The increasing prevalence of IgE-mediated cow\'s milk allergy (CMA) in childhood is a worldwide health concern. There is a growing awareness that the gut microbiome (GM) might play an important role in CMA development. Therefore, treatment with probiotics and prebiotics has gained popularity. This systematic review provides an overview of the alterations of the GM, metabolome, and immune response in CMA children and animal models, including post-treatment modifications. MEDLINE, PubMed, Scopus, and Web of Science were searched for studies on GM in CMA-diagnosed children, published before 1 March 2023. A total of 21 articles (13 on children and 8 on animal models) were included. The studies suggest that the GM, characterized by an enrichment of the Clostridia class and reductions in the Lactobacillales order and Bifidobacterium genus, is associated with CMA in early life. Additionally, reduced levels of short-chain fatty acids (SCFAs) and altered amino acid metabolism were reported in CMA children. Commonly used probiotic strains belong to the Bifidobacterium and Lactobacillus genera. However, only Bifidobacterium levels were consistently upregulated after the intervention, while alterations of other bacteria taxa remain inconclusive. These interventions appear to contribute to the restoration of SCFAs and amino acid metabolism balance. Mouse models indicate that these interventions tend to restore the Th 2/Th 1 balance, increase the Treg response, and/or silence the overall pro- and anti-inflammatory cytokine response. Overall, this systematic review highlights the need for multi-omics-related research in CMA children to gain a mechanistic understanding of this disease and to develop effective treatments and preventive strategies.

The aim of this study was to systematically review the evidence across studies that assessed DNA methylome variations in association with food allergy (FA).
A systematic review of the literature and meta-analysis were carried out within several databases. However, the risk of bias in the included articles was not evaluated.
PubMed, Cochrane Database of Systematic Reviews, and Web of Science were used to search up to July 2022.
We included targeted and epigenome-wide association studies (EWASs) that assessed DNA methylome alterations in association with FA in adult or paediatric populations.
Among 366 publications, only 16 were retained, which were mainly focused on FA in children. Seven candidate gene-targeted studies found associations in Th1/Th2 imbalance (IL4, IL5, IL10, INFG, IL2 and IL12B genes), regulatory T cell function (FOXP3 gene), Toll-like receptors pathway (TLR2, CD14 genes) and digestive barrier integrity (FLG gene). Nine EWAS assessed the association with peanut allergy (n = 3), cow\'s milk allergy (n = 2) or various food allergens (n = 4). They highlighted 11 differentially methylated loci in at least two studies (RPS6KA2, CAMTA1, CTBP2, RYR2, TRAPPC9, DOCK1, GALNTL4, HDAC4, UMODL1, ZAK and TNS3 genes). Among them, CAMTA1 and RPS6KA2, and CTBP2 are involved in regulatory T cell function and Th2 cell differentiation, respectively. Gene-functional analysis revealed two enriched gene clusters involved in immune responses and protein phosphorylation. ChIP-X Enrichment Analysis 3 showed eight significant transcription factors (RXRA, ZBTB7A, ESR1, TCF3, MYOD1, CTCF, GATA3 and CBX2). Ingenuity Pathway Analysis identified canonical pathways involved, among other, in B cell development, pathogen-induced cytokine storm signalling pathway and dendritic cell maturation.
This review highlights the involvement of epigenomic alterations of loci in Th1/Th2 and regulatory T cell differentiation in both candidate gene studies and EWAS. These alterations provide a better insight into the mechanistic aspects in FA pathogenesis and may guide the development of epigenome-based biomarkers for FA.

BACKGROUND: Cow\'s milk allergy (CMA) is the most common allergy in infants that decreases the quality of life of patients and their families. Standard treatment for CMA is the strict avoidance of milk; new treatment strategies such as oral immunotherapy (OIT) have been sought for patients with CMA. We aimed to assess the clinical efficacy and safety of OIT in the treatment of children with immunoglobulin E-mediated CMA (IMCMA).
METHODS: We searched all randomized controlled trials in which OIT is used to treat children with IMCMA from five international electronic databases. We estimated a pooled risk ratio (RR) for each outcome using a Mantel-Haenzel fixed-effects model if statistical heterogeneity was low.
RESULTS: Eleven studies were chosen for meta-analysis, including a total of 469 children (242 OITs, 227 controls). One hundred and seventy-six patients (72.7%) in the OIT were desensitized compared with 49 patients (21.6%) in the control group (RR: 7.35, 95% confidence interval (CI): 2.82-19.13, p < .0001). The desensitization effect of OIT was particularly significant in children over 3 years old (RR: 18.05, 95% CI: 6.48-50.26, p < .00001). Although adverse effects were common, they usually involved mild reactions, but epinephrine use was more common in the OIT group (RR: 7.69, 95% CI: 2.16-27.33, p < .002).
CONCLUSIONS: OIT can lead to desensitization in the majority of individuals with IMCMA, especially in patients over 3 years old. A major problem of OIT is the frequency of adverse events, although most are mild. OIT may be an alternative treatment in the future.

Objective: Cow\'s milk allergy (CMA) is a common allergic disease. Probiotics have been suggested as a treatment for CMA, with Lactobacillus rhamnosus GG (LGG) being one of the important predominant choices. Despite reports on this topic, the effectiveness of application in CMA remains to be firmly established. Methods: To assess the effects of LGG on CMA in children, the PubMed/Medline, Embase, Cochrane Library, and Web of Science databases were searched for studies on LGG in treatment of CMA, which were published in the English language. Results: Ten studies were finally included. Significantly higher tolerability rates favoring LGG over controls were observed [risk ratio (RR), 2.22; 95% confidence interval (CI), 1.86-2.66; I 2 = 0.00; moderate-quality evidence]. There were no significant differences in SCORAD values favoring LGG over the placebo (mean difference, 1.41; 95% CI, -4.99-7.82; p = 0.67; very low-quality evidence), and LGG may have improved fecal occult blood (risk ratio, 0.36; 95% CI, 0.14-0.92; p = 0.03; low-quality evidence). Conclusion: We found that LGG may have moderate-quality evidence to promote oral tolerance in children with CMA and may facilitate recovery from intestinal symptoms. However, this finding must be treated with caution, and more gpowerful RCTs are needed to evaluate the most effective dose and treatment time for children with CMA. Registration number: CRD42021237221.

Cow\'s milk protein allergy (CMPA) is an immune-mediated allergic response to proteins in milk that is common in infants. Broad CMPA symptoms make diagnosis a challenge, particularly in primary care. Symptom scores may improve a clinician\'s awareness of symptoms, indicating a need for further testing. This systematic review examined the development and evaluation of such symptom scores for use in infants.
CENTRAL, MEDLINE, EMBASE and CINAHL databases were searched from inception to 3 December 2019 (Updated 14 November 2020) for diagnostic accuracy studies, randomised controlled trials, observational studies, economic evaluations, qualitative studies and studies reporting development of the tools. Data were not suitable for meta-analysis due to clinical and methodological heterogeneity, so were narratively synthesised.
We found two symptom scores evaluated in one and fourteen studies, respectively. Estimated sensitivity and specificity ranged from 37% to 98% and 38% to 93%. The evaluations of each tool were at high risk of bias or failed to address issues such as clinical and cost-effectiveness.
Estimates of accuracy of symptom scores for CMPA offered so far should be interpreted cautiously. Rigorous, conflict-free research based on well-defined roles for the tools is urgently required.