**1. Introduction**

Helicobacter pylori (*H. pylori*) is one of the most common infections affecting the epithelial lining of the stomach [1]. It is correlated with antral gastritis, peptic ulcers and promotes gastric malignancies [2]. There were approximately 4.4 billion individuals with *H. pylori* infection worldwide in 2015 [1]. *H. pylori* infection is prevalent in developing countries [1] and risk factors for *H. pylori* including age and socioeconomic status [2].

There is ongoing debate over the relationship between obesity and *H. pylori* infection, within the acknowledgment that the etiology of obesity is far more complex [3–5]. A recent ecological review of several cross sectional studies found an inverse correlation between *H. pylori* prevalence and rate of overweight/obesity in countries of the developed world i.e., increase in *H. pylori* positive infection associated with reduction in obesity [6]. This was further corroborated with Intervention studies reporting that eradication of *H. pylori* was associated with significant weight gain as compared to subjects with untreated *H. pylori* [7,8]. In contrast, observational or clinical studies from developing countries reported a linear relationship between *H. pylori* positive infection and obesity [9–11].

Saudi Arabia has the highest obesity and overweight prevalence rates in the Middle East which is linked to multiple factors including adapting a westernized life style [12]. The prevalence of *H. pylori* within the Saudi Arabian population and related factors remains unknown and most available data is reported from medical care settings with a range of prevalence between 33–85% [9,13–17]. A study randomly selecting university students reported a prevalence of 35% for *H. pylori* [18]. Specifically, high *H. pylori* prevalence was reported among morbid obese patients who underwent upper endoscopy prior to bariatric surgery was 88% [9]. Yet the matching of this latter group with normal body weight patients to substantiate such findings within the context of Saudi Arabia has not been attempted specifically in the light of controversy of the association of *H. pylori* with obesity [6–8].

Morbid obesity has been widely treated with various type of bariatric surgery. Bariatric surgery includes laparo-scopic adjustable gastric bands (LAGB), lap band, the Roux-Y gastric bypass (RYGB) and sleeve gastrectomy or gastric sleeve [19]. Routine upper endoscopy with *H. pylori* screening and biopsies to rule out pathological abnormalities (e.g., gastritis, duodenitis, esophagitis, ulceration, hiatus hernia, ..., etc.) is able to detect abnormalities in up to 91% of bariatric candidates [20] with a higher rate in patients with concomitant *H. pylori* infection [21–24].

The American Association of Clinical Endocrinologists/The Obesity Society/American Society for Metabolic and Bariatric Surgery guidelines [25] have not provided any clear indication about preoperative *H. pylori* screening and managemen<sup>t</sup> but recommended *H. pylori* screening in patients belonging to high-prevalence areas and upper endoscopy in selected cases. On the other hand, the European guidelines [26] have recommended upper gastrointestinal endoscopy before bariatric surgery in both symptomatic and asymptomatic patients and to treat *H. pylori* infection and other abnormalities, which may cause postoperative complications.

In light of the limited literature to assess the prevalence of HPPI in patients undergoing bariatric surgery from the Middle East and North Africa (MENA) and specifically Saudi Arabia therefore, we aimed in this hospital-based study to determine the estimate of *H. pylori* positive infection (HPPI) in group of morbidly obese subjects undergoing sleeve gastrectomy and compare it to a match control group (age and gender) who had an upper endoscopy in the same period and same setting with different indications but had normal body weight. Based on the conflicting results of the current literature, we hypothesized, after controlling for age and gender, that we will be able to find out whether there is correlation between HPPI and obesity.
