In this effect size analysis, Bristol Stool Score (BSS) explained the largest part of the variance of genus-level microbiome composition (R2 = 1.84%, p-value = 0.003), followed by bodyweight (R2 = 1.16%, p-value = 0.001), alanine-aminotransferase levels (ALAT, R2 = 1.08%, p-value = 0.003) and obesity status (R2 = 1.03%, p-value = 0.003). Here, GPT is linked to obesity due to melanocortin 4 receptor deficiency.