Polymerase chain reaction detection of Streptococcus anginosus in digestive diseases and its immunomodulation in rat gastric cancer model

Table 1 Comparison of general characteristics among patients with different diseases, mean ± SD/n (%)

Group	n	Gender (male/female)	Age (years)	BMI (kg/m2)	Helicobacter pylori positivity
Erosive gastritis group	45	23 (51.11)/22 (48.89)	50.66 ± 5.31	22.87 ± 3.02	13 (28.89)
Gastrointestinal polyp group	14	7 (50.00)/7 (50.00)	55.49 ± 5.78	23.04 ± 2.95	4 (28.57)
Peptic ulcer group	24	10 (41.67)/14 (58.33)	52.41 ± 5.02	23.22 ± 3.08	6 (25.00)
Gastrointestinal tumor group	10	4 (40.00)/6 (60.00)	66.20 ± 6.97a	22.41 ± 2.90	3 (30.00)
F/χ2	-	0.831	9.32	0.176	0.154
P value	-	0.843	< 0.001	0.913	0.991

^aP < 0.05: Compared with the erosive gastritis group, gastrointestinal polyp group, and peptic ulcer group.

BMI: Body mass index.

Table 2 Comparison of Streptococcus pharyngitidis positivity rate and relative bacterial load among patients with different gastrointestinal diseases, n (%)

Group	n	Mucosal positivity	Luminal content positivity
Erosive gastritis group	45	6 (13.33)	5 (11.11)
Gastrointestinal polyp group	14	4 (28.57)	3 (21.43)
Peptic ulcer group	24	7 (29.17)	5 (20.83)
Gastrointestinal tumor group	10	8 (80.00)a	6 (60.00)a
χ2/H	-	10.213	8.014
P value	-	0.017	0.046

^aP < 0.05: Compared with the erosive gastritis group, gastrointestinal polyp group, and peptic ulcer group.

Table 3 Comparison of Streptococcus pharyngitidis positivity rates and bacterial load in different anatomical sites among patients with various gastrointestinal diseases, n (%)/median (interquartile range)

Group	n	Lesional mucosa positivity	Distal mucosa positivity	Gastric juice/feces positivity	Relative bacterial load (lesional mucosa, 2-ΔΔCt)	Relative bacterial load (distal mucosa, 2-ΔΔCt)	Relative bacterial load (gastric juice/feces, 2-ΔΔCt)
Erosive gastritis group	45	6 (13.33)	3 (6.67)	4 (8.87)	0.18 (0.10, 0.32)	0.12 (0.06, 0.25)	0.16 (0.09, 0.28)
Gastrointestinal polyp group	14	4 (28.57)	1 (7.14)	2 (14.29)	0.34 (0.20, 0.55)	0.21 (0.12, 0.39)	0.30 (0.18, 0.48)
Peptic ulcer group	24	7 (29.17)	5 (20.83)	6 (25.00)	0.36 (0.22, 0.60)	0.24 (0.18, 0.41)	0.32 (0.20, 0.50)
Gastrointestinal tumor group	10	8 (80.00)a	6 (60.00)	5 (50.00)	0.92 (0.65, 1.35)a,b	0.61 (0.42, 1.06)a	0.82 (0.55, 1.20)a
χ2/H	-	10.213	7.86	8.40	44.0	38.6	42.7
P value	-	0.017	0.044	0.038	< 0.001	< 0.001	< 0.001

^aP < 0.05: Compared with the erosive gastritis group, gastrointestinal polyp group, and peptic ulcer group.

^bP < 0.05: Compared with the relative bacterial load of the distal mucosa.

Table 4 Comparison of Streptococcus pharyngitidis positivity rates among patients with different clinical-pathological characteristics, n (%)

Clinicopathological characteristics	n = 10	S. anginosus		P value
		Positive	Negative
Degree of mucosal inflammation				< 0.0011
Mild-moderate	6	3 (50.00)	3 (50.00)
Severe	4	4 (100.00)	0 (0.00)
TNM staging				< 0.0011
Stage I-II	6	2 (50.00)	4 (50.00)
Stage III-IV	4	4 (100.00)	0 (0.00)
Lymph node metastasis				< 0.0011
Present	3	3 (100.00)	0 (0.001)
Absent	7	3 (42.86)	4 (57.14)

¹: It indicates Fisher’s test.

S. anginosus: Streptococcus anginosus.

Table 5 Correlation between relative bacterial load of Streptococcus pharyngitidis and pathological characteristics in patients with gastrointestinal tumors

Pathological characteristics	Relative bacterial load of S. anginosus
	r value	P value
Mucosal inflammation score	0.436	< 0.001
Tumor invasion depth	0.382	< 0.001

S. anginosus: Streptococcus anginosus.

Table 6 Multivariate analysis of factors affecting gastrointestinal tumors

Factors	β	SE	χ²	OR	95%CI	P value
Gender	-2.008	0.500	6.746	0.135	0.050-0.358	0.744
Age	1.890	0.609	11.029	1.389	1.642-2.598	0.004
Smoking	-2.000	0.509	6.841	0.139	0.113-0.161	0.722
Alcohol consumption	-2.011	0.513	6.802	0.135	0.049-0.366	0.613
S. anginosus positivity	1.486	0.736	14.539	2.385	1.846-5.102	< 0.001
Helicobacter pylori infection	-2.015	0.510	6.940	0.133	0.049-0.362	0.849

OR: Odds ratio; S. anginosus: Streptococcus anginosus.

Table 7 Comparison of tumor burden between different model groups, mean ± SD

Group	Tumor nodules (n)	Maximum diameter (mm)	Tumor volume (mm3)	Tumor weight (g)
Normal control group (n = 5)	0.11 ± 0.02	-	-	-
Gastric cancer model group (n = 5)	4.62 ± 0.21a	6.85 ± 0.66	185.46 ± 16.22	0.86 ± 0.02
Gastric cancer + S. anginosus intervention group (n = 5)	6.28 ± 0.36a,b	8.41 ± 0.52	248.63 ± 20.17	1.17 ± 0.09
F/t value	878.8	4.152	5.463	7.518
P value	< 0.001	0.003	0.001	< 0.001

^aP < 0.05: Compared with the control group.

^bP < 0.05: Compared with the model group.

S. anginosus: Streptococcus anginosus.

Table 8 Comparison of serum interleukin-6 and tumor necrosis factor-α levels between different model groups, mean ± SD

Group	IL-6 (pg/mL)	TNF-α (pg/mL)
Normal control group (n = 5)	20.02 ± 3.22	16.41 ± 2.33
Gastric cancer model group (n = 5)	76.48 ± 5.96a	60.58 ± 8.26
Gastric cancer + S. anginosus intervention group (n = 5)	102.71 ± 8.52a,b	84.23 ± 10.12
F value	225.6	101.0
P value	< 0.001	< 0.001

^aP < 0.05: Compared with the control group.

^bP < 0.05: Compared with the model group.

IL-6: Interleukin-6; S. anginosus: Streptococcus anginosus; TNF-α: Tumor necrosis factor-α.

Table 9 Comparison of immune cell infiltration between different model groups, mean ± SD

Group	CD4+ T	CD8+ T	CD68+ macrophages
Normal control group (n = 5)	8.42 ± 3.14	6.58 ± 1.16	5.87 ± 0.74
Gastric cancer model group (n = 5)	24.68 ± 6.22a	18.74 ± 2.52a	22.18 ± 3.06a
Gastric cancer + S. anginosus intervention group (n = 5)	36.55 ± 7.51a,b	26.47 ± 3.44a,b	29.85 ± 3.71a,b
F value	28.50	77.22	95.02
P value	< 0.001	< 0.001	< 0.001

^aP < 0.05: Compared with the control group.

^bP < 0.05: Compared with the model group.

S. anginosus: Streptococcus anginosus.

Table 10 Relationship between relative bacterial load of pharyngitis streptococcus and serum interleukin-6, tumor necrosis factor-α levels, and immune cell infiltration score

Indicators	Relative bacterial load of S. anginosus
	r value	P value
IL-6	0.458	< 0.001
TNF-α	0.469	< 0.001
CD4+ T cell infiltration score	0.587	< 0.001
CD8+ T cell infiltration score	0.506	< 0.001
CD68+ macrophage infiltration score	0.545	< 0.001

Relative bacterial load of Streptococcus anginosus in this section refers to the relative DNA abundance of Streptococcus anginosus detected by speciesspecific quantitative real-time polymerase chain reaction in gastric tumor/adjacent mucosal tissues at the experimental endpoint. IL-6: Interleukin-6; S. anginosus: Streptococcus anginosus; TNF-α: Tumor necrosis factor-α.