Gluten-Free Diet Luca Elli www.mdpi.com/journal/nutrients Edited by Printed Edition of the Special Issue Published in Nutrients nutrients Gluten-Free Diet Gluten-Free Diet Special Issue Editor Luca Elli MDPI • Basel • Beijing • Wuhan • Barcelona • Belgrade Special Issue Editor Luca Elli Fondazione IRCCS Ca Granda Ospedale Maggiore Policlinico Italy Editorial Office MDPI St. Alban-Anlage 66 4052 Basel, Switzerland This is a reprint of articles from the Special Issue published online in the open access journal Nutrients (ISSN 2072-6643) from 2018 to 2019 (available at: https://www.mdpi.com/journal/nutrients/ special issues/gluten free diet) For citation purposes, cite each article independently as indicated on the article page online and as indicated below: LastName, A.A.; LastName, B.B.; LastName, C.C. Article Title. Journal Name Year , Article Number , Page Range. ISBN 978-3-03897-736-0 (Pbk) ISBN 978-3-03897-737-7 (PDF) c © 2019 by the authors. Articles in this book are Open Access and distributed under the Creative Commons Attribution (CC BY) license, which allows users to download, copy and build upon published articles, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. The book as a whole is distributed by MDPI under the terms and conditions of the Creative Commons license CC BY-NC-ND. Contents About the Special Issue Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Luca Elli and Beatrice Marinoni Gluten Rhapsody Reprinted from: Nutrients 2019 , 11 , 589, doi:10.3390/nu11030589 . . . . . . . . . . . . . . . . . . . 1 Andrew M. Joelson, Marilyn G. Geller, Haley M. Zylberberg, Peter H. R. Green and Benjamin Lebwohl The Effect of Depressive Symptoms on the Association between Gluten-Free Diet Adherence and Symptoms in Celiac Disease: Analysis of a Patient Powered Research Network Reprinted from: Nutrients 2018 , 10 , 538, doi:10.3390/nu10050538 . . . . . . . . . . . . . . . . . . . 5 Sara Massironi, Federica Branchi, Mirella Fraquelli, Alessandra Baccarin, Francesco Somalvico, Francesca Ferretti, Dario Conte and Luca Elli Effects of a Gluten-Containing Meal on Gastric Emptying and Gallbladder Contraction Reprinted from: Nutrients 2018 , 10 , 910, doi:10.3390/nu10070910 . . . . . . . . . . . . . . . . . . . 14 Leda Roncoroni, Karla A. Bascu ̃ n ́ an, Luisa Doneda, Alice Scricciolo, Vincenza Lombardo, Federica Branchi, Francesca Ferretti, Bernardo Dell’Osso, Valeria Montanari, Maria Teresa Bardella and Luca Elli A Low FODMAP Gluten-Free Diet Improves Functional Gastrointestinal Disorders and Overall Mental Health of Celiac Disease Patients: A Randomized Controlled Trial Reprinted from: Nutrients 2018 , 10 , 1023, doi:10.3390/nu10081023 . . . . . . . . . . . . . . . . . . 22 Leda Roncoroni, Karla A. Bascu ̃ n ́ an, Luisa Doneda, Alice Scricciolo, Vincenza Lombardo, Federica Branchi, Francesca Ferretti, Bernardo Dell’Osso, Valeria Montanari, Maria Teresa Bardella and Luca Ellii Correction: Roncoroni, L. et al. A Low FODMAP Gluten-Free Diet Improves Functional Gastrointestinal Disorders and Overall Mental Health of Celiac Disease Patients: A Randomized Controlled Trial. Nutrients 2018, 10 , 1023 Reprinted from: Nutrients 2019 , 11 , 566, doi:10.3390/nu11030566 . . . . . . . . . . . . . . . . . . . 36 Claudia P. Pratesi, Winfred H ̈ auser, Rosa Harumi Uenishi, Nicole Selleski, Eduardo Yoshio Nakano, Lenora Gandolfi, Riccardo Pratesi and Renata Puppin Zandonadi Quality of Life of Celiac Patients in Brazil: Questionnaire Translation, Cultural Adaptation and Validation Reprinted from: Nutrients 2018 , 10 , 1167, doi:10.3390/nu10091167 . . . . . . . . . . . . . . . . . . 40 Beatrice Allen and Caroline Orfila The Availability and Nutritional Adequacy of Gluten-Free Bread and Pasta Reprinted from: Nutrients 2018 , 10 , 1370, doi:10.3390/nu10101370 . . . . . . . . . . . . . . . . . . 52 Herbert Wieser and Katharina A. Scherf Preparation of a Defined Gluten Hydrolysate for Diagnosis and Clinical Investigations of Wheat Hypersensitivities Reprinted from: Nutrients 2018 , 10 , 1411, doi:10.3390/nu10101411 . . . . . . . . . . . . . . . . . . 64 Wioleta Zysk, Dominika Głabska and Dominika Guzek Social and Emotional Fears and Worries Influencing the Quality of Life of Female Celiac Disease Patients Following a Gluten-Free Diet Reprinted from: Nutrients 2018 , 10 , 1414, doi:10.3390/nu10101414 . . . . . . . . . . . . . . . . . . 78 v Jose F. Garcia-Mazcorro, Giuliana Noratto and Jose M. Remes-Troche The Effect of Gluten-Free Diet on Health and the Gut Microbiota Cannot Be Extrapolated from One Population to Others Reprinted from: Nutrients 2018 , 10 , 1421, doi:10.3390/nu10101421 . . . . . . . . . . . . . . . . . . 92 Gra ̇ zyna Czaja-Bulsa and Michał Bulsa Adherence to Gluten-Free Diet in Children with Celiac Disease Reprinted from: Nutrients 2018 , 10 , 1424, doi:10.3390/nu10101424 . . . . . . . . . . . . . . . . . . 106 Jose F. Garcia-Mazcorro, Xaira Rivera-Gutierrez, Orestes De Jesus Cobos-Quevedo, Peter Grube-Pagola, Arturo Meixueiro-Daza, Karina Hernandez-Flores, Francisco J. Cabrera-Jorge, Hector Vivanco-Cid, Scot E. Dowd and Jose M. Remes-Troche First Insights into the Gut Microbiota of Mexican Patients with Celiac Disease and Non-Celiac Gluten Sensitivity Reprinted from: Nutrients 2018 , 10 , 1641, doi:10.3390/nu10111641 . . . . . . . . . . . . . . . . . . 116 Iga Rybicka The Handbook of Minerals on a Gluten-Free Diet Reprinted from: Nutrients 2018 , 10 , 1683, doi:10.3390/nu10111683 . . . . . . . . . . . . . . . . . . 135 Paolo Usai-Satta, Francesco Oppia, Mariantonia Lai and Francesco Cabras Motility Disorders in Celiac Disease and Non-Celiac Gluten Sensitivity: The Impact of a Gluten-Free Diet Reprinted from: Nutrients 2018 , 10 , 1705, doi:10.3390/nu10111705 . . . . . . . . . . . . . . . . . . 143 Eleanor Busby, Justine Bold, Lindsey Fellows and Kamran Rostami Mood Disorders and Gluten: It’s Not All in Your Mind! A Systematic Review with Meta-Analysis Reprinted from: Nutrients 2018 , 10 , 1708, doi:10.3390/nu10111708 . . . . . . . . . . . . . . . . . . 150 Teba Gonz ́ alez, Idoia Larretxi, Juan Carlos Vitoria, Luis Casta ̃ no, Edurne Sim ́ on, Itziar Churruca, Virginia Navarro and Arrate Lasa Celiac Male’s Gluten-Free Diet Profile: Comparison to that of the Control Population and Celiac Women Reprinted from: Nutrients 2018 , 10 , 1713, doi:10.3390/nu10111713 . . . . . . . . . . . . . . . . . . 174 Anupam Rej and David Surendran Sanders Gluten-Free Diet and Its ‘Cousins’ in Irritable Bowel Syndrome Reprinted from: Nutrients 2018 , 10 , 1727, doi:10.3390/nu10111727 . . . . . . . . . . . . . . . . . . 187 Martin Haupt-Jorgensen, Laurits J. Holm, Knud Josefsen and Karsten Buschard Possible Prevention of Diabetes with a Gluten-Free Diet Reprinted from: Nutrients 2018 , 10 , 1746, doi:10.3390/nu10111746 . . . . . . . . . . . . . . . . . . 199 Leda Roncoroni, Luca Elli, Luisa Doneda, Karla A. Bascu ̃ n ́ an, Maurizio Vecchi, Federico Morreale, Alice Scricciolo, Vincenza Lombardo and Nicoletta Pellegrini A Retrospective Study on Dietary FODMAP Intake in Celiac Patients Following a Gluten-Free Diet Reprinted from: Nutrients 2018 , 10 , 1769, doi:10.3390/nu10111769 . . . . . . . . . . . . . . . . . . 219 Luis Rodrigo, Isabel P ́ erez-Martinez, Eugenia Lauret-Bra ̃ na and Adolfo Su ́ arez-Gonz ́ alez Descriptive Study of the Different Tools Used to Evaluate the Adherence to a Gluten-Free Diet in Celiac Disease Patients Reprinted from: Nutrients 2018 , 10 , 1777, doi:10.3390/nu10111777 . . . . . . . . . . . . . . . . . . 231 vi Alice Itzlinger, Federica Branchi, Luca Elli and Michael Schumann Gluten-Free Diet in Celiac Disease—Forever and for All? Reprinted from: Nutrients 2018 , 10 , 1796, doi:10.3390/nu10111796 . . . . . . . . . . . . . . . . . . 244 Paweł Wiech, Zdzisława Chmiel, Dariusz Bazali ́ nski, Izabela Sałaci ́ nska, Anna Bartosiewicz, Artur Mazur, Bartosz Korczowski, Monika Binkowska-Bury and Mariusz Dabrowski The Relationship between Body Composition and a Gluten Free Diet in Children with Celiac Disease Reprinted from: Nutrients 2018 , 10 , 1817, doi:10.3390/nu10111817 . . . . . . . . . . . . . . . . . . 258 Francesco Tovoli, Giulia Negrini, Vito Sansone, Chiara Faggiano, Teresa Catenaro, Luigi Bolondi and Alessandro Granito Celiac Disease Diagnosed through Screening Programs in At-Risk Adults Is Not Associated with Worse Adherence to the Gluten-Free Diet and Might Protect from Osteopenia/Osteoporosis Reprinted from: Nutrients 2018 , 10 , 1940, doi:10.3390/nu10121940 . . . . . . . . . . . . . . . . . . 269 Leda Roncoroni, Karla A. Bascu ̃ n ́ an, Maurizio Vecchi, Luisa Doneda, Maria T. Bardella, Vincenza Lombardo, Alice Scricciolo, Federica Branchi and Luca Elli Exposure to Different Amounts of Dietary Gluten in Patients with Non-Celiac Gluten Sensitivity (NCGS): An Exploratory Study Reprinted from: Nutrients 2019 , 11 , 136, doi:10.3390/nu11010136 . . . . . . . . . . . . . . . . . . . 278 Ángela Ruiz-Carnicer, Isabel Comino, Verónica Segura, Carmen V. Ozuna, María de Lourdes Moreno, Miguel Ángel López-Casado, María Isabel Torres, Francisco Barro and Carolina Sousa Celiac Immunogenic Potential of α -Gliadin Epitope Variants from Triticum and Aegilops Species Reprinted from: Nutrients 2019 , 11 , 220, doi:10.3390/nu11020220 . . . . . . . . . . . . . . . . . . . 293 vii About the Special Issue Editor Luca Elli , MD received his degree in Medicine at the University of Milano and in 2004 became a specialist in Gastroenterology and Endoscopy. Again at the University of Milano, he received his PhD in Gastroenterological sciences. Throughout his career, Luca Elli has dealt with celiac disease, acquiring an important clinical and scientific experience. He is the author of more than 100 articles published in international journals. Moreover, during the last few years, Luca Elli has become an expert in small bowel endoscopy both videocapsule and double balloon enteroscopy, which has successfully been applied in the management of celiac disease. In fact, he is the head of the Center for Prevention and Diagnosis of Celiac Disease, Fondazione IRCCS Ca’ Granda Opsedale Maggiore Policlinico, Milano, Italy. ix nutrients Editorial Gluten Rhapsody Luca Elli * and Beatrice Marinoni Center for the Prevention and Diagnosis of Coeliac Disease, Division of Gastroenterology and Endoscopy, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan 20122, Italy; beatrice.marinoni@unimi.it * Correspondence: luca.elli@policlinico.mi.it Received: 3 March 2019; Accepted: 5 March 2019; Published: 11 March 2019 Keywords: gluten; gluten-free diet; coeliac disease; non-celiac gluten sensitivity; non-coeliac wheat sensitivity; gliadin; microbiota For decades, gluten-free dieting (GFD) has been accepted as the only therapeutic approach to coeliac disease (CD) and, more recently, for non-coeliac gluten sensitivity (NCGS), a term to refer to the so-called gluten-related disorders (GRD) [1]. GFD has become popular among the general population for its supposed beneficial effects on human health [ 2 ]. GFD is also the most frequently suggested dietary regimen in irritable bowel syndrome (IBS) [3]. In fact, there are several concerns and misconceptions regarding GFD, which deserve special attention. For such a reason, this Special Issue on “Gluten-Free Diet” comprises 23 peer-reviewed papers, reporting on the most recent evidence and topics about GFD. In particular, the impact of GFD on human health and quality of life; the emerging evidence of its beneficial effects in IBS; and the difficult problems of compliance, costs, and availability of GF food are discussed. Several sources of evidence support the notion that, despite its remarkable effectiveness in remitting the vast majority of GRD symptoms, GFD comes with both a social and financial burden. Gluten-free foods are still less available and more expensive than their gluten-containing versions [ 4 ], thus causing patients social and psychological consequences in securing good quality of life and compliance with the advised dietary regimen. As Joelson AM et al. have shown, the prevalence of depression among the sufferers of coeliac disease (CD) is high and depressive symptoms may mask the relationship between symptoms and inadvertent gluten exposure, and thus make it more difficult to detect any lack of adherence to GFD [ 5 ]. With a systematic review and meta-analysis, Busby at al. have confirmed that gluten elimination may well represent an effective treatment strategy for mood disorders for individuals with GRD [6]. As permanent adherence to GFD is difficult, with repeated transgression and frequent contaminations, a reliable tool to assess compliance is currently advocated [ 7 ]. In their review, Rodrigo L. et al. establish that the determination of the immunogenic gluten peptides in isolated samples of faeces or urine has proven useful for assessing adherence to GFD [8]. In the opinion of some authors, several factors contribute to greater adherence to GFD; that is, good knowledge of the disease and its treatment, high level of education, high economic status, female sex, young age, high self-esteem, good grades at school, good availability and labelling of products, good contact with a doctor and a dietitian, and finally membership of the Coeliac Society [ 9 – 12 ]. Conversely, the factors responsible for not adhering to GFD are poor taste of gluten-free products, high price and poor availability, being adolescent, the absence of immediate symptoms following the intake of small amounts of gluten, and low awareness of the disease [9,11,12]. From a study conducted by Czaja-Bulsa et al., it has emerged that GFD adherence has improved over the last ten years, thanks to the popularity gained by GFD and GF food becoming more available [13]. Nutrients 2019 , 11 , 589; doi:10.3390/nu11030589 www.mdpi.com/journal/nutrients 1 Nutrients 2019 , 11 , 589 Further evidence, recently accepted, shows that in spite of improvements in food formulation over the last few years, GF foods still present with a reduced nutritional profile when compared with gluten-containing products, with higher lipid and trans-fat content; lower level of proteins; and lower degree of fortification with micronutrients, especially Ca, Fe, Mg, and Zn [ 14 ]. Similarly, Wiech et al. have shown that CD children adhering to GFD for a year showed a higher increase in weight and body mass index (BMI) when compared with healthy controls, suggesting a tendency towards metabolic syndrome [ 15 ]. However, there is growing evidence supporting the protective effect of GFD on bone metabolism [16] and the possible prevention of diabetes through GFD [17]. In preparing this Special Issue, GFD and fermentable oligo/di/monosaccharides and polyols (FODMAP) as dietary therapies in individuals with IBS was an issue that the Editors found to be important [ 18 ]. In a study evaluating the intake of foods containing fermentable oligo/di/monosaccharides and polyols (FODMAP) in CD patients, Roncoroni et al. confirmed that the prevalence of IBS-type symptoms among CD patients is higher than in the general population. Moreover, they demonstrated that CD patients consume a diet high on FODMAP, which is a factor that possibly induces gastrointestinal symptoms in treated CD patients [ 19 , 20 ]. Moreover, in the first RCT DB intervention controlled study, the same researchers showed that CD patients on GFD, but with persisting functional gastrointestinal symptoms, had a positive response to a diet low on FODMAP. Thus, GFD associated with a low-FODMAP content is beneficial, as a support therapy, for a group of CD patients with persistent gastrointestinal symptoms [21]. A number of questions still remain unanswered; namely, the modifications by GFD of the gut microbiota in different populations [ 22 , 23 ]; the effects of gluten intake on both gastric and gallbladder motility [ 24 ]; and the persistent motor disorders in CD patients, despite GFD, which can be explained by low-grade mucosal inflammation [25]. Several open issues regarding GFD also remain, such as, most importantly, the ingestion threshold for the amount of gluten considered tolerable has not been defined yet. Furthermore, the appropriateness of a lifelong indication to GFD, particularly for patients with sub-clinical and potential CD (i.e., not confirmed by histology), is still a matter of debate [ 26 ], especially on consideration of the impact on patients’ quality of life posed by a restrictive gluten-free diet [ 27 ]. Finally, in a study on the immunogenic potential of α -gliadins in Triticale, Ruiz-Carnicer et al. demonstrated that by substituting a natural amino acid to the most immunogenic fraction of gluten (DQ2.5-glia-a 1, DQ2.5-glia-a2, and DQ2.5-glia-a3), the toxicity of three T-cell epitopes was eliminated, while the technological properties of commercial wheat were maintained [ 28 ]. These results may offer the opportunity to generate wheat varieties with a reduced CD immunogenicity not safe for consumption by patients, but that might help to prevent the onset of CD in people that carry genetic risk factors. In conclusion, we would like to acknowledge all the authors for their valuable contributions and the reviewers for their constructive comments. Special thanks are owed to the publishing team of Nutrients for their professional assistance in the development of this Special Issue. Funding: This research received no external funding Conflicts of Interest: Luca Elli is a member of special dietary foods manufacturer Dr. Schär’s Advisory Board. References 1. Elli, L.; Villalta, D.; Roncoroni, L.; Barisani, D.; Ferrero, S.; Pellegrini, N.; Bardella, M.T.; Valiante, F.; Tomba, C.; Carroccio, A.; et al. Nomenclature and diagnosis of gluten-related disorders: A position statement by the Italian Association of Hospital Gastroenterologists and Endoscopists (AIGO). Dig. Liver Dis. 2017 , 49 , 138–146. [CrossRef] [PubMed] 2. Kim, H.S.; Patel, K.G.; Orosz, E.; Kothari, N.; Demyen, M.F.; Pyrsopoulos, N.; Ahlawat, S.K. Time Trends in the Prevalence of Celiac Disease and Gluten-Free Diet in the US Population: Results from the National Health and Nutrition Examination Surveys 2009–2014. JAMA Intern. Med. 2016 , 176 , 1716–1717. [CrossRef] 2 Nutrients 2019 , 11 , 589 3. Catassi, C.; Alaedini, A.; Bojarski, C.; Bonaz, B.; Bouma, G.; Carroccio, A.; Castillejo, G.; De Magistris, L.; Dieterich, W.; Di Liberto, D.; et al. The Overlapping Area of Non-Celiac Gluten Sensitivity (NCGS) and Wheat-Sensitive Irritable Bowel Syndrome (IBS): An Update. Nutrients 2017 , 9 , 1268. [CrossRef] [PubMed] 4. Allen, B.; Orfila, C. The Availability and Nutritional Adequacy of Gluten-Free Bread and Pasta. Nutrients 2018 , 10 , 1370. [CrossRef] [PubMed] 5. Joelson, A.M.; Geller, M.G.; Zylberberg, H.M.; Green, P.H.R.; Lebwohl, B. The Effect of Depressive Symptoms on the Association between Gluten-Free Diet Adherence and Symptoms in Celiac Disease: Analysis of a Patient Powered Research Network. Nutrients 2018 , 10 , 538. [CrossRef] [PubMed] 6. Busby, E.; Bold, J.; Fellows, L.; Rostami, K. Mood Disorders and Gluten: It’s Not All in Your Mind! A Systematic Review with Meta-Analysis. Nutrients 2018 , 10 , 1708. [CrossRef] [PubMed] 7. Syage, J.A.; Kelly, C.P.; Dickason, M.A.; Ramirez, A.C.; Leon, F.; Dominguez, R.; Sealey-Voyksner, J.A. Determination of gluten consumption in celiac disease patients on a gluten-free diet. Am. J. Clin. Nutr. 2018 , 107 , 201–207. [CrossRef] [PubMed] 8. Rodrigo, L.; Perez-Martinez, I.; Lauret-Brana, E.; Suarez-Gonzalez, A. Descriptive Study of the Different Tools Used to Evaluate the Adherence to a Gluten-Free Diet in Celiac Disease Patients. Nutrients 2018 , 10 , 1777. [CrossRef] [PubMed] 9. Freeman, H.J. Dietary compliance in celiac disease. World J. Gastroenterol. 2017 , 23 , 2635–2639. [CrossRef] [PubMed] 10. Silvester, J.A.; Weiten, D.; Graff, L.A.; Walker, J.R.; Duerksen, D.R. Is it gluten-free? Relationship between self-reported gluten-free diet adherence and knowledge of gluten content of foods. Nutrition 2016 , 32 , 777–783. [CrossRef] [PubMed] 11. Greco, L.; Mayer, M.; Ciccarelli, G.; Troncone, R.; Auricchio, S. Compliance to a gluten-free diet in adolescents, or “what do 300 coeliac adolescents eat every day?”. Ital. J. Gastroenterol. Hepatol. 1997 , 29 , 305–310. [PubMed] 12. Kurppa, K.; Lauronen, O.; Collin, P.; Ukkola, A.; Laurila, K.; Huhtala, H.; Maki, M.; Kaukinen, K. Factors associated with dietary adherence in celiac disease: A nationwide study. Digestion 2012 , 86 , 309–314. [CrossRef] [PubMed] 13. Czaja-Bulsa, G.; Bulsa, M. Adherence to Gluten-Free Diet in Children with Celiac Disease. Nutrients 2018 , 10 , 1424. [CrossRef] [PubMed] 14. Rybicka, I. The Handbook of Minerals on a Gluten-Free Diet. Nutrients 2018 , 10 , 1683. [CrossRef] [PubMed] 15. Wiech, P.; Chmiel, Z.; Bazalinski, D.; Salacinska, I.; Bartosiewicz, A.; Mazur, A.; Korczowski, B.; Binkowska-Bury, M.; Dabrowski, M. The Relationship between Body Composition and a Gluten Free Diet in Children with Celiac Disease. Nutrients 2018 , 10 , 1817. [CrossRef] [PubMed] 16. Tovoli, F.; Negrini, G.; Sansone, V.; Faggiano, C.; Catenaro, T.; Bolondi, L.; Granito, A. Celiac Disease Diagnosed through Screening Programs in At-Risk Adults Is Not Associated with Worse Adherence to the Gluten-Free Diet and Might Protect from Osteopenia/Osteoporosis. Nutrients 2018 , 10 , 1940. [CrossRef] [PubMed] 17. Haupt-Jorgensen, M.; Holm, L.J.; Josefsen, K.; Buschard, K. Possible Prevention of Diabetes with a Gluten-Free Diet. Nutrients 2018 , 10 , 1746. [CrossRef] [PubMed] 18. Rej, A.; Sanders, D.S. Gluten-Free Diet and Its ‘Cousins’ in Irritable Bowel Syndrome. Nutrients 2018 , 10 , 1727. [CrossRef] [PubMed] 19. Sainsbury, A.; Sanders, D.S.; Ford, A.C. Prevalence of irritable bowel syndrome-type symptoms in patients with celiac disease: A meta-analysis. Clin. Gastroenterol. Hepatol. 2013 , 11 , 359–365. [CrossRef] [PubMed] 20. Roncoroni, L.; Elli, L.; Doneda, L.; Bascunan, K.A.; Vecchi, M.; Morreale, F.; Scricciolo, A.; Lombardo, V.; Pellegrini, N. A Retrospective Study on Dietary FODMAP Intake in Celiac Patients Following a Gluten-Free Diet. Nutrients 2018 , 10 , 1769. [CrossRef] [PubMed] 21. Roncoroni, L.; Bascunan, K.A.; Doneda, L.; Scricciolo, A.; Lombardo, V.; Branchi, F.; Ferretti, F.; Dell’Osso, B.; Montanari, V.; Bardella, M.T.; et al. A Low FODMAP Gluten-Free Diet Improves Functional Gastrointestinal Disorders and Overall Mental Health of Celiac Disease Patients: A Randomized Controlled Trial. Nutrients 2018 , 10 , 1023. [CrossRef] [PubMed] 22. Garcia-Mazcorro, J.F.; Noratto, G.; Remes-Troche, J.M. The Effect of Gluten-Free Diet on Health and the Gut Microbiota Cannot Be Extrapolated from One Population to Others. Nutrients 2018 , 10 , 1421. [CrossRef] [PubMed] 3 Nutrients 2019 , 11 , 589 23. Garcia-Mazcorro, J.F.; Rivera-Gutierrez, X.; Cobos-Quevedo, O.J.; Grube-Pagola, P.; Meixueiro-Daza, A.; Hernandez-Flores, K.; Cabrera-Jorge, F.J.; Vivanco-Cid, H.; Dowd, S.E.; Remes-Troche, J.M. First Insights into the Gut Microbiota of Mexican Patients with Celiac Disease and Non-Celiac Gluten Sensitivity. Nutrients 2018 , 10 , 1641. [CrossRef] [PubMed] 24. Massironi, S.; Branchi, F.; Fraquelli, M.; Baccarin, A.; Somalvico, F.; Ferretti, F.; Conte, D.; Elli, L. Effects of a Gluten-Containing Meal on Gastric Emptying and Gallbladder Contraction. Nutrients 2018 , 10 , 910. [CrossRef] [PubMed] 25. Usai-Satta, P.; Oppia, F.; Lai, M.; Cabras, F. Motility Disorders in Celiac Disease and Non-Celiac Gluten Sensitivity: The Impact of a Gluten-Free Diet. Nutrients 2018 , 10 , 1705. [CrossRef] [PubMed] 26. 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This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). 4 nutrients Article The Effect of Depressive Symptoms on the Association between Gluten-Free Diet Adherence and Symptoms in Celiac Disease: Analysis of a Patient Powered Research Network Andrew M. Joelson 1 , Marilyn G. Geller 2 , Haley M. Zylberberg 3 , Peter H. R. Green 3 and Benjamin Lebwohl 3,4, * 1 Department of Internal Medicine, New York Presbyterian Hospital, New York, NY 10032, USA; amj9033@nyp.org 2 Celiac Disease Foundation, Woodland Hills, CA 91364, USA; marilyn.geller@celiac.org 3 Celiac Disease Center, Department of Medicine, Columbia University Medical Center, 180 Fort Washington Avenue, Suite 936, New York, NY 10032, USA; hmz2105@columbia.edu (H.M.Z.); pg11@cumc.columbia.edu (P.H.R.G.) 4 Deartment of Epidemiology, Mailman School of Public Health, Columbia University Medical Center, New York, NY 10032, USA * Correspondence: BL114@columbia.edu; Tel.: +1-212-305-5590 Received: 8 March 2018; Accepted: 23 April 2018; Published: 26 April 2018 Abstract: Background: The prevalence of depression in celiac disease (CD) is high, and patients are often burdened socially and financially by a gluten-free diet. However, the relationship between depression, somatic symptoms and dietary adherence in CD is complex and poorly understood. We used a patient powered research network (iCureCeliac ® ) to explore the effect that depression has on patients’ symptomatic response to a gluten-free diet (GFD). Methods: We identified patients with biopsy-diagnosed celiac disease who answered questions pertaining to symptoms (Celiac Symptom Index (CSI)), GFD adherence (Celiac Dietary Adherence Test (CDAT)), and a 5-point, scaled question regarding depressive symptoms relating to patients’ celiac disease. We then measured the correlation between symptoms and adherence (CSI vs. CDAT) in patients with depression versus those without depression. We also tested for interaction of depression with regard to the association with symptoms using a multiple linear regression model. Results: Among 519 patients, 86% were female and the mean age was 40.9 years. 46% of patients indicated that they felt “somewhat,” “quite a bit,” or “very much” depressed because of their disorder. There was a moderate correlation between worsened celiac symptoms and poorer GFD adherence ( r = 0.6, p < 0.0001). In those with a positive depression screen, there was a moderate correlation between worsening symptoms and worsening dietary adherence ( r = 0.5, p < 0.0001) whereas in those without depression, the correlation was stronger ( r = 0.64, p < 0.0001). We performed a linear regression analysis, which suggests that the relationship between CSI and CDAT is modified by depression. Conclusions: In patients with depressive symptoms related to their disorder, correlation between adherence and symptoms was weaker than those without depressive symptoms. This finding was confirmed with a linear regression analysis, showing that depressive symptoms may modify the effect of a GFD on celiac symptoms. Depressive symptoms may therefore mask the relationship between inadvertent gluten exposure and symptoms. Additional longitudinal and prospective studies are needed to further explore this potentially important finding. Keywords: Celiac Disease; depression; gluten-free diet; dietary adherence Nutrients 2018 , 10 , 538; doi:10.3390/nu10050538 www.mdpi.com/journal/nutrients 5 Nutrients 2018 , 10 , 538 1. Introduction Celiac Disease (CD) is an autoimmune disorder that, by recent estimates, affects roughly 0.7% of the United States population [ 1 ]. The disease is caused by gut mucosal immune activation against gluten, a protein component of wheat, rye, and barley [ 2 ]. The clinical manifestations are numerous and often differ between adults and children. While potential new therapies are being studied, the only current treatment is strict avoidance of gluten in the diet [ 3 ]; a treatment that for many is expensive, socially isolating, and can result in anxiety about accidental ingestion [3]. There are many well-described neuropsychiatric manifestations of CD. Many studies have examined the association between CD and depression [ 4 – 12 ], anxiety [ 7 , 10 ], bipolar disorder [ 10 ], and schizophrenia [ 3 , 6 ]. The prevalence of depression in CD has been reported as anywhere between 6% and 57% [ 13 ], and a 2011 meta-analysis showed that depression is more common in CD than the general population [ 5 ]. However, other studies have demonstrated that the prevalence of depression in CD is the same as in the general population [ 14 ] and in other cohorts that suffer from chronic illness [ 5 , 15 ]. Many pathophysiologic mechanisms behind the CD-depression association have been postulated and studied including regional cerebral hypoperfusion [ 12 ], comorbid autoimmune thyroid disease [ 11 ], and decreased levels of cerebrospinal fluid monoamines in celiac patients, which improve with a gluten-free diet (GFD) [ 16 , 17 ]. The GFD can be expensive, burdensome, and socially isolating [ 3 ]. It is therefore conceivable that adhering to such a diet may be associated with worsening of affective symptoms. However, one cross-sectional study demonstrated an association between less severe depression scores and being on a gluten-free diet for more than five years [ 8 ] and another longitudinal study found improvements in quality of life after one year of treatment of a GFD, with less improvement in those who adhered poorly [ 18 ]. Simsek et al. (2015) identified improved depression scores in pediatric patients adherent to a GFD [ 19 ] as did Borghini et al. [ 20 ] in adult patients, where another study suggested improvement in anxiety only, with no change in depressive symptoms after one year of a GFD [ 21 ]. Furthermore, depressed patients who suffer from chronic illnesses have been found to be less compliant with treatment than non-depressed individuals [ 22 ]. A recent meta-analysis examined 8 cross-sectional studies and concluded that an association between poorer GFD adherence and self-reported depressive symptoms is likely [ 23 ]. Another study followed 66 patients, randomized to receive or not receive psychological support and found reduced depression scores and better adherence to their diet at six months in patients receiving psychological support [ 24 ]. This suggests that a relationship may exist between depressive symptoms and GFD adherence; however, the common use of self-reported depression and dietary adherence scales challenges the study of the topic. Furthermore, many of these studies do not specifically examine symptoms of CD. As many common CD symptoms may mimic those of depression, this remains a challenging relationship to evaluate scientifically. In order to involve patients in clinical research, the Patient-Centered Outcomes Research Institute (PCORI) created the National Patient-Centered Clinical Research Network. As an outcome of this initiative, the Celiac Disease Foundation created iCureCeliac ® , a patient-governed forum for clinical research. We implemented this tool to study the effect of self-reported depressive symptoms as relating to CD on the association between CD symptoms and adherence to a GFD. We hypothesized that the presence of depressive symptoms modifies the symptomatic response to a GFD. 2. Patients and Methods We performed a cross-sectional analysis of pre-existing study data, utilizing the research questionnaire from iCureCeliac ® a patient-powered research network. Beginning in January 2016, the questionnaire was posted on the Celiac Disease Foundation website and reminders were periodically emailed to newsletter subscribers. Patients had the option to enter as much or as little data as they desired on an entirely voluntary basis with no financial incentive offered. 6 Nutrients 2018 , 10 , 538 2.1. Inclusion Criteria At the time of data analysis, the iCureCeliac ® questionnaire included data from 1724 individuals, with gluten-related disorders that included CD, non-celiac gluten sensitivity, dermatitis herpetiformis, wheat allergy, and self-diagnosed gluten-related disorder. We included patients of all ages who indicated in the questionnaire a diagnosis of CD, diagnosed at any age by endoscopy and biopsy and who answered the questions that applied to our study between the inception of the patient-powered research network on 30 January 2016 and 25 August 2016. A parent or legal guardian completed responses for children. Although per ACG and AGA guidelines [ 25 , 26 ], a diagnosis of CD is made using a combination of serology and a confirmatory biopsy of the small bowel to diagnose CD in patients with typical signs and symptoms, we assumed that biopsy-proven diagnoses were made in patients with symptoms and serology suggestive of celiac disease. 2.2. Data Collection We collected basic demographic information including age, sex, education level, time to diagnosis from symptom onset, and degree of adherence to a gluten-free diet. We extracted data from one question asking patients about depression as it relates to their gluten-related disorder, phrased as follows: “I feel depressed because of my gluten-related disorder”. Five responses were offered ranging from “not at all” to “very much”. We considered the responses “somewhat”, “quite a bit”, and “very much” to indicate the presence of depressive symptoms, whereas “not at all” and “a little bit” to indicate the absence of depressive symptoms. A smaller subset of patients responded to the PROMIS (Patient Reported Outcomes Measurement Information System) Depression instrument. PROMIS is a set of validated, self-reported measures that evaluate various physical, psychological and social symptoms designed for use in adult and pediatric populations for research. The PROMIS Depression instruments include a complete 28-item assessment, as well as 4-, 6-, and 8-question short forms. Upon completion of the questionnaire, a raw score is generated, which corresponds to a T-score (based on a conversion table provided) with an instrument-specific range (41.0 to 79.4 for the 4-question short form used in the iCureCeliac ® questionnaire). The T score is compared to the population mean with standard errors provided. We also extracted data from questions administered to questionnaire respondents relating to symptoms and dietary adherence, which comprised most of the Celiac Symptom Index (CSI) and Celiac Dietary Adherence Test (CDAT) questions outlined by Leffler et al. [ 27 , 28 ]. The CSI and CDAT are clinically oriented, easily administered, questionnaires with 16 and 7-items, respectively. The CSI performed well as a surrogate measure of disease activity [ 27 ] and the CDAT was shown to perform better than tissue transglutaminase titers for evaluating dietary adherence [28]. 2.3. Data Analysis The iCureCeliac ® questionnaire asked fifteen of the sixteen questions included in the CSI (missing question: “How much physical pain have you had during the last 4 weeks”?) and five out of the seven questions included in the CDAT (missing scaled questions: “I do not consider myself a failure” and “Before I do something, I carefully consider the consequences”). As not all of the CSI and CDAT questions were included in the initial iCureCeliac ® questionnaire, the instruments are incomplete. We therefore analyzed these responses out of a total of 75 and 25 possible points, respectively (compared with 80 and 35, respectively). Higher CSI scores correlate with more severe symptoms and higher CDAT scores correlate with poorer dietary adherence, as described by Leffler et al. [27,28]. We calculated correlation coefficients with 95% confidence intervals between: (1) adherence to a GFD (CDAT) and CD symptoms (CSI); (2) depression and CD symptoms (CSI); and (3) depression and adherence to a GFD (CDAT). We then stratified patients based on the presence of depressive symptoms so as to determine whether these symptoms modify the association between adherence to a GFD and CD symptoms. To formally test for interaction, we constructed a multiple linear regression 7 Nutrients 2018 , 10 , 538 model with CSI score as the outcome, and CDAT score, the presence of depression, and the interaction term (depression*CDAT) as the dependent variables. As a means of validating our chosen screening question for depressive symptoms, we calculated a correlation coefficient to compare our question to the 4-item PROMIS depression score in the smaller subset of respondents who completed both sets of questions regarding depression. For all PROMIS Depression instruments, a T-score of 50 is equivalent to the mean of the general population with a standard deviation of 10. The 4-item depression short form has been validated against the Center for Epidemiologic Studies Depression Scale [29]. For the purpose of this study, patients with a raw score greater than or equal to 11 (corresponding to a T score of, ≥ 60.5 or 1 SD above the mean of the general population) were considered to have a positive depression screen. We used the guidelines set forth by Evans [ 30 ] for interpretation of correlation coefficient values. We used SAS version 9.4 (SAS Institute Inc. 2013, Cary, NC, USA) to calculate Pearson correlation coefficients for the variables listed above. Although the study was designed after data collection, our hypothesis was developed prior to data analysis. Informed consent was obtained from each patient prior to completion of the survey. This study conforms to the ethical guidelines set forth by the 1975 declaration of Helsinki and was approved by the Institutional Review Board of Columbia University Medical Center on 22 September 2016. 3. Results We identified 519 patients with biopsy-diagnosed CD who met criteria for inclusion in our study. The characteristics of our study population are displayed in Table 1. The participants were predominantly female (86%). The mean age was 40.9 years (standard deviation (SD) ± 16.7), 26 patients were aged 16 years or less, 92% of our study population self-reported their race as white and 65% had completed at least one year of college-level education. Feeling depressed was reported by 46% of respondents (“very much” by 6.7%, “quite a bit” by 12.5%, and “somewhat” by 26.8%). The mean ( ± SD) CDAT score was 12.81 ( ± 2.53, out of a 25-point scale, IQR = 16) and the mean ( ± SD) CSI score was 36.1 ( ± 11.2 out of a 75-point scale, IQR = 11). Depression had a weak correlation with worse symptoms ( r = 0.35, 95% CI 0.26–0.43, p < 0.0001) and a weaker correlation with GFD adherence ( r = 0.25, 95% CI 0.16–032, p < 0.0001). There was a moderate correlation between worse symptoms and poorer GFD adherence ( r = 0.60, 95% CI 0.53–0.66, p < 0.0001). In patients with a positive depression screen, there was a moderate correlation between worsening symptoms and worsening dietary adherence ( r = 0.50, 95% CI 0.37–0.60, p < 0.0001) whereas in those without depression, the correlation was still moderate, although stronger ( r = 0.64, 95% CI 0.55–0.71, p < 0.0001). When patients <16 years of age were removed from the analysis ( n = 370), the results were unchanged. The difference in CSI v