The study investigated the association between DTAC and H pylori in a case–control study. We found that DTAC had an inverse association with risk of H pylori infection. Participants with higher DTAC score had a significantly lower OR for H pylori infection compared with low DTAC score, after adjustment for potential factors. Our study suggests that DTAC may potentially reduce the risk of NAFLD.
According to our information, this is the first time that the inverse relationship between DTAC and risk of H pylori infection has been proven H pylori infection has been documented. In the previous evidences, dietary TAC has been inversely associated with several chronic diseases such as cardiovascular diseases(17), cancer (26)diabetes (13), and metabolic disorders(14), which share common metabolic parameters with H pylori infection.
Overall, an inverse associations between intake of antioxidant micronutrients and antioxidant-rich foods with risk of H pylori infection was registered. For example, The DASH diet (Dietary Approaches to Stop Hypertension), dietary patterns with antioxidant-rich component based on fruit and vegetables, low-fat dairy products, and whole grains, has been shown to eradicate Helicobacter pylori and its gastric cancer(27), as well as an inverse association in chronic diseases associated with H pylori infection (28). Furthermore, coffee has been investigated as an antioxidant-rich nutrient as a risk reduction for coffee. So that, Coffee showed a strong antibacterial action against Helicobacter pylori (H. pylori)(29).This action against H. pylon suggests that coffee may have action as a useful natural inhibitor of gastritis and gastric ulcers. Also, the ability of other antioxidant-rich nutrient to increase plasma TAC and finally reduced risk of H pylori infection through several mechanism, garlic, ginger, quercetin, green tea and Cranberry (19–22) was well revealed. The findings were confirmed even in complementary interventions with antioxidants. Besides, the beneficial effects of the combination of antioxidant compounds were also reported, as demonstrated the synergistic effect of Simultaneous administration and combination of one or more antioxidant supplements reducing risk of H pylori infection(19).
The mechanism of action of dietary antioxidant compounds on H. pylori is not clear. However, the intake of antioxidant-rich nutrients in animals with Helicobacter pylori has been shown to reduce both the number of bacteria in the gastric mucosa and the inflammatory process(8, 20). On the other hand, it is possible that these cultivations, by destroying the Iklova factor, have direct antiseptic properties and prevent NF-κβ nuclear transfer, thereby reducing genetic expression and producing mediators associated with relevant inflammation such as TNF-α, IL-1β, IL-6 and IL-8.It is possible that antioxidant-rich nutrient, by controlling some of the toxins that cause enough bacteria to grow by creating special anionic channels in the plasma membrane associated with the release of bicarbonate and organic anions in gastric cells, they have a beneficial effect(30). On the other hand, it is possible that these compounds reduce the action of urease on H. pylori, because it has been shown that several polyphenolic compounds can alter the activity of this enzyme, which is responsible for the survival of bacteria in acid.(31) In addition, fiber, as part of a healthy diet in many high-antioxidant plant foods, may have health benefits through protection against oxidative damage, as well as improving glucose metabolism and serum lipids (32). Also, some prior studies have declared that dietary fibers can alter abundances of specific gut microbes and change the profile of human gut microbiota (33–36). Fiber fermentation is dependent on microbiota (37) and it has been seen that fiber may increase gram-positive bacteria (38), by decreasing the gut transit time and pH (39, 40). Moreover, we know that H pylori is the gram-negative bacteria so it may be negatively affected by fiber. Also, a high fiber diet in rich of vegetables, fruits, whole grains and beans (41) can exert a protective effect against H pylori infection (42, 43). This may be due to their prebiotic properties which is confirmed in a meta-analysis (44). Besides, fresh vegetables are the source of vitamin C which has been mentioned as a chemopreventive factor against digestive disorders caused by H pylori infection (42). As far as we know, vitamin C can lessen stomach cancer risk and exert an effect on the cycle of H pylori infection (45). Vitamin C is highly concentrated in stomach mucosa and gastric juice. it has a positive effect on the production and function of immune cells and immunoglobulin (46). In our study, dietary vitamin c consumption was significantly lesser in case group. Also, Dietary antioxidants may reduce the risk of developing this disease by reducing the body's obesity and visceral fat, which are known to be one of the risk factors for Helicobacter pylori infection(47, 48).
This is the first study to assess the relationships between DTAC with risk of H pylori Our sample size was sufficient and we tried to eliminate the effect of confounders as far as possible, by adjusting wide range of variables and a validated questionnaire has been used. As for most case-control studies, the causal relationship can be determined but it cannot be quite definite. Furthermore, some conditions of foods such as the growing condition, cultivation method, storage, processing and cooking condition, and assay method might affect the antioxidants content of the foods (25) Also, information collecting in these kinds of studies are based on individual’s reports and memory which is not totally reliable. We have tried to minimize information bias by administrating a questionnaire by trained interviewers.