Table 2.
Characteristics of the study participants at the start of the trial. Data is shown as ratio, number (percentage), mean ± standard deviation, or median (interquartile range). N = 61, if not otherwise stated.
| Characteristics | Total (N = 61) | PRO group (n = 28) | PLC group (n = 33) | p |
|---|---|---|---|---|
| Sex (F:M) | 53:8 | 24:4 | 29:4 | 1 |
| Age (y) | 33.8 (22.5–41.9)# | 32.3 (22.4–42.4)# | 33.8 (24.1–40.1)# | 0.948 |
| Diagnosis according to ICD−11 (6A70/6A71:6A73) | 21:40 | 14:14 | 7:26 | 0.178 |
| Psychotropic medications (%) | 40 (65.6 %) | 16 (57.1 %) | 24 (72.7 %) | 0.314 |
| Antidepressants (%) | 40 (65.6 %) | 16 (57.1 %) | 24 (72.7 %) | 0.314 |
| SSRIs | 27 (44.3 %) | 11 (39.3 %) | 16 (48.5 %) | 0.644 |
| Non-SSRIs | 13 (21.3 %) | 5 (17.9 %) | 8 (24.2 %) | 0.769 |
| Fluoxetine dose equivalents (mg) (n = 32) | 22.2 (20.3–43.1) | 31.2 (20.3–47.2) | 22.2 (20.3–40.2) | 0.638 |
| Antipsychotics (%) | 4 (6.6 %) | 3 (10.7 %) | 1 (3 %) | 0.491 |
| Mood stabilizers | 6 (9.8 %) | 3 (10.7 %) | 3 (9.1 %) | 1 |
| Other psychotropicmedications | 5 (8.2 %) | 3 (10.7 %) | 2 (6.1 %) | 0.848 |
| Psychotropic polypharmacotherapy (%) | 18 (29.5 %) | 9 (32.1 %) | 9 (27.3 %) | 0.229 |
| Comorbidities (%) | 31 (50.8 %) | 16 (57.1 %) | 15 (45.4 %) | 0.514 |
| Other than psychotropic pharmacological treatment (%) | 31 (34.3 %) | 12 (42.9 %) | 9 (27.3 %) | 0.314 |
| Smoking cigarettes (%) | 9 (14.8 %) | 4 (14.3 %) | 5 (15.2 %) | 1 |
| Dietary supplements (%) | 32 (52.5 %) | 18 (64.3 %) | 14 (42.4 %) | 0.148 |
| Obesity (according to BMI) (%) | 5 (8.2 %) | 1 (3.6 %) | 4 (12.1 %) | 0.456 |
| Abdominal obesity (%) | 35 (57.4 %) | 17 (60.7 %) | 18 (54.5 %) | 0.821 |
| Metabolic syndrome (%) | 13 (21.3 %) | 7 (25 %) | 6 (18.2 %) | 0.738 |
| Chronic low-grade inflammation (%) | 15 (24.6 %) | 7 (25 %) | 8 (24.2 %) | 1 |
| Physical activity (MET-min/week) (n = 17) | 2108 ± 1615$ | 2755 ± 1960$ | 1656 ± 1235$ | 0.175 |
| Fecal SCFAs (%) | ||||
| Acetic acid (C2) | 67.9 ± 8.54$ | 68.7 ± 10.4$ | 67.3 ± 6.66$ | 0.507 |
| Propionic acid (C3) | 0.68 (0.24–1.9)# | 0.47 (0–1.91)# | 0.77 (0.33–1.49)# | 0.472 |
| Butyric acid (C4n) | 13.1 ± 7.12$ | 13.4 ± 8.26$ | 12.9 ± 6.12$ | 0.809 |
| Isobutyric acid (C4i) | 15.8 (12.9–19.8)# | 14.4 (12.5–17.9)# | 16.9 (13.6–21.2)# | 0.089 |
| Valeric acid (C5n) | 0 (0−0)# | 0 (0–0.02)# | 0 (0−0)# | 0.672 |
| Isovaleric acid (C5i) | 0.05 (0–1.72)# | 0 (0–1.91)# | 0.14 (0–1.47)# | 0.793 |
| Fecal SCFAs (mM) | ||||
| Total | 4.24 (3.37–6.98)# | 4.03 (3.38–6.79)# | 4.54 (3.35–6.98)# | 0.914 |
| Acetic acid (C2) | 3 (2.23–4.3)# | 2.9 (2.21–4.73)# | 3 (2.27–4.25)# | 0.937 |
| Propionic acid (C3) | 0.03 (0.01–0.08)# | 0.02 (0–0.08)# | 0.04 (0.02–0.08)# | 0.365 |
| Butyric acid (C4n) | 0.57 (0.28–0.97)# | 0.64 (0.27–1.21)# | 0.41 (0.31–0.83)# | 0.757 |
| Isobutyric acid (C4i) | 0.72 (0.5–1.19)# | 0.64 (0.49–1.21)# | 0.82 (0.52–1.04)# | 0.486 |
| Valeric acid (C5n) | 0 (0–0.01)# | 0 (0–0.0009)# | 0 (0−0)# | 0.716 |
| Isovaleric acid (C5i) | 0.001 (0–0.08)# | 0 (0–0.1)# | 0.01 (0–0.07)# | 0.926 |
|
Dietary habits Food frequency intake assessed on a scale 1–6: 1—never or almost never; 2—once a month; 3—several times a month; 4—several times a week; 5—every day; 6—several times a day. | ||||
| Sweets and snacks | 2.72 ± 0.73$ | 2.57 ± 0.69$ | 2.85 ± 0.75$ | 0.145 |
| Diary and eggs | 3.25 (2.79–3.67)# | 2.92 (2.62–3.33)# | 3.5 (2.96–3.67)# | 0.038 * |
| Cereal products | 3.2 (2.8–3.6)# | 3.2 (2.75–3.4)# | 3.2 (3–3.6)# | 0.301 |
| Oils | 2.64 ± 0.66$ | 2.6 ± 0.68$ | 2.67 ± 0.65$ | 0.706 |
| Fruits | 2.7 (2.48–3.12)# | 2.7 (2.5–3.1)# | 2.75 (2.4–3.23)# | 0.629 |
| Vegetables and seeds | 3.44 ± 0.61$ | 3.36 ± 0.52$ | 3.5 ± 0.68$ | 0.391 |
| Meat | 2.34 ± 0.67$ | 2.37 ± 0.65$ | 2.3 ± 0.703$ | 0.711 |
| Drinks (excluding water) | 2.04 ± 0.55$ | 2.05 ± 0.59$ | 2.03 ± 0.53$ | 0.891 |
| Processed food products | 2.43 ± 0.45$ | 2.36 ± 0.49$ | 2.5 ± 0.41$ | 0.244 |
| Psychometric parameters | ||||
| MADRS score total | 19 (16−23)# | 19.5 (16−25)# | 18 (14−20)# | 0.079 |
|
MADRS score domain Sadness |
4 (3−5)# | 5 (3.5–5)# | 4 (3−5)# | 0.434 |
| Neurovegetative | 5.29 ± 2.03$ | 6.15 ± 2.16$ | 4.56 ± 1.61$ | 0.002 * |
| Detachment | 6.83 ± 2.06$ | 7 ± 2.22$ | 6.69 ± 1.94$ | 0.566 |
| Negative thoughts | 3 (2−4)# | 3 (2−3)# | 3 (2−4)# | 0.297 |
| DASS score | 62.6 ± 20.9$ | 62.4 ± 21.3$ | 62.7 ± 20.9$ | 0.962 |
| Depression | 20.4 ± 9.84$ | 19.6 ± 11.2$ | 21.1 ± 8.64$ | 0.573 |
| Anxiety | 16 (10−23)# | 20 (10−24)# | 14 (10−23)# | 0.503 |
| Stress | 25.6 ± 8.43$ | 25.3 ± 7.92$ | 25.8 ± 8.98$ | 0.822 |
| QoL score | 73 ± 11.8$ | 74.6 ± 12.4$ | 71.6 ± 11.3$ | 0.322 |
| Physical | 18.9 ± 4$ | 18.7 ± 4.11$ | 19.2 ± 3.96$ | 0.648 |
| Psychological | 15.4 ± 3.42$ | 15.6 ± 3.6$ | 15.2 ± 3.29$ | 0.719 |
| Social | 8.5 (7−10)# | 8 (7−11)# | 9 (7–9.25)# | 0.527 |
| Environment | 24.9 ± 4.73$ | 26.2 ± 4.82$ | 23.7 ± 4.4$ | 0.040 * |
| Circulating intestine- and microbiota-related parameters | ||||
| I-FABP | 1784 (1196–2305) | 1920 (1217–2354) | 1629 (1145–2256) | 0.561 |
| citrulline | 47.9 (34−56) | 48.7 (35.6–56.7) | 46.6 (33.6–55.5) | 0.551 |
| bSCFAs | 4672 (3535–6230) | 5318 (3292–6496) | 4541 (3610–5396) | 0.22 |
| propionic acid | 66.4 (40.2–96.8) | 64 (41.4–79.5) | 67.4 (40.2–127) | 0.477 |
Legend: $: mean ± standard deviation; #: median (interquartile range); * : p < 0.05; 6A70: single episode depressive disorder; 6A71: recurrent depressive disorder; 6A73: mixed depressive and anxiety disorder.
Abbreviations: BMI: body mass index; bSCFAS – blood short-chain fatty acids; DASS – Depression, Anxiety, and Stress Scale; F: females; I-FABP – intestinal fatty acid-binding protein; M: males; QoL – quality of life; MADRS: Montgomery–Åsberg Depression Rating Scale.