Microbiota signatures and genetic risk in pediatric celiac disease

Table 1 Taxonomic changes and functional effects in pediatric celiac disease

Bacterial taxon/group	Reported change	Context/condition	Sample type	Possible functional consequence	Nature of evidence
Bifidobacterium spp.	Decrease	Active CD; may change after GFD	Mostly stool	Decreased SCFA production and interleukin-10-related tolerogenic response; weakened barrier support	Clinical cohort findings + mechanistic support
Lactobacillus spp.	Decrease	Active CD; strain-dependent effect	Stool; in vitro studies	Reduced gluten peptide hydrolysis capacity; increased inflammatory stimulation	Clinical cohort findings + in vitro/functional support
Bacteroides spp.	Increase/variable	Active CD; GFD effect may vary	Stool; duodenal biopsy in some studies	Increased permeability and proinflammatory cytokine responses	Clinical cohort findings + mechanistic interpretation
Proteobacteria	Increase	Active inflammation/dysbiosis	Stool; duodenal biopsy in some studies	Increased oxidative stress, epithelial damage, and inflammation	Clinical cohort findings + mechanistic support
Escherichia coli	Increase	Active CD; strain-dependent	Stool; duodenal biopsy in some studies	Increased virulence-associated epithelial damage and T-cell activation	Clinical cohort findings + strain-dependent support
Staphylococcaceae	Increase	Some pediatric CD cohorts	Mostly stool	Increased dysbiosis, inflammation, and symptom burden	Limited clinical observation
Akkermansia spp.	Decrease/variable	Barrier function; influenced by GFD/age	Mostly stool	Reduced mucus layer and barrier support	Mechanistic support + limited CD-specific findings

CD: Celiac disease; GFD: Gluten-free diet; SCFAs: Short-chain fatty acids.