The ‘Nutrients’ published findings highlight the increasingly established link between the microbiome and the immune system, and thus, the vital role that it plays in the prevention of allergy development.
It notes the observed relationship between gut dysbiosis, altered intestinal barrier function and immune response and allergic disease, such as asthma and necrotizing enterocolitis, stressing the potential target points for dietary intervention strategies.
“The relationship between the gut microbiota and food allergies highlights the potential to develop novel treatments that target the gut microbiota to improve intestinal barrier function and modulate the immune response to food allergens,” the Romanian researchers concluded.
With regards to the need for future study into this area, they added: “By deepening our knowledge in this area, we can pave the way for more targeted and effective interventions that could potentially transform the prevention and management of allergies in children.”
It has been established that a healthy human microbiome is an essential determinant of overall health. The composition has been determined to be influenced by a range of factors, including genotype, mode of delivery, breastfeeding, diet, antibiotic usage, and environmental factors.
Previous studies have established the significant role of the microbiome in the development of allergies within children, such as atopic dermatitis, food allergies, and asthma. Specifically, it has been suggested that children with allergies may have a lower level of biodiversity within their colonic microbiota, with increases in Firmicutes and Bacteriodaceae.
Following this, there has been heightened interest into establishing prevention and treatment strategies for such allergies within children. The present literature review aimed to bridge the gap between the available science on the microbiome with allergies, to assess the potential efficacy of dietary intervention methods.
The review highlights the established importance of maintaining healthy microbial populations within the microbiome, to ensure the regular functioning of processes such as digestion, metabolism, and immunity. As a result, the occurrence of dysbiosis can potentially incur an abnormal immune response, and thus, an allergic disease.
The researchers note the specific importance that Bifidobacteria and Lactobacilli species may have in sustaining immune homeostasis, due to their role in stimulating regulatory T-cells, which play a vital role in the mitigation of allergic responses. In addition, observed decreases in butyric-acid-producing bacteria (BAPB) following the occurrence of caesarean delivery and antibiotic use has been linked to the reduction in Tregs.
Therefore, the researchers hypothesise the potential therapeutic benefits of prebiotic and probiotics containing such species for children with allergies, as well as postbiotics rich in butyric acid.
The report also notes that the production of inflammatory cytokines, such as Interleukin-4 (IL-4) and Interleukin-5 (IL-5), have an essential role in producing an allergic response. The review notes the evidence highlighting the abilities of probiotics to enhance the production of anti-inflammatory types (IL-10, TGF-β)
Microbiome and allergies explained
The researchers explain: “There are many potential mechanisms involved in the relationship between the microbiota and allergies; one of them is immune system modulation in which the gut microbiota can modulate the immune system by inducing regulatory T-cells (Tregs) and promoting the production of anti-inflammatory cytokines such as IL-10.
“Tregs help maintain immune tolerance to harmless antigens, such as food proteins. In individuals with a disrupted gut microbiome, the reduced production of Tregs and anti-inflammatory cytokines may lead to the loss of immune tolerance and the development of food allergies.”
The report spotlights another potential mechanism linking allergy prevalence to the microbiome, by which the occurrence of dysbiosis may contribute to a compromised gut barrier; an event which may allow food allergens to cross the gut epithelium to trigger an immune response.
Whilst the collated evidence suggests a strong link between the microbiome, immunity and disease, the researchers stress the need for further RCTs to establish this relationship.
“Relationship between Gut Microbiota and Allergies in Children: A Literature Review”
by Alexandru Cosmin Pantazi, Cristina Maria Mihai, Adriana Luminita Balasa, Tatiana Chisnoiu, Ancuta Lupu, Corina Elena Frecus, Larisia Mihai, Adina Ungureanu, Mustafa Ali Kassim Kassim, Antonio Andrusca, Maria Nicolae, Viviana Cuzic, Vasile Valeriu Lupu and Simona Claudia Cambrea