Table 5.

Adverse health effects of POPs in inflammatory bowel disease.

Study	References	Experiment model/human group	Exposure time/dose	Route of exposure	Source of dietary intake	Impact on the gut	Other health risks
New pesticide
Chlorpyrifos (CPF)	Huang et al. (163)	Eight-week-old DSS-induced male C57BL/6 mice	AIN-93 diet at doses of 1, 2.5, or 5 mg/kg/day CPF,6 days	Diet exposure	Artificial feeding	° Affect immune-cell populations °↑Inflammatory responses	° Lead to severe tissue injury ° Exert adverse effect on the gut microenvironment
Imidacloprid (IMI)	Luo et al. (164)	Adult male zebrafish	IMI (100 and 1,000 μg/L) in water solution, 3 weeks	Water surroundings	Not mentioned	°↑Superoxide dismutase and catalase (CAT) levels °↑LPS levels and inflammatory factors	° Cause intestinal barrier injury, oxidative stress, inflammatory response and gut microbiota dysbiosis
	Fu et al. (165)	The Pacific white shrimp L. vannamei	IMI (50, 100, 200, 400, and 800 μg/L) in water solution, 28 days	Water surroundings	Not mentioned	° Reshape the structure and interaction of gut microbiota °↑Gut pathogenic microbiota abundance ° Function disorders	°↓Growth performance ° Gause tissue damage in shrimp ° Cause disorder of differential gene expression
Chemicals and by-products of industrial production
TCDD, TCDF, and PCBs	Tian et al. (166)	Cecal contents isolated from 7-week-old C57BL/6 J male wild type mice	TCDD (0.6, 0.06 μM), TCDF and PCBs (6, 0.6 μM), 37°C for 4 h	Direct contact: incubation	/	°↓Metabolic activity (dose-dependent) °↑Low nucleic acid (LNA) bacteria °↓High nucleic acid (HNA) bacteria	° Alter transcriptional and metabolic pathways in cecal bacterial mixtures ° Affect the physiological metabolism of individual bacteria
PBDD/F	Fernandes and Falandysz (167)	/	Some groups, particularly young children, may exceed the tolerable limit (2 pg TEQ/kg bw/week)	Present not only in soil, but also in plant foliage; Accumulate in the food chain	Mainly from dietary intakes: plant-based foods contain more PBDD/Fs	/	° Bind to the AhR, having carcinogenesis, immunotoxicity, enzyme induction and reproductive effects
TCDD	Li et al. (168)	C57BL/6 mice, 8–10 weeks old	0.1 and 10 μg/kg bw TCDD on embryonic day 0.5, ED 12.5, and post-natal 7 days	Oral gavage	Dissolved in dimethyl sulfoxide (DMSO) and diluted in olive oil	° Affect the structure and composition of the colonic microbiota ° Do not change the community diversity and richness ° Change the functional pathways of the colonic microbiota	/

“↑” means increased level or concentration; “↓” means decreased level or concentration.