Varol TUNALI

Dr. Varol TUNALI

Manisa Celal Bayar University, Manisa, Turkey (Türkiye)
orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 2022 in Gut Microbes
Verified
Journal Article
Open access
TKTarkan Karakan
Tarkan Karakan
AGAycan Gundogdu
Aycan Gundogdu
HAHakan Alagözlü
Hakan Alagözlü
NENergiz Ekmen
Nergiz Ekmen
SOSeckin Ozgul
Seckin Ozgul
ONOzkan Nalbantoglu
Ozkan Nalbantoglu
We enrolled consecutive IBS-M patients (n = 25) according to Rome IV criteria. Fecal samples were obtained from all patients twice (pre-and post-intervention) and high-throughput 16S rRNA sequencing was performed. Six weeks of personalized nutrition diet (n = 14) for group 1 and a standard IBS diet (n = 11) for group 2 were followed. AI-based diet was designed based on optimizing a personalized nutritional strategy by an algorithm regarding individual gut microbiome features. The IBS-SSS evaluation for pre- and post-intervention exhibited significant improvement (p < .02 and p < .001 for the standard IBS diet and personalized nutrition groups, respectively). While the IBS-SSS evaluation changed to moderate from severe in 78% (11 out of 14) of the personalized nutrition group, no such change was observed in the standard IBS diet group. A statistically significant increase in the Faecalibacterium genus was observed in the personalized nutrition group (p = .04). Bacteroides and putatively probiotic genus Propionibacterium were increased in the personalized nutrition group. The change (delta) values in IBS-SSS scores (before-after) in personalized nutrition and standard IBS diet groups are significantly higher in the personalized nutrition group. AI-based personalized microbiome modulation through diet significantly improves IBS-related symptoms in patients with IBS-M. Further large-scale, randomized placebo-controlled trials with long-term follow-up (durability) are needed. GRAPHICAL ABSTRACT

8 May 2024 in American Journal of Gastroenterology
Verified
Journal Article
Open access
VTVarol TUNALI
Varol TUNALI
NANaciye Çiğdem Arslan
Naciye Çiğdem Arslan
BEBeyza Hilal Ermiş
Beyza Hilal Ermiş
GHGozde Dervis Hakim
Gozde Dervis Hakim
AGAycan Gundogdu
Aycan Gundogdu
ONOzkan Nalbantoglu
Ozkan Nalbantoglu
INTRODUCTION: Personalized management strategies are pivotal in addressing irritable bowel syndrome (IBS). This multicenter randomized controlled trial focuses on comparing the efficacy of a microbiome-based artificial intelligence-assisted personalized diet (PD) with a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet (FODMAP) for IBS management. METHODS: One hundred twenty-one patients participated, with 70 assigned to the PD group and 51 to the FODMAP diet group. IBS subtypes, demographics, symptom severity (IBS-SSS), anxiety, depression, and quality of life (IBS-QOL) were evaluated. Both interventions spanned 6 weeks. The trial's primary outcome was the within-individual difference in IBS-SSS compared between intervention groups. RESULTS: For the primary outcome, there was a change in IBS-SSS of −112.7 for those in the PD group vs −99.9 for those in the FODMAP diet group (P = 0.29). Significant improvement occurred in IBS-SSS scores (P < 0.001), frequency (P < 0.001), abdominal distension (P < 0.001), and life interference (P < 0.001) in both groups. In addition, there were significant improvements in anxiety levels and IBS-QOL scores for both groups (P < 0.001). Importantly, PD was effective in reducing IBS SSS scores across all IBS subtypes IBS-Constipation (IBS-C; P < 0.001), IBS-Diarrhea (IBS-D; P = 0.01), and IBS-Mixed (IBS-M; P < 0.001) while FODMAP diet exhibited comparable improvements in IBS-C (P = 0.004) and IBS-M (P < 0.001). PD intervention significantly improved IBS-QOL scores for all subtypes (IBS-C [P < 0.001], IBS-D [P < 0.001], and IBS-M [P = 0.008]) while the FODMAP diet did so for the IBS-C (P = 0.004) and IBS-D (P = 0.022). Notably, PD intervention led to significant microbiome diversity shifts (P < 0.05) and taxa alterations compared with FODMAP diet. DISCUSSION: The artificial intelligence-assisted PD emerges as a promising approach for comprehensive IBS management. With its ability to address individual variation, the PD approach demonstrates significant symptom relief, enhanced QOL, and notable diversity shifts in the gut microbiome, making it a valuable strategy in the evolving landscape of IBS care.

15 October 2023 in Current Research in Parasitology & Vector-Borne Diseases
Verified
Journal Article
Open access
VTVarol TUNALI
Varol TUNALI
AÖAhmet Özbilgin
Ahmet Özbilgin
Leishmaniasis epidemiology is currently undergoing substantial transformations in both Turkey and Europe, signifying potential implications for public health. This review analyzes the evolving patterns within Turkey and their potential ramifications for Europe. Within Turkey, the dynamics of leishmaniasis are undergoing noteworthy alterations, manifesting in a rise in cutaneous leishmaniasis (CL) cases and the emergence of Leishmania major and Leishmania donovani. These transformations are predominantly driven by factors such as the distribution of vectors, human activities, climate fluctuations, and migration. Across Europe, particularly in countries within the Mediterranean basin, leishmaniasis is endemic, primarily attributed to Leishmania infantum. Recent evidence suggests a resurgence of the disease even in previously non-endemic areas, propelled by climate change, urbanization, and migration. The changing landscape of leishmaniasis in Turkey carries direct implications for Europe. The presence and distribution of Leishmania tropica, L. major, and L. donovani raise concerns regarding cross-border transmission. Turkeyʼs strategic position along migration routes further compounds the risk, alongside the facilitative effects of climate change and host mobility. Embracing a One Health approach with public awareness campaigns should be a priority. To ensure the protection of public health in Europe, it is imperative to adopt a proactive approach by establishing robust surveillance mechanisms, implementing preventive measures, and cultivating collaboration with Turkey. The invaluable experience, strategic geographical location, and well-established infrastructure of Turkey make this collaboration crucial in effectively addressing the evolving dynamics of leishmaniasis and its potential impacts on Europe.

13 November 2019 in Acta Parasitologica
Verified
Journal Article
Closed access
PDF file
AÖAhmet Özbilgin
Ahmet Özbilgin
GGGülsüm Gençoğlan
Gülsüm Gençoğlan
VTVarol TUNALI
Varol TUNALI
IÇİbRahim Çavuş
İbRahim Çavuş
AYAhmet Yıldırım
Ahmet Yıldırım
MHMehmet Harman
Mehmet Harman
Purpose Due to mass population movements driven by internal conflicts and wars, cutaneous leishmaniasis (CL) is becoming increasingly important in Turkey. This study is aimed at determining the...

8 November 2022 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
NANaciye Çiğdem Arslan
Naciye Çiğdem Arslan
AGAycan Gündoğdu
Aycan Gündoğdu
VTVarol TUNALI
Varol TUNALI
OTOğuzhan Hakan Topgül
Oğuzhan Hakan Topgül
DBDamla Beyazgül
Damla Beyazgül
ONOzkan Nalbantoglu
Ozkan Nalbantoglu
Background: Currently, medications and behavioral modifications have limited success in the treatment of functional constipation (FC). An individualized diet based on microbiome analysis may improve symptoms in FC. In the present study, we aimed to investigate the impacts of microbiome modulation on chronic constipation. Methods: Between December 2020–December 2021, 50 patients fulfilling the Rome IV criteria for functional constipation were randomized into two groups. The control group received sodium picosulfate plus conventional treatments (i.e., laxatives, enemas, increased fiber, and fluid intake). The study group underwent microbiome analysis and received an individualized diet with the assistance of a soft computing system (Enbiosis Biotechnology®, Sariyer, Istanbul). Differences in patient assessment constipation–quality of life (PAC-QoL) scores and complete bowel movements per week (CBMpW) were compared between groups after 6-weeks of intervention. Results: The mean age of the overall cohort (n = 45) was 31.5 ± 10.2 years, with 88.9% female predominance. The customized diet developed for subjects in the study arm resulted in a 2.5-fold increase in CBMpW after 6-weeks (1.7 vs. 4.3). The proportion of the study group patients with CBMpW > 3 was 83% at the end of the study, and the satisfaction score was increased 4-fold from the baseline (3.1 to 10.7 points). More than 50% improvement in PAC-QoL scores was observed in 88% of the study cohort compared to 40% in the control group (p = 0.001). Conclusion: The AI-assisted customized diet based on individual microbiome analysis performed significantly better compared to conventional therapy based on patient-reported outcomes in the treatment of functional constipation.

2 September 2016 in Turkish Journal of Parasitology
Verified
Journal Article
Closed access
SUSerhat Uysal
Serhat Uysal
VTVarol TUNALI
Varol TUNALI
EOEylem Akdur Ozturk
Eylem Akdur Ozturk
OAOmur Ardeniz
Omur Ardeniz
MTMeltem Taşbakan
Meltem Taşbakan
BABilgin Arda
Bilgin Arda
Parasites might cause atypical and severe infections in immunocompromised hosts. The prevalence of diarrhea among common variable immune deficiency (CVID) syndrome patients varies between 20% and 94%, which indicates that diarrhea and gastrointestinal system (GIS) complaints could be the second leading cause of morbidity in CVID patients after respiratory tract infections. This study aimed to assess the prevalence of intestinal parasites in CVID patients with GIS complaints and diarrhea. In this study, all cases followed up in the Immunology and Allergy Clinic of Ege University School of Medicine from July 2008 to August 2015 with the diagnosis of CVID were reviewed retrospectively. The stool samples of patients with diarrhea were identified using direct microscopy of native (0.09% NaCl) and Lugol's iodine preparations followed by formol-ethyl acetate concentration to apply modified Kinyoun, trichrome, acid-fast trichrome, and modified trichrome stains for the presence of intestinal parasites. Overall, 26 of 37 CVID patients had diarrhea; white and red blood cells (WBCs and RBCs, respectively) were identified in 11 and 10 of these 26 samples, respectively. Intestinal parasites were found to be present in 7 of the 11 patients with WBCs and 3 of the 10 patients with RBCs. With the addition of patients who neither had WBCs nor RBCs in their stool, a parasitic agent was detected in 13 (50%) of the 26 patients with diarrhea. There was no significant difference between the diarrheic patients with or without intestinal parasites with respect to cramps, fever, nausea and vomiting, tenesmus, bloody feces, and presence of mucus in the stool. Only one patient had malabsorption, which was not associated with intestinal parasites. The most common parasites detected in this study were Cryptosporidium spp. (n=9; 69.2%), Giardia spp. (n=7; 53.8%), and Blastocystis spp. (n=3; 23.1%). We also identified that parasitic diarrhea in CVID patients tended to last longer (M (mean): 16.2 days) than other causes of infectious diarrhea; this is in accordance with previous studies. Cryptosporidium spp. was found be the major cause of parasitic intestinal infection in this patient population. It was concluded that parasitic infections may cause chronic diarrhea, which are major causes of morbidity in CVID patients. Therefore, special attention is necessary for the identification of intestinal parasites in CVID patients with diarrhea.