In recent studies, the relationship between delivery methods and atopic-allergic diseases has gained increased attention. Asthma, allergic rhinoconjunctivitis, AD, and food allergies have been extensively studied in this context [1, 2]. In a meta-analysis conducted by Bager et al. with 26 studies, it was observed that CS moderately increases the risk of allergic rhinitis, asthma, and food allergy, but not inhalant atopy or AD [12].

In our study, patients with various allergies were grouped together due to a low number of patients in each subtype. Comparing the delivery method and allergic conditions, it was found that CS birth carried a 3.3 times increased risk of developing allergies (Table 2). Although the precise mechanisms underlying this relationship are still not clarified, it is clear that the early formation and maturation of the infant microbiome has a significant impact on immune system development and prevention of allergic diseases.

Some studies suggest a link between delivery method and AD [13], but most studies have not found conclusive evidence to support this association [12, 14, 15]. Ofcourse, factors such as genetics, environment, age, and sociodemographic characteristics may influence this relationship. In our study, no significant association was found between delivery method and AD (p=0.864) (Table 2).

Sociodemographic characteristics and allergy status were also analyzed in normal and cesarean births separately for their impact on AD (Table 3). Herein, PSE showed a significant association with increased AD in CS (p=0.045). Literature suggests that active smoking and passive smoke exposure are linked to higher AD prevalence in children and adults [16]. Smoking likely contributes to AD indirectly by disrupting the microbiota, in addition to its direct effects on the immune system and skin barrier. Consequently, it can be concluded that PSE in CS-born patients may enhance AD susceptibility by influencing the microbiota, immune system, or underlying mechanisms.

In our study, it was observed that having allergies increased the risk of AD in both normal and CS delivery, but this risk was 3.1 times higher in CS (p=0.038, 95% CI=1.065-9.139) (Table 3). The mechanism behind AD is not fully understood, but factors such as gene interactions, skin barrier defects, infectious agents, host environments, and immunological responses are believed to play a role [17]. Recent research emphasizes the importance of allergens in AD [18]. The skin’s immune response to allergens in AD involves complex processes, including both immediate IgE-mediated and delayed T-cell-mediated responses [19]. In this intricate mechanism influenced by multiple factors, a balanced microbiota associated with NVD seems to partially mitigate the occurrence of AD in individuals with allergies.

The study found that the delivery method had no effect on NAD similar to AD (p=0.923) (Table 2). However, unlike AD, allergy did not impact NAD, and NAD cases were less common in normally born children exposed to parental smoke (Table 4). This unexpected effect of smoking on NAD contradicts existing literature, which indicates that smoking irritates the skin due to toxic substances and disrupts blood flow and skin oxygenation [20]. Although this result may be influenced by the limited number of patients in the study, it is worth investigating the distinct effects of smoking on the microbiota of normal and cesarean-born children through non-atopic pathways.

ISD was more common in patients born by CS (p=0.057) (Table 2). Conversely, scabies cases were significantly more prevalent in those born by NVD (p=0.032) (Table 2). The association between the ISD and CS may be linked to disrupted microbiota and compromised immune response. However, distinct factors need to be considered for the scabies group. The higher incidence of scabies in NVD births could be attributed to differences in the mechanism of parasitic diseases or the presence of unique sociodemographic characteristics among those opting for normal birth, potentially leading to living in less hygienic and more crowded environments.

The infection rate in both the 0-3 and 3+ age groups was similar and high in CS, but it decreased from 21.2% to 10.3% in NVD (Table 5). Studies on the gut microbiota indicate significant changes until the age of 2-3 years [21]. Zhu et al. demonstrated that the delivery method continues to affect skin microbiota even up to 10 years of age [22]. In this study, the decrease in cases of ISD among the 3+ age group born via NVD may be attributed to the gradual development of the microbiome, enhancing its physical and immunological protective functions over time. The elevated ISD rate in CS up to 10 years of age (26.8%) is likely due to the long-term impact of altered microbiota.

Allergies were found to be associated with a decreased risk of ISD in patients delivered by CS (p=0.037) (Table 5). The exact immunological mechanism is unknown, but it is worth noting that attentive care provided to allergic children born via CS and their upbringing in a hygienic environment may have contributed to these results. Additionally, although not statistically significant, CM appears to decrease the risk of ISD in CS (p=0.080). It is important to consider that besides systemic and local factors, genetic and sociodemographic factors, as well as the limited number of patients, may have influenced these results.

The high risk of ISD and allergies in CS reveals the importance of a balanced and healthy microbiota in the postpartum period. Taking into consideration the systemic, local, and immunological impacts of the microbiota, it can be inferred that the microbiota could play a crucial role as an etiological factor in a broad range of diseases. It is also crucial to consider that certain sociodemographic characteristics can have an impact on the microbiota.

Among so many factors, it is necessary to develop patient-specific treatment methods rather than disease. In addition to the standard treatments for diseases, establishing a balanced and healthy microbiota, particularly during early childhood, and maintaining its stability through personal and environmental measures will constitute a significant aspect of the treatment.