In this study, the mean differences of D3, calcium level, zinc level, iron level and Mn level between study groups including (children with early dental caries and control group) were significant decrease (P≤ 0.05) in of D3, calcium level, zinc level, iron level and Mn level in children with early dental caries compared with the control group. In addition, There were statistically significant increases in total protein intake across groups (P<0.01) in total protein in children with early dental caries compared with control group. A total 50 saliva samples of children suffering from early dental caries, the findings indicated that, out of 50 samples, 42(84 percent ) provide positive culture, whereas 8(16 percent ) samples were negative culture. Out of 42 positive culture on different types of growth media, and the bacterial was identified according to gram stain, biochemical test and Vitek system, the results showed that, Streptococcus sobrinus was considered the most commonly bacterial isolates from children suffering from early dental caries in rate (42.8 percent ), followed by Streptococcus mutans in rate (30.9 percent ), (14.3 percent ) were related to Lactobacillus fermentum and Prevottella oralis in rate (11.9 percent ) (11.9 percent ) DNA was taken from all probable isolates that previously recognized as Streptococcus sobrinus by vitek2 system, These DNA samples were used in conventional polymerase chain reaction (PCR) to amplify primers specific to the 16s ribosomal RNA gene of Streptococcus sobrinus. After generating a 546 bp DNA fragment, gel electrophoresis showed that all 18 samples of Streptococcus sobrinus matched the allelic ladder. Molecular identification of 16srRNA gene was done for isolates that previously identified as Streptococcus mutans by vitek2 method. The findings indicated all of 13(100 percent ) provided good outcomes. Positive findings were identified by the presence of (282bp) bands when compared with allelic ladder. In addition, molecular detection of 16srRNA gene was done for (5) isolates Prevottella oralis isolates and the findings revealed that all 5(100 percent ) isolates had this gene. The positive findings were identified by the presence of (530 bp) band compared with allelic ladder.