Table 2.
Association between urinary metabolite values, microbial community characteristics and NECa
| Characteristic | Alanine | Histidine | Alanine:histidine ratio |
|---|---|---|---|
|
Spearman’s rho (P value) | |||
| Firmicutes, relative abundance |
+0.49 |
+0.32 |
+0.20 |
| (
P
= 0.009) |
(P = 0.095) |
(P = 0.315) |
|
| Proteobacteria, relative abundance |
−0.42 |
−0.24 |
−0.16 |
| (
P
= 0.027) |
(P = 0.221) |
(P = 0.413) |
|
|
Propionibacterium, relative abundance |
−0.45 |
+0.02 |
−0.57 |
| (
P
= 0.015) |
(P = 0.920) |
(
P
= 0.002) |
|
|
Median values by cluster or NEC status (Kruskal–Wallis P value) | |||
| Cluster I samples versus |
3.34 |
0.59 |
4.97 |
| All other samples |
1.52 |
0.44 |
3.46 |
| (
P
< 0.001) |
(P = 0.140) |
(
P
= 0.029) |
|
| Cluster II samples versus |
1.52 |
0.44 |
3.51 |
| All other samples |
2.46 |
0.59 |
4.86 |
| (
P
= 0.007) |
(P = 0.104) |
(P = 0.403) |
|
| NEC samples versus |
2.13 |
0.33 |
6.32 |
| All others excluding non-NEC deaths |
1.72 |
0.53 |
3.42 |
| (P = 0.467) |
(P = 0.169) |
(
P
= 0.022) |
|
| NEC-I versus |
2.81 |
0.55 |
4.86 |
| All others excluding non-NEC deaths |
1.57 |
0.44 |
3.51 |
| (
P
= 0.023) |
(P = 0.394) |
(P = 0.177) |
|
| NEC-II versus |
1.50 |
0.25 |
7.35 |
| All others excluding non-NEC deaths |
1.84 |
0.53 |
3.53 |
| (P = 0.229) | ( P = 0.015) | (P = 0.126) | |
aThe urine and stool samples were collected from 28 infants between postnatal days 4 to 9. Analyses include 9 NEC cases, 2 deaths and 17 controls, except analysis of NEC, NEC-I and NEC-II, for which the non-NEC deaths were removed as a competing cause. Metabolites measured as normalized peak intensity. Significant values are bolded.