Table 1.

Summary of studies that examined air pollutants and the gut microbiota in murine models.

Study	Animal Model	Experimental Design	Key Findings
Kish et al.19	Wild-type 129/SvEv female fasted mice (n = 6-9)	Exposure to PM10 via gavage compared to vehicle control group daily for 7 or 14 d	Alterations in gut microbial composition ↑ Intestinal permeability and inflammatory cytokines ↑ Intestinal damage
Li et al.20	Low-density lipoprotein receptor null mice (n = 12 and 11)	Consumption of high-fat diet exposed to ultrafine particles compared to vehicle control for 3 d/week for 10 weeks	↑ Verrucomicrobia bacteria and TNF-alpha levels ↓ Actinobacteria, Cyanobacteria, Firmicutes, and beta-diversity ↑ Intestinal inflammation
Ribière et al.21	C57BL/6 mice (n = 8-11)	Consumption of BaP diet, sunflower seed oil, or saline solution via oral gavage for 28 d	Alterations in composition and abundance of gut microbiota in BaP group ↑ Ileum and colon mucosa inflammation
Mutlu et al.22	C57BL/6 male mice (n = 10 and 10)	Exposure to concentrated PM2.5 air compared to filtered air	↑ Alpha diversity in some parts of GI tract ↑ Beta-diversity throughout the GI tract ↑ TNF-alpha expression in the colon
Wang et al.23	C57Bl/6 J mice (n = 10 and 10)	Exposure to concentrated PM2.5 air compared to filtered air for 12 months	↓ Fecal bacterial community richness ↑ Insulin resistance

The table shows the five murine studies included in this review. The table describes the animals examined, experimental design, and key findings. These studies examined the associations between inhaled and/or ingested air pollutants and gut microbial diversity, the relative abundance of gut bacterial taxa, gut barrier integrity, intestinal inflammation, and/or insulin resistance.