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Celiac.com 01/23/2025 - This study explored how a gluten-free diet influences gut function and microbiome composition in individuals newly diagnosed with celiac disease over a one-year period. Celiac disease, an autoimmune disorder triggered by gluten, primarily damages the small intestine, leading to digestive issues, nutrient malabsorption, and changes in gut health. The primary treatment for celiac disease is a strict gluten-free diet, but its broader effects on the gut environment and microbiome were not fully understood until now. To investigate these impacts, researchers compared individuals with newly diagnosed celiac disease to healthy volunteers who did not follow a gluten-free diet. How the Study Was Conducted The study involved two groups: 36 newly diagnosed celiac disease patients and 36 healthy individuals matched by age and gender. Before starting their gluten-free diet, the celiac group underwent tests to assess their gut function, such as small bowel water content, colon volume, and whole gut transit time (the time it takes for food to move through the digestive tract). Stool samples were collected for microbiome analysis, which determined the types of bacteria present and their functions. These tests were repeated after one year of following a gluten-free diet. Healthy participants provided a baseline for comparison and were tested over the same period without dietary changes. Researchers also evaluated gastrointestinal symptoms, general wellbeing, and psychological factors to understand the diet's broader impacts on quality of life. Key Findings: Gut Function Changes Small Bowel Water Content At the start of the study, individuals with celiac disease had significantly higher small bowel water content than the healthy group. This increase likely reflects damage caused by celiac disease, such as poor nutrient absorption and excessive fluid secretion in the small intestine. Although there was improvement after one year on a gluten-free diet, the levels did not fully return to those seen in the healthy group. Gut Transit Time Whole gut transit time, which measures how quickly food moves through the digestive system, was much slower in celiac patients at the start of the study. After following a gluten-free diet for a year, there was some improvement, but transit time remained slower compared to the healthy group. This delay in gut movement may be due to inflammation, malabsorption, and other gut function disruptions caused by celiac disease. Colon Volume Unlike small bowel water content and transit time, colon volume did not show significant differences between the two groups at the start of the study or after one year. This indicates that the gluten-free diet had a more noticeable effect on small intestinal function than on the large intestine. Gut Microbiome: Changes in Bacterial Composition Differences in Microbiome Before the Gluten-Free Diet At the start of the study, the gut microbiome of celiac patients showed higher levels of certain bacteria, such as Escherichia coli, Enterobacter, and Peptostreptococcus. These bacteria are associated with increased protein breakdown, which may reflect the malabsorption of nutrients in the damaged intestine. In contrast, beneficial bacteria like Bifidobacteria, known for supporting gut health, were less abundant in celiac patients. Impact of a Gluten-Free Diet on Microbiome After one year of following a gluten-free diet, significant changes occurred in the gut microbiome. The gluten-free diet reduced the levels of Bifidobacteria even further. This decline is likely due to the removal of dietary fibers, such as resistant starch and arabinoxylan, which are found in gluten-containing foods like wheat. These fibers are important for feeding Bifidobacteria and maintaining a healthy gut environment. Additionally, a bacterium called Blautia wexlerae increased after the gluten-free diet. Changes in gut bacterial species were also linked to gut function, such as transit time and colonic volume, showing that the diet indirectly influenced the microbiome by altering the gut environment. Carbohydrate Metabolism Changes The gluten-free diet significantly altered the gut microbiome's ability to break down certain carbohydrates. Enzymes responsible for digesting resistant starch and arabinoxylan decreased after the gluten-free diet. This shift reflects the reduced intake of wheat-based fibers, which may contribute to further disruptions in the gut microbiome. Quality of Life and Symptoms At the start of the study, patients with celiac disease reported significantly worse gastrointestinal symptoms and overall wellbeing compared to the healthy group. Symptoms such as abdominal pain, bloating, and nausea were more common in the celiac group. After one year on a gluten-free diet, patients experienced significant improvements in their symptoms and general wellbeing. However, their quality of life and symptoms did not fully return to the levels reported by healthy individuals. Why This Study Matters for Celiac Disease Patients This study highlights the complex relationship between celiac disease, gut function, and the gut microbiome. While a gluten-free diet remains the cornerstone of celiac disease management, the findings suggest that it does not fully reverse the damage caused to gut function or restore a balanced microbiome. The reduction in beneficial bacteria like Bifidobacteria and the altered carbohydrate metabolism highlight potential downsides of the gluten-free diet. For individuals with celiac disease, this research provides insight into why symptoms may persist even after strict adherence to a gluten-free diet. It also emphasizes the need for further strategies to support gut health, such as including prebiotic or fiber-rich foods that feed beneficial bacteria or developing targeted probiotics to restore balance in the gut microbiome. Conclusion The gluten-free diet improves symptoms and partially restores gut function in celiac disease patients, but it also causes significant changes to the gut microbiome. Understanding these effects opens the door for new treatments aimed at improving gut health alongside dietary management. For those with celiac disease, this research underscores the importance of ongoing care and potential future therapies to address the gut's long-term health. Read more at: biorxiv.org Watch the video version of this article:

Celiac.com 05/31/2021 - For people without celiac disease, does eating gluten have an impact on brain health, specifically on cognitive function? A recent study of nearly 14,000 non-celiac women at midlife revealed no statistical evidence of any association of long- or short-term gluten intake with cognitive function. More and more people are eating gluten-free for perceived health benefits that may not be real. It's true that cognitive impairment, sometimes called "brain fog," is a common symptom reported by many people before they are diagnosed with celiac disease. In those cases a gluten-free diet generally results in improvement of the symptoms. However, data are lacking in individuals without celiac disease. A recent study set out to "examine whether gluten intake is associated with cognitive function in women without celiac disease." Their study included US women who participated in the longitudinal, population-based Nurses’ Health Study II and had not previously or subsequently been diagnosed with celiac disease. Subjects answered a questionnaire that was used to cumulatively average gluten intake cycles prior to cognitive assessment. They then took a battery of tests on psychomotor speed and attention score, learning and working memory score, and global cognition score. They research team found no connection between long-term gluten intake and cognitive scores in middle-aged women without celiac disease. Their results, "do not support recommendations to restrict dietary gluten to maintain cognitive function in the absence of celiac disease or established gluten sensitivity." But how useful was the study? What did they actually measure? What did they actually show us? The study actually reveals very little, if anything. Celiac.com does not recommend a gluten-free diet for people who do not have celiac disease or gluten sensitivity, but we also do not oppose it. A properly structured gluten-free diet can be every bit as nutritious and health-promoting as a diet that contains gluten. However, we also do not agree with studies with conclusions that seem to be designed to scare people off of a gluten-free diet, or to soft-pedal a diet that contains wheat. The study does not say that there is no cognitive benefit to giving up gluten for people who do not have celiac disease or gluten intolerance, or that those without celiac disease might also benefit from a gluten-free diet. The benefits or harm of a gluten-free diet in people who are not gluten-free remains poorly studied. Even in people with celiac disease, the implications of a long-term gluten-free diet have not been well-studied, and plenty of studies make unproven nutritional assumptions about those implications based on scant data. We believe that each person must choose their diet for themselves, and that many folks without celiac disease may choose to eat gluten-free for reasons that make sense to them. Some may do so because they perceive themselves to think more clearly when they do not eat wheat. The problem, from our perspective is that the study basically says: We looked at a bunch of women who eat wheat and gluten in various quantities. Their brains seem fine. Nothing to see here. People concerned about a potential connection between brain function and wheat consumption deserve more than a study that says, in effect, "hey, plenty of women eat gluten, and whether they eat a lot or a little, their brain test results seem fine." Telling us that eating wheat does not seem to cause brain impairment in non-celiacs is helpful. It is. But it's only part of the picture. As far as we can see, none of these subjects had brain function tests when eating gluten compared with tests when they were gluten-free. Nor did the test compare women who ate wheat to similar women on a gluten-free diet (but really, what was needed here was the former, a comparison of the same group of people, perhaps tested when eating different gluten levels, then re-tested after a prolonged gluten-free diet). For all of the seemingly grand implications of the study, it really doesn't tell us much about brain function in people who eat gluten. It doesn't tell us if there are any benefits brain wise to giving up gluten. Look, it could be that giving up gluten has a negative impact on non-celiacs, but that remains unproven. We really need a more comprehensive and focused study to help tell us what, if any, impact gluten has on the cognitive function of non-celiacs, along with what benefits, if any, they might have when giving up gluten. Read more in JAMA Netw Open. 2021;4(5):e2113020 The research team included Yiqing Wang, PhD; Benjamin Lebwohl, MD, MS; Raaj Mehta, MD; et al Yin Cao, ScD, MPH; Peter H. R. Green, MD; Francine Grodstein, ScD; Manol Jovani, MD; Paul Lochhead, MBChB, PhD; Olivia I. Okereke, MD, MS; Laura Sampson, MS, RD; Walter C. Willett, MD, DrPH; Qi Sun, MD, ScD, MMS; Andrew T. Chan, MD, MPH. They are variously affiliated with the Clinical and Translational Epidemiology Unit, Massachusetts General Hospital, Harvard Medical School, Boston; the Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston; the Celiac Disease Center, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York; the Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York; the Division of Public Health Sciences, Department of Surgery, Washington University in St Louis, St Louis, Missouri; the Division of Gastroenterology, Department of Medicine, Washington University in St Louis, St Louis, Missouri; the Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, Illinois; the Department of Internal Medicine, Rush Medical College, Chicago, Illinois; the Division of Gastroenterology and Hepatology, Johns Hopkins Hospital, Baltimore, Maryland; the Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts; the Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston; the Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts; and the Department of Nutrition, Harvard T. H. Chan School of Public Health, Boston, Massachusetts.

Celiac.com 09/01/2015 - Current medical guidelines recommend routine screening of liver function tests (LFTs) in patients diagnosed with celiac disease. However, there isn't much good data on rates of liver disorders in celiac disease outside of Europe. A team of researchers recently set out to accurately estimate rates of LFT abnormalities in celiac disease in the USA, and to assess the effect of a gluten-free diet on LFTs. The research team included Natalia E Castillo, Rohini R Vanga, Thimmaiah G Theethira, Alberto Rubio-Tapia, Joseph A Murray, Javier Villafuerte, Alan Bonder, Rupa Mukherjee, Joshua Hansen, Melinda Dennis, Ciaran P Kelly and Daniel A Leffler. To identify adult patients with biopsy-proven celiac disease, they used a prospectively maintained database, which they matched with healthy controls. They defined abnormal LFT levels for women and men based on the Third National Health and Nutrition Examination Survey (NHANES III) criteria. The team gathered data on demographics, coexisting liver diseases, and laboratory work-ups including aspartate transaminase (AST) and alanine transaminase (ALT) values at the time of diagnosis and on a gluten-free diet. They later compared data from this group with data from 7,789 individuals participating in the National Health and Nutrition Examination Survey, 2009–2010, and applied univariate logistic regression, Wilcox on signed-ranks, Student's t-test, χ2, and Fischer's exact test for statistical analysis. In 463 celiac disease patients with ALT or AST levels at the time of celiac disease diagnosis, 40.6% had elevated LFTs compared with 24.2% of treated celiac disease patients (P<0.001). Similarly, nearly forty percent of celiac disease patients on the NHANES database showed abnormal ALT values compared with less than twenty percent of non-celiac patients (P=0.03). Just over forty percent of individuals will show elevated LFTs at celiac disease diagnosis, but the vast majority, nearly eighty percent of those patients will show normal LFTs within a year and a half of adopting a gluten-free diet. The team suggests that doctors check all celiac patients for LFTs, and coexisting liver disorder be considered in patients whose LFTs have not improved within a year on a gluten-free diet. Source: The American Journal of Gastroenterology 110, 1216-1222 (August 2015). doi:10.1038/ajg.2015.192

Celiac.com 09/09/2013 - Many people with celiac disease show slightly elevated liver enzymes, though these enzyme levels usually return to normal after gluten-free diet. A team of researchers recently set out to investigate the cause and prevalence of altered liver function tests in celiac patients, basally and after 1 year of gluten-free diet. The research team included Giovanni Casella, Elisabetta Antonelli, Camillo Di Bella, Vincenzo Villanacci, Lucia Fanini, Vittorio Baldini, and Gabrio Bassotti. They are affiliated with the Medical Department, and the Clinical Pathology Department of Desio Hospital in Monza and Brianza, Italy, the Department of Clinical and Experimental Medicine, Gastroenterology and Hepatology Section at the University of Perugia in Perugia, Italy, and with the Department of Laboratory Diagnostics, Pathology Section, Brescia, Italy. The team gathered data from 245 untreated celiac disease patients, 196 women and 49 men, ranging in age from 15 to 80 years. They then analyzed the data, and assessed the results of liver function tests performed before and after diet, as well as associated liver pathologies. They found that 43 (17.5%) of the 245 patients, showed elevated levels of one or both aminotransferases; In 41 patients (95%) the elevation was mild, meaning that it was less than five times the upper reference limit. The remaining two patients (5%) showed marked elevation, meaning levels more than ten times the upper reference limit. After patients eliminated gluten for one year, aminotransferase levels normalized in all but four patients, who had HCV infection or primary biliary cirrhosis. Celiac patients who show hypertransaminaseaemia at diagnosis, and who do not show normalization of liver enzymes after 12 months of gluten-free diet, likely suffer from coexisting liver disease. In such cases, the research team recommends further assessment to assess the possible coexisting liver disease. Spotting and treating coexisting liver disease in celiac patients is important for improving liver function and preventing possible complications. Source: Liver International. 2013;33(7):1128-1131.

Celiac.com 06/21/2017 - Circulating gluten-specific FOXP3+CD39+ regulatory T cells have impaired suppressive function in patients with celiac disease. What does that mean? Although researchers understand the effector T-cell response in patients with celiac disease pretty well, they really don't know very much about the role played by regulatory T cells (Treg cells) in the loss of tolerance to gluten. To get a better picture, a team of researchers recently set out to define whether patients with celiac disease have a dysfunction or lack of gluten-specific forkhead box protein 3 (FOXP3)+ Treg cells. The research team included L Cook, CML Munier, N3 Seddiki, D van Bockel, N Ontiveros, MY Hardy, JK Gillies, MK Levings, HH Reid, J Petersen, J Rossjohn, RP Anderson, JJ Zaunders, JA Tye-Din, AD Kelleher. For the study, gluten-free patients with celiac disease underwent oral wheat challenge to stimulate recirculation of gluten-specific T cells. The research team collected peripheral blood before and after challenge. To effectively measure the gluten-specific CD4+ T-cell response, they combined traditional IFN-γ ELISpot with a test for antigen-specific CD4+ T cells that does not rely on tetramers, antigen-stimulated cytokine production, or proliferation, but relies instead on antigen-induced co-expression of CD25 and OX40 (CD134). During the gluten challenge, levels of circulating gluten-specific Treg cells and effector T cells both rose sharply, peaking on the sixth day. The team recounts surprise on discovering that about 80% of the ex vivo circulating gluten-specific CD4+ T cells were FOXP3+CD39+Treg cells, which reside within the pool of memory CD4+CD25+CD127lowCD45RO+ Treg cells. Even though they saw normal suppressive function in peripheral polyclonal Treg cells from celiac patients, after a short in vitro expansion, the gluten-specific FOXP3+CD39+ Treg cells showed sharply reduced suppressive function compared with polyclonal Treg cells. The team's study offers the first estimates of FOXP3+CD39+ Treg cell frequency within circulating gluten-specific CD4+ T cells after oral gluten challenge of celiac patients. FOXP3+CD39+ Treg cells made up the majority of all circulating gluten-specific CD4+ T cells, but they showed reduced suppressive function, indicating that Treg cell dysfunction might be a key factor in celiac disease development. This type of research is crucial to help document the genetic physiology of celiac disease, which will help researchers to better understand and treat the disease itself. Source: J Allergy Clin Immunol. 2017 Mar 8. pii: S0091-6749(17)30343-3. doi: 10.1016/j.jaci.2017.02.015. The researchers are variously affiliated with the Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia; the Infection and Immunity Program, The Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Australia; the Immunovirology and Pathogenesis Program, The Kirby Institute, UNSW Sydney, Sydney, Australia; St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia, Immunology Division, Walter and Eliza Hall Institute, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada; the Institute of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom; the Immunology Division, Walter and Eliza Hall Institute, Parkville, Australia; Department of Medical Biology, University of Melbourne, Parkville, Australia; ImmusanT, Cambridge, Massachusetts; and the Department of Gastroenterology, Royal Melbourne Hospital, Parkville, Australia.

Celiac.com 02/16/2015 - Celiac is predominantly a disease of the small intestine characterized by chronic malabsorption in genetically susceptible individuals who ingest grains containing. gluten, such as wheat, barley, and rye. Using strain and strain rate echocardiography imaging, a research team set out to assess left ventricular function in patients with celiac disease. The research team included S. Cenk, D.B. Aylin, A. Fatma Ebru, A.B. Nihal, Ö.S. Sevil, B. Serdal, B. Emine, A. Hüseyin, K. Telat, D. Tahir, E. Osman, and B. Engin. For their study, the team included twenty celiac patients and twenty healthy control subjects. They assessed left ventricle systolic and diastolic functions using standard 2-dimension, M-mode, conventional Doppler echocardiography. They obtained strain and strain rate parameters for 8 segments of the left ventricle. They found no significant differences between patients and controls regarding left ventricle function as assessed by 2-dimensional, M-mode, conventional Doppler. Initially, differences between strain rate values did not reach statistical significance, but when strain and average strain values were considered together, statistically significant differences emerged between the groups. For the first time a research team has been able to determine the subclinical effect of celiac disease on left ventricular systolic function by using strain echocardiography imaging. Their success shows the potential value of assessing cardiac involvement in celiac patients using these echocardiographic techniques. Source: Turk J Med Sci. 2014;44(2):173-7.