Methods Ten elderly patients with type 2 diabetes mellitus were selected as the T2D group, 10 elderly patients with idiopathic gastric paralysis as the G group, 9 elderly patients with type 2 diabetes mellitus and gastroparesis as the DG group, and 10 healthy elderly as the control group at the same time. The age, gender, body mass index (BMI), tumor necrosis factor-alpha (TNF-α), leukotriene B4 (LTB-4), fasting glucose and glycosylated serum protein (GSP) were recorded and compared among the four groups. Fresh fecal samples were taken and DNA was extracted; then the high-throughput sequence and bioinformatics of 16s ribosomal RNA (rRNA) gene were analyzed using Illumina MiSeq 2000 sequencing platform.
Results The age (H = 8.754, P = 0.053), gender (χ2 = 2.976, P = 0.395), BMI (H = 1.229, P = 0.746), TNF-α (H = 3.195, P = 0.363), LTB-4 (F = 1.460, P = 0.246), fasting glucose (H = 6.109, P = 0.106) and GSP (H = 3.530, P = 0.317) all showed no significant differences among the four groups. There were also no significant differences in the indexes of Chao1, Ace, Observed operational taxonomic units (OTUs), Simpson, Shannon and Pielou among the four groups (H = 1.288, 1.067, 1.115, 1.693, 0.988, 1.322; all P > 0.05). Based on the weighted Unifrac distance, the β-diversity showed significant difference among the four groups (F = 2.719, P = 0.043), and it was significantly different in the DG group as compared with the control group and T2D group (P = 0.039, 0.047). The relative abundance of Bacteroidaceae [19.19 (10.32, 23.93)%, 9.80 (6.48, 27.87)%, 39.63 (13.86, 64.76)%, 63.36 (33.42, 72.17)%; H = 11.319, P = 0.010], Burkholderiaceae [2.57 (0.93, 3.71)%, 1.81 (1.15, 2.37)%, 2.14 (1.57, 2.86)%, 8.61 (5.24, 10.93)%; H = 19.572, P < 0.001], Prevotellaceae [40.14 (16.92, 45.39)%, 68.80 (15.48, 76.16)%, 5.66 (3.43, 39.31)%, 3.65 (1.70, 32.90)%; H = 9.593, P = 0.022], Bacteroides [19.2 (10.3, 23.9)%, 9.8 (6.5, 27.9)%, 39.2 (13.9, 64.8)%, 63.4 (33.4, 72.2)%; H = 11.319, P = 0.010], Prevotella 9 [32.5 (15.8, 40.6)%, 55.3 (2.7, 65.2)%, 4.0 (1.8, 36.7)%, 1.8 (0.7, 27.6)%; H = 8.701, P = 0.034] and Klebsiella [0.9 (0.4, 2.0)%, 0.5 (0.2, 2.4)%, 0.6 (0.4, 2.6)%, 0.1 (0.0, 0.2)%; H = 10.091, P = 0.018] all showed significant differences among the four groups. Moreover, in the DG group, the relative abundance of Bacteroidaceae and Bacteroides was significantly higher than that in the control group and T2D group; the relative abundance of Burkholderiaceae was significantly higher than that in the control group, T2D group and G group; the relative abundance of Prevotellaceae and Prevotella 9 was significantly lower than that in the T2D group; the relative abundance of Klebsiella was lower than that in the control group (all P < 0.05).