bifidum PI22, three strains that were previously identified for their interesting immunomodulatory properties in allergy and/or colitis models, were assessed in the prevention of chronic skin inflammation induced by repeated applications of 12-O-tetradecanoylphorbol-13-acetate in hairless SKH-1 mice. Macroscopic and microscopic evaluation of skin lesions was performed together with measurements of serum levels of interleukin (IL)-1β, IL-6, tumour necrosis factor alpha (TNF-α), IL-17, IL-22, IL-10 and IL-4. Daily oral treatment with the three strains at the dose of 1×109 cfu/day for 3 weeks limited the development of chronic skin inflammation, the effects being strain dependent. Indeed the two Lactobacillus strains significantly limited the intensity of skin inflammation both at the macroscopic and microscopic levels. Macroscopic observations were correlated to the histological observations and the resulting microscopic score. This limitation of the development of AD-like skin lesions involved the modulation of cytokine production. Treatment with the two Lactobacillus strains induced a decrease in the serum levels of pro-inflammatory cytokines IL-1β, IL-6, TNF-α, IL-17, IL-22 and at the opposite an increase in the production of the anti-inflammatory cytokine IL-10 and also of IL-4. Globally, B. bifidum PI22 had lower benefits. These results obtained in mice suggest that L. salivarius LA307 and L. rhamnosus LA305 could be good candidates for preserving skin integrity and homeostasis via the modulation of the gut microbiota and that their use could be beneficial in dermatological conditions such as AD.

Pre- and probiotics for allergy prevention: time to revisit recommendations?

Reduced intensity and diversity of microbial exposure is considered a major factor driving abnormal postnatal immune maturation and increasing allergy prevalence, particularly in more affluent regions. Quantitatively, the largest important source of early immune-microbial interaction, the gut microbiota, is of particular interest in this context, with variations in composition and diversity in the first months of life associated with subsequent allergy development. Attempting to restore the health consequences of the 'dysbiotic drift' in modern society, interventions modulating gut microbiota for allergy prevention have been evaluated in several randomized placebo-controlled trials. In this review, we provide an overview of these trials and discuss recommendations from international expert bodies regarding prebiotic, probiotic and synbiotic interventions. Recent guidelines from the World Allergy Organization recommend the use of probiotics for the primary prevention of eczema in pregnant and breastfeeding mothers of infants at high risk for developing allergy and in high-risk infants. It is however stressed that these recommendations are conditional, based on very low-quality evidence and great heterogeneity between studies, which also impedes specific and practical advice to consumers on the most effective regimens. We discuss how the choice of probiotic strains, timing and duration of administration can critically influence the outcome due to different effects on immune modulation and gut microbiota composition. Furthermore, we propose strategies to potentially improve allergy-preventive effects and enable future evidence-based implementation.

The mother-offspring dyad: microbial transmission, immune interactions and allergy development

The increasing prevalence of allergy in affluent countries may be caused by reduced intensity and diversity of microbial stimulation, resulting in abnormal postnatal immune maturation. Most studies investigating the underlying immunomodulatory mechanisms have focused on postnatal microbial exposure, for example demonstrating that the gut microbiota differs in composition and diversity during the first months of life in children who later do or do not develop allergic disease. However, it is also becoming increasingly evident that the maternal microbial environment during pregnancy is important in childhood immune programming, and the first microbial encounters may occur already in utero. During pregnancy, there is a close immunological interaction between the mother and her offspring, which provides important opportunities for the maternal microbial environment to influence the immune development of the child. In support of this theory, combined pre- and postnatal supplementations seem to be crucial for the preventive effect of probiotics on infant eczema. Here, the influence of microbial and immune interactions within the mother-offspring dyad on childhood allergy development will be discussed. In addition, how perinatal transmission of microbes and immunomodulatory factors from mother to offspring may shape appropriate immune maturation during infancy and beyond, potentially via epigenetic mechanisms, will be examined. Deeper understanding of these interactions between the maternal and offspring microbiome and immunity is needed to identify efficacious preventive measures to combat the allergy epidemic.