**2.2 Exploration of factors influencing the neonatal microbiome, including mode of delivery**

The composition and development of the neonatal microbiome are influenced by various factors, including the mode of delivery. Here, we explore the factors that impact the neonatal microbiome, with a specific focus on the influence of delivery mode.

#### *2.2.1 Mode of delivery*

Vaginal delivery: During a vaginal birth, the newborn is exposed to the microorganisms present in the birth canal, including bacteria from the maternal vaginal and fecal microbiota. This exposure leads to the colonization of the neonate's gut, skin, and mucosal surfaces with a diverse range of microorganisms, primarily bacteria. Infants born vaginally tend to have a microbiome composition characterized by an abundance of beneficial bacteria, such as Bifidobacterium and Lactobacillus species [9–11].

Cesarean section (C-section): Bypassing the birth canal, a C-section includes the surgical delivery of the infant through an incision in the belly and uterus. Infants delivered by C-section experience a different level of microbial exposure than those delivered vaginally. They are initially colonized by microorganisms present in the surrounding environment, including skin and hospital surfaces. The microbiome of C-section-born infants tends to be less diverse and dominated by bacteria associated with the hospital environment [11–13].

#### *2.2.2 Maternal factors*

Maternal microbiota: The composition of the maternal microbiota, particularly the vaginal and gut microbiota, can influence the initial colonization of the neonatal microbiome. The transfer of maternal microorganisms during vaginal birth contributes to the establishment of the neonatal microbiome. Differences in the maternal microbiota, such as bacterial diversity and composition, can impact the microbial transmission to the newborn.

Maternal health and lifestyle: Maternal health conditions, such as obesity, diabetes, and gestational infections, can influence the microbial composition and diversity transferred to the neonate. Maternal lifestyle factors, including diet, antibiotic use, and exposure to environmental factors, may also affect the microbiota and potentially impact the neonatal microbiome [11–13].

#### *2.2.3 Breastfeeding*

Breast milk composition: Prebiotics, other bioactive substances, and a wide variety of helpful bacteria are all present in breast milk, which helps some bacteria flourish in the neonatal gut. Lactobacillus and Bifidobacterium, two helpful bacteria that support the development of a healthy microbial community in the infant's gut, are found in breast milk.

Mode of feeding: Neonatal microbiota composition has been linked to breastfeeding vs. formula feeding. In order to encourage the construction of a healthy gut microbiome in the infant, breast milk helps to generate a more diversified and advantageous microbial community [11–13].

#### *2.2.4 Environmental exposures*

Early life exposures: Factors, such as the home environment, hygiene practices, and exposure to pets or siblings, can influence the neonatal microbiome. These early life exposures can introduce additional microorganisms and potentially impact the diversity and composition of the neonatal microbiome.

It makes it easier to understand the intricacies of microbial colonization throughout the early stages of life to be aware of the factors that affect the newborn microbiome such as the manner of delivery, maternal factors, nursing, and environmental exposures. It highlights how crucial it is to take these aspects into account when examining how interventions, such as vaginal seeding, affect the newborn microbiota and health consequences [11–13].

#### **2.3 Introduction to vaginal seeding and its potential benefits and controversies**

Vaginal seeding is an emerging practice that aims to mimic the microbial exposure of a vaginal birth for infants born *via* cesarean section (C-section). It involves transferring maternal vaginal fluids, including microorganisms, onto the newborn shortly after birth. The rationale behind vaginal seeding is to introduce beneficial bacteria from the mother's vaginal microbiota to the newborn, potentially influencing the establishment of the neonatal microbiome and promoting optimal immune development [13–17].

The potential benefits associated with vaginal seeding are rooted in the understanding that the early colonization of the neonatal gut with beneficial bacteria plays a crucial role in immune system maturation, metabolic processes, and protection against certain health conditions. Proponents of vaginal seeding hypothesize that by replicating the microbial exposure of a vaginal birth, this intervention may help restore the microbiome composition of C-section-born infants, making it more similar to that of vaginally delivered infants. This, in turn, could potentially lead to a reduced risk of certain health conditions such as allergies, asthma, obesity, and autoimmune disorders.

However, the practice of vaginal seeding is not without controversy and debates. One of the main concerns revolves around the potential transmission of harmful

#### *Vaginal Seeding in Term Cesarean Section Is a Mandatory Condition for Improvement… DOI: http://dx.doi.org/10.5772/intechopen.114043*

microorganisms from the maternal vaginal canal to the newborn. This includes the risk of transmitting pathogens such as group B Streptococcus, herpes simplex virus, or antibiotic-resistant bacteria. The lack of standardized protocols for evaluating the maternal vaginal microbiota and screening for infections poses challenges in ensuring the safety of vaginal seeding [13–17].

Additionally, the scientific evidence supporting the efficacy and safety of vaginal seeding is limited and often based on small-scale studies or anecdotal reports. The existing studies on vaginal seeding have reported conflicting findings, making it challenging to draw definitive conclusions. There is a need for larger, well-designed studies to evaluate the impact of vaginal seeding on the neonatal microbiome, immune development, and long-term health outcomes. Moreover, the practice of vaginal seeding is not currently recommended by major healthcare organizations, such as the American College of Obstetricians and Gynecologists (ACOG), due to safety concerns and the lack of sufficient evidence. In particular, the ACOG recommends that clinicians and patients avoid this practice, unless as part of an approved research protocol [13–18].

Addressing the controversies and debates surrounding vaginal seeding requires further research and scientific investigation. This includes developing standardized protocols for assessing the maternal vaginal microbiota, screening for infections, and evaluating the short- and long-term effects of vaginal seeding on neonatal health outcomes. The potential benefits and risks of vaginal seeding need to be carefully considered and weighed against each other with a focus on ensuring the safety and well-being of the newborns.
