Table 1.
Participant characteristics.
| Characteristics | Controls | At-risk | MCI | AD |
|---|---|---|---|---|
| (n = 50, fecal = 44, oral = 17) | (n = 17, fecal = 17, oral = 8) | (n = 17, fecal = 14, oral = 7) | (n = 67, fecal = 58, oral = 39) | |
| Age (mean ± SD) | 73.82 ± 9.21 | 63.59 ± 14.3** | 75.18 ± 7.6 | 76.1 ± 7.7 |
| Sex (female, %) | 27 (54.0%) | 10 (58.82%) | 4 (23.53%) | 29 (43.28%) |
| Education (yrs, mean ± SD) | 13.17 ± 2.74 | 13.94 ± 2.44 | 12.88 ± 3.02 | 12.57 ± 2.46 |
| BMI (kg/m2, mean ± SD) | 25.71 ± 6.63 | 27.96 ± 6.11 | 25.59 ± 2.36 | 25.2 ± 3.75 |
| Disease-specific marker | ||||
| Disease severity | NA | NA | NA | |
| Mild (Ncases (%)) | 23 (34.33) | |||
| Moderate (Ncases (%)) | 28 (41.79) | |||
| Severe (Ncases (%)) | 16 (23.88) | |||
| APO E4/3 (Ncases (%)) | 0 | 14 (82.35) | 1 (5.88) | 0 |
| APO E4/4 (Ncases (%)) | 0 | 3 (17.65% | 1 (5.88) | 0 |
| Antidementives (Ncases (%)) | 0 | 0 | 3 (17.65) | 6 (8.96) |
| MoCA z-score (mean ± SD) | NA | NA | −1.18 ± 1.68 | −2.47 ± 1.34 |
| MMSE z-score (mean ± SD) | NA | NA | −1.85 ± 2.1 | −2.45 ± 2.28 |
| Cognition score (mean ± SD) | NA | NA | −1.14 ± 1.43 | −2.22 ± 1.61# |
| MTA-score (mean ± SD) | NA | NA | 1.83 ± 1.0 | 2.01 ± 0.97 |
| CSF parameters | ||||
| p-tau/Aβ1–42 (mean ± SD) | NA | NA | 0.36 ± 0.87 | 0.21 ± 0.25 |
| Tau (pg/mL, mean ± SD) | NA | NA | 504.29 ± 318.1 | 658.68 ± 373.75 |
| p-tau (pg/mL, mean ± SD) | NA | NA | 199.73 ± 497.38 | 105.8 ± 144.48 |
| Aβ1–42 (pg/mL, mean ± SD) | NA | NA | 576.86 ± 233.87 | 569.35 ± 294.35 |
| Aβ-Ratio1–40/1–42 (mean ± SD) | NA | NA | 0.62 ± 0.2 | 0.75 ± 0.11 |
| Blood parameters | ||||
| Leukocytes (×109/L, mean ± SD) | NA | NA | 5.71 ± 2.73 | 6.75 ± 2.23 |
| CRP (mg/l, mean ± SD) | NA | NA | 2.31 ± 2.41 | 4.54 ± 8.68 |
| Dietary and lifestyle habits (Ncases (%)) | N = 48 | N = 16 | N = 11 | N = 52 |
| Vegetarian | 0 | 0 | 0 | 3 (5.77) |
| Vegan | 1 (2.08) | 0 | 0 | 0 |
| Currently smoking | 0 | 1 (6.25) | 1 (9.09) | 0 |
| Probiotic consumption | 2 (4.17) | 2 (12.5) | 1 (9.09) | 5 (9.62) |
| Antibiotic consumption (last 6 months) | 16 (33.33) | 5 (31.25) | 1 (9.09) | 7 (13.46)* |
| Gastrointestinal complaints | 0 | 3 (18.75) | 0 | 3 (5.77) |
| Comorbidities (Ncases (%)) | ||||
| Depression | 4 (8.33) | 1 (6.25) | 2 (18.18) | 5 (9.62) |
| Coronary heart disease | 7 (14.58) | 1 (6.25) | 2 (18.18) | 10 (19.23) |
| Diabetes | 6 (12.5) | 1 (6.25) | 2 (18.18) | 4 (7.69) |
| Metabolic syndrome | 0 | 1 (6.25) | 0 | 1 (1.92) |
| Hypertension | 29 (60.52%) | 8 (50) | 8 (72.73) | 31 (59.62) |
| Inflammatory bowel disease | 1 (2.08%) | 0 | 0 | 2 (3.85) |
| Hypercholesterolemia | 13 (27.08%) | 9 (56.25) | 2 (18.18) | 18 (34.62) |
*P < 0.05 and **P < 0.01 compared with controls; #P <0.05 compared with MCI group using student's t-test or Mann–Whitney U-test (in case of violating parametric test requirements) for continuous variables as well as Fisher's exact test in case of categorical data. Unless indicated differently no significant differences were observed between cohorts. MCI, mild cognitive impairment; AD, Alzheimer's disease; SD, standard deviation; BMI, body mass index; APO, apolipoprotein; MMSE, mini-mental state examination; MoCA, Montreal cognitive assessment; CSF, cerebrospinal fluid; p-tau, phospho-tau; Aβ, Amyloid-β; MTA-score, medial temporal atrophy score; CPR, C-reactive protein.