WHILE a gluten-free diet (GFD) improves wellbeing for those with coeliac disease (CD), it does not fully reverse its impact on gut function or microbiota composition, according to new research.
The team studied 36 newly diagnosed patients with CD alongside 36 healthy volunteers to explore gut health over 1 year. Using advanced MRI techniques, they measured small bowel water content (SBWC), whole gut transit time (WGTT), and colon volumes. They also analysed stool samples using metagenomic sequencing to explore microbial species and gene functions.
Key findings highlighted a stark difference in gut function between the two groups. At baseline, patients with CD had significantly higher SBWC (157±15 mL) compared to healthy volunteers (100±12 mL), with a P-value of 0.003. WGTT was also notably delayed, taking 68±8 hours for patients with CD versus 41±5 hours for the healthy group (P=0.002). While GFD improved these metrics slightly after a year, the differences remained statistically insignificant.
The gut microbiota composition of patients with CD also differed from healthy participants, showing an abundance of proteolytic gene functions linked to Escherichia coli, Enterobacter, and Peptostreptococcus. A year of GFD brought changes, significantly reducing beneficial Bifidobacteria levels while increasing Blautia wexlerae. These shifts were tied to reduced intake of resistant starch and arabinoxylan, compounds naturally found in wheat.
The study also found that microbiota composition was positively associated with WGTT, colonic volume, and Akkermansia muciniphila, but negatively linked to B. wexlerae. Importantly, changes in WGTT and colonic volume after GFD were strongly associated with increased B. wexlerae abundance.
While the GFD improved subjective well-being in CD patients, it didn’t fully restore gut health to match healthy controls. This research brings to light the complex challenges patients with CD face even with strict dietary adherence, emphasising the need for further investigation into complementary treatments to address the lingering effects of CD on gut health and microbiota.
Ada Enesco, EMJ
Reference
Costigan CM et al. One year of gluten free diet impacts gut function and microbiome in celiac disease. Clin Gastroenterol and Hepatol. 2024; DOI:10.1016/j.cgh.2024.11.006.
