Bugs for atopy: the Lactobacillus rhamnosus GG strategy for food allergy prevention and treatment in children

Prebiotic Supplementation During Gestation Induces a Tolerogenic Environment and a Protective Microbiota in Offspring Mitigating Food Allergy

Food allergy is associated with alterations in the gut microbiota, epithelial barrier, and immune tolerance. These dysfunctions are observed within the first months of life, indicating that early intervention is crucial for disease prevention. Preventive nutritional strategies with prebiotics are an attractive option, as prebiotics such as galacto-oligosaccharides and inulin can promote tolerance, epithelial barrier reinforcement, and gut microbiota modulation. Nonetheless, the ideal period for intervention remains unknown. Here, we investigated whether galacto-oligosaccharide/inulin supplementation during gestation could protect offspring from wheat allergy development in BALB/cJRj mice. We demonstrated that gestational prebiotic supplementation promoted the presence of beneficial strains in the fecal microbiota of dams during gestation and partially during mid-lactation. This specific microbiota was transferred to their offspring and maintained to adulthood. The presence of B and T regulatory immune cell subsets was also increased in the lymph nodes of offspring born from supplemented mothers, suggestive of a more tolerogenic immune environment. Indeed, antenatal prebiotic supplementation reduced the development of wheat allergy symptoms in offspring. Our study thus demonstrates that prebiotic supplementation during pregnancy induces, in the offspring, a tolerogenic environment and a microbial imprint that mitigates food allergy development.

Maternal Influences and Intervention Strategies on the Development of Food Allergy in Offspring

Food allergies and other immune-mediated diseases have become serious health concerns amongst infants and children in developed and developing countries. The absence of available cures limits disease management to allergen avoidance and symptomatic treatments. Research has suggested that the presence of maternal food allergies may expose the offspring to genetic predisposition, making them more susceptible to allergen sensitization. The following review has focused on epidemiologic studies regarding maternal influences of proneness to develop food allergy in offspring. The search strategy was "food allergy OR maternal effects OR offspring OR prevention". A systematically search from PubMed/MEDLINE, Science Direct and Google Scholar was conducted. Specifically, it discussed the effects of maternal immunity, microbiota, breastfeeding, genotype and allergy exposure on the development of food allergy in offspring. In addition, several commonly utilized prenatal and postpartum strategies to reduce food allergy proneness were presented, including early diagnosis of high-risk infants and various dietary interventions.

Lactobacillus rhamnosus MP108: Toxicological evaluation

A lyophilized powder of Lactobacillus rhamnosus MP108, a strain isolated from infant feces, has been developed for potential as a probiotic. To assess safety, three genetic toxicity studies (Ames, in vivo mouse micronucleus, and in vivo mouse spermatocyte chromosome aberration assays) and one 90-day oral rat toxicity study were conducted. Lactobacillus rhamnosus MP108 had no activity in the Ames assay, with or without metabolic activation, up to the highest dose tested (5000 µg/plate). Also, no evidence of genotoxicity was observed in the two in vivo genotoxicity assays up to the maximum dose tested of 5.6 g/kg body weight. Feeding of L. rhamnosus MP108 to SD rats at doses of 0, 0.25, 0.5, or 1.5 g/kg body weight/day had no statistically or biologically significant effects on any of the parameters measured. An evaluation of Lactobacillus spp. generally, and L. rhamnosus specifically, showed no indication of concern for translocation or pathogenicity. The results of the toxicology studies showed no indications for safety concerns. PRACTICAL APPLICATION: Lactobacillus rhamnosus MP108 is a bacterium that shows potential as a probiotic. While this bacterium has been used in food and food production, a series of studies were conducted to provide further assurance that this particular strain of L. rhamnosus is safe.

Lactobacillus rhamnosus GG alleviates β-conglycinin-induced allergy by regulating the T cell receptor signaling pathway

Currently, the need for safe and effective methods for relieving allergies is an important concern. In this study, we evaluated the role of Lactobacillus rhamnosus GG (LGG) in alleviating β-conglycinin (β-CG)-induced allergies and elucidated the related molecular mechanisms. Typical allergy symptoms and inflammatory factors in the serum showed that LGG intervention effectively alleviated β-CG induced allergy in mice, which was better than natural recovery (NR). Intestinal villi were restored and lower levels of CD4+ T cells infiltrated after LGG intervention. We evaluated whether LGG intervention weakened the proliferation ability of the spleen cells of allergic mice, balancing between T/B cells and Th1/Th2 and Th17/Treg cytokines. Transcriptome analysis revealed that 4106 differentially expressed mRNAs were identified by comparing the LGG group and β-CG group, and 546 differentially expressed mRNAs were identified by comparing the LGG group and NR group. KEGG pathway analysis identified that the T cell receptor (TCR) signaling pathway was significantly enriched upon LGG intervention, and the upregulated Ifnar2 and the downregulated Tgfbr2, Il13r2 and Il4ra were further validated by qPCR analysis. Therefore, the above results fully revealed the important role of LGG in alleviating β-CG-induced allergies.

Administration of Extensive Hydrolysates From Caseins and Lactobacillus rhamnosus GG Probiotic Does Not Prevent Cow's Milk Proteins Allergy in a Mouse Model

Background

Early nutrition may influence the development of food allergies later in life. In the absence of breastfeeding, hydrolysates from cow’s milk proteins (CMP) were indicated as a prevention strategy in at risk infants, but their proof of effectiveness in clinical and pre-clinical studies is still insufficient. Thanks to a validated mouse model, we then assessed specific and nonspecific preventive effects of administration of extensive hydrolysates from caseins (eHC) on the development of food allergy to CMP. The additional nonspecific effect of the probiotic Lactobacillus GG (LGG), commonly used in infant formula, was also assessed.

Methods

Groups of young BALB/cByJ female mice were pretreated by repeated gavage either with PBS (control mice), or with PBS solution containing non-hydrolyzed milk protein isolate (MPI), eHC or eHC+LGG (eq. of 10 mg of protein/gavage). All mice were then experimentally sensitized to CMP by gavage with whole CM mixed with the Th2 mucosal adjuvant Cholera toxin. All mice were further chronically exposed to cow’s milk. A group of mice was kept naïve. Sensitization to both caseins and to the non-related whey protein β-lactoglobulin (BLG) was evaluated by measuring specific antibodies in plasma and specific ex vivo Th2/Th1/Th17 cytokine secretion. Elicitation of the allergic reaction was assessed by measuring mMCP1 in plasma obtained after oral food challenge (OFC) with CMP. Th/Treg cell frequencies in gut-associated lymphoid tissue and spleen were analyzed by flow cytometry at the end of the protocol. Robust statistical procedure combining non-supervised and supervised multivariate analyses and univariate analyses, was conducted to reveal any effect of the pretreatments.

Results

PBS pretreated mice were efficiently sensitized and demonstrated elicitation of allergic reaction after OFC, whereas mice pretreated with MPI were durably protected from allergy to CMP. eHC+/-LGG pretreatments had no protective effect on sensitization to casein (specific) or BLG (non-specific), nor on CMP-induced allergic reactions. Surprisingly, eHC+LGG mice demonstrated significantly enhanced humoral and cellular immune responses after sensitization with CMP. Only some subtle changes were evidenced by flow cytometry.

Conclusion

Neither specific nor nonspecific preventive effects of administration of casein-derived peptides on the development of CMP food allergy were evidenced in our experimental setup. Further studies should be conducted to delineate the mechanisms involved in the immunostimulatory potential of LGG and to clarify its significance in clinical use.

Antibiotic-induced dysbiosis of the rat oral and gut microbiota and resistance to Salmonella

OBJECTIVES

Antibiotics play a great role in the treatment of infectious diseases, but meantime, they cause great disturbances to host microbiota. Studies on different antibiotic-induced changes in host microbiota are relatively scarce. This study aimed to investigate the changes in oral and gut microbiota and possible alterations of gut resistance to Salmonella induced by the administration of antibiotics.

METHODS

The experiment was conducted by administering antibiotics to rats and detecting oral and gut microbiota by 16S rRNA gene sequencing. In second part, after treating with antibiotics or Lactobacillus rhamnosus the rats were infected by Salmonella Typhimurium and the pathogen burden in the gut was counted by colony forming unit assay.

RESULTS

The gut microbiota underwent dramatic changes after both vancomycin and ampicillin treatment. The alpha diversity sharply decreased, and the microbiota composition showed a significant difference. However, the gut microbiota recovered within four weeks after stopping antibiotics administration, although this recovery was incomplete. Oral microbiota did not show significant alterations in both alpha and beta diversities. The number of pathogens in the gut in the control group was significantly lower than that in the antibiotic-treated group but only lasted for the first 4 days after infection.

CONCLUSIONS

Antibiotics cause dramatic alterations in the number and diversity of gut microbiota but not oral microbiota. These changes in the gut microbiota could incompletely recover four weeks later. When infected with pathogens after antibiotic administration, the rats show a decrease in colonization resistance in the gut for the first four days after infection.

Biotherapeutic Approaches in Atopic Dermatitis

The skin microbiome plays a central role in inflammatory skin disorders such as atopic dermatitis (AD). In AD patients, an imbalance between pathogenic Staphylococcus aureus (S. aureus) and resident skin symbionts creates a state of dysbiosis which induces immune dysregulation and impairs skin barrier function. There are now exciting new prospects for microbiome-based interventions for AD prevention. In the hopes of achieving sustained control and management of disease in AD patients, current emerging biotherapeutic strategies aim to harness the skin microbiome associated with health by restoring a more diverse symbiotic skin microbiome, while selectively removing pathogenic S. aureus. Examples of such strategies are demonstrated in skin microbiome transplants, phage-derived anti-S. aureus endolysins, monoclonal antibodies, and quorum sensing (QS) inhibitors. However, further understanding of the skin microbiome and its role in AD pathogenesis is still needed to understand how these biotherapeutics alter the dynamics of the microbiome community; to optimize patient selection, drug delivery, and treatment duration; overcome rapid recolonization upon treatment cessation; and improve efficacy to allow these therapeutic options to eventually reach routine clinical practice.

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.

Phytase-Producing Potential and Other Functional Attributes of Lactic Acid Bacteria Isolates for Prospective Probiotic Applications

Wide variations among multifaceted-health benefitting attributes of probiotics fueled investigations on targeting efficacious probiotics. In the current study, lactic acid bacteria (LAB) isolated from poultry gut, feces of rat, chicken, human infants, and fermented foods were characterized for desired probiotic functional properties including the phytase-producing ability which is one of the wanted characteristics for probiotics for potential applications for upgrading animal nutrition, enhancing feed conversion, and minimizing anti-nutritional properties. Among 62 LAB isolates Weissella kimchii R-3 an isolate from poultry gut exhibited substantial phytase-producing ability (1.77 U/ml) in addition to other functional probiotic characteristics viz. hydrophobicity, autoaggregation, coaggregation with bacterial pathogens, and antimicrobial activity against pathogens. Survival of W. kimchii R-3 cells (in free and calcium alginate encapsulated state) was examined sequentially in simulated gastric and intestinal juices. Encapsulated cells exhibited better survival under simulated gut conditions indicating that encapsulation conferred considerable protection against adverse gut conditions. Furthermore, simulated gastric and intestinal juices with pepsin and pancreatin showed higher survival of cells than the juices without pepsin and pancreatin. W. kimchii R-3 due to its significant functional probiotic attributes may have prospective for commercial applications in human/animal nutrition.

Effective identification of Lactobacillus casei group species: genome-based selection of the gene mutL as the target of a novel multiplex PCR assay

Lactobacillus casei,Lactobacillus paracasei and Lactobacillusrhamnosus form a closely related taxonomic group (the L. casei group) within the facultatively heterofermentative lactobacilli. Strains of these species have been used for a long time as probiotics in a wide range of products, and they represent the dominant species of nonstarter lactic acid bacteria in ripened cheeses, where they contribute to flavour development. The close genetic relationship among those species, as well as the similarity of biochemical properties of the strains, hinders the development of an adequate selective method to identify these bacteria. Despite this being a hot topic, as demonstrated by the large amount of literature about it, the results of different proposed identification methods are often ambiguous and unsatisfactory. The aim of this study was to develop a more robust species-specific identification assay for differentiating the species of the L. casei group. A taxonomy-driven comparative genomic analysis was carried out to select the potential target genes whose similarity could better reflect genome-wide diversity. The gene mutL appeared to be the most promising one and, therefore, a novel species-specific multiplex PCR assay was developed to rapidly and effectively distinguish L. casei, L. paracasei and L. rhamnosus strains. The analysis of a collection of 76 wild dairy isolates, previously identified as members of the L. casei group combining the results of multiple approaches, revealed that the novel designed primers, especially in combination with already existing ones, were able to improve the discrimination power at the species level and reveal previously undiscovered intraspecific biodiversity.

Extensively hydrolyzed casein formula alone or with L. rhamnosus GG reduces β-lactoglobulin sensitization in mice

BACKGROUND

Extensively hydrolyzed casein formula (EHCF) has been proposed for the prevention and is commonly used for the treatment of cow's milk allergy (CMA). The addition of the probiotic Lactobacillus rhamnosus GG (LGG) to EHCF may induce faster acquisition of tolerance to cow's milk. The mechanisms underlying this effect are largely unexplored. We investigated the effects of EHCF alone or in combination with LGG on β-lactoglobulin (BLG) sensitization in mice.

METHODS

Three-week-old C3H/HeOuJ mice were sensitized by oral administration of BLG using cholera toxin as adjuvant at weekly intervals for 5 weeks (sensitization period). Two experimental phases were conducted: (i) EHCF or EHCF+LGG given daily, starting 2 weeks before the sensitization period and then given daily for 5 weeks and (ii) EHCF or EHCF+LGG given daily for 4 weeks, starting 1 week after the sensitization period. Diet free of cow's milk protein was used as control. Acute allergic skin response, anaphylactic symptom score, body temperature, intestinal permeability, anti-BLG serum IgE, and interleukin (IL)-4, IL-5, IL-10, IL-13, IFN-γ mRNA expression were analyzed. Peptide fractions of EHCF were characterized by reversed-phase (RP)-HPLC, MALDI-TOF mass spectrometry, and nano-HPLC/ESI-MS/MS.

RESULTS

Extensively hydrolyzed casein formula administration before or after BLG-induced sensitization significantly reduced acute allergic skin reaction, anaphylactic symptom score, body temperature decrease, intestinal permeability increase, IL-4, IL-5, IL-13, and anti-BLG IgE production. EHCF increased expression of IFN-γ and IL-10. Many of these effects were significantly enhanced by LGG supplementation. The peptide panels were similar between the two study formulas and contained sequences that could have immunoregulatory activities.

CONCLUSIONS

The data support dietary intervention with EHCF for CMA prevention and treatment through a favorable immunomodulatory action. The observed effects are significantly enhanced by LGG supplementation.

Probiotics and allergic diseases

The prevalence of allergic diseases including atopic dermatitis, asthma, allergic rhinitis (AR) and food allergy is increasing worldwide and they cause a big economic and social burden. Understanding of reasons that contribute to the etiology of allergic diseases as well as new treatment approaches are very important for the follow-up and prevention of these diseases. In recent years, probiotics seem to be promising for allergic diseases. The effect of probiotics in the prevention and treatment of eczema is more extensively studied, but little is known about the association of the microbial flora of the host and allergic airway diseases and the efficacy of probiotics in decreasing the symptoms of patients with asthma and rhinitis. Hitherto, there is no strong evidence for use of probiotics in the treatment of eczema; however, administration of probiotics in breastfeeding mothers in the prenatal period and infants in the postnatal period can be accepted as a safe and helpful option in the prevention of eczema. In contrast, there is not yet reliable evidence or recommendations on use of probiotics for the prevention or treatment of asthma, AR, food allergy, and anaphylaxis currently. More standardized studies should be performed with different strains of probiotics to evaluate the protective and therapeutic effects of probiotics on other allergic diseases as well as eczema. In this review, the relationship between allergy and probiotics is handled in the light of current literature.

Probiotics for Prevention of Atopy and Food Hypersensitivity in Early Childhood: A PRISMA-Compliant Systematic Review and Meta-Analysis of Randomized Controlled Trials

Most studies investigated probiotics on food hypersensitivity, not on oral food challenge confirmed food allergy in children. The authors systematically reviewed the literature to investigate whether probiotic supplementation prenatally and/or postnatally could reduce the risk of atopy and food hypersensitivity in young children.PubMed, Embase, the Cochrane Central Register of Controlled Trials, and 4 main Chinese literature databases (Wan Fang, VIP, China National Knowledge Infrastructure, and SinoMed) were searched for randomized controlled trials regarding the effect of probiotics on the prevention of allergy in children. The last search was conducted on July 11, 2015.Seventeen trials involving 2947 infants were included. The first follow-up studies were analyzed. Pooled analysis indicated that probiotics administered prenatally and postnatally could reduce the risk of atopy (relative risk [RR] 0.78; 95% confidence interval [CI] 0.66-0.92; I = 0%), especially when administered prenatally to pregnant mother and postnatally to child (RR 0.71; 95% CI 0.57-0.89; I = 0%), and the risk of food hypersensitivity (RR 0.77; 95% CI 0.61-0.98; I = 0%). When probiotics were administered either only prenatally or only postnatally, no effects of probiotics on atopy and food hypersensitivity were observed.Probiotics administered prenatally and postnatally appears to be a feasible way to prevent atopy and food hypersensitivity in young children. The long-term effects of probiotics, however, remain to be defined in the follow-up of existing trials. Still, studies on probiotics and confirmed food allergy, rather than surrogate measure of food hypersensitivity, are warranted.

SLE: Another Autoimmune Disorder Influenced by Microbes and Diet?

Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease. Despite years of study, the etiology of SLE is still unclear. Both genetic and environmental factors have been implicated in the disease mechanisms. In the past decade, a growing body of evidence has indicated an important role of gut microbes in the development of autoimmune diseases, including type 1 diabetes, rheumatoid arthritis, and multiple sclerosis. However, such knowledge on SLE is little, though we have already known that environmental factors can trigger the development of lupus. Several recent studies have suggested that alterations of the gut microbial composition may be correlated with SLE disease manifestations, while the exact roles of either symbiotic or pathogenic microbes in this disease remain to be explored. Elucidation of the roles of gut microbes - as well as the roles of diet that can modulate the composition of gut microbes - in SLE will shed light on how this autoimmune disorder develops, and provide opportunities for improved biomarkers of the disease and the potential to probe new therapies. In this review, we aim to compile the available evidence on the contributions of diet and gut microbes to SLE occurrence and pathogenesis.

Foreword: All things considered about probiotics, prebiotics and ıntestinal microbiota in children – from bench to bedside

There are numerorus published and ongoing experimental/clinical studies about probiotics and prebiotics, intestinal microbiota and nutrition. Three years ago, at the first International Symposium of Probiotics Prebiotics in Paediatrics in Istanbul (2012) we highlighted the ‘paediatric perspective’ on these issues and brought together more than 40 global key opinion leaders and 400 attendants to have a chance to extensively discuss the past, present and the future. In 2014, the second state of art congress, held in Antalya, aimed to discuss the gut microbiota and microbiotics and their impact through lifespan. Selected papers of this conference are presented in this special issue ‘prebiotics and probiotics in paediatrics’ of Beneficial Microbes. A summary of the conference results is provided below.