This cross-sectional study was conducted to assess adherence to the MD in the young Lebanese population during the economic crisis and its association with H. pylori infection. Our results indicate that more than one-third of the participants had low adherence to the MD. This could be explained by limited financial means to procure food, as approximately 80% of the sample was classified as having low socioeconomic status based on monthly income. Another possible reason could be a lack of awareness regarding the health benefits of adhering to this dietary pattern.
Helicobacter pylori was detected in 12.1% of children and adolescents. A lower prevalence has been documented in Japan (3.7%) (
22), whereas higher prevalence rates have been reported in Iran (64.2%) and African countries, including Uganda (24.3%), Cameroon (52.27%), and Egypt (64.6%) (
23-
26). These disparities may be attributed to factors like poor sanitation and untreated water supplies (
27). Furthermore, we examined the association between
H. pylori infection and various patient characteristics, including anthropometric, sociodemographic, and behavioral factors. Bivariate analysis revealed a statistical association between
H. pylori infection and infrequent washing of fruits and vegetables before eating, supporting the hypothesis by some authors that
H. pylori may be transmitted as a foodborne pathogen (
28,
29). However, this factor did not remain statistically significant in the multiple binary logistic regression analysis.
Recently, several studies have explored the potential relationship between dietary patterns and the risk of gastric cancer. Higher adherence to the MD has been linked to a reduced risk of gastric cancer and its subtypes (
30,
31). In Lebanon, the MD is widely followed as a primary dietary pattern, prompting us to investigate its association with
H. pylori infection. Our findings showed that the overall MD score was not associated with
H. pylori infection. However, when analyzing specific components of the MD, the consumption of olive oil and dairy products were found to be associated with
H. pylori infection.
Previous studies have demonstrated a strong antibacterial effect of olive oil phenolics against
H. pylori in vitro (
32). Additionally, two olive-leaf extracts were shown to reduce IL-8 secretion and suppress reactive oxygen species production in human gastric cells infected with
H. pylori, highlighting olive oil's potential in mitigating the pathogenic effects of
H. pylori infection (
33). These beneficial properties may be due to olive oil’s and olive leaf extract’s capacity to bind metal ions, which slow free radical production (
34), as well as their ability to inhibit various inflammatory enzymes, including lipoxygenases (
35).
Milk and dairy products are important sources of essential micronutrients such as calcium, magnesium, potassium, zinc, and phosphorus (
36). The relationship between dairy products and
H. pylori is controversial. Some cohort studies have shown an association between increased dairy consumption and a reduced risk of gastric cancer in
H. pylori–positive patients (
37), while other case-control studies found no association (
38). Focusing on probiotic dairy products, a randomized control trial revealed that the average clearance rates of
H. pylori were higher in the probiotic group than in the conventional therapy (control) group. The beneficial effect of probiotics in eradicating
H. pylori includes promoting anti-inflammatory and antioxidative mechanisms and modulating the intestinal microbiota (
39). Additionally, vitamin D3 in dairy products has been shown to stimulate the synthesis of antibacterial components, enhancing antimicrobial activity across various cell types (
40). Furthermore, vitamin D3 supplementation in healthy human stomach epithelial cells has demonstrated anti-
H. pylori activity.
H. pylori infection can alter the release of Ca
2+ from lysosomes in gastric epithelial cells, allowing its survival in the gastric epithelium (
41).
This is the first study to assess the association between the MD and H. pylori infection in Lebanon. However, some limitations should be noted. The sample consisted of hospitalized patients who may have been previously diagnosed with gastrointestinal disorders, potentially leading them to modify their eating habits. Additionally, as a cross-sectional study, this research cannot establish causality. Future large-scale, multicenter epidemiological studies with comprehensive dietary assessments, such as food frequency questionnaires or 24-hour recalls, could provide a more detailed understanding of daily macronutrient and micronutrient intake.
5.1. Conclusions
This study found a significant correlation between H. pylori infection and the consumption of olive oil and dairy products. Thus, longitudinal studies on nutritional knowledge and food security are essential to further investigate dietary factors associated with poor adherence to the MD and H. pylori infection. Additionally, studies on the antimicrobial properties of natural products against H. pylori may lead to new approaches in clinical practice, especially for antibiotic-resistant strains.