Table 3.

Summary of studies examining the effect of Helicobacter pylori infection on colonic microbiota

Detection method	Author, year	Participants	Age	Country	α-diversity	Findings
Cultivation	Bühling et al., 200198	51 H. pylori vs. 27 control	Adult	Germany	N/A	↓Anaerobes in H. pylori patients; ↓Enterobacteria, Clostridium innocuum and Veillonella spp. in H. pylori patients; ↑Lactobacilli, esp. Lactobacillus acidophilus in H. pylori patients
	Myllyluoma et al., 200799	39 H. pylori vs. 19 control	Adult	Finland	N/A	↓Clostridium histolyticum and anaerobes in H. pylori patients
	Yang et al., 2012100	38 H. pylori vs. 38 matched control	Child	Taiwan	N/A	↓Bifidobacterium, Bifidobacterium:Escherechia coli ratio; ↑E. coli
	Benavides-Ward et al., 2018103	28 H. pylori vs. 28 control	Child	Peru	N/A	↑Proteobacteria, Firmicutes and Prevotella in H. pylori patients
Next-Generation Sequencing	Chen et al., 2018101	70 H. pylori vs. 35 control	Adult	China	↑ richness (Sobs index)	22 genera and 38 bacterial species differ; predicted metabolic pathways differ
	Iino et al., 2018102	226 H. pylori vs. 524 control (111 non-AG, mild AG, severe AG)	Adult	Japan	N/A	↑Lactobacillus in severe AG vs. mild & non-AG
	Gao et al., 2018104	24 H. pylori vs. 22 non−H. pylori (negative control + past infection)	Adult	China	Non-significant ↑ Shannon index in gastritis and metaplasia	No differences in β-diversity; some genera differ; ↓Bacteroidetes, ↑Firmicutes and ↑Proteobacteria associated with H. pylori–related gastric lesion progression
	Osaki et al., 2018105	5 H. pylori–infected children and 13 family members	Child and adult	Japan	N/A	No differences in β-diversity and Firmicutes/Bacteroidetes ratio; some genera differ
	Iino et al., 2019106	226 H. pylori vs. propensity score matched control	Adult	Japan	↑	β-diversity differs; some genera differ; ↑Streptococcus in severe AG vs. non-AG in H. pylori patients
	Wang et al., 2019107	128 H. pylori vs. 158 control	Adult	China	No differences	β-diversity differs; some genera differ
	Dash et al., 2019108	12 H. pylori vs. 48 control	Adult	United ArabEmirates	↑	No difference in β-diversity; some genera differ
	He et al., 201954	17 H. pylori vs. 7 control	Adult	China	↑	β-diversity differs; ↑Proteobacteria, Actinobacteria, and Acidobacteria; some genera differ
	Vasapolli et al., 201947	6 H. pylori, 15 non−H. pylori	Adult	Germany	N/A	No differences in β-diversity
	Yang et al., 2019109	50 H. pylori, 42 control	Child	China	No differences	β-diversity differs; some genera differ
	Frost et al., 2019110	212 H. pylori vs. 212 control	Adult	Germany	↑	β-diversity differs; some genera differ; more enterotype 2 in H. pylori patients; Bacteroides, Barnesiella, Alistipes, and Fusicatenibacter negatively associated with HpSA load
	Cornejo-Pareja et al., 2019111	40 H. pylori vs. 20 control	Adult	Spain	↓	β-diversity differs
	Zhou et al., 2020112	22 H. pylori vs. 23 control	Child	China	No differences	No differences in α-diversity and β-diversity; some genera differ

AG, atrophic gastritis; N/A, not available; HpSA, Helicobacter pylori stool antigen