Gluten-Free Diet Bad for Gut Health

VALENCIA, Spain—Researcher recently found a gluten-free diet (GFD) led to reductions in beneficial gut bacteria populations and the ability of faecal samples to stimulate the host's immunity (Br J Nutr. 2009) (DOI:10.1017/S0007114509371767). The effects of a GFD on the composition and immune function of the gut microbiota were analyzed in 10 healthy subjects (mean age 30.3 years) over a period of one month. No significant differences in dietary intake were found before and after the GFD except for reductions (P=0.001) in polysaccharides. Bifidobacterium, Clostridium lituseburense and Faecalibacterium prausnitzii proportions decreased (P=0.007, P=0.031 and P=0.009, respectively) as a result of the GFD analysed by fluorescence in situ hybridisation (FISH). Bifidobacterium, Lactobacillus and Bifidobacterium longum counts decreased (P=0.020, P=0.001 and P=0.017, respectively), while Enterobacteriaceae and Escherichia coli counts increased (P=0.005 and P=0.003) after the GFD assessed by quantitative PCR (qPCR). TNF-alpha, interferon-gamma, IL-10 and IL-8 production by PBMC stimulated with faecal samples was also reduced (P=0.021, P=0.037, P=0.002 and P=0.007, respectively) after the diet. The GFD may constitute an environmental variable to be considered in treated Coeliac disease (CD) patients for its possible effects on gut health.