DOI: https://doi.org/10.21203/rs.3.rs-2982958/v1
Recent data support a relationship between gut microbiota and various chronic diseases, with emerging evidence indicating a similar association with skin microbiota. This study examined the impact of delivery method on skin microbiota and explored its effects on skin diseases and allergies. Sociodemographic characteristics and allergy status, which are potential factors impacting skin microbiota, were also considered to investigate this relationship.
A cross-sectional study was conducted with 285 pediatric patients. The delivery method, allergy status, age, gender, consanguineous marriage and parental smoking exposure factors were questioned. The present diagnoses of the patients were also recorded by the dermatologist. Categorical variables were analyzed using chi-square analysis and a binary logistic test was used for further analysis.
Results revealed an increased risk of allergy and infectious skin diseases (viral, bacterial, fungal) in cesarean section (p < 0.001, p = 0.057). However, the risk of scabies was higher in normal delivery (p = 0.032). There was no significant relationship between the method of delivery and atopic or non-atopic dermatitis. For children born by cesarean section, parental smoking exposure and allergies were identified as factors increasing the risk of atopic dermatitis (p = 0.045, p = 0.018). On the other hand, children born by normal delivery and exposed to parental smoking had a decreased occurrence of non-atopic dermatitis (p = 0,051). Allergic children born by cesarean section exhibited a lower prevalence of infectious skin diseases (p = 0.037). In addition, a decrease in infectious skin diseases from 21,2% to 10,3% was observed after 3 years of age in normal births (p = 0,139).
The etiopathogenesis of diseases is a complex process influenced by multiple factors, including delivery method, sociodemographic characteristics, and other unidentified factors. These factors interact and exert their effects on the microbiota and other systems, including immunological mechanisms. Minimizing risk factors and creating a balanced and healthy microbiota, especially in early life, through personal and environmental measures, will be an important part of the microbiota-targeted treatment.
The increasing number of cesarean delivery method and changing disease profiles in recent years have made it necessary to compare the diseases in those born by normal vaginal delivery (NVD) and those born by cesarean section (CS). Especially in the last decades, the correlation of the increase in the prevalence of atopic and allergic diseases with the change in the choice of delivery method has led to new studies in this field.
The association between mode of delivery and atopic-allergic diseases (asthma, allergic rhinitis, atopic dermatitis, food allergy etc.) have been discussed in several studies, and delivery by CS is generally cited as a risk factor [1–7]. There are also studies suggesting that CS may be a risk factor for some immune-related diseases such as inflammatory bowel diseases, immune deficiencies, and connective tissue disorders [8, 9].
The hygiene hypothesis and microbiota come to the fore in explaining these relations. In the early stages of the hygiene hypothesis, it was predicted that infectious agents transmitted by unhygienic contact in the first years of life could prevent allergies [10–12]. Later, this approach was extended and its effects on autoimmune and inflammatory diseases were revealed by including commensal, symbiotic, and pathogenic microorganisms [13, 14].
At this point, the concept of the “microbiome” and the disorders caused by the disturbed balance in it come into play. The structure in which microorganisms come together and form collectively is called “microbiota”, and the structure that includes microorganisms, their genomes, and the environmental conditions in which they live is called the “microbiome” [15]. Until now, the functions of microbiota such as shaping the immune system, protecting against pathogens, and creating a physical barrier have been determined [16, 17]. If the balance in the microbiome is disturbed, which is called dysbiosis, then these functions can undergo disturbances and various disorders can occur. The most comprehensive studies on this subject have been conducted on the relationship between gut microbiota and various chronic diseases such as inflammatory bowel, endocrine and neurodegenerative diseases [18–20].
Microorganisms also form the skin microbiota as well as the gastrointestinal tract and provide a physical barrier to the skin, protect against other pathogens, and play an important role in the immune function of the skin [21, 22]. If an imbalance occurs in the commensal bacteria of the skin microbiota, it can lead to changes in the number and diversity of microorganisms on the skin. Consequently, this disruption in the physical and immune barrier functions of the skin can result in the development of both skin and systemic disorders.
Similar to gut microbiota, studies investigating the relationship between skin microbiota and diseases have increased recently. Atopic dermatitis (AD), seborrheic dermatitis, acne vulgaris, rosacea, and infectious skin diseases (ISD) are some of these diseases [22, 23]. Of course, since gut and skin microbiota play a role in a common immune response system, it would be more accurate to evaluate their effects on diseases together. AD in food allergy, dermatitis herpetiformis in celiac disease, and psoriasis in gluten intolerance demonstrate the importance of gut-skin axis [23]. The interaction between skin and gut appears to be modulated through the host immune system.
Both skin and gut microbiota can be affected by various factors such as age, gender, genetic structure, chronic disease status, diet, drug use, method of delivery, feeding with breast milk or formula, supplementary food, western-type nutrition, high-fat low-fiber foods, antibiotics, etc. [24].
One of the most important factors affecting skin flora in the first years of life is the method of delivery. Babies born by CS are predominantly colonized by commensal skin bacteria (Staphylococcus, Streptococcus, Corynebacterium, and Propionibacterium), while babies born by the normal cervicovaginal route are colonized by organisms found in the vaginal flora (Lactobacillus, Prevotella, Sneatia, Corynebacterium and Candida albicans) [25, 26]. These microbiota differences, which occur depending on whether the neonatal comes into contact with the microflora of the mother's birth canal, affect the Th1/Th2 balance and the anti-inflammatory cytokine response depending on the interaction of bacterial and viral components with the molecular structures of immune cells [27]. As a result, in addition to the local and physical effects caused by the content of the microbiota, chronic systemic inflammatory conditions may also occur due to altered immune responses. This demonstrates that the microbiota and thus the method of delivery can form the basis for a wide range of diseases.
Although the relationship between delivery method and allergic diseases has been examined in studies conducted so far, there are not many studies on its relationship with skin diseases. In the present study, unlike the existing studies, the effect on skin diseases was examined by considering sociodemographic characteristics that may affect the skin microbiota together with the delivery method.
285 pediatric patients under the age of 10 who visited the dermatology outpatient clinic of Kirsehir Training and Research Hospital were included in this cross-sectional prospective study. All patients and their parents participated in the study voluntarily, and an informed consent form was obtained from all of them. In the questionnaire applied to the participants (parents), age, gender, consanguineous marriage, family history of smoking, allergy-atopy status, and delivery methods were questioned. Patients with a definitive diagnosis of allergy-atopy and whose information was also confirmed by the hospital information system were included in the study.
For family history of smoking, antenatal and postnatal smoking exposure was questioned. Parents taking little or no care not to smoke in the presence of their children were considered as parental smoking exposure (PSE).
The present diagnoses of the patients at the dermatology outpatient clinic were also recorded by the dermatologist. In addition to the examination for complaints, patients underwent a complete systemic dermatologic examination, and those who had an extra dermatological diagnosis other than the main diagnosis were not included in the study.
Other dermatitis group diseases (except atopic dermatitis), which do not contain any allergic and atopic components, were grouped as "non-atopic dermatitis (NAD)". Among the patients, those with seborrheic dermatitis, irritant contact dermatitis, nummular dermatitis, napkin dermatitis, neurodermatitis, and photocontact dermatitis diagnoses were included in this group.
Factors that could affect the flora were tried to be excluded as much as possible. According to this; those who had an emergency CS for any reason, those who had any complications at birth, and those who used antepartum or intrapartum antibiotics were not included in the study. Those who had not breastfed for at least 6 months and a chronic disease in the mother or child were also considered as reasons for exclusion.
The dermatological diagnoses and allergy status of children born by NVD and CS were compared in terms of determined sociodemographic characteristics.
The data were analyzed with the SPSS 25.0 package program. Qualitative data are presented as numbers and percentages, while quantitative data are presented as means with standard deviation. Differences between categorical variables were examined with chi-square analysis. The binary logistic regression test was used for further analysis of the significance of the difference between groups. Statistical significance was set as p < 0.05.
The mean age of 285 pediatric patients included in the study was 5.25 ± 2.92. The youngest patient was 4 months old and the oldest one was 10 years old. 205 (71,9%) patients were between the ages of 0–3 and 80 (28,1%) were older than 3 years. While 147 (51.6%) of the patients were male, 138 (48.4%) were female. 46 (16,1%) patients had a history of consanguineous marriage (Table 1).
| N | % | |||
|---|---|---|---|---|
| Sex | Male | 147 | 51.6% | |
| Female | 138 | 48.4% | ||
| Age Groups | 0–3 | 205 | 71.9% | |
| > 3 | 80 | 28.1% | ||
| Consanguineous Marriage | Yes | 46 | 16.1% | |
| No | 239 | 83.9% | ||
| Smoking in Family | Yes | 143 | 50.2% | |
| No | 142 | 49.8% | ||
| Mode of Delivery | Normal | 124 | 43.5% | |
| Cesarean | 161 | 56.5% | ||
| Allergy | has | 58 | 20.4% | |
| not | 227 | 79.6% | ||
| Dermatological Diagnosis | Atopic Dermatitis | 75 | 26.3% | |
| Non-atopic Dermatitis | 59 | 20.7% | ||
| ISDa | 66 | 23.2% | ||
| Scabies | 27 | 9.5% | ||
| Other Diseases | 58 | 20.4% | ||
| a ISD includes viral, bacterial and fungal skin infections. ISD Infectious Skin Diseases | ||||
The number of children born by NVD was 124 (43.5%) and the number of children born by CS was 161 (56,5%). Half of the patients (50,2%) had a family history of smoking. Allergy history (pollen, dust, food, drug, bee allergy, allergic asthma and allergic rhinitis) was detected in 58 (20.4%) patients (Table 1).
When the current dermatological diagnoses of the patients were examined, there were 75 (26,3%) patients with AD and 59 (20,7%) with NAD (seborrheic dermatitis, irritant contact dermatitis, nummular dermatitis, napkin dermatitis, neurodermatitis, and photocontact dermatitis). 34 (11,9%) patients had a viral infection (molluscum or verruca vulgaris), 14 (4,9%) patients had impetigo, 18 (6,3%) patients had tinea or candida which were grouped as “infectious skin diseases”. There were 27 (9,5%) patients who had scabies. Other diagnoses (vitiligo, nevus, urticaria, acne vulgaris, hemangioma, pityriasis alba) in 58 (20,4%) patients were grouped as "other diseases". All characteristics of patients are shown in Table 1.
The delivery method of 45 (77,6%) of 58 patients with allergy diagnosis was CS. When the allergy status of the patients was compared with the mode of delivery, it was observed that allergy diagnoses were 3.3 times higher in those born by CS than in those born by NVD (p < 0.001, 95% CI = 1.695–6.472) (Table 2).
| Normal | Cesarean | P-value | ||||
| n | % | n | % | |||
| Allergy | has | 13 | 10,5% | 45 | 28,0% | < 0,001 |
| not | 111 | 89,5% | 116 | 72,0% | ||
| AD | has | 32 | 25,8% | 43 | 26,7% | 0,864 |
| not | 92 | 74,2% | 118 | 73,3% | ||
| NAD | has | 26 | 21,0% | 33 | 20,5% | 0,923 |
| not | 98 | 79,0% | 128 | 79,5% | ||
| ISDa | has | 22 | 17,7% | 44 | 27,3% | 0,057 |
| not | 102 | 82,3% | 117 | 72,7% | ||
| Scabies | has | 17 | 13,7% | 10 | 6,2% | 0,032 |
| not | 107 | 86,3% | 151 | 93,8% | ||
| a ISD includes viral, bacterial and fungal skin infections. AD Atopic Dermatitis, NAD Non-atopic Dermatitis, ISD Infectious Skin Diseases | ||||||
As a result of the comparison of delivery methods and dermatological diagnoses, no significant difference was found in both AD and NAD groups. However, scabies was found to be 2.4 times higher in those born by NVD (p = 0,032, 95% CI = 1,057 − 5,444). It was also noted in the present study that ISD were more common in those born by CS (p = 0,057). Comparisons of delivery methods and dermatological diagnoses are shown in Table 2.
In addition to examining the distribution of dermatological diagnoses by delivery method, the comparison was expanded to include the identified sociodemographic characteristics. Comparison of AD status in normal or cesarean delivery groups according to sociodemographic characteristics is shown in Table 3. Accordingly, the risk of AD was found to be significantly higher in children with PSE who were born by CS (p = 0,045), while no relationship was found in NVD (p = 0,308). No relationship was found between other sociodemographic characteristics (gender, age, consanguineous marriage) and delivery method in terms of AD. Allergy status was also examined in Table 3, and it was observed that allergic children had a risk for AD in both NVD (p = 0,076) and CS (p = 0,018), but this risk was 3.1 times higher in CS delivery (p = 0,038, 95% CI = 1,065-9.139 ).
| Normal Delivery | Cesarean Delivery | ||||||||||
| Atopic Dermatitis | Atopic Dermatitis | ||||||||||
| has | not | has | not | ||||||||
| n | % | n | % | P-value | n | % | n | % | P-value | ||
| Gender | Female | 13 | 21,3% | 48 | 78,7% | 0,260 | 24 | 31,2% | 53 | 68,8% | 0,221 |
| Male | 19 | 30,2% | 44 | 69,8% | 19 | 22,6% | 65 | 77,4% | |||
| Age | 0–3 | 19 | 22,4% | 66 | 77,6% | 0,194 | 34 | 28,3% | 86 | 71,7% | 0,425 |
| > 3 | 13 | 33,3% | 26 | 66,7% | 9 | 22% | 32 | 78% | |||
| CM | Yes | 8 | 29,6% | 19 | 70,4% | 0,608 | 4 | 21,1% | 15 | 78,9% | 0,553 |
| No | 24 | 24,7% | 73 | 75,3% | 39 | 27,5% | 103 | 72,5% | |||
| PSE | Yes | 19 | 29,7% | 45 | 70,3% | 0,308 | 27 | 33,8% | 53 | 66,2% | 0,045 |
| No | 13 | 21,7% | 47 | 78,3% | 16 | 19,8% | 65 | 80,2% | |||
| Allergy | has | 6 | 46,2% | 7 | 53,8% | 0,076 | 18 | 40% | 27 | 60% | 0,018 |
| not | 26 | 23,4% | 85 | 76,6% | 25 | 21,6% | 91 | 78,4% | |||
| CM Consanguineous Marriage, PSE Parental Smoking Exposure | |||||||||||
In the study, PSE was found to reduce the risk of NAD in children born by NVD (p = 0,051). However, there was no relationship between other sociodemographic characteristics and delivery methods in terms of NAD group diseases (Table 4).
| Normal Delivery | Cesarean Delivery | ||||||||||
| Non-atopic Dermatitis | Non-atopic Dermatitis | ||||||||||
| has | not | has | not | ||||||||
| n | % | n | % | P-value | n | % | n | % | P-value | ||
| Gender | Female | 14 | 23% | 47 | 77% | 0,593 | 14 | 18,2% | 63 | 81,8% | 0,486 |
| Male | 12 | 19% | 51 | 81% | 19 | 22,6% | 65 | 77,4% | |||
| Age | 0–3 | 18 | 21,2% | 67 | 78,8% | 0,933 | 26 | 21,7% | 94 | 78,3% | 0,529 |
| > 3 | 8 | 20,5% | 31 | 79,5% | 7 | 17,1% | 34 | 82,9% | |||
| CM | Yes | 4 | 14,8% | 23 | 85,2% | 0,375 | 4 | 21,1% | 15 | 78,9% | 1,000a |
| No | 22 | 22,7% | 75 | 77,3% | 29 | 20,4% | 113 | 79,6% | |||
| PSE | Yes | 9 | 14,1% | 55 | 85,9% | 0,051 | 14 | 17,5% | 66 | 82,5% | 0,349 |
| No | 17 | 28,3% | 43 | 71,7% | 19 | 23,5% | 62 | 76,5% | |||
| Allergy | has | 1 | 7,7% | 12 | 92,3% | 0,298a | 7 | 15,6% | 38 | 84,4% | 0,333 |
| not | 25 | 22,5% | 86 | 77,5% | 26 | 22,4% | 90 | 77,6% | |||
| a These have at least 1 cell with an expected count of less than 5. Therefore, the P-value obtained from Fisher's Exact Test took precedence over Pearson's Chi-square. CM Consanguineous Marriage, PSE Parental Smoking Exposure | |||||||||||
The risk of ISD was lower in children born by CS whose parents were consanguineous (p = 0,080) (Table 5). It was also noteworthy that the rate of ISD in the 0–3 age group in normal-born children decreased from 21,2% to 10,3% in children over 3 years of age (p = 0,139). In addition, ISD were found to be less common in allergic children born by CS (p = 0,037). For scabies, it was observed that sociodemographic characteristics and allergy status did not have a significant effect on it in both normal and cesarean deliveries.
| Normal | Cesarean | ||||||||||
| ISD | ISD | ||||||||||
| has | not | has | not | ||||||||
| n | % | n | % | P-value | n | % | n | % | P-value | ||
| Gender | Female | 10 | 16,4% | 51 | 83,6% | 0,699 | 18 | 23,4% | 59 | 76,6% | 0,281 |
| Male | 12 | 19% | 51 | 81% | 26 | 31% | 58 | 69% | |||
| Age | 0–3 | 18 | 21,2% | 67 | 78,8% | 0,139 | 33 | 27,5% | 87 | 72,5% | 0,934 |
| > 3 | 4 | 10,3% | 35 | 89,7% | 11 | 26,8% | 30 | 73,2% | |||
| CM | Yes | 6 | 22,2% | 21 | 77,8% | 0,570a | 2 | 10,5% | 17 | 89,5% | 0,080 |
| No | 16 | 16,5% | 81 | 83,5% | 42 | 29,6% | 100 | 70,4% | |||
| PSE | Yes | 14 | 21,9% | 50 | 78,1% | 0,213 | 19 | 23,8% | 61 | 76,3% | 0,311 |
| No | 8 | 13,3% | 52 | 86,7% | 25 | 30,9% | 56 | 69,1% | |||
| Allergy | has | 1 | 7,7% | 12 | 92,3% | 0,461a | 7 | 15,6% | 38 | 84,4% | 0,037 |
| not | 21 | 18,9% | 90 | 81,1% | 37 | 31,9% | 79 | 68,1% | |||
| a These have at least 1 cell with an expected count of less than 5. Therefore, the P-value obtained from Fisher's Exact Test took precedence over Pearson's Chi-square. ISD Infectious Skin Diseases, CM Consanguineous Marriage, PSE Parental Smoking Exposure | |||||||||||
When the relationship between sociodemographic characteristics and allergy status was evaluated according to the mode of delivery, there was no significant relationship between them (Table 6).
| Normal | Cesarean | ||||||||||
| Allergy | Allergy | ||||||||||
| has | not | has | not | ||||||||
| n | % | n | % | P-value | n | % | n | % | P-value | ||
| Gender | Female | 6 | 9,8% | 55 | 90,2% | 0,817 | 23 | 29,9% | 54 | 70,1% | 0,603 |
| Male | 7 | 11,1% | 56 | 88,9% | 22 | 26,2% | 62 | 73,8% | |||
| Age | 0–3 | 7 | 8,2% | 78 | 91,8% | 0,343a | 32 | 26,7% | 88 | 73,3% | 0,535 |
| > 3 | 6 | 15,4% | 33 | 84,6% | 13 | 31,7% | 28 | 68,3% | |||
| CM | Yes | 1 | 3,7% | 26 | 96,3% | 0,295a | 7 | 36,8% | 12 | 63,2% | 0,358 |
| No | 12 | 12,4% | 85 | 87,6% | 38 | 26,8% | 104 | 73,2% | |||
| PSE | Yes | 6 | 9,4% | 58 | 90,6% | 0,677 | 23 | 28,7% | 57 | 71,3% | 0,822 |
| No | 7 | 11,7% | 53 | 88,3% | 22 | 27,2% | 59 | 72,8% | |||
| a These have at least 1 cell with an expected count of less than 5. Therefore, the P-value obtained from Fisher's Exact Test took precedence over Pearson's Chi-square. CM Consanguineous Marriage, PSE Parental Smoking Exposure | |||||||||||
Recently, the number of studies examining the relationship between delivery methods and atopic-allergic diseases has increased. Asthma, allergic rhinoconjunctivitis, AD, and food allergies are among the most studied diseases in this regard [1–7]. In a large number of these studies, delivery by CS was associated with increased risk of allergic rhinitis, asthma, and food allergy [1, 3–5]. However, there are also studies showing that these diseases, and AD, may be unrelated to delivery methods [3, 6, 7, 28]. In a meta-analysis of Bager et al. with 26 studies, it was observed that delivery by CS is associated with a moderate risk increase for allergic rhinitis, asthma, and food allergy but not with inhalant atopy or AD [29].
In this study, there were patients with pollen, dust, food, drug, bee allergy, and allergic asthma in the patient group with allergies. Due to the low number of patients in allergy subtypes, all allergic diseases were grouped under a single allergy group and compared in terms of delivery method. As a result, patients born by CS were found to be 3.3 times more likely to develop any allergies (Table 2). Although the precise molecular and cellular mechanisms underlying the relationship between delivery method and allergies 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.
While a few studies have suggested a potential link between delivery method and AD [30], the majority of studies have not yielded conclusive evidence to substantiate this association [3, 28, 29]. Of course, along with genetic and environmental factors, the age of the patient and other sociodemographic characteristics are also the factors that may affect this relationship. In the study, no significant relationship was found between the delivery method and AD (p = 0,864) (Table 2). The effects of sociodemographic characteristics and allergy status on AD were also examined in normal and cesarean births separately (Table 3). While gender, age, and CM did not have a significant effect on AD in both normal and cesarean delivery, PSE significantly increased AD in CS (p = 0,045). It has been stated in the literature that active smoking and exposure to passive smoke are associated with a higher prevalence of AD in both children and adults [31]. Although the mechanism of this relationship is not yet known, it is likely that smoking may cause AD indirectly by creating dysbiosis in the microbiota in addition to its direct effect on the immune system and skin barrier. Consequently, it can be concluded that PSE in patients born by CS enhances the susceptibility to AD by influencing the patient's microbiota, immune system, or other underlying mechanisms.
It was also 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). Although the mechanism of AD is not fully understood, interaction between various genes, defects in skin barrier, infectious agents, host environments, and various immunologic responses are among the possible factors [32]. In addition, extensive research in recent years has revealed the importance of allergens in AD [33]. The skin's immunological response to the allergens in AD involves a complex process involving both IgE-mediated immediate immune responses and T-cell–mediated delayed immune responses [34]. In this intricate mechanism influenced by multifactorial elements, the presence of a balanced microbiota associated with NVD appears to provide partial compensation for the occurrence of AD in patients with allergies.
There are also studies showing that dysbiosis can cause seborrheic dermatitis [35]. On this basis, the effect of microbiota on NAD group diseases cannot be ignored. Although the relationship between AD and delivery method is mostly examined in the literature, it is an open topic for investigation in other dermatitis group diseases. In the present study, patients with other dermatitis (seborrheic dermatitis, irritant contact dermatitis, nummular dermatitis, napkin dermatitis, neurodermatitis, and photocontact dermatitis) were formed into a single group because they were few in number. Dermatitis types with an allergic or atopic component were not included in this group. Therefore, the group was named as “non-atopic dermatitis”. In the study, it was observed that the method of delivery had no effect in NAD as in AD (p = 0,923) (Table 2). However, unlike AD, allergy had no effect on NAD, and NAD diseases were less common in normal-born children with a PSE (Table 4). Such an effect of smoking has not been reported in the literature; on the contrary, besides the irritation caused by the toxic substances produced by cigarettes, it damages the skin barrier by disrupting the blood flow and oxygenation of the skin [36]. Although this result in the present study seems to be related to the low number of patients, it is worth evaluating the potential distinct effects of smoking on the microbiota of normal and cesarean births through non-atopic pathways.
In addition to providing a physical barrier, the skin microbiota also plays a role in the immune function of the skin [21, 22]. Hence, it can be hypothesized that the method of delivery, which can alter the skin microbiota, could potentially heighten the vulnerability to ISD. Although there is no detailed study on this subject, the results of the present study will be a reference for more comprehensive studies. In the study, all bacterial, viral, and fungal skin infections were grouped together as “infectious skin diseases”. On the other hand, scabies, which is slightly higher in number, was examined separately. As a result, it was observed that ISD were more common in those born by CS (p = 0,057) (Table 2). On the contrary, scabies were found to be significantly more common in those born by NVD (p = 0,032) (Table 2). Assuming that the relationship of the infectious group with CS is related to the disrupted microbiota and thus to an impaired immune response, it will be necessary to mention distinct factors for the scabies group. The higher prevalence of scabies in NVD may be attributed to differences in the mechanism of parasitic diseases or to the presence of distinct sociodemographic characteristics among those who opt for normal birth, potentially leading to living in less hygienic and more crowded environments. Alternatively, although less likely, it could be hypothesized that the microbiome of normal births may provide a more favorable environment for scabies infestation.
The effect of sociodemographic characteristics and allergy on ISD is shown in Table 5. Here, while the infection rate of 0–3 and 3 + age group patients is similar and high in CS, this rate decreases from 21.2–10.3% in NVD. In studies (especially on the gut microbiota), it is noteworthy that the microbiota shows great changes until the age of 2–3 years [37]. Zhu et al. showed that the method of delivery still has an effect on skin microbiota even up to 10 years of age [38]. In the present study, the decrease in ISD cases in the 3 + age group among those born by normal birth may be attributed to the microbiome being gradually shaped to enhance its physical and immunological protective functions over time. The high skin infection rate up to 10 years of age in CS (26,8%) was also likely due to the long-term effect of the altered microbiota.
The presence of allergies appears to be associated with a reduced risk of ISD in patients delivered by CS (p = 0,037) (Table 5). Although the exact immunological mechanism is unknown, it is worth mentioning that the diligent care provided to allergic children delivered by CS and their upbringing in a more hygienic environment may have potentially contributed to a decreased risk of ISD. Although it is not statistically significant, CM also seems to decrease the risk of ISD in CS (p = 0,080). Of course, in addition to systemic and local factors, many genetic and sociodemographic factors and low number of patients may also be effective in the formation of these results.
Unlike the ISD group, age, CM, and allergy status had no effect on scabies. The determined sociodemographic characteristics also had no effect on allergy status as well as scabies in normal or cesarean delivery (Table 6). Of course, more comprehensive and detailed studies are needed to confirm the results and explain the possible mechanisms.
The statistical significance was adversely impacted by the division of patients into smaller groups due to the extensive examination of numerous factors and diseases within the same study. For this reason, diseases were compared in normal and cesarean delivery categories separately. Further studies involving a large number of patients, which will be conducted separately for certain diseases and factors, will yield more significant results.
Dysbiosis within the microbiota can precipitate allergic, dermatological, or other pathologies via immunological, physiological, or alternative pathways. While the majority of investigations have concentrated on gut microbiota, there is a growing recognition of the significance of skin microbiota. Indeed, the various microbiota distributed throughout the body, despite their distinct locations and functions, can be perceived as a unified super-organism that communicates and maintains equilibrium with one another. Numerous factors have the potential to influence this equilibrium, and research has shown that CS is among these factors that can impact the balance of both gut and skin microbiota.
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, immunological, and local 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, including skin diseases. Therefore, restoring and maintaining a healthy and balanced microbiota can be regarded as a potential therapeutic approach in disease management.
The presence of divergent findings in the literature regarding the association between CS and AD prompts consideration of sociodemographic and other factors that may impact the microbiota. Although there was no relationship between AD and NAD with the mode of delivery in the present study, the fact that certain sociodemographic factors (age, PSE, CM) had divergent effects on it supports this view. Therefore, taking other factors into account when assessing the microbiota will significantly affect the results.
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 also constitute a significant aspect of the treatment.
Acknowledgments Author would like to thank Mustafa Metin, MD and Bensu Onentasci Demir, MD for support and feedback throughout this project.
Author contributions The design, data collection, analysis, and manuscript writing were exclusively conducted by ZM and the final draft was read and approved by her.
Funding No funding was received for conducting this study.
Financial or non-financial interests Author has no relevant financial or non-financial interests to disclose.
Data availability The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.
Conflict of interest None
Ethical Approval This study was conducted in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of Kirsehir Ahi Evran University (Date: 04.04.2023/ No:2023-07/48).
Consent to Participate All patients and their parents participated in the study voluntarily, and an informed consent form was obtained from all of the parents.
Consent for Publication Given by all parents, and the author.