Relationship Between Mutans Streptococci and Lactobacilli in the Oral Cavity and Intestine of Obese and Eutrophic Children With Early Childhood Caries-Preliminary Findings of a Cross-Sectional Study

Relationship between cariogenic bacteria and molar incisor hypomineralization in Brazilian schoolchildren

Background

Teeth with defects in their structure, such as the ones affected by molar-incisor hypomineralization (MIH), are more susceptible to carious lesions. Caries is a complex and multifactorial disease highly prevalent in childhood. The present research evaluated the relationship between the stages of MIH and cariogenic bacteria in children.

Methods

After examining 566 schoolchildren, four groups of 10 children each were formed: healthy (G1), mild MIH (G2 and G3), and severe MIH + caries (G4). Dental biofilm was assessed to quantify Streptococcus mutans (SM) and Lactobacillus spp. (LB) using real-time polymerase chain reaction (RT-PCR).

Results

LB counting in biofilm samples of healthy children (G1) and those with mild MIH characterized by white opacities (G2) were not significantly different. The same happened when the ones with yellow opacities (G3) were compared with severe MIH + caries (G4) (P>0.05). The post hoc Tukey test proved that G4 had greater levels of SM and LB when compared with G2 (P<0.05); however, the control group did not diverge from the others considering SM (P>0.05). Increased LB enhanced the severity of MIH [rate ratio (RR): 7.706; P=0.035].

Conclusions

LB was influenced by different degrees of MIH and the presence of caries and could guide clinical decisions and patients' recommendations to prevent carious lesions in MIH children.

Possible Relationship Between the Oral and Gut Microbiome, Caries Development, and Obesity in Children During the COVID-19 Pandemic

The COVID-19 pandemic has brought health damage and socioeconomic disruptions, together with lifestyle disorders around the world. Children are one of the most commonly affected, mainly due to social isolation and changes in eating habits and physical activities. This way, the risk of weight gain and obesity is possibly enhanced, as well as poor oral hygiene conditions and early childhood caries (ECC) development during the lockdown. In children under 6 years of age, ECC is defined as carious lesions in one or more primary teeth, with or without cavitation. Importantly, alterations in the oral microbiome caused by changes in children lifestyles have much more than a local impact on oral tissues, interplaying with the gut microbiome and influencing systemic environments. Recent studies have been exploring the oral health conditions, eating habits, and weight gain in the childhood population during the COVID-19 pandemic; however, there is a lack of information concerning the association among oral and gut microbiome, dental caries, and obesity in the COVID-19 era. In this context, this review aimed at analyzing a possible relationship between the oral and gut microbiome, caries, and obesity in children during the COVID-19 pandemic.

Exploring the Relationship between Salivary Levels of TNF-α, Lactobacillus acidophilus, Lactobacillus gasseri, Obesity, and Caries in Early Childhood

This research aimed to explore the relationship between tumor necrosis factor-α (TNF-α), Lactobacillus acidophilus (L. acidophilus), Lactobacillus gasseri (L. gasseri), obesity, and early childhood caries. After caries and obesity diagnosis based on the WHO criteria, 94 preschoolers were assessed. Unstimulated saliva was collected for analysis of TNF-α by the Milliplex system and for L. acidophilus and L. gasseri using real-time polymerase chain reaction (RT-PCR). In obese children, each unit increase in the body mass index (BMI), and the TNF-α levels was associated with a one-time increase in the number of decayed surfaces (p < 0.05). Meanwhile, in eutrophic preschoolers, the presence of L. gasseri and L. acidophilus was linked, respectively, to an increase of 3.04 and 1.59 times in the number of decayed surfaces (p < 0.05); in obese children, the presence of L. acidophilus was not significant (p > 0.05) and L. gasseri was shown as a possible protective indicator (RR:0.49−p < 0.05). In conclusion, TNF-α and BMI were connected to carious lesions only in obese preschoolers, suggesting that inflammation could be underscored when both pathologies are concomitant. The presence of both species of lactobacilli investigated was connected with early childhood caries in eutrophic children, whereas in obese children only L. gasseri was significant, and in an opposite way, reinforcing that obesity can modulate oral bacteria.

Exploring the Interplay Between Oral Diseases, Microbiome, and Chronic Diseases Driven by Metabolic Dysfunction in Childhood

Oral childhood diseases, such as caries and gingivitis, have much more than a local impact on the dentition and tooth surrounding tissues, which can affect systemic conditions. While the mouth is frequently exposed to microbial stressors that can contribute to an inflammatory state in the entire body, chronic disorders can also interfere with oral health. Sharing common risk factors, a dynamic interplay can be driven between 1. dental caries, gingivitis, and type I diabetes mellitus, 2. early childhood caries and obesity, and 3. caries and cardiovascular diseases. Considering that there are ~2.2 billion children worldwide and that childhood provides unique opportunities for intervention targeting future health promotion, this review is of prime importance and aimed to explore the relationship between the oral microbiome and oral chronic diseases driven by metabolic dysfunction in childhood.