Table 2.
Changes in dietary intake, anthropo-metabolic outcomes, and gut microbiome during the study.
| Control Group | Vegan Group | Treatment Effect | p Value a | p Value b | |||
|---|---|---|---|---|---|---|---|
| Baseline | Week 16 | Baseline | Week 16 | ||||
| Total Physical activity (metabolic equivalents) | 2840 (2064–3616) | 2107 (1555–2658) * | 2982 (1696–4267) | 2000 (1394–2606) | −248 (−1549 to +1053) | 0.71 | 0.87 |
| Dietary Intake | |||||||
| Caloric Intake (kcal/day) | 1726 (1606–1847) | 1692 (1562–1821) | 1827 (1689–1965) | 1294 (1212–1376) *** | −498 (−696 to −300) | <0.001 | <0.001 |
| Total Fat (g/day) | 72.2 (66.1–78.3) | 71.5 (63.9–79.0) | 74.1 (67.9–80.4) | 24.3 (21.7–26.9) *** | −49.1 (−58.5 to −39.8) | <0.001 | <0.001 |
| Total Carbohydrate (g/day) | 204 (187–221) | 196 (178–214) | 222 (202–241) | 236 (219–254) | +22.6 (−6.5 to +51.7) | 0.13 | 0.17 |
| Total Protein (g/day) | 67.2 (62.2–72.1) | 68.9 (63.1–74.6) | 69.0 (63.9–74.1) | 42.9 (40.0–45.7) *** | −27.9 (−36.0 to −19.7) | <0.001 | <0.001 |
| Animal Protein (g/day) | 37.5 (32.5–42.4) | 39.3 (33.4–45.3) | 38.5 (33.7–43.2) | 1.2 (0.5–1.9) *** | −39.1 (−46.4 to −31.9) | <0.001 | <0.001 |
| Veg Protein (g/day) | 29.7 (26.8–32.6) | 29.5 (26.0–33.0) | 30.6 (27.5–33.7) | 41.7 (39.0–44.3) *** | +11.3 (+6.6 to +16.0) | <0.001 | <0.001 |
| Cholesterol (mg/day) | 227 (190–263) | 243 (201–285) | 227 (196–258) | 5.1 (3.3–6.9) *** | −238 (−285 to −191) | <0.001 | <0.001 |
| Total SFA (g/day) | 21.7 (19.3–24.0) | 21.9 (18.9–24.9) | 23.3 (20.4–26.1) | 4.8 (4.2–5.4) *** | −18.7 (−22.7 to −14.8) | <0.001 | <0.001 |
| Total MUFA (g/day) | 26.7 (24.1–29.3) | 25.8 (23.0–28.5) | 26.4 (24.2–28.6) | 7.9 (7.0–8.7) *** | −17.6 (−21.2 to −14.0) | <0.001 | <0.001 |
| Total PUFA (g/day) | 17.9 (16.4–19.5) | 17.8 (15.8–19.9) | 18.4 (16.7–20.2) | 9.0 (7.9–10.2) *** | −9.3 (−12.1 to −6.6) | <0.001 | <0.001 |
| Total Dietary Fiber (g/day) | 23.1 (21.0–25.2) | 23.1 (20.7–25.4) | 24.0 (21.6–26.5) | 33.2 (30.8–35.6) *** | +9.2 (+5.6 to +12.8) | <0.001 | <0.001 |
| Soluble Fiber (g/day) | 6.0 (5.5–6.5) | 6.6 (6.0–7.2) * | 6.9 (6.2–7.5) | 8.5 (7.8–9.2) *** | +1.0 (+0.1 to +2.0) | 0.03 | 0.01 |
| Insoluble Fiber (g/day) | 17.0 (15.3–18.8) | 16.4 (14.5–18.2) | 17.1 (15.1–19.0) | 24.6 (22.7–26.4) *** | +8.2 (+5.2 to +11.1) | <0.001 | <0.001 |
| Anthropo-Metabolic Outcomes | |||||||
| Weight (kg) | 93.4 (90.1–96.7) | 92.9 (89.6–96.3) | 92.9 (89.7–96.1) | 86.5 (83.5–89.5) *** | −5.9 (−7.0 to −4.9) | <0.001 | <0.001 |
| BMI (kg/m2) | 33.6 (32.6–34.5) | 33.4 (32.4–34.4) | 32.6 (31.8–33.5) | 30.5 (29.6–31.3) *** | −2.0 (−2.4 to −1.6) | <0.001 | <0.001 |
| Fat Mass (kg) | 42.0 (39.7–44.2) | 41.7 (39.4–44.1) | 39.8 (37.7–42.0) | 35.7 (33.6–37.9) *** | −3.9 (−4.6 to −3.1) | <0.001 | <0.001 |
| VAT Volume (cm3) | 1590 (1365–1814) | 1589 (1360–1818) | 1511 (1291–1732) | 1271 (1084–1457) *** | −240 (−345 to −135) | <0.001 | <0.001 |
| PREDIM (mg/min/kg) | 4.4 (4.0–4.8) | 4.2 (3.8–4.6) | 4.0 (3.7–4.3) | 4.8 (4.4–5.1) *** | +0.83 (+0.48 to +1.2) | <0.001 | <0.001 |
| Gut Microbiota Composition | |||||||
| Diversity | 1.6 (1.5–1.7) | 1.8 (1.7–1.9) *** | 1.7 (1.6–1.8) | 1.7 (1.6–1.8) | −0.20 (−0.34 to −0.06) | 0.0043 | 0.003 |
| Firmicutes | 60,997 (41,121–80,874) | 60,599 (51,612–69,586) | 52,038 (41,221–62,856) | 64,734 (53,368–76,100) | +13,094 (−11,808 to +37,996) | 0.30 | 0.42 |
| Firmicutes % | 52.2 (48.7–55.7) | 49.8 (46.6–52.9) | 55.4 (51.7–59.1) | 54.6 (51.4–57.9) | +1.7 (−2.7 to +6.1) | 0.45 | 0.72 |
| Bacteroidetes | 41,690 (33,401–49,980) | 53,871 (41,691–66,051) | 31,944 (24,747–39,141) | 42,855 (34,088–51,622) * | −1270 (−17,950 to +15,409) | 0.88 | 1.00 |
| Bacteroidetes % | 37.6 (34.1–41.1) | 38.3 (34.9–41.7) | 31.6 (28.4–34.8) | 35.1 (31.4–38.8) | +2.8 (−2.0 to +7.5) | 0.25 | 0.06 |
| Enterobacteriaceae | 600 (−109–1308) | 709 (−153–1570) | 293 (135–451) | 683 (−79.0–1444) | +280.6 (−545 to +1106) | 0.50 | 0.44 |
| Enterobacteriaceae % | 0.47 (0.02–0.93) | 0.66 (0.02–1.3) | 0.73 (0.03–1.4) | 0.47 (0.02–0.92) | −0.44 (−1.3 to +0.45) | 0.33 | 0.25 |
| Firmicutes:Bacteroidetes ratio | 3.0 (0.38–5.6) | 2.0 (0.92–3.1) | 2.4 (1.6–3.1) | 2.3 (1.7–2.9) | +0.90 (−0.76 to +2.6) | 0.28 | 0.26 |
| Butyrate producing bacteria | 41,781 (34,410–49,152) | 34358 (27,310–41,407) * | 37,169 (29,540–44,799) | 38,143 (30,371–45,915) | +8396 (−4458 to +21249) | 0.20 | 0.32 |
| Butyrate producing bacteria % | 22.0 (19.5–24.5) | 19.4 (16.8–21.9) | 23.4 (21.5–25.2) | 21.2 (19.2–23.2) | +0.48 (−4.0 to +5.0) | 0.83 | 0.74 |
| Prevotella | 240 (104–376) | 554 (49.4–1059) | 224 (111–336) | 402 (169–636) | −135 (−711 to +439) | 0.64 | 0.61 |
| Prevotella % | 0.35 (0.09–0.60) | 1.15 (0.08–2.2) | 0.69 (0.01–1.4) | 0.84 (0.02–1.7) | −0.65 (−2.1 to +0.8) | 0.39 | 0.56 |
| Akkermansia | 1089 (495–1684) | 5073 (66.0–10080) | 2256 (640–3871) | 3215 (1873–4557) | −3024 (−8211 to +2163) | 0.25 | 0.26 |
| Akkermansia % | 1.4 (0.74–2.1) | 2.4 (0.85–4.0) | 2.1 (1.0–3.1) | 2.3 (1.5–3.2) | −0.74 (−2.6 to +1.1) | 0.43 | 0.40 |
| Faecalibacterium prausnitzii | 6935 (4905–8966) | 7142 (4502–9783) | 6304 (4127–8481) | 12405 (8417–16394) * | +5895 (+506 to +11283) | 0.03 | 0.17 |
| Faecalibacterium prausnitzii % | 7.2 (5.2–9.2) | 5.3 (3.8–6.9) | 5.5 (4.3–6.8) | 8.8 (7.0–10.6) *** | +5.1 (+2.4 to +7.9) | 0.0003 | 0.002 |
| Bacteroides fragilis | 31212 (23918–38505) | 602 (−275–1478) *** | 10641 (5513–15769) | 524 (−19.0–1067) *** | +20493 (+11790 to +29195) | <.001 | <.001 |
| Bacteroides fragilis % | 27.1 (23.6–30.6) | 0.3 (0.0–0.60) *** | 8.3 (5.1–11.5) | 0.40 (0.10–0.70) *** | +18.9 (+14.2 to +23.7) | <.001 | <.001 |
| Clostridium | 844 (529–1160) | 956 (705–1206) | 631 (432–829) | 880 (694–1066) | +138 (−245 to +521) | 0.48 | 0.62 |
| Clostridium % | 0.72 (0.54–0.90) | 0.74 (0.58–0.90) | 0.68 (0.55–0.81) | 0.76 (0.63–0.88) | +0.05 (−0.17 to +0.27) | 0.63 | 0.71 |
| Methanobrevibacter | 71.4 (22.9–120) | 506 (156–856) * | 299 (37.1–560) | 826 (−2.8–1655) | +93.1 (−817 to +1003) | 0.84 | 0.51 |
| Methanobrevibacter % | 0.09 (0.03–0.14) | 0.35 (0.14–0.57) ** | 0.23 (0.07–0.39) | 0.57 (0.18–0.96) | +0.07 (−0.35 to +0.49) | 0.74 | 0.25 |
| Eubacterium | 0.42 (0.05–0.79) | 2.0 (0.37–3.7) * | 1.0 (0.08–2.0) | 0.9 (0.03–1.8) | −1.7 (−3.5 to +0.09) | 0.06 | 0.05 |
| Eubacterium % | 0.001 (0.00002–0.001) | 0.002 (0.0002–0.003) | 0.0009 (0.0001–0.002) | 0.002 (−0.0005–0.004) | −0.0003 (−0.002 to +0.002) | 0.77 | 0.88 |
| Bifidobacterium | 1254 (412–2096) | 1712 (764–2659) | 1278 (738–1818) | 2313 (1286–3339) * | +577 (−700 to +1854) | 0.37 | 0.89 |
| Bifidobacterium % | 1.4 (0.48–2.3) | 1.8 (0.35–3.3) | 1.3 (0.79–1.8) | 1.7 (1.1–2.3) | −0.05 (−0.91 to +0.81) | 0.91 | 0.64 |
| Proteobacteria | 5278 (3672–6883) | 5195 (3305–7086) | 3561 (2503–4619) | 4165 (2798–5533) | +686 (−1622 to +2994) | 0.56 | 0.78 |
| Proteobacteria % | 4.9 (3.7–6.0) | 4.0 (3.0–5.1) | 4.4 (3.2–5.5) | 3.1 (2.4–3.9) * | −0.40 (−2.0 to +1.2) | 0.61 | 0.58 |
| Actinobacteria | 2736 (1395–4077) | 2247 (1261–3233) | 2459 (1716–3203) | 2729 (1658–3800) | +758 (−1071 to +2588) | 0.41 | 0.85 |
| Actinobacteria % | 3.1 (1.9–4.4) | 2.9 (1.2–4.7) | 2.6 (2.0–3.1) | 2.4 (1.6–3.2) | +0.05 (−1.4 to +1.5) | 0.94 | 0.91 |
| Ruminococcaceae | 15,842 (11,727–19,956) | 15775 (12,261–19,289) | 18,807 (14,337–23,277) | 22,265 (17,204–27,326) | +3525 (−4962 to +12011) | 0.41 | 0.96 |
| Ruminococcaceae % | 15.4 (13.0–17.8) | 12.9 (10.5–15.2) | 19.0 (16.7–21.3) | 18.5 (16.2–20.8) | +2.1 (−1.4 to +5.5) | 0.24 | 0.66 |
| Lachnospiraceae | 26,182 (20,879–31,485) | 18,224 (12,241–24,207) ** | 22,871 (18,631–27,111) | 15,881 (11,212–20,550) * | +968 (−7106 to +9042) | 0.81 | 0.79 |
| Lachnospiraceae % | 24.4 (22.1–26.7) | 15.4 (11.3–19.4) *** | 24.8 (22.5–27.1) | 16.9 (13.6–20.2) *** | +1.2 (−4.6 to +7.0) | 0.69 | 0.91 |
| Roseburia | 5993 (4634–7351) | 5639 (4367–6912) | 5821 (4255–7387) | 6649 (4953–8345) | +1181 (−1469 to +3831) | 0.38 | 0.34 |
| Roseburia % | 5.8 (4.7–6.9) | 5.1 (4.1–6.1) | 6.4 (5.3–7.5) | 6.0 (4.8–7.2) | +0.28 (−1.6 to +2.2) | 0.77 | 0.90 |
| Anaerostipes | 1502 (1020–1985) | 2061 (1496–2625) | 1481 (1103–1858) | 2203 (1614–2792) * | +164 (−772 to +1100) | 0.73 | 0.45 |
| Anaerostipes % | 1.4 (1.1–1.8) | 1.5 (1.2–1.8) | 1.6 (1.2–1.9) | 1.8 (1.4–2.1) | +0.10 (−0.48 to +0.69) | 0.72 | 0.33 |
| Megasphaera | 324 (−264–912) | 334 (−270–938) | 60.7 (19.5–102) | 123 (−9.2–255) | +51.8 (−58.0 to +162) | 0.35 | 0.80 |
| Megasphaera % | 0.72 (−0.67–2.1) | 0.62 (−0.42–1.7) | 0.12 (0.00–0.25) | 0.19 (−0.05–0.42) | +0.16 (−0.24 to +0.56) | 0.42 | 0.67 |
Data are means with 95% confidence interval (CI) mean. The treatment effect, which is tested by the group-by-time interaction in a repeated measures ANOVA model, does effectively compare the differences in outcomes from baseline to week 16 between the two study arms. Bonferroni correction for multiple comparisons was used for four hypotheses at p = 0.0125 (0.05/4). The rest of the outcomes, performed in an exploratory manner, are presented for complete overview. The treatment effect is the difference in outcomes, from baseline to week 16, between the vegan and control group. Diversity is defined as alpha diversity, which was calculated using an abundance-weighted phylogenetic diversity measure. Values listed under gut microbiota composition values are read counts and relative abundances (%). Relative abundance was calculated by dividing the number of reads assigned to each taxon by the total number of filtered reads. Listed p values are for interactions assessed by repeated measures ANOVA, first unadjusted (p-value a: unadjusted, group x time) and then adjusted for age and gender (p-value b, including all study participants). * p < 0.05, ** p < 0.01, and *** p < 0.001 for within-group changes from baseline assessed by paired comparison t tests. Abbreviations: SFA, saturated fatty acids; MUFA, monounsaturated fatty acids; PUFA, polyunsaturated fatty acids; BMI, body mass index; VAT, visceral adipose tissue; PREDIM (PREDIcted M, insulin sensitivity index).