Dietary Inflammatory Index and the Risk of Gastric Precancerous Lesions Among Korean Adults in a Rural Area

<b>Background/Objectives</b>: Gastric cancer is known to occur through a multistep process from gastric precancerous lesions, such as atrophic gastritis, intestinal metaplasia, and gastric dysplasia. Gastric precancerous lesions may have different risk factors for each stage, and it can be prevented by an anti-inflammatory diet. In this study, we examined the association between the dietary inflammatory index (DII) and the risk of gastric precancerous lesions among adults in a rural area. Moreover, we analyzed the interaction between the DII and <i>H. pylori</i> infection in relation to the risk of gastric precancerous lesion. <b>Methods</b>: Among 711 participants who had a gastroscopy in a community cohort study, 564 subjects were included in this analysis and were divided into three groups (233 in normal, 128 in atrophic gastritis, and 203 in intestinal metaplasia). Atrophic gastritis and intestinal metaplasia were diagnosed by endoscopy and histopathology in accordance with the Updated Sydney System. DII was derived from a food-frequency questionnaire and categorized into tertiles. <i>H. pylori</i> infection was determined by the Campylobacter-like organism test. <b>Results</b>: <i>H. pylori</i> infection was significantly associated with the increased risk of intestinal metaplasia (OR = 2.75, 95% CI = 1.76-4.27), but not with atrophic gastritis. The inflammation diet itself was not associated with both the risk of atrophic gastritis (OR = 0.93, 95% CI = 0.53-1.64) and intestinal metaplasia (OR = 1.32, 95% CI = 0.78-2.24). However, the risk of intestinal metaplasia was more increased in the inflammatory diet group with <i>H. pylori</i> infection (OR = 3.35, 95% CI = 1.54-7.30) compared to the anti-inflammatory diet group without <i>H. pylori</i> infection. <b>Conclusions</b>: This study found that <i>H. pylori</i> infection increased the risk of intestinal metaplasia, and this risk was further enhanced by a pro-inflammatory diet, suggesting that both diet and infection management are important for prevention of gastric precancerous lesions.