In vitro comparison of biofilm formation and acidogenicity between human breast milk and other milk formulas

Evaluation of Streptococcus mutans Biofilm Formation and Acidogenicity of Infant Milk Formulas for Treating Cow Milk Allergy: An in vitro Study

INTRODUCTION

When infants cannot consume breast milk, the most commonly available alternative milk formula is cow milk-based. Due to a rise in the prevalence of cow milk protein allergy (CMPA) among children, this study aimed to assess the biofilm formation and acidogenicity of cow milk-based formulas as well as milk formulas suggested for children with CMPA.

METHODS

Cow milk-based formulas with 0%, 10%, or 18% sucrose added, partially hydrolyzed formula (pHF), extensively hydrolyzed formula (eHF), amino acid-based formula (AAF), and soy-based formulas with 0%, or 11% sucrose added were evaluated. Streptococcus mutans was used as a representative microorganism associated with caries. The acidogenicity after 24-h incubation was assessed by the pH of the formed biofilm and lactic acid formation. Biofilm formation was quantified using crystal violet staining. Additionally, the biofilm characteristics were determined using confocal laser scanning microscopy (CLSM). Comparisons were made among formulas without added sucrose to observe protein-based differences. Furthermore, formulas with different sucrose percentages were compared to explore the impact of sucrose content.

RESULTS

When comparing the formulas without added sucrose, the biofilm formation in the cow milk-based formula and pHF were significantly greater than the soy-based formula, eHF, and AAF. In the presence of S. mutans, all formulas reduced the biofilm pH below the critical enamel pH. The cow milk-based formula and AAF showed a significantly lower biofilm pH than the pHF, soy-based, and eHF groups, while the lactic acid production was markedly higher in the cow milk-based formula, pHF and AAF, compared with the eHF and soy-based formula. Adding sucrose into the cow milk-based and soy-based formulas substantially increased biofilm mass. The biofilm pH of the cow milk-based formulas, with or without sucrose, was significantly lower than that of the soy-based formulas. The CLSM indicated distinct biofilm characteristics among the different protein-based formulas, with sucrose supplementation promoting S. mutans aggregation in cow milk-based formula biofilm and increased density and intact biofilm in the soy-based formula.

CONCLUSION

All assessed milk formulas had caries-inducing factors, including those without supplemental sucrose. Among them, the eHF demonstrated the least caries-inducing factors, attributed to its minimal biofilm formation and the highest biofilm pH.

Prevalence of Dental Caries in Children in Mymensingh and Its Associated Risk Factors: A Cross-Sectional Study

Background: Children suffer from various oral and periodontal diseases. Dental caries is one of the most prevalent oral diseases among children in the world. This study was conducted to identify the prevalence and risk factors of dental caries in children in Mymensingh, Bangladesh. Methods: A cross-sectional study was conducted on 362 pediatric patients who attended the Dental Unit of Mymensingh Medical College from March to September 2019. The sample size was calculated using a statistical formula and the children were selected using a systematic random sampling technique. Children and their guardians were interviewed and data were recorded using a structured questionnaire. Risk factors were analyzed using multivariate logistic regression. Results: The overall prevalence of dental caries was 82.7%. The prevalence of caries was significantly higher in aged children (8–10 years) and also in rural, low-income, and illiterate families. Seven significant risk factors were identified that included residence in the rural area (OR: 7.31 [1.73–30.83]), a parental income of BDT ≤ 20,000 per month (OR: 4.75 [1.49–15.05]), reduced duration (≤1 min) of teeth cleaning (OR: 18.54 [2.05–168.17]), teeth cleaning before breakfast (OR: 93.30 [10.95–795.32]), the spoon-feeding method (OR: 12.57 [2.09–75.61]), long-term (37–48 months) breastfeeding (OR: 212.53 [8.69–5195.25]), and family oral problem (OR: 8.20 [2.57–26.16]). Conclusions: The prevalence of dental caries among the children in Mymensingh is very high and was associated with residence in rural areas, parental income, reduced duration of teeth cleaning, teeth cleaning before breakfast, the spoon-feeding method, long-term breastfeeding, and family oral problems.