## 4 Discussion  
Breast milk is an extremely important source of gut microbiota for newborns, since this is the single natural source of nutrients that they receive [17]. Up to 20 years ago, it was believed that breast milk was sterile and any bacteria present were associated with the infant's mouth or mother's skin [18]. However, [PERSON] et al. (2011) [19] identified the diversity and temporal stability of bacterial communities in three different milk samples collected from sixteen women in the USA within a period of one month. According to this analysis, nine genera were identified in every sample, including _Staphylococcus_, _Streptococcus_, _Serratia_, _Pseudomonas_, _Corynebacterium_, _Ralstonia_, _Propionibacterium_, _Spingomonas_, and _Bradyrhizobium_. [PERSON] et al. (2014) [20] characterized the human milk microbiota by culture and molecular techniques and reported the presence of _Enterococcus_ and _Lactobacillus_ in 9.5% and 15% of the tested samples, respectively. [PERSON] et al. (2014) [21] using qualitative PCR analysis reported the presence of lactobacilli and bifidobacterial DNA in 67.50% and 25.62%, respectively, of the samples analyzed (160 samples). [PERSON] et al. (2014) [22] reported the presence of _Lactobacillus_, _Enterococcus_, _Staphylococcus_, and _Bifidobacterium_ in milk collected from 47 women in Slovenia. [PERSON] et al. (2013) [23] identified as the most persistent bacterial groups in milk collected from women in Mozambique as _Staphylococcus_, the species _Streptococcus_ and _Lactobacillus_. In the present study PCR techniques were utilized in a large number of human milk samples (100) and detected two species of _Bifidobacterium_ and _Lactobacillus_. Moreover, the population may harbor different bacteria in different locations of the globe reflecting environmental, cultural, and nutritional differences. Several studies have reported differences in the composition and core microbiota of BM in different geographic locations [24; 25]. One study suggested that women in the USA might have less _Lactobacillus_ and _Bifidobacterium_ in their BM compared with women in Europe [19]. Recently, a link between the infant's and adults' gut microbiome has been reported, indicating that the infant's gut is initially colonized by bacteria originating from either breast milk or the environment [26]. At the same time, human milk contains high concentrations of non-digestible complex oligosaccharides (prebiotics), which reach the colon and subsequently nourish the infant gut microbiota [8]. It has been reported that the establishment of gastrointestinal tract microbiota in infants may be critical for maintaining the health and homeostasis of animals, including humans. Breast milk is a major factor for immunological programming, metabolome, and microbiome [9; 27]. However, further studies are indicated in order to highlight the correlation between human milk microbiota and the immune system stimulation in newborns, as up to now no evidence about this association has been reported [28]. Based only on the findings, we are still unable to suggest which maternal behavior serves best the infants' microbiota colonization, as it is unclear which kind of bacteria and at which concentration, serve optimally the colonization of infant gut and stimulate its immune system. Women aged less than 29 years, thinner with BMI less than 25, residing at rural areas, and consuming yogurt had a larger population of milk bacteria. As these \begin{table}
\begin{tabular}{c c c} \hline \hline
**Data** & **Number of Women** & **Total Positive Samples** \\ \hline Place of residence & & \\ Urban areas & 65 & 22 (33.8\%) \\ Rural areas & 35 & 34 (97.1\%) \\ Probiotics Supplements & & \\ Yes & 40 & 24 (60\%) \\ No & 60 & 32 (53.3\%) \\ Dairy Products & & \\ Yogurt & 70 & 45 (64.3\%) \\ Dairy products enriched with & 30 & 11 (36.7\%) \\ probiotics & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: _Cont._factors are indicators of a healthier condition of the mother, they could also be factors for a healthier infant microbiome.