Baseline characteristics
| Variable | Probiotics | Placebo |
| n | 48 | 48 |
| Female, n (%) | 23 (47.9) | 18 (37.5) |
| Age (years) | 12.31±2.13 | 13.17±2.59 |
| Height (SDS) | 0.62±1.01 | 0.64±1.02 |
| Height (cm) | 156.64±11.91 | 160.66±14.79 |
| Weight, SDS | 0.42±0.80 | 0.50±0.88 |
| Weight (kg) | 47.50±10.22 | 53.01±15.54 |
| BMI (SDS) | 0.20±0.84 | 0.24±1.02 |
| Time from diagnosis to recruitment, days (SD) | 40.4±16.2 | 29.65±19.6 |
| Tanner scale (4–5), n (%) | 12 (25.0) | 16 (33.3) |
| AUCCpep | 4.68 (3.55; 6.98) | 3.90 (2.93; 6.89) |
| C-peptide (ng/mL), median (Q1; Q3) | 1.03 (0.75; 1.37) | 0.97 (0.60; 1.54) |
| Insulin requirement (U/kg body mass) | 0.29±0.17 | 0.36±0.2 |
| Basal insulin (% of TDD), median (Q1; Q3) | 29.31 (17.80; 44.77) | 25 (16.44; 42.81) |
| HbA1c (%) | 7.8 (7.08; 8.30) | 8.10 (7.30; 9.70) |
| HbA1c (mmol/mol), median (Q1; Q3) | 65 (56; 83) | 62 (54; 67) |
| IL-1β (fg/mL), median (Q1; Q3) | 0.00 (0.00; 79.39) | 0.00 (0.00; 39.17) |
| IL-2 (fg/mL), median (Q1; Q3) | 0.00 (0.00; 0.88) | 0.00 (0.00; 0.00) |
| IL-10 (fg/mL), median (Q1; Q3) | 281.69 (99.04; 465.96) | 151.09 (73.27; 370.84) |
| IFN-γ (fg/mL), median (Q1; Q3) | 0.00 (0.00; 0.00) | 0.00 (0.00; 0.00) |
| TNF-α (fg/mL), median (Q1; Q3) | 0.00 (0.00; 18.22) | 0.00 (0.00; 14.71) |
| GADA (IU/mL), median (Q1; Q3) | 7.16 (0.78; 48.05) | 5.81 (1.7; 24.03) |
| GADA positive, n (%) | 35 (72.9) | 38 (79.2) |
| IA2A (IU/mL), median (Q1; Q3) | 12.3 (1.11; 21.13) | 3.99 (0.8; 21.8) |
| IA2A positive, n (%) | 33 (68.8) | 30 (62.5) |
| ICA positive, n (%) | 45 (93.8) | 48 (100.0) |
| TSH | 2.08±0.95 | 2.22±1.22 |
| fT4 | 1.02±0.11 | 1.03±0.13 |
| Thyroid antibodies, n (%) | 20 (41.7) | 10 (20.8) |
| Celiac autoimmunity, n (%) | 0 (0.0) | 0 (0.0) |
AUC, area under the curve of the C-peptide during 2-hour responses to a mixed meal; BMI, body mass index; GADA, glutamic acid decarboxylase antibodies; HbA1c, glycated hemoglobin; IA2A, antityrosine phosphatase antibodies; ICA, islet cell antibodies; IFN-γ, interferon-gamma; IL, interleukin; SDS, SD scores; TDD, total daily insulin; TNF-α, tumor necrosis factor-α; TSH, thyroid-stimulating hormone.