Association of Salivary Microbial, Fungal Population and Salivary Acidity with Obesity in Children

Childhood obesity is an increasing global health concern associated with both systemic and oral complications. While studies suggest links between body mass index (BMI) and oral health markers, these relationships remain poorly defined.

This study evaluated the association between salivary microbial/fungal populations, salivary acidity, and obesity in children.

In this cross-sectional descriptive study (2021-2022), 90 children aged 8-12 from public schools in Qom, Iran, were categorized into three groups based on BMI: 30 children with normal weight, 30 overweight children, and 30 obese children. Demographic information, including parental education and occupation, was recorded. Unstimulated saliva samples were collected using the passive drooling method. A total of 0.5 ml of saliva was mixed with 5 ml of phosphate-buffered saline (PBS) and homogenized thoroughly by using a shaker. Microbiological analysis involved quantifying colonies of Streptococcus mutans, Lactobacillus, and Candida albicans and measuring salivary pH using a calibrated pH meter. Data were analyzed using appropriate statistical tests with significance set at p Value< 0.05.

No significant relationship was found between childhood obesity and parental education (father's p= 0.051, mother's p= 0.862) or occupation (father's p= 0.224, mother's p= 0.893). Salivary pH did not differ significantly between weight groups (p= 0.639). Overweight children had lower Lactobacillus levels (p= 0.857), and obese children had higher Streptococcus mutans levels (p= 0.777); though neither correlated significantly with BMI. Candida albicans colonies showed a significant negative correlation with childhood obesity (p= 0.046). Significant associations were also observed between Streptococcus mutans (p= 0.046) and Lactobacillus (p= 0.002) levels with Candida albicans levels.

Although oral bacterial levels did not differ significantly across weight groups, fungal species, particularly Candida albicans, varied significantly. A negative association between obesity and Candida albicans counts suggests that obesity may impact the salivary microbial ecosystem, highlighting the need for further research into its systemic and oral health implications.