Mahmoud Hallal
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Mahmoud Hallal has a total of 24 co-authors. Here are the top co-authors by number of shared publications:
- Bilal Hotayt
Badaro Endoscopic Center, Moarbes Hospital, Beirut P.O. Box 50-223, Lebanon
3 shared publications - Maha Hoteit
PHENOL Research Program, Faculty of Public Health, Section 1, Lebanese University, Beirut P.O. Box 6573, Lebanon
3 shared publications - Nadeen Zayour
PHENOL research group (Public HEalth Nutrition prOgram-Lebanon), Faculty of Public Health, Lebanese University, Beirut, Lebanon
3 shared publications - Nikolaos Tzenios
Charisma University
2 shared publications - Zahra Sadek
Physiotherapy department, Faculty of Public Health, Lebanese University, Beirut, Lebanon
2 shared publications - Abbas Zreik
Gastroenterology Department, Faculty of Medical Sciences, Lebanese University, Beirut P.O. Box 14-6573, Lebanon
1 shared publication
Latest Publications
- Open Access
- 22 July 2026
- Published by Springer Nature in BMC Gastroenterology
- Vol. 26 (1)
Patient-, endoscopist-, and procedure-related factors associated with adenoma detection in first screening colonoscopies at a Lebanese tertiary hospital: a retrospective cohort study
Background: Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide, and is largely preventable through colonoscopy, during which adenomatous polyps can be detected and removed. The adenoma detection rate (ADR) and polyp detection rate (PDR) are key quality indicators of colonoscopy quality and are inversely associated with post-colonoscopy CRC. These indicators may be influenced by patient-, physician-, and procedure-related factors. This study aimed to evaluate the ADR and PDR, identify factors influencing these indicators, and compare them among gastroenterologists at a Lebanese medical center. Methods: This observational, single-center, retrospective cohort study included 257 patients aged 50–75 years who underwent first-time screening colonoscopy over 3 years. Data on patient characteristics and colonoscopy findings were collected. ADR and PDR were calculated according to established guidelines, with ADR additionally estimated using the adenoma-to-polyp detection rate quotient (APDRQ). Descriptive statistics were applied, and chi-square or Fisher’s exact tests were used to assess associations between patient-, physician-, and procedural related factors and adenoma detection. Results: Out of 257 patients, 159 had polyps detected during colonoscopy. The overall ADR was 44.4%, and the PDR was 61.8% over the three-year study period. The ADR was 52.1% in men and 38.0% in women, whereas the PDR was 68.6% in men and 56.3% in women. Although the overall ADR and PDR met or exceeded the recommended benchmarks, disparities were noted in detection rates between males and females. Bowel preparation quality and guarantor type significantly influenced adenoma detection, whereas other factors related to patients and endoscopists had no significant effect. The estimated ADRs derived from the PDRs for five endoscopists were also high, surpassing the 25% benchmark; however, their annual estimated ADRs were relatively below this threshold. Conclusion: This study provides valuable regional data and underscores the need for standardized quality monitoring and further multicentric prospective research to optimize CRC prevention in Lebanon.
- 22 July 2026
- Published by Springer Nature in BMC Gastroenterology
- Vol. 26 (1)
Open AccessPatient-, endoscopist-, and procedure-related factors associated with adenoma detection in first screening colonoscopies at a Lebanese tertiary hospital: a retrospective cohort study
Background: Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide, and is largely preventable through colonoscopy, during which adenomatous polyps can be detected and removed. The adenoma detection rate (ADR) and polyp detection rate (PDR) are key quality indicators of colonoscopy quality and are inversely associated with post-colonoscopy CRC. These indicators may be influenced by patient-, physician-, and procedure-related factors. This study aimed to evaluate the ADR and PDR, identify factors influencing these indicators, and compare them among gastroenterologists at a Lebanese medical center. Methods: This observational, single-center, retrospective cohort study included 257 patients aged 50–75 years who underwent first-time screening colonoscopy over 3 years. Data on patient characteristics and colonoscopy findings were collected. ADR and PDR were calculated according to established guidelines, with ADR additionally estimated using the adenoma-to-polyp detection rate quotient (APDRQ). Descriptive statistics were applied, and chi-square or Fisher’s exact tests were used to assess associations between patient-, physician-, and procedural related factors and adenoma detection. Results: Out of 257 patients, 159 had polyps detected during colonoscopy. The overall ADR was 44.4%, and the PDR was 61.8% over the three-year study period. The ADR was 52.1% in men and 38.0% in women, whereas the PDR was 68.6% in men and 56.3% in women. Although the overall ADR and PDR met or exceeded the recommended benchmarks, disparities were noted in detection rates between males and females. Bowel preparation quality and guarantor type significantly influenced adenoma detection, whereas other factors related to patients and endoscopists had no significant effect. The estimated ADRs derived from the PDRs for five endoscopists were also high, surpassing the 25% benchmark; however, their annual estimated ADRs were relatively below this threshold. Conclusion: This study provides valuable regional data and underscores the need for standardized quality monitoring and further multicentric prospective research to optimize CRC prevention in Lebanon.
- Open Access
- 11 October 2025
- Published by MDPI AG in Antibiotics
- Vol. 14 (10) , 1013
Prevalence, Risk Factors, and Endoscopic Findings of Helicobacter pylori Infection Among Lebanese Patients Undergoing Gastroscopy: A Retrospective Study from a Single Tertiary Center
(1) Background: Gastric cancer continues to pose a significant public health challenge, with its incidence influenced by various factors, including Helicobacter pylori (H. pylori) infection. In Lebanon, data on H. pylori prevalence and its associated risk factors remain limited. This study aimed to determine the prevalence of H. pylori infection among Lebanese outpatients presenting with gastrointestinal symptoms undergoing gastroscopy, to explore correlations between the infection and demographic and clinical variables, and to evaluate the prevalence of associated conditions such as gastritis, duodenitis, and intestinal metaplasia. (2) Methods: Using a retrospective design, data from 786 patients admitted at a hospital in Beirut over a three-year period were extracted from records. (3) Results: The prevalence of H. pylori infection was 29.6% despite 91.5% of patients showing signs of gastritis on endoscopy. The infection showed significant associations with erosive gastritis, non-erosive gastritis, mosaic gastritis, as well as with both erosive and non-erosive duodenitis. No significant relationships were observed between H. pylori and demographic factors, atrophic, or nodular gastritis. (4) Conclusions: These findings underscore the importance of targeted testing and early eradication of H. pylori to manage gastritis effectively and reduce the risk of progression to more serious gastric conditions in the Lebanese population.
- 11 October 2025
- Published by MDPI AG in Antibiotics
- Vol. 14 (10) , 1013
Open AccessPrevalence, Risk Factors, and Endoscopic Findings of Helicobacter pylori Infection Among Lebanese Patients Undergoing Gastroscopy: A Retrospective Study from a Single Tertiary Center
(1) Background: Gastric cancer continues to pose a significant public health challenge, with its incidence influenced by various factors, including Helicobacter pylori (H. pylori) infection. In Lebanon, data on H. pylori prevalence and its associated risk factors remain limited. This study aimed to determine the prevalence of H. pylori infection among Lebanese outpatients presenting with gastrointestinal symptoms undergoing gastroscopy, to explore correlations between the infection and demographic and clinical variables, and to evaluate the prevalence of associated conditions such as gastritis, duodenitis, and intestinal metaplasia. (2) Methods: Using a retrospective design, data from 786 patients admitted at a hospital in Beirut over a three-year period were extracted from records. (3) Results: The prevalence of H. pylori infection was 29.6% despite 91.5% of patients showing signs of gastritis on endoscopy. The infection showed significant associations with erosive gastritis, non-erosive gastritis, mosaic gastritis, as well as with both erosive and non-erosive duodenitis. No significant relationships were observed between H. pylori and demographic factors, atrophic, or nodular gastritis. (4) Conclusions: These findings underscore the importance of targeted testing and early eradication of H. pylori to manage gastritis effectively and reduce the risk of progression to more serious gastric conditions in the Lebanese population.
- Open Access
Evaluating the Efficacy of Probiotics on Disease Progression, Quality of Life, and Nutritional Status Among Patients with Crohn’s Disease: A Multicenter, Randomized, Single-Blinded Controlled Trial
Background: There is growing interest in the role of gut microbiota in the pathophysiology of inflammatory bowel diseases (IBDs), including Crohn’s disease (CD). Probiotics have been proposed as a potential adjunct therapy for these conditions by altering the intestinal environment, although studies on their effectiveness have yielded mixed results. Aim: This study aims to evaluate the short-term (2 months) effects of a dietary supplement containing Lactobacilli, Bifidobacteria, and Lactococcus bacillus on disease progression, remission, quality of life, and nutritional intake in Lebanese patients with CD. Method: A multicenter, randomized, single-blind controlled trial was conducted in 2 medical centers in Beirut from 1 April 2024 to 1 August 2024. Recruitment, prescreening, screening, enrollment, and protocol implementation were carried out at both centers. Data were collected from 21 patients with CD, who were randomly assigned to the control group (n = 10) and the intervention group (n = 11). At baseline and after two months, participants underwent clinical assessments, WHOQOL-BREF evaluation, and 24 h dietary recalls. Follow-up visits included surveys on disease progression, quality of life, adherence, and adverse events, along with repeat body composition and anthropometric measurements. Results: Probiotic supplementation over two months did not significantly alter symptoms, flares, or hospitalizations outcomes between the control and intervention groups. However, the intervention group experienced notable increases in body weight (p = 0.01), BMI (p = 0.01), body fat mass (p = 0.04), and arm muscle circumference (p = 0.01). Nutrient intake patterns differed, with the intervention group showing increased consumption of calcium, riboflavin, and folate compared to controls (p = 0.01, p = 0.04, p = 0.013, respectively). Probiotic supplementation led to significant within-group increases in dietary fiber (p = 0.01), total sugar (p = 0.02), and caffeine (p = 0.01) among the intervention participants. Adverse effects in the intervention group were mild, including nausea (18.2%) and abdominal discomfort (9.1%). QOL improved significantly in the intervention group, particularly in physical (p = 0.03), psychological (p = 0.04), and environmental domains (p = 0.003), while the control group exhibited improvements only in psychological health. Conclusions: Overall, the findings suggest that probiotics can enhance body composition, nutrient intake, and certain aspects of QOL among CD patients, despite minimal impact on disease symptoms or dietary patterns.
Open AccessEvaluating the Efficacy of Probiotics on Disease Progression, Quality of Life, and Nutritional Status Among Patients with Crohn’s Disease: A Multicenter, Randomized, Single-Blinded Controlled Trial
Background: There is growing interest in the role of gut microbiota in the pathophysiology of inflammatory bowel diseases (IBDs), including Crohn’s disease (CD). Probiotics have been proposed as a potential adjunct therapy for these conditions by altering the intestinal environment, although studies on their effectiveness have yielded mixed results. Aim: This study aims to evaluate the short-term (2 months) effects of a dietary supplement containing Lactobacilli, Bifidobacteria, and Lactococcus bacillus on disease progression, remission, quality of life, and nutritional intake in Lebanese patients with CD. Method: A multicenter, randomized, single-blind controlled trial was conducted in 2 medical centers in Beirut from 1 April 2024 to 1 August 2024. Recruitment, prescreening, screening, enrollment, and protocol implementation were carried out at both centers. Data were collected from 21 patients with CD, who were randomly assigned to the control group (n = 10) and the intervention group (n = 11). At baseline and after two months, participants underwent clinical assessments, WHOQOL-BREF evaluation, and 24 h dietary recalls. Follow-up visits included surveys on disease progression, quality of life, adherence, and adverse events, along with repeat body composition and anthropometric measurements. Results: Probiotic supplementation over two months did not significantly alter symptoms, flares, or hospitalizations outcomes between the control and intervention groups. However, the intervention group experienced notable increases in body weight (p = 0.01), BMI (p = 0.01), body fat mass (p = 0.04), and arm muscle circumference (p = 0.01). Nutrient intake patterns differed, with the intervention group showing increased consumption of calcium, riboflavin, and folate compared to controls (p = 0.01, p = 0.04, p = 0.013, respectively). Probiotic supplementation led to significant within-group increases in dietary fiber (p = 0.01), total sugar (p = 0.02), and caffeine (p = 0.01) among the intervention participants. Adverse effects in the intervention group were mild, including nausea (18.2%) and abdominal discomfort (9.1%). QOL improved significantly in the intervention group, particularly in physical (p = 0.03), psychological (p = 0.04), and environmental domains (p = 0.003), while the control group exhibited improvements only in psychological health. Conclusions: Overall, the findings suggest that probiotics can enhance body composition, nutrient intake, and certain aspects of QOL among CD patients, despite minimal impact on disease symptoms or dietary patterns.