Methyltetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism

and its single nucleotide polymorphism (SNP) site C677T may be associated with gastrointestinal cancer. However

the relationship between MTHFR C677T polymorphism and gastrointestinal tumor markers carcinoma embryonic antigen (CEA)

carbohydrate antigen 199 (CA199) and carbohydrate antigen 724 (CA724) in

Helicobacter pylori

(

H. pylori

) infection is not specified. This study aims to identify the association between MTHFR C677T polymorphism and gastrointestinal tumor markers (CEA

CA199 and CA724) in H. pylori infection. The relationship between MTHFR C677T polymorphism and gastrointestinal tumor markers in 58 patients with H. pylori infection and 94 non-infected patients was studied. We found that TT genotype was a susceptibility factor of

H. pylori

infection

which was also associated with increased CEA and CA724 levels. Moreover

there was a negative additive interaction between

MTHFR

gene C677T polymorphism and CEA levels in

H.pylori

infection. Meanwhile

there were significant differences in CEA levels between MTHFR C677T polymorphism and

H.pylori

infection. The presence of T allele led to a decrease in CEA levels when

13

C urea breath test (

13

C-UBT) was positive

while the presence of T allele led to an increase in CEA levels when

13

C-UBT was negative. Therefore

we suggest that healthy people should take MTHFR C677T polymorphism screening

combined with

13

C-UBT and gastrointestinal tumor markers detection

which can screen out the susceptible population of H. pylori

and help to detect gastrointestinal cancer in the early stage.