Gluten Does Not Change Gut Microbiome in Patients with Celiac Disease and Non-Celiac Gluten Sensitivity

Celiac.com 03/08/2022 - There's been some evidence to connect celiac disease with an imbalance in gut microflora. However, researchers still don't know much about how gluten exposure in people with well-controlled celiac disease might influence microbial balance in the gut. A better understanding of this connection could help to improve our knowledge of celiac disease activity and its symptoms. 

To get a better idea of such a possible connection, a team of researchers recently set out to evaluate the impact of gluten exposure on the gut microbiome in patients with celiac disease and non-celiac gluten sensitivity (NCGS).

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The research team included Nobel, Yael R. MD; Rozenberg, Felix BA; Park, Heekuk PhD; Freedberg, Daniel E. MD, MS; Blaser, Martin J. MD; Green, Peter H.R. MD; Uhlemann, Anne-Catrin MD, PhD; and Lebwohl, Benjamin MD, MS.

They are variously affiliated with the Celiac Disease Center, Columbia University Irving Medical Center, New York, New York, USA; the Microbiome and Pathogen Genomics Collaborative Center, Columbia University Irving Medical Center, New York, New York, USA; the Center for Advanced Biotechnology and Medicine, Rutgers University, New Brunswick, New Jersey, USA; the Department of Epidemiology, Mailman School of Public Health, Columbia University Irving Medical Center, New York, New York, USA; the Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, New York, USA.

The team conducted a 14-day gluten challenge of 5 grams of gluten per day on nine patients with celiac disease and eight with NCGS, all of whom had been on a gluten-free diet. They then compared the results from the two groups against results from eight control subjects on a standard gluten-containing diet. 

The team used 16S rRNA gene and metagenomic sequencing before, during, and after the gluten challenge, to conduct fecal microbiome analysis on patient stool samples. They assessed symptoms using two 2 validated clinical scales. The results showed that patients with celiac disease and NCGS showed no significant fecal microbial changes in response to the gluten challenge. 

Interestingly, gut microbiome composition differed between all thee groups at baseline, and these differences continued regardless of gluten exposure. 

Celiac and NCGS subjects reported worse symptoms and general health in the middle of gluten challenge, and slightly better by the end. However, the symptoms and general health issues showed no consistent connections with the composition of the gut microbiome.

In this study, fecal microbiome diversity remained unchanged by gluten challenge in adult subjects with celiac disease and NCGS. 

These results indicate that celiac disease and NCGS activity and severity may be unrelated to gut microbiome status.

Since the gut microbiome is crucial to good health, it may be some comfort to people with celiac disease and NCGS that gluten exposure doesn't seem to damage the microbiome balance, and so is unlikely to worsen disease symptoms, at least in the short term.

Read more in Clinical and Translational Gastroenterology: December 2021