Vitamins and Helicobacter pylori: An Updated Comprehensive Meta-Analysis and Systematic Review

Abstract

Background: Over recent decades, epidemiological studies have shown relationships between vitamins and Helicobacter pylori (H. pylori) infection and eradication, but the results are controversial.

Methods: A comprehensive meta-analysis and systematic review were conducted to clarify the relationships between common types of vitamins and H. pylori. We applied meta-regression, subgroup analysis and sensitivity analysis to obtain available evidence. Articles published from January 1991 to June 2021 in PubMed, EMBASE, and the Cochrane Library were searched.

Results: In total, we identified 48 studies. The results indicate that H. pylori -positive patients had lower serum vitamin B₁₂ [standardized mean difference (SMD) = -0.30; 95% confidence interval (CI): -0.53 - -0.08], folate (SMD = -0.69; 95% CI: -1.34 - -0.04), vitamin C (SMD = -0.37; 95%CI: -0.57 - -0.18) and vitamin D (SMD = -0.34; 95% CI: -0.49 - -0.18) levels than H. pylori-negative patients. Patients in which H. pylori had been successfully eradicated had higher serum vitamin D levels (SMD = 1.37; 95% CI: 0.37-2.38) than in patients in which eradication had been unsuccessful. The serum vitamin B₁₂ levels of H. pylori-positive patients improved after successful H. pylori eradication therapy (SMD = 1.85; 95% CI: 0.81-2.90), and antioxidant vitamin supplementation to an H. pylori eradication regimen improved the eradication rate (risk ratio = 1.22; 95% CI: 1.02-1.44 for per-protocol analysis; risk ratio = 1.25; 95% CI: 1.06-1.47 for intention-to-treat analysis).

Conclusions: H. pylori infections decrease the serum levels of several types of vitamins, eradication of H. pylori could rescue its adverse effects, and antioxidant vitamin supplementation may improve the H. pylori eradication rate.

Systematic review registration: identifier: CRD42021268127.

Keywords: helicobacter pylori; meta-analysis; relationship; systematic review; vitamins.

Figure 1

Flow diagram of the studies search process.

Figure 2

Forest plot of the meta-analysis on comparison of serum vitamin levels between H. pylori - positive and H. pylori - negative patients (n1: number of H. pylori – positive patients; n2: number of H. pylori – negative patients); H. pylori – positive patients had lower serum vitamin B12 levels than H. pylori – negative patients (SMD = –0.30; 95% CI: −0.53 – −0.08; P < 0.001; I² = 71.4%); H. pylori – positive patients had lower serum folate levels than H. pylori-negative patients (SMD = −0.69; 95% CI: −1.34 – −0.04; P < 0.001; I² = 95.8%); H. pylori – positive patients had lower serum vitamin C levels than H. pylori-negative patients (SMD = −0.37; 95% CI: −0.57 – −0.18; P < 0.001; I² = 87.9%); H. pylori – positive patients had lower serum vitamin D levels than H. pylori-negative patients (SMD = −0.34; 95% CI: −0.49 – −0.18; P < 0.001; I² = 95.0%).

Figure 3

Funnel plots of the meta-analysis on relationships between H. pylori and vitamins: (A) Comparison of serum vitamin levels between H. pylori - positive and H. pylori - negative patients; (B) Comparison of serum vitamin levels between H. pylori successful and failed eradication patients; (C) Comparison of serum vitamin levels before and after successful H. pylori eradication therapy; (D) Effect of vitamin supplements on the H. pylori eradication rate.

Figure 4

Forest plot of the meta-analysis on the comparison of serum vitamin levels between H. pylori successful and failed eradication patients (n1: number of successful eradication patients; n2: number of failed eradication patients); The patients with successful H. pylori eradication had higher serum vitamin D levels than the failed patients (SMD = 1.37; 95% CI: 0.37 – 2.38; P < 0.001; I² = 98.4%).

Figure 5

Forest plot of the meta-analysis on the comparison of serum vitamin levels before and after successful H. pylori eradication therapy (n1: number of patients after eradication therapy; n2: number of patients before eradication therapy); After successful H. pylori eradication, serum vitamin B12 increased (SMD = 1.85; 95% CI: 0.81–2.90; P < 0.001; I² = 96.0%); H. pylori eradication did not increase the serum vitamin C level (SMD = −0.32; 95% CI: −1.56–0.91; P = 0.002; I² = 79.7%).

Figure 6

Forest plot of the meta-analysis on the effects of vitamin supplements on H. pylori eradication rate (n1: number of eradication regimen plus vitamin supplement group; n2: number of eradication regimen group); For the per-protocol analysis, combining antioxidant vitamin supplementation with the standard therapy increased the H. pylori eradication rate (RR = 1.22; 95% CI: 1.02–1.44; P < 0.001; I² = 81.0%); For the intention-to-treat analysis, antioxidant vitamins supplementation increased the H. pylori eradication rate (RR = 1.25; 95%CI: 1.06–1.47; P < 0.001; I² = 75.1%).