Probiotics for cow's milk protein allergy: a systematic review of randomized controlled trials

Probiotics in Infancy and Childhood for Food Allergy Prevention and Treatment

Food allergy represents a failure of oral tolerance mechanisms to dietary antigens. Over the past few years, food allergies have become a growing public health problem worldwide. Gut microbiota is believed to have a significant impact on oral tolerance to food antigens and in initiation and maintenance of food allergies. Therefore, probiotics have also been proposed in this field as a possible strategy for modulating both the gut microbiota and the immune system. In recent years, results from preclinical and clinical studies suggest a promising role for probiotics in food allergy prevention and treatment. However, future studies are needed to better understand the mechanisms of action of probiotics in food allergies and to design comparable study protocols using specific probiotic strains, defined doses and exposure times, and longer follow-up periods.

Prevalence and Risk Factors for IgE and IgG Cow's Milk Protein Allergies in Saudi Arabia

Cow's milk protein allergies (CMPAs) particularly occur in infancy and early childhood due to an immunological allergic reaction to milk proteins. This issue is increasing in Saudi Arabia and requires research to improve health status and provide alternatives. Our study aims to investigate the important aspects of immunoglobulin E (IgE) and IgG CMPA in Saudi Arabia regarding its prevalence and association with demographic and health-related factors in both adult and pediatric populations. A descriptive retrospective cross-sectional study was conducted on 376 patients, comprising 314 adults aged between 19 and 86 years, and 62 pediatric patients aged between one and 12 years. The study focused on individuals who attended a private medical center in Jeddah city over the past five years. Laboratory results for food allergy of IgE and IgG tests, including cow's milk proteins (CMPs), serum 25-hydroxyvitamin D (25OHD), specific IgE inhalant allergy results, and other health-related factors were collected from an electronic record system. Results have shown that casein was the most common sensitizing allergen of CMPs in adults, whereas α-lactalbumin was the most common sensitizing allergen in pediatrics. The most frequent sensitizing allergen in IgG CMP was cow's milk in 54/92 (58.7%) adults, followed by cow's sour milk products 41 (44.6%). Cow's milk was the most common sensitizing allergen in 20/20 (100%) children. The rate of CMPA was significantly higher in children younger than five years old (P =0.003), while children who interacted with pets had a marginal significantly reduced rate (P = 0.054). Thus, cow's milk is the most sensitizing allergen in IgG CMPs in adults and pediatrics.

Risk factors predisposing children to food allergies

BACKGROUND

Food allergies are the most common cause of anaphylaxis in children, and their incidence is increasing globally. The aim of this study was to determine the risk factors leading to food allergies in childhood.

METHODS

Children with food allergies and non-atopic healthy children were compared using a questionnaire that included prenatal, neonatal, and postnatal risk factors.

RESULTS

A total of 314 subjects, 155 patients and 159 healthy children for the control group, were enrolled in the study. The median age of patients with a food allergy at diagnosis was 6 months (1-156 months), and 71 patients (45.8%) were males. The median age of the control group was 12 months (1-61 months), and 67.0% were males. Older maternal age (P = 0.023), birth by caesarean section (P = 0.001), birth in the summer or autumn (P = 0.011), crowded housing (P = 0.001), damp houses (P = 0.001), being fed with breast milk and complementary food (P = 0.001), use of synthetic bedding (P = 0.024), and being the oldest child in the family (P = 0.001) were the considered risk factors for an immunoglobulin-E (IgE)-mediated food allergy. A low frequency of yoghurt consumption by mother (P = 0.001) and use of wool bedding (P = 0.018) were identified as risk factors for non-IgE-mediated food allergies. Low socioeconomic status (P = 0.001) played a protective role against both IgE- and non-IgE-mediated food allergies whereas breastfeeding played a protective role against IgE-mediated food allergies (P = 0.030).

CONCLUSION

The most important aspect of this study was that it separately identified prenatal, neonatal, and postnatal risk factors for IgE- and non-IgE-mediated food allergies.

Allergic Proctocolitis: Literature Review and Proposal of a Diagnostic-Therapeutic Algorithm

Allergic proctocolitis (AP) is a benign condition, frequent in childhood, that is classified as a non-IgE-mediated food allergy. The prevalence is unknown; however, its frequency appears to be increasing, especially in exclusively breastfed infants. Clinical manifestations typically begin in the first few months of life with the appearance of bright red blood (hematochezia), with or without mucus, in the stool of apparently healthy, thriving infants. Most cases of AP are caused by cow's milk proteins; however, other allergens, such as soy, egg, corn, and wheat, may be potential triggers. Diagnosis is based on the patient's clinical history and on the resolution of signs and symptoms with the elimination of the suspected food antigen from the diet and their reappearance when the food is reintroduced into the diet. The treatment of AP is based on an elimination diet of the trigger food, with resolution of the symptoms within 72-96 h from the beginning of the diet. The prognosis of AP is good; it is a self-limiting condition, because most children can tolerate the trigger food within one year of life, with an excellent long-term prognosis. The purpose of this review is to provide an update on the current knowledge and recommendations in epidemiological, diagnostic, and therapeutic terms to the pediatricians, allergists, and gastroenterologists who may find themselves managing a patient with AP.

Clarifying the effect of gut microbiota on allergic conjunctivitis risk is instrumental for predictive, preventive, and personalized medicine: a Mendelian randomization analysis

Background

Allergic conjunctivitis is an ocular immune disease which affects the conjunctiva, eyelids, and cornea. Growing evidence implicates the gut microbiota in balancing and modulating immunity response, and in the pathogenesis of allergic disease. As a result, gut microbial imbalance could be a useful indicator for allergic conjunctivitis. From the perspective of predictive, preventive, and personalized medicine (PPPM), clarifying the role of gut microbial imbalance in the development of allergic conjunctivitis could provide a window of opportunity for primary prediction, targeted prevention, and personalized treatment of the disease.

Working hypothesis and methodology

In our study, we hypothesized that individuals with microbial dysbiosis may be more susceptible to allergic conjunctivitis due to an increased inflammatory response. To verify the working hypothesis, our analysis selected genetic variants linked with gut microbiota features (N = 18,340) and allergic conjunctivitis (4513 cases, 649,376 controls) from genome-wide association studies. The inverse-variance weighted (IVW) estimate, Mendelian randomization (MR)-Egger, weighted median estimator, maximum likelihood estimator (MLE), and MR robust adjusted profile score (MR.RAPS) were employed to analyze the impact of gut microbiota on the risk of allergic conjunctivitis and identify allergic conjunctivitis-related gut microbes. Ultimately, these findings may enable the identification of individuals at risk of allergic conjunctivitis through screening of gut microbial imbalances, and allow for new targeted prevention and personalized treatment strategies.

Results

Genetic liability to Ruminococcaceae_UCG_002 (OR, 0.83; 95% CI, 0.70-0.99; P = 4.04×10^-2), Holdemanella (OR, 0.78; 95% CI, 0.64-0.96; P = 2.04×10^-2), Catenibacterium (OR, 0.69; 95% CI, 0.56-0.86; P = 1.09×10^-3), Senegalimassilia (OR, 0.71; 95% CI, 0.55-0.93; P = 1.23×10^-2) genus were associated with a low risk of allergic conjunctivitis with IVW. Besides, we found suggestive associations of a genetic-driven increase in the Oscillospira (OR, 1.41; 95% CI, 1.00-2.00; P = 4.63×10^-2) genus with a higher risk of allergic conjunctivitis. Moreover, MLE and MR.RAPS show consistent results with IVW after further validation and strengthened confidence in the true causal associations. No heterogeneity and pleiotropy was detected.

Conclusions

Our study suggests that gut microbiota may play a causal role in the development of allergic conjunctivitis and provides new insights into the microbiota-mediated mechanism of the disease. Gut microbiota may serve as a target for future predictive diagnostics, targeted prevention, and individualized therapy in allergic conjunctivitis, facilitating the transition from reactive medical services to PPPM in the management of the disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-023-00321-9.

Current Practice in Pediatric Cow's Milk Protein Allergy-Immunological Features and Beyond

Cow's milk protein allergy is one of the most common pediatric food allergies. It poses a significant socioeconomic burden in industrialized countries and has a profound effect on the quality of life of affected individuals and their families. Diverse immunologic pathways can lead to the clinical symptoms of cow's milk protein allergy; some of the pathomechanisms are known in detail, but others need further elucidation. A comprehensive understanding of the development of food allergies and the features of oral tolerance could have the potential to unlock more precise diagnostic tools and novel therapeutic approaches for patients with cow's milk protein allergy.

Gut microbiome modulation by probiotics, prebiotics, synbiotics and postbiotics: a novel strategy in food allergy prevention and treatment

Food allergy has caused lots of global public health issues, particularly in developed countries. Presently, gut microbiota has been widely studied on allergy, while the role of dysbiosis in food allergy remains unknown. Scientists found that changes in gut microbial compositions and functions are strongly associated with a dramatic increase in the prevalence of food allergy. Altering microbial composition is crucial in modulating food antigens' immunogenicity. Thus, the potential roles of probiotics, prebiotics, synbiotics, and postbiotics in affecting gut bacteria communities and the immune system, as innovative strategies against food allergy, begins to attract high attention of scientists. This review briefly summarized the mechanisms of food allergy and discussed the role of the gut microbiota and the use of probiotics, prebiotics, synbiotics, and postbiotics as novel therapies for the prevention and treatment of food allergy. The perspective studies on the development of novel immunotherapy in food allergy were also described. A better understanding of these mechanisms will facilitate the development of preventive and therapeutic strategies for food allergy.

Using probiotics in paediatric populations

This statement defines probiotics and reviews the most recent literature on their use in paediatrics. Many studies have examined the potential benefit of probiotics, but significant variation in the strains and doses of probiotics used, the patient populations studied, and in study design, have led to heterogeneous results. Present evidence suggests that probiotics can decrease mortality and lower incidence of necrotizing enterocolitis in preterm and low birth weight neonates. Probiotics may also be beneficial in reducing feeding intolerance. In infants, probiotics may be considered to reduce symptoms of colic. In older children, probiotics can be considered to prevent antibiotic-associated diarrhea and Clostridium difficile -associated diarrhea. Probiotic supplements used in conjunction with standard therapy can help with Helicobacter pylori eradication and decrease the side effects of treatment. Lactobacillus species can be considered to treat irritable bowel syndrome. Probiotics can also be considered to help prevent atopic dermatitis and eczema. To optimize paediatric policy and practice, large, quality studies are needed to determine what types and combinations of probiotics are most efficacious.

L’utilisation des probiotiques dans la population pédiatrique

Le présent document de principes définit les probiotiques et fournit une analyse des publications scientifiques les plus récentes sur leur utilisation en pédiatrie. De nombreuses études ont évalué les avantages potentiels des probiotiques, mais en raison des variations importantes dans les souches et les doses utilisées, des populations de patients étudiées et des méthodologies privilégiées, les résultats sont hétérogènes. Selon les données probantes à jour, les probiotiques peuvent réduire le taux de mortalité et l’incidence d’entérocolite nécrosante chez les nouveau-nés prématurés et de petit poids à la naissance. Ils peuvent également être bénéfiques pour réduire l’intolérance alimentaire. Chez les nourrissons, on peut envisager de les utiliser pour limiter les symptômes de coliques, et chez les enfants plus âgés, pour prévenir la diarrhée associée aux antibiotiques ou au Clostridium difficile . Les suppléments de probiotiques utilisés conjointement avec un traitement standard peuvent contribuer à éradiquer l’Helicobacter pylori et à atténuer les effets secondaires du traitement. On peut envisager d’utiliser des espèces de Lactobacillus pour traiter le syndrome du côlon irritable ou de recourir à des probiotiques pour contribuer à prévenir la dermatite atopique et l’eczéma. Afin d’optimiser les politiques et les pratiques en pédiatrie, de vastes études de qualité devront être réalisées pour déterminer les types et les combinaisons de probiotiques les plus efficaces.

Special Diets in Infants and Children and Impact on Gut Microbioma

Gut microbiota is a complex system that starts to take shape early in life. Several factors influence the rise of microbial gut colonization, such as term and mode of delivery, exposure to antibiotics, maternal diet, presence of siblings and family members, pets, genetics, local environment, and geographical location. Breastfeeding, complementary feeding, and later dietary patterns during infancy and toddlerhood are major players in the proper development of microbial communities. Nonetheless, if dysbiosis occurs, gut microbiota may remain impaired throughout life, leading to deleterious consequences, such as greater predisposition to non-communicable diseases, more susceptible immune system and altered gut–brain axis. Children with specific diseases (i.e., food allergies, inborn errors of metabolism, celiac disease) need a special formula and later a special diet, excluding certain foods or nutrients. We searched on PubMed/Medline, Scopus and Embase for relevant pediatric studies published over the last twenty years on gut microbiota dietary patterns and excluded case reports or series and letters. The aim of this review is to highlight the changes in the gut microbiota in infants and children fed with special formula or diets for therapeutic requirements and, its potential health implications, with respect to gut microbiota under standard diets.

Contribution of Gut Microbiota to Immune Tolerance in Infants

The prevalence of food allergy has increased in recent years, especially among the pediatric population. Differences in the gut microbiota composition between children with FA and healthy children have brought this topic into the spotlight as a possible explanation for the increase in FA. The gut microbiota characteristics are acquired through environmental interactions starting early in life, such as type of delivery during birth and breastfeeding. The microbiota features may be shaped by a plethora of immunomodulatory mechanisms, including a predominant role of Tregs and the transcription factor FOXP3. Additionally, a pivotal role has been given to vitamin A and butyrate, the main anti-inflammatory metabolite. These observations have led to the study and development of therapies oriented to modifying the microbiota and metabolite profiles, such as the use of pre- and probiotics and the determination of their capacity to induce tolerance to allergens that are relevant to FA. To date, evidence supporting these approaches in humans is scarce and inconclusive. Larger cohorts and dose-titration studies are mandatory to evaluate whether the observed changes in gut microbiota composition reflect medical recovery and increased tolerance in pediatric patients with FA. In this article, we discuss the establishment of the microbiota, the immunological mechanisms that regulate the microbiota of children with food allergies, and the evidence in research focused on its regulation as a means to achieve tolerance to food allergens.

Can fecal calprotectin levels be used to monitor infant milk protein allergies?

Background

Milk protein allergy is one of the most common food allergies in infants. We aimed to test whether fecal calprotectin can be used to monitor food allergies in infants by comparing the fecal calprotectin levels in infants with a milk protein allergy before and after an intervention treatment.

Methods

The study was designed as a prospective case–control trial. Stool samples were collected at follow-up, and the concentration of fecal calprotectin was determined using an enzyme-linked immunosorbent assay. The infant’s weight and length were measured.

Results

The allergic group comprised 90 milk-allergic infants (41 boys, 49 girls), and the nonallergic group comprised 90 nonallergic infants (51 boys, 39 girls). Compared with the fecal calprotectin level in the nonallergic group (median: 141 μg/g), that in the allergic group (median: 410 μg/g) was significantly higher (z = − 9.335, p < 0.001). After two dietary interventions and treatments, the fecal calprotectin levels of the infants with a milk protein allergy at the first (median: 253 μg/g) and second follow-up visits (median: 160 μg/g) were significantly lower than those before the intervention (z = − 7.884, p < 0.001 and z = − 8.239, p < 0.001, respectively). The growth index values (LAZ and WAZ) of the infants with a milk protein allergy at the first and second follow-up visits were significantly higher than those before dietary intervention (p < 0.05). Fecal calprotectin was negatively and significantly correlated with the WLZ and WAZ at the second follow-up visit (Spearman’s rho = − 0.234, p = 0.01 and Spearman’s rho = − 0.193, p = 0.03, respectively).

Conclusion

The level of fecal calprotectin in infants with a milk protein allergy decreased after dietary intervention and seems to be a promising biological indicator for monitoring intestinal allergies.

Potential Biomarkers, Risk Factors and their Associations with IgE-mediated Food Allergy in Early Life: A Narrative Review

Food allergy affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. In the past few decades, the prevalence of allergic disease has been on the rise worldwide. Identified risk factors for food allergy include family history, mode of delivery, variations in infant feeding practices, prior diagnosis of other atopic diseases such as eczema, and social economic status. Identifying reliable biomarkers which predict the risk of developing food allergy in early life would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. There is also the potential to identify new therapeutic targets. This narrative review provides details on the genetic, epigenetic, dietary and microbiome influences upon the development of food allergy and synthesizes the currently available data indicating potential biomarkers. While there is a large body of research evidence available within each field of potential risk factors, there are very limited number of studies which span multiple methodological fields, for example including immunology, microbiome, genetic/epigenetic factors and dietary assessment. We recommend that further collaborative research with detailed cohort phenotyping is required to identify biomarkers, and whether these vary between at-risk populations and the wider population. The low incidence of oral food challenge confirmed food allergy in the general population, and the complexities of designing nutritional intervention studies will provide challenges for researchers to address in generating high quality, reliable and reproducible research findings.

STATEMENT OF SIGNIFICANCE

Food allergy affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. Identifying reliable biomarkers which predict the risk of developing food allergy would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. This review provides details on the genetic, epigenetic, dietary and microbiome influences upon the development of food allergy. This helps in identifying reliable biomarkers to predict the risk of developing food allergy, which could be valuable in both preventing morbidity and mortality and by making interventions available at the earliest opportunity.

Prevalence, Risk Factors, Clinical Manifestation, Diagnosis Aspects and Nutrition Therapy in Relation to both IgE and IgG Cow’s Milk Protein Allergies among a Population of Saudi Arabia: A Literature Review

Cow milk protein allergy (CMPA) becoming a major public health issue that has attracted the attention of health professionals and researchers. This paper aimed to review the important aspects of both IgE and IgG types of cow’s milk protein allergy in terms of prevalence, clinical manifestation, risk factors, other health-related issues and nutritional therapy proposed for such allergies in the adult and pediatric population in Saudi Arabia. A search on “cow’s milk allergy” was done using PubMed, Google Scholar and Scopus Engine for published papers between 1993 and 2020 to find studies yielding knowledge on that context. The prevalence of cow’s milk protein allergy (CMPA) among infants is now in the range of 2–3%. This type of allergy is also detected in adulthood but less frequently. CMPA is defined as an immunological reaction to specific proteins in milk. CMPA is classified based on its type as an immunoglobulin E (IgE)-mediated form and an immunoglobulin G (IgG)-mediated form, each type representing different immunological pathways. The presence of Genetic aspects, family history and short duration of breastfeeding in the infant are among the risk factors contributing to this form of allergy. Its manifestations mainly present as skin presentation, followed by the gastrointestinal and respiratory presentation in most cases in addition to a life-threatening anaphylactic reaction that may occur in 12% of cases. food allergy committees have developed strict diagnosis criteria, including blood testing for food-specific immunoglobulin E (sIgE), a skin prick test and double-blind placebo-controlled food challenges (DBPCFC) as the gold standard. A diet free of cow’s milk protein (CMP) allergen and including the appropriate alternative milk formula is the first line of prevention recommended by many organizations and food allergy experts. As for Saudi Arabia, more research and clinical trials are required to discuss the various aspects of adult and pediatric CMPA and to provide a better understanding along with good control strategies implementation.

Advances in the Relationships Between Cow's Milk Protein Allergy and Gut Microbiota in Infants

Cow's milk protein allergy (CMPA) is an immune response to cow's milk proteins, which is one of the most common food allergies in infants and young children. It is estimated that 2-3% of infants and young children have CMPA. The diet, gut microbiota, and their interactions are believed to be involved in the alterations of mucosal immune tolerance, which might lead to the development of CMPA and other food allergies. In this review, the potential molecular mechanisms of CMPA, including omics technologies used for analyzing microbiota, impacts of early microbial exposures on CMPA development, and microbiota-host interactions, are summarized. The probiotics, prebiotics, synbiotics, fecal microbiota transplantation, and other modulation strategies for gut microbiota and the potential application of microbiota-based design of diets for the CMPA treatment are also discussed. This review not only summarizes the current studies about the interactions of CMPA with gut microbiota but also gives insights into the possible CMPA treatment strategies by modulating gut microbiota, which might help in improving the life quality of CMPA patients in the future.

Stress Effect of Food Matrices on Viability of Probiotic Cells during Model Digestion

The aim of this study was to evaluate the influence of model (alcohol, sugar, salt, protein and acid) and real foods and beverages on the viability of probiotics during incubation and artificial digestion. Viability of monocultures Lactobacillus acidophilus CCM4833 and Bifidobacterium breve CCM7825T, and a commercial mixture of 9 probiotic bacterial strains, was tested by cultivation assay and flow cytometry. In model foods, the best viability was determined in the presence of 0.2 g/L glucose, 10% albumin and 10% ethanol. As the most suitable real food for probiotic survival, complex protein and carbohydrate substrates were found, such as beef broth, potato salad with pork, chicken with rice, chocolate spread, porridge and yoghurt. The best liquid was milk and meat broth, followed by Coca-Cola, beer and coffee. Viability of probiotics was higher when consumed with meals than with beverages only. Addition of prebiotics increased the viability of probiotics, especially in presence of instant and fast foods. Generally, the highest viability of probiotics during artificial digestion was observed in mixed culture in the presence of protein, sugar and fat, or their combination. The increase of cell viability observed in such foods during model digestion may further contribute to the positive effect of probiotics on human health.

The Use of an Amino Acid Formula Containing Synbiotics in Infants with Cow's Milk Protein Allergy-Effect on Clinical Outcomes

Cow’s milk protein allergy (CMPA) is common and costly. Clinical trials of infants with CMPA have shown that the use of an amino acid formula containing pre- and probiotics (synbiotics) (AAF-Syn) may lead to significant reductions in infections, medication prescriptions and hospital admissions, compared to AAF without synbiotics. These effects have not yet been confirmed in real-world practice. This retrospective matched cohort study examined clinical and healthcare data from The Health Improvement Network database, from 148 infants with CMPA (54% male, mean age at diagnosis 4.69 months), prescribed either AAF-Syn (probiotic Bifidobacterium breve M16-V and prebiotics, including chicory-derived oligo-fructose and long-chain inulin) or AAF. AAF-Syn was associated with fewer symptoms (−37%, p < 0.001), infections (−35%, p < 0.001), medication prescriptions (−19%, p < 0.001) and healthcare contacts (−18%, p = 0.15) vs. AAF. Infants prescribed AAF-Syn had a significantly higher probability of achieving asymptomatic management without hypoallergenic formula (HAF) (adjusted HR 3.70, 95% CI 1.97–6.95, p < 0.001), with a shorter clinical course of symptoms (median time to asymptomatic management without HAF 1.35 years vs. 1.95 years). AAF-Syn was associated with potential cost-savings of £452.18 per infant over the clinical course of symptoms. These findings may be attributable to the effect of the specific synbiotic on the gut microbiome. Further research is warranted to explore this. This real-world study provides evidence consistent with clinical trials that AAF-Syn may produce clinical and healthcare benefits with potential economic impact.

Amino Acid Formula Containing Synbiotics in Infants with Cow's Milk Protein Allergy: A Systematic Review and Meta-Analysis

Cow's milk protein allergy (CMPA) is associated with dysbiosis of the infant gut microbiome, with allergic and immune development implications. Studies show benefits of combining synbiotics with hypoallergenic formulae, although evidence has never been systematically examined. This review identified seven publications of four randomised controlled trials comparing an amino acid formula (AAF) with an AAF containing synbiotics (AAF-Syn) in infants with CMPA (mean age 8.6 months; 68% male, mean intervention 27.3 weeks, n = 410). AAF and AAF-Syn were equally effective in managing allergic symptoms and promoting normal growth. Compared to AAF, significantly fewer infants fed AAF-Syn had infections (OR 0.35 (95% CI 0.19-0.67), p = 0.001). Overall medication use, including antibacterials and antifectives, was lower among infants fed AAF-Syn. Significantly fewer infants had hospital admissions with AAF-Syn compared to AAF (8.8% vs. 20.2%, p = 0.036; 56% reduction), leading to potential cost savings per infant of £164.05-£338.77. AAF-Syn was associated with increased bifidobacteria (difference in means 31.75, 95% CI 26.04-37.45, p < 0.0001); reduced Eubacterium rectale and Clostridium coccoides (difference in means -19.06, 95% CI -23.15 to -14.97, p < 0.0001); and reduced microbial diversity (p < 0.05), similar to that described in healthy breastfed infants, and may be associated with the improved clinical outcomes described. This review provides evidence that suggests combining synbiotics with AAF produces clinical benefits with potential economic implications.

Generation of Lactose- and Protease-Positive Probiotic Lacticaseibacillus rhamnosus GG by Conjugation with Lactococcus lactis NCDO 712

Lacticaseibacillus rhamnosus GG (LGG) is the most studied probiotic bacterium in the world. It is used as a probiotic supplement in many foods, including various dairy products. However, LGG grows poorly in milk, as it neither metabolizes the main milk carbohydrate lactose nor degrades the major milk protein casein effectively. In this study, we made L. rhamnosus GG lactose and protease positive by conjugation with the dairy Lactococcus lactis strain NCDO 712 carrying the lactose-protease plasmid pLP712. A lactose-hydrolyzing transconjugant colony was obtained on agar containing lactose as the sole source of carbohydrates. By microscopic analysis and PCR with LGG- and pLP712-specific primers, the transconjugant was confirmed to have originated from LGG and to carry the plasmid pLP712. The transconjugant was named L. rhamnosus LAB49. The isolation of plasmids revealed that not only pLP712 but also other plasmids had been transferred from L. lactis into LGG during conjugation. With plasmid-specific PCR primers, four additional lactococcal plasmids were detected in LAB49. Proteolytic activity assay and SDS-PAGE analysis verified that L. rhamnosus LAB49 effectively degraded β-casein. In contrast to its parental strain, LGG, the ability of LAB49 to metabolize lactose and degrade casein enabled strong and fast growth in milk. As strains with new properties made by conjugation are not regarded as genetically modified organisms (GMOs), L. rhamnosus LAB49 could be beneficial in dairy fermentations as a probiotic starter culture.IMPORTANCE Probiotic strain Lacticaseibacillus rhamnosus GG (LGG) is widely sold on the market as a probiotic or added as a supplement in dairy foods because of its benefits in human health. However, due to the deficiency of lactose and casein utilization, LGG does not grow well in milk. On the other hand, lactose intolerance and cow's milk protein allergy are the two major problems related to milk consumption. One option to help with these two conditions is the use of probiotic or lactose- and casein-hydrolyzing bacteria in dairy products. The purpose of this study was to equip LGG with lactose/casein-hydrolyzing ability by bacterial conjugation. As a result, we generated a non-GMO LGG derivative with improved properties and better growth in milk.

Gut Microbiota Profile in Children with IgE-Mediated Cow's Milk Allergy and Cow's Milk Sensitization and Probiotic Intestinal Persistence Evaluation

Food allergy (FA) and, in particular, IgE-mediated cow's milk allergy is associated with compositional and functional changes of gut microbiota. In this study, we compared the gut microbiota of cow's milk allergic (CMA) infants with that of cow's milk sensitized (CMS) infants and Healthy controls. The effect of the intake of a mixture of Bifidobacterium longum subsp. longum BB536, Bifidobacterium breve M-16V and Bifidobacterium longum subsp. infantis M-63 on gut microbiota modulation of CMA infants and probiotic persistence was also investigated. Gut microbiota of CMA infants resulted to be characterized by a dysbiotic status with a prevalence of some bacteria as Haemophilus, Klebsiella, Prevotella, Actinobacillus and Streptococcus. Among the three strains administered, B.longum subsp. infantis colonized the gastrointestinal tract and persisted in the gut microbiota of infants with CMA for 60 days. This colonization was associated with perturbations of the gut microbiota, specifically with the increase of Akkermansia and Ruminococcus. Multi-strain probiotic formulations can be studied for their persistence in the intestine by monitoring specific bacterial probes persistence and exploiting microbiota profiling modulation before the evaluation of their therapeutic effects.

Food protein-induced allergic proctocolitis in infants: Literature review and proposal of a management protocol

Food protein-induced allergic proctocolitis (FPIAP) is a condition characterized by inflammatory changes in the distal colon in response to one or more foreign food proteins because of immune-mediated reactions.

FPIAP prevalence estimates range widely from 0.16% in healthy children and 64% in patients with blood in stools.

In clinical practice, FPIAP is diagnosed when patients respond positively to the elimination of a suspected triggering food allergen. Nevertheless, significant proportions of infants get misdiagnosed with IgE mediated allergy and undergo unnecessary dietary changes.

Diagnosis is based on clinical symptoms, a good response to an allergen-free diet and the recurrence of symptoms during the “allergy challenge test”. Sometimes clinical features may be non-specific and the etiology of rectal bleeding in childhood may be heterogeneous. Therefore, it is crucial to exclude a variety of other possible causes of rectal bleeding in the pediatric age group, including infection, anal fissure, intestinal intussusception and, in infants, necrotizing enterocolitis and very early onset inflammatory bowel disease. The diagnostic workup includes in those cases invasive procedures such as sigmoidoscopy and colonoscopy with biopsies.

The high prevalence of FPIAP contrasts with the lack of known information about the pathogenesis of this condition. For this reason and due to the absence of a review of the evidence, a literature review appears necessary to clarify some aspects of allergic colitis.

The aim of the review is to fill this gap and to lay the foundations for a subsequent evidence-based approach to the condition.

Non-IgE-Mediated Gastrointestinal Food Allergies in Children: An Update

Non-immunoglobulin E-mediated gastrointestinal food allergic disorders (non-IgE-GI-FA) include food protein-induced enterocolitis syndrome (FPIES), food protein-induced enteropathy (FPE) and food protein-induced allergic proctocolitis (FPIAP), which present with symptoms of variable severity, affecting the gastrointestinal tract in response to specific dietary antigens. The diagnosis of non-IgE-GI-FA is made clinically, and relies on a constellation of typical symptoms that improve upon removal of the culprit food. When possible, food reintroduction should be attempted, with the documentation of symptoms relapse to establish a conclusive diagnosis. Management includes dietary avoidance, nutritional counselling, and supportive measures in the case of accidental exposure. The prognosis is generally favorable, with the majority of cases resolved before school age. Serial follow-up to establish whether the acquisition of tolerance has occurred is therefore essential in order to avoid unnecessary food restriction and potential consequent nutritional deficiencies. The purpose of this review is to delineate the distinctive clinical features of non-IgE-mediated food allergies presenting with gastrointestinal symptomatology, to summarize our current understanding of the pathogenesis driving these diseases, to discuss recent findings, and to address currents gaps in the knowledge, to guide future management opportunities.

Efficacy and safety of hydrolyzed formulas for cow's milk allergy management: A systematic review of randomized controlled trials

OBJECTIVE

To summarize evidence on the efficacy and safety of the use of extensively hydrolyzed formulas (EHFs) for the treatment of children with cow's milk allergy (CMA).

DESIGN

Systematic review of randomized controlled trials (RCTs) per PRISMA guidelines. The risk of bias of included RCTs was assessed using the Cochrane Collaboration's risk of bias tool. In general, a narrative synthesis of the findings was performed. When sufficient data were available, a meta-analysis using the random-effect model was performed.

DATA SOURCES

The Cochrane Library, MEDLINE, and EMBASE databases were searched up to February 2020.

ELIGIBILITY CRITERIA

RCTs, including cross-over trials, assessing children of any age with any type of CMA that compared use of a formula containing extensively hydrolyzed bovine proteins (whey and/or casein) with use of any other formula for CMA management, were eligible for inclusion. Each type of EHF was evaluated separately. Outcome measures included allergic reactions (ie gastrointestinal, dermatological, and respiratory symptoms), growth, tolerance acquisition to cow's milk proteins, health-related quality of life, and safety.

RESULTS

Fifteen trials reported in 18 publications (1285 children) fulfilled the inclusion criteria. The study findings were limited by numerous methodological issues, including differences in outcome measures and their definitions, lack of pre-specified protocols and/or trial registration, and poor reporting of adverse events, methods of sequence generation and allocation concealment. The EHF products evaluated to date appear to be well-tolerated by most children with CMA. However, published studies do not allow for any conclusion to be reached regarding the benefit of one formula over another formula intended for CMA management.

CONCLUSIONS

This systematic review highlights the need for standardized treatment protocols, including an agreed-upon standardized set of outcomes that should be measured and reported in all clinical trials of specialized milk formula for the management of CMA.