Microbiome Composition and Its Impact on the Development of Allergic Diseases

Abstract

Allergic diseases, such as food allergy (FA), atopic dermatitis (AD), and asthma, are heterogeneous inflammatory immune-mediated disorders that currently constitute a public health issue in many developed countries worldwide. The significant increase in the prevalence of allergic diseases reported over the last few years has closely paralleled substantial environmental changes both on a macro and micro scale, which have led to reduced microbial exposure in early life and perturbation of the human microbiome composition. Increasing evidence shows that early life interactions between the human microbiome and the immune cells play a pivotal role in the development of the immune system. Therefore, the process of early colonization by a "healthy" microbiome is emerging as a key determinant of life-long health. In stark contrast, the perturbation of such a process, which results in changes in the host-microbiome biodiversity and metabolic activities, has been associated with greater susceptibility to immune-mediated disorders later in life, including allergic diseases. Here, we outline recent findings on the potential contribution of the microbiome in the gastrointestinal tract, skin, and airways to the development of FA, AD, and asthma. Furthermore, we address how the modulation of the microbiome composition in these different body districts could be a potential strategy for the prevention and treatment of allergic diseases.

Probiotics in the prevention and treatment of atopic dermatitis

“…A recent Cochrane Review 15 included 39 randomized controlled trials with 2599 randomized participants of either gender, aged from the first year of life through to 55 years (only six studies assessed adults) 1 . The probiotics included were bacteria of the Lactobacillus and Bifidobacteria species taken alone or in combination with other probiotics for a period ranging from four weeks up to six months.…”

“…The early microbiota is proposed to have a role in the pathogenesis of atopic dermatitis (AD) 1 . Therefore, it has been argued that modulating the host's gut microbiota could be an approach for preventing and/or treating allergic diseases.…”

“…Zhao et al analyzed eight clinical trials (741 infants) and revealed that the overall pooled change in the Scoring Atopic Dermatitis index (95% CI) in infants treated with Lactobacillus strains was −5.71 (−8.37, −3.04), P < .01. 14 Subgroup analysis revealed that the effect was −8.32 (−16.35, −0.28) in moderate-to-severe patients and higher for treatment duration < 8 weeks (−8.65 (−14.32, −2.98)).A recent Cochrane Review15 included 39 randomized controlled trials with 2599 randomized participants of either gender, aged from the first year of life through to 55 years (only six studies assessed adults) 1. The probiotics included were bacteria of the Lactobacillus and Bifidobacteria species taken alone or in combination with other probiotics for a period ranging from four weeks up to six months.…”

Advances and novel developments in environmental influences on the development of atopic diseases

“…60 Characterizing the constituents of the human gastrointestinal, skin, and airway microbiota as well as microbial peptides and metabolites that influence host immunity and immune response to allergens in food allergy, atopic dermatitis, and asthma is the focus of ongoing research. 60,61 Composition of the microbiome has been found to vary even within an organ system, such as the skin, with variations in the microbiome observed between the scalp, arm, and axilla. 62 Advances in our understanding of host-microbe interactions have been made possible by 16S rRNA sequencing, which permits precise identification and quantification of bacteria.…”

Dietary Interventions and Nutritional Factors in the Prevention of Pediatric Asthma

“…Given the central role of the first 1,000 days of life for the development of the immune system, numerous studies have investigated the role of intrauterine exposures in the pathogenesis of allergic diseases (11). Recent evidence supports the hypothesis that colonization by a healthy gut microbiome during early infancy can affect the immune system development and the predisposition to immune-mediated diseases later in life, including asthma (12,13). It has been shown that the maternal diet during pregnancy could influence the composition of the gut microbiome and the immune system development of the neonate, and therefore potentially affect the predisposition to asthma and allergies in childhood (14,15).…”