Probiotics in the treatment of pediatric allergic rhinitis: An old story with a new entity

Allergic rhinitis is a chronic immunoglobulin E (IgE)-mediated inflammation of the nasal mucosa that usually arises after exposure to sensitized allergens. It is defined by chronic nasal symptoms, like nasal blockage, sneezing, nasal pruritus (itching), and mostly clear nasal discharge. Sensitization to indoor allergens occurs before sensitization to pollens, and it starts to develop during the first year of life. It is exceedingly challenging to identify and distinguish allergic rhinitis in the first two or three years of life because of viral respiratory infections, which commonly affect young children and elicit similar symptoms. In children, sleep, cognitive function, growth and development, academic performance, and quality of life can all be significantly affected by poorly controlled allergic rhinitis [1], [2].

Current available treatments

Normally, the majority of symptoms of allergic rhinitis can be efficiently treated with numerous available traditional therapeutic options which include:

• Allergen avoidance

• Pharmacotherapy (oral or intranasal H1-antihistamines, intranasal corticosteroids, and leukotriene receptor antagonists)

• Immunotherapy

However, most pharmacotherapeutic agents are associated with side effects such as fatigue, drowsiness, and dizziness that interfere with the children's daily activities and academic performance. Immunotherapy may provide long-term relief from allergic symptoms, by exposing patients to higher concentrations of allergens to develop desensitization. However, a high level of compliance is required and the treatment cycle is always lengthy (3-5 years). Nevertheless, in some patients, the disease itself remains uncontrolled despite the use of the currently recommended therapies. As a result, more effective and well-tolerated therapies have been required that target the etiologic pathways of underlying allergic diseases rather than only treating their symptoms [2].

Is treating allergic rhinitis with probiotics a pragmatic way?

Probiotics have recently received a lot of attention as a potential alternative therapy for allergic rhinitis that may control the host immune system. There are numerous varieties of probiotics in the human body, and they can be roughly categorized based on the following five groups:

• Streptococcus

• Lactobacillus

• Bifidobacterium

• Bacillus

• Other probiotics

The best probiotics are made of human origin, are risk-free, and are devoid of pathogenic or virulent factors as well as carriers that can lead to antibiotic resistance. Probiotics also exhibit a significant ability to survive in the intestinal environment (acidic pH, enzymes, bile salts, etc.) while also having major significant beneficial impacts on the body by fighting pathogens and boosting the immune system [3]. Certain probiotic strains can be used effectively to reduce the characteristic nasal and ocular symptoms of allergic rhinitis in both children and adults, enhancing the quality of life and productivity at work. Probiotics have been found to have a variety of effects, including:

• The regulation of T helper (Th1/Th2) balance

• Restoration of disturbed intestinal microbiota

• Decrease in Th2 cell inflammatory factors

• Increase in Th1 cell inflammatory factors

• Changes in allergy-related immunoglobulins and cell migration

Moreover, oral probiotics show benefits for individuals with restricted activity or allergic rhinitis with more attacks and longer attack duration. Probiotics are remarkably effective in both preventing and treating allergic rhinitis, but more research is needed to determine how exactly they work [3].

Lights and shadows of a probiotics treatment for pediatric allergic rhinitis

Probiotics can alleviate allergic rhinitis symptoms and enhance the quality of life. Recent research in this direction has shown that probiotics can be used to treat allergic rhinitis in adults. According to previous researchers, probiotics may help allergic rhinitis patients to improve their symptoms and quality of life. Applying the findings of the studies in adult patients to pediatric patients, however, may not be accurate due to the difference in the age and immune system, as well as the development characteristics. Also, relevant research on children is limited. However, due to the changes in age, immune system, and developmental traits, applying adult study findings to pediatric patients may not be appropriate. There is also a dearth of pertinent research on children. Probiotic use in children with allergic rhinitis has been extensively explored in randomized controlled trials, although opinions are still conflicted. According to previous research, regular oral probiotic use produces superior outcomes than pharmacological therapy alone by lowering nasal symptoms and medication scores. It also improved the quality of life, immunologic parameters, and lung function in children. Nevertheless, there is a need for more thorough research supporting the use of probiotics in pediatric allergic rhinitis [2].

Is there a positioning for probiotics?

Probiotics are a valuable therapeutic option, particularly for young children, to modify the progression of allergic diseases like rhinitis. The promise of probiotic therapy for pediatric allergic rhinitis may be realized shortly. The beneficial effects of probiotics partially improve pediatric allergic rhinitis outcomes in a minimally harmful way, by altering immunological balance and lowering the usage of anti-allergic medications. Thus, the substantial efforts that have been made and the encouraging outcomes of the probiotics research have opened up new avenues that allow us to change our perspectives toward therapeutic options for allergic diseases, including allergic rhinitis.

References

1. L. M. Wheatley and A. Togias, “Allergic Rhinitis,” N Engl J Med, vol. 372, no. 5, pp. 456–463, Jan. 2015, DOI: 10.1056/NEJMcp1412282.

2. X. Wang, X. Tan, and J. Zhou, “Effectiveness and safety of probiotic therapy for pediatric allergic rhinitis management: A systematic review and meta-analysis,” International Journal of Pediatric Otorhinolaryngology, vol. 162, p. 111300, Nov. 2022, DOI: 10.1016/j.ijporl.2022.111300.

3. P. Liu et al., “Research Advances in the Treatment of Allergic Rhinitis by Probiotics,” JAA, vol. 15, pp. 1413–1428, Oct. 2022, DOI: 10.2147/JAA.S382978.