Microplastics and nanoplastics in inflammatory bowel disease: Mechanistic plausibility, human evidence and future research priorities

Table 1 Human studies investigating micro- and nanoplastic burden in inflammatory bowel disease

Ref.	Publication status	Number	Population	Study design	Biospecimen	Analytical method	Main findings
Yan et al[107], 2022	Full article	52 IBD; 50 healthy controls	Adults with IBD and healthy controls	Cross sectional case-controlled study	Feces	Raman spectrometry	Fecal MNP concentration was higher in IBD than controls (41.8 items/g dry matter vs 28.0 items/g dry matter). Fecal MP burden correlated with IBD severity
Lykkemark et al[108], 2025	Abstract	4 CD; 7 non-IBD	Pregnant patients in third trimester with and without CD	Prospective pilot study	Feces	μFTIR	MNPs > 10 μm were detected in all stool samples, with counts ranging 34 particles/g to 410 particles/g dry weight. MNPs count correlated positively with fecal calprotectin, after adjusting for IBD status (Spearman r = 0.65, P = 0.04)
Wu et al[110], 2025	Full article	10 CD patients (32 tissue samples)	CD patients undergoing intestinal resection for CD complication	Cross sectional paired tissue study	Surgical specimens: Paired involved ileum, uninvolved ileum, creeping fat and mesenteric adipose	Laser infrared spectroscopy	MNPs were detected in fibrotic intestine and adjacent mesenteric adipose tissue. MNPs concentrations correlated positively with fibrosis severity, and fibrotic sites showed significantly greater accumulation than surrounding tissue. Approximately 31.96% of detected particles were 20-50 μm in size
Huang et al[109], 2026	Abstract	241 CD patients; 43 healthy controls	Adults with CD and healthy controls	Two centers, prospective; cross sectional baseline analysis with longitudinal follow up	Serum	Py-GC-MS	Serum total MNPs were higher in CD than controls (90.7 ± 33.7 μg/g vs 32.8 ± 12.5 μg/g; P < 0.001). MNPs burden associated with more severe endoscopic or MRE inflammation, and with structuring or penetrating phenotype (OR = 2.65, 95%CI: 1.41-5.11). High MNPs baseline concentration associated with disease progression (45.7% vs 25.8%) and independently increased progression risk (HR = 2.95, 95%CI: 1.57-5.57)

IBD: Inflammatory bowel disease; CD: Crohn’s disease; μFTIR: Micro-Fourier transform infrared spectroscopy; Py-GC-MS: Pyrolysis gas chromatography mass spectrometry; MNPs: Microplastics and nanoplastics; MP: Microplastics; OR: Odds ratio; CI: Confidence interval; HR: Hazard ratio.

Table 2 Planned and ongoing human studies evaluating micro- and nanoplastic burden in inflammatory bowel disease

Study title	Ref.	Trial acronym	Registry ID	Study design	Key population	Planned biospecimen	Outcomes	Target enrollment
Microplastic Analysis in Pediatric Inflammatory Bowel Disease	Marszk[111]	MAP-IBD	NCT07141238	Observational case-controlled study; single center	Children < 18 years undergoing clinically indicated colonoscopy, with and without a previous diagnosis of UC or CD	Intestinal mucosal biopsies, stool, urine and blood	Detect and quantify MNPs in intestinal biopsies	40 (20 IBD + 20 controls)
The Presence of Microplastics and Nanoplastics in the Humans Ileum, Colon, and Rectum and Their Relation With Inflammatory Bowel Disease	Sileri[112]	MATISSE	NCT06525558	Cross sections observational case controlled	Adults undergoing planned surgical resection involving ileum, colon or rectum with and without IBD	Resected bowel specimens	Determine presence and characterization of MNPs in bowel tissue and assess correlation with IBD; exploratory metabolomics/proteomics and plastic-exposure assessment	102 (25 UC + 26 CD + 51 healthy controls)
Pregnant Women With and Without Crohn’s Disease to Explore the Role of Plastics and Toxins in Intestinal Inflammation	Agrawal[113]	PLANET	NCT06001450	Prospective observational maternal-infant cohort	Women > 18 years old who are pregnant or planning pregnancy with and without a diagnosis of CD	Maternal stool & saliva; placenta; cord blood; breast milk; infant stool	Measuring the concentration, size and shape distributions of MNPs in stool samples of women with CD, healthy controls and any relatives. Microbiome characterization and fecal calprotectin	46

An additional active research project OPTICS (the impact of microplastics and other synthetic particles on intestinal inflammation in Crohn’s disease) is listed in Aalborg University research portal, however a public registry entry was not identified. UC: Ulcerative colitis; CD: Crohn’s disease; IBD: Inflammatory bowel disease; MNPs: Microplastics and nanoplastics.