Children's gut microbiota predicts the efficacy of obesity treatment.

Higher baseline Shannon and Simpson diversity indices were associated with greater improvements in metabolic risk score (MetScore) after one year of obesity intervention.

• Study included 41 children with obesity aged 8-14 years.
• Faecal samples were collected at baseline and after one year of dietary intervention.
• Associations were evaluated using Spearman's correlation and linear regression models.
• Intervention success was defined by improvements in MetScore, which incorporated anthropometry, triglycerides, HDL-cholesterol, HOMA-IR, and systolic and diastolic blood pressure.

Faecalibacterium was the most influential microbiota feature for predicting obesity intervention success in the Random Forest classifier.

• Faecalibacterium had the highest importance score in the Random Forest (RF) model.
• The RF model achieved an AUC of 0.876 for MetScore improvement.
• The RF model achieved an AUC of 0.873 for BMI z-score improvement.
• Greater abundance of Faecalibacterium at baseline was associated with greater improvements in MetScore.

Eighty-four microbial features differed significantly between MetScore response groups.

• Differential abundance was analyzed using ANCOM-BC2.
• 84 features differed between MetScore response groups at FDR < 0.05.
• Some genus-level overlap was found with exploratory LEfSe analysis, including Eubacterium coprostanoligenes and Ruminococcus.
• The Eubacterium coprostanoligenes group was among genera associated with greater improvements in MetScore in both analyses.

A Simpson index cut-off of 0.849 stratified participants into high- and low-diversity groups with significantly different clinical outcomes.

• Children above the Simpson index threshold of 0.849 exhibited greater improvements in MetScore (p = 0.028).
• Children above the threshold also showed greater improvements in systolic blood pressure (p = 0.043).
• Children above the threshold showed greater improvements in HDL-cholesterol (p = 0.028).
• ROC curve analysis was used to determine the Simpson index cut-off value.

Greater baseline abundance of Faecalibacterium and the Eubacterium coprostanoligenes group were associated with greater improvements in MetScore.

• Both taxa were identified through Spearman's correlation and linear regression models linking baseline microbiota composition to intervention outcomes.
• These genera were also highlighted in exploratory biomarker discovery using LEfSe analysis.
• The Eubacterium coprostanoligenes group also showed genus-level overlap between ANCOM-BC2 and LEfSe analyses.
• The study included 41 children with obesity over a one-year intervention period (ClinicalTrials.gov NCT03749291).