Table 3.
Concentrations of phenolic acid metabolites and precursor polyphenols (catechin/epicatechin) detected in blank broth and bacterial fermented broth samples.
| Sample ID | GA | 3,4-diHBA | 3,4-diHPAA | ( + )-C | 4-HBA | 3,4-diHPPA | HA | VA | CA | ( − )-EC | HVA | 3-HBA | 3-HPAA | diHCA | p-CA | FA | 3-HPPA | 4-HPVA |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Blank | 407 | 151 | 619 | N.D. | 909 | N.D. | 1249 | 1152 | N.D. | N.D. | N.D. | N.D. | N.D. | 1067 | 96.9 | 59.4 | 1213 | N.D. |
| (2.44) | (4.24) | (11.4) | (−) | (25.4) | (−) | (24.8) | (31.3) | (−) | (−) | (−) | (−) | (−) | (11.8) | (0.83) | (0.96) | (2.87) | (−) | |
| Ctl ( − ) | 719 | 138 | 631 | N.D. | 972 | N.D. | 1289 | 1129 | N.D. | N.D. | N.D. | N.D. | N.D. | 1184 | 97.4 | 63.1 | 1281 | N.D. |
| (10.7) | (6.35) | (24.0) | (−) | (47.8) | (−) | (17.0) | (50.6) | (−) | (−) | (−) | (−) | (−) | (14.1) | (2.99) | (1.40) | (14.8) | (−) | |
| Ctl ( + ) | 963 | 128 | 631 | 42389 | 912 | N.D. | 1276 | 1059 | N.D. | 42710 | N.D. | N.D. | N.D. | 1164 | 93.5 | 61.2 | 1282 | N.D. |
| (30.6) | (6.65) | (6.66) | (271) | (17.2) | (−) | (20.6) | (11.0) | (−) | (389) | (−) | (−) | (−) | (3.71) | (0.88) | (0.73) | (7.67) | (−) | |
| Donor 1 ( − ) | 772 | 570 | 637 | N.D. | 1017 | N.D. | 13.4 | 1012 | N.D. | N.D. | 238 | N.D. | N.D. | 1203 | 57.0 | 121 | 1353 | 274 |
| (16.9) | (3.81) | (4.55) | (−) | (10.8) | (−) | (1.73) | (20.8) | (−) | (−) | (10.0) | (−) | (−) | (11.9) | (0.40) | (1.34) | (3.78) | (6.91) | |
| Donor 1 ( + ) | 990 | 648 | 617 | 55.1 | 1097 | N.D. | 19.2 | 986 | N.D. | 45.8 | 267 | Trace | N.D. | 1260 | 59.7 | 120 | 1316 | 322 |
| (19.3) | (15.3) | (12.9) | (1.46) | (28.6) | (−) | (0.45) | (25.9) | (−) | (1.38) | (1.29) | (−) | (−) | (9.95) | (0.19) | (1.09) | (5.73) | (3.43) | |
| Donor 2 ( − ) | 1912 | 708 | 643 | N.D. | 1005 | N.D. | 91.4 | 751 | N.D. | N.D. | 222 | N.D. | N.D. | 1352 | 29.2 | 95.4 | 1278 | N.D. |
| (52.9) | (30.7) | (8.23) | (−) | (42.2) | (−) | (2.16) | (19.7) | (−) | (0.00) | (8.12) | (−) | (−) | (5.85) | (0.67) | (3.34) | (4.28) | (−) | |
| Donor 2 ( + ) | 2012 | 611 | 646 | 54.0 | 927 | N.D. | 106 | 748 | N.D. | Trace | 219 | Trace | N.D. | 1260 | 28.7 | 54.2 | 1283 | N.D. |
| (110) | (21.6) | (15.0) | (1.59) | (27.4) | (−) | (1.79) | (21.1) | (−) | (−) | (9.02) | (−) | (−) | (11.3) | (0.08) | (0.40) | (5.39) | (−) | |
| Bact 1 ( − ) | 378 | 135 | 677 | N.D. | 1004 | N.D. | 1323 | 1034 | N.D. | N.D. | Trace | N.D. | N.D. | 1177 | 85.9 | 41.0 | 1258 | 774 |
| (15.3) | (11.0) | (13.9) | (−) | (67.7) | (−) | (19.3) | (18.1) | (−) | (−) | (−) | (−) | (−) | (11.3) | (0.94) | (0.85) | (10.5) | (34.2) | |
| Bact 1 ( + ) | 1063 | 120 | 648 | 15645 | 939 | N.D. | 1351 | 1051 | N.D. | 6735 | Trace | Trace | N.D. | 1182 | 92.4 | 109 | 1360 | Trace |
| (26.7) | (1.76) | (12.1) | (359) | (4.62) | (−) | (15.5) | (10.1) | (−) | (219) | (−) | (−) | (−) | (6.10) | (1.41) | (4.07) | (3.30) | (−) |
Data are expressed as ng/mL (standard deviation shown in parentheses). Abbreviations are the same as in Table 1.
The “Blank” sample refers to non-incubated nutrient broth in the absence of ( + )-C/( − )-EC or bacteria. Six extractions were carried out to find out the endogenous levels of targeted phenolic acids. Ctl samples refers to negative control “Ctl ( − )” or positive control “Ctl ( + )”, containing pure nutrient broth incubated at 37 °C for 24 h; Bact 1 refers to a bacteria strain isolated from human feces. A plus sign ( + ) refers to the supplementation of grape polyphenols, ( + )-C and ( − )-EC.
N.D., not detected. Trace, trace amount, below the limit of quantification.