**4. Microbiome and metabolic health**

The genetic set of the microbiome provides extensive metabolic and immunological potential. Genetic and environmental factors influence microbiota composition and function, and these complex host-microbe interactions contribute to health and disease state. The gut microorganisms have a significant role in epithelial barrier function, fermentation of dietary fiber, synthesis of vitamins, regulation of the immune system, and defense against pathogens. This community has also been found to play some important roles in angiogenesis, brain development, and behavior [15, 42].

Given the various functions of microbiota, alterations in this community (dysbiosis) have been associated with a range of non-communicable diseases, including obesity, diabetes, inflammatory bowel disease, metabolic syndrome, cancer, asthma, allergy, non-alcoholic fatty liver disease (NAFLD), and even certain neuropsychiatric disorders [43–46].

The early-life microbiota presents a unique microbial communities consisting of numerous bacteria and viruses. A part of this microbiota already has identified by using different kinds of technologies including 16S rRNA sequencing. Over the last decades, the paradigm of a sterile condition *in utero* is shifting to the possibility of the prenatal maternal-fetal coexist with commensal and symbiotic microbes. Recent studies also support a prenatal microbial milieu through bacterial presentation in placenta, amniotic fluid, umbilical cord, and meconium. In addition, there are emerging reports of the prenatal microbial composition on fetal and postnatal development [47–49].

A maternal condition during pregnancy and postnatal period can provide a critical window for susceptibility to microbiome development through environmental factors such as mode of delivery and maternal diet. The delivery mode has a crucial function in the early gut microbiota composition. Infants by vaginally delivery have higher levels of intestinal *Bacteroides, Lactobacilli*, and *Bifidobacterium*, which are commonly present in vaginal route, whereas infants by cesarean section (C-section) have higher level of *Enterococcus*, and *Clostridium* from skin, oral, or hospital environment [47, 50].

The gestational age is another important influencer for gut microbiome development. It is reported that the gut microbiota of preterm infants has shown delayed colonization by limited microbial diversity and this risk of gut dysbiosis.

**179**

**5. Conclusions**

**Conflict of interest**

*Metabolic Programming and Nutrition DOI: http://dx.doi.org/10.5772/intechopen.92201*

bacteria than those in full-term infants [51, 52].

The gut microbiota composition of preterm infants has *Enterobacter, Enterococcus, Escherichia*, and *Klebsiella* predominantly and relatively low level of gammaproteo-

may affect the DNA methylation through breast milk, which influences the gut microbiome composition. Breastfeeding is associated with greater *Bacteroides* and *Bifidobacterium*, which are folate producers, thereby affecting DNA methylation. Breast milk oligosaccharides alter core microbiome community that secretes shortchain fatty acid (SCFA). Therefore, the strain of *Bifidobacterium* and *Lactobacillus* by breastfeeding could make intestinal contents more acidic with SCFA, which modulate a defense mechanism against pathogens and have epigenetic effects [53–55]. The microbial metabolites such as B vitamins, short-chain fatty acids, polyphenols, and omega 3 polyunsaturated fatty acids are reported to influence epigenetic mechanisms. Maternal gut microbe metabolites can change the host cellular levels of important epigenetic modifiers like histone acetyl transferases (HATs), histone deacetylases (HDACs), DNA methyltransferases (DNMTs), and DNA demethylases. The microbial SCFAs from the fermentation of dietary fiber were shown to maintain the nervous and immune systems through epigenetic modification. These, acetate and butyrate are the most abundant in the intestinal tract and can be produced with acetyl-CoA which is universal acetyl group donor for histone acetylation [45, 47]. Different essential functions for human health develop correspondingly with gut microorganism increase, including vitamin biosynthesis, energy extraction from the diet, gut barrier function, and immune system maturation. The immune system of neonates is immature and requires the exposure of gut bacteria to develop properly. Depending on the health of the mother, maternal bacterial communities may already be imbalanced when passed on to the infant. In children, metabolic diseases, including obesity, insulin resistance, and NAFLD, along with other related immune-based diseases, are associated with modifications in infant gut bacterial composition; however, the mechanisms involved are not entirely clear [43, 56].

It is known that there is a close relationship between maternal obesity, diet consumption during pregnancy and lactation, and their impact on the microbiota of both mother and infant, including their links to early gut colonization and innate

For the most effective confrontation of metabolic diseases, which represent a great burden of global health, it is important to consider the issues involving early nutrition, metabolic programming, and epigenetics. Thus, the adoption of health policies during critical stages of development, including pregnancy, lactation, and

immunity in the infants that drive an increased risk for metabolic diseases.

puberty, is essential to achieve long-term consistent results.

The authors declare no conflict of interest.

It is known that breastfeeding influences the infant microbiota. The microbiome

### *Metabolic Programming and Nutrition DOI: http://dx.doi.org/10.5772/intechopen.92201*

*New Insights into Metabolic Syndrome*

**4. Microbiome and metabolic health**

*involved in the susceptibility to obesity and metabolic changes.*

neuropsychiatric disorders [43–46].

behavior [15, 42].

**Figure 2.**

development [47–49].

environment [47, 50].

The genetic set of the microbiome provides extensive metabolic and immunological potential. Genetic and environmental factors influence microbiota composition and function, and these complex host-microbe interactions contribute to health and disease state. The gut microorganisms have a significant role in epithelial barrier function, fermentation of dietary fiber, synthesis of vitamins, regulation of the immune system, and defense against pathogens. This community has also been found to play some important roles in angiogenesis, brain development, and

*Scheme demonstrative of developmental origins of health and disease, during prenatal and early postnatal life,* 

Given the various functions of microbiota, alterations in this community (dysbiosis) have been associated with a range of non-communicable diseases, including obesity, diabetes, inflammatory bowel disease, metabolic syndrome, cancer, asthma, allergy, non-alcoholic fatty liver disease (NAFLD), and even certain

The early-life microbiota presents a unique microbial communities consisting of numerous bacteria and viruses. A part of this microbiota already has identified by using different kinds of technologies including 16S rRNA sequencing. Over the last decades, the paradigm of a sterile condition *in utero* is shifting to the possibility of the prenatal maternal-fetal coexist with commensal and symbiotic microbes. Recent studies also support a prenatal microbial milieu through bacterial presentation in placenta, amniotic fluid, umbilical cord, and meconium. In addition, there are emerging reports of the prenatal microbial composition on fetal and postnatal

A maternal condition during pregnancy and postnatal period can provide a critical window for susceptibility to microbiome development through environmental factors such as mode of delivery and maternal diet. The delivery mode has a crucial function in the early gut microbiota composition. Infants by vaginally delivery have higher levels of intestinal *Bacteroides, Lactobacilli*, and *Bifidobacterium*, which are commonly present in vaginal route, whereas infants by cesarean section (C-section)

have higher level of *Enterococcus*, and *Clostridium* from skin, oral, or hospital

The gestational age is another important influencer for gut microbiome development. It is reported that the gut microbiota of preterm infants has shown delayed colonization by limited microbial diversity and this risk of gut dysbiosis.

**178**

The gut microbiota composition of preterm infants has *Enterobacter, Enterococcus, Escherichia*, and *Klebsiella* predominantly and relatively low level of gammaproteobacteria than those in full-term infants [51, 52].

It is known that breastfeeding influences the infant microbiota. The microbiome may affect the DNA methylation through breast milk, which influences the gut microbiome composition. Breastfeeding is associated with greater *Bacteroides* and *Bifidobacterium*, which are folate producers, thereby affecting DNA methylation. Breast milk oligosaccharides alter core microbiome community that secretes shortchain fatty acid (SCFA). Therefore, the strain of *Bifidobacterium* and *Lactobacillus* by breastfeeding could make intestinal contents more acidic with SCFA, which modulate a defense mechanism against pathogens and have epigenetic effects [53–55].

The microbial metabolites such as B vitamins, short-chain fatty acids, polyphenols, and omega 3 polyunsaturated fatty acids are reported to influence epigenetic mechanisms. Maternal gut microbe metabolites can change the host cellular levels of important epigenetic modifiers like histone acetyl transferases (HATs), histone deacetylases (HDACs), DNA methyltransferases (DNMTs), and DNA demethylases. The microbial SCFAs from the fermentation of dietary fiber were shown to maintain the nervous and immune systems through epigenetic modification. These, acetate and butyrate are the most abundant in the intestinal tract and can be produced with acetyl-CoA which is universal acetyl group donor for histone acetylation [45, 47].

Different essential functions for human health develop correspondingly with gut microorganism increase, including vitamin biosynthesis, energy extraction from the diet, gut barrier function, and immune system maturation. The immune system of neonates is immature and requires the exposure of gut bacteria to develop properly. Depending on the health of the mother, maternal bacterial communities may already be imbalanced when passed on to the infant. In children, metabolic diseases, including obesity, insulin resistance, and NAFLD, along with other related immune-based diseases, are associated with modifications in infant gut bacterial composition; however, the mechanisms involved are not entirely clear [43, 56].
