Table 4.

Summary of the effects of MPs exposure on the immune system during the early developmental stage.

Organisms	Types of MPs	Size (µm) and Concentration	Age and Duration of Exposure	Consequences to Early Life Stages	References
ICR mice	PS-MPs	Size: 40–48 µm Concentration: 10 mg/kg/day	Age: 6 weeks Exposure: 90 days	-Induce immune response -Physical stress on stomach walls -Disrupt metabolic homeostasis -Alter composition of lymphocytes -Increase IgA concentration -Accumulation of damaged organelles	[47]
Mice (BALB/C and C57BL/6)	PS-MPs	Size: 10 µm Concentration: —	Age: 8–10 weeks (old mice) Exposure: during peri-implantation period	-Decrease percentage of decidual natural killer cells -Cytokine secretion shifts toward an immunosuppressive state -Decrease NK cells in the decidua -Disturb pro-inflammatory cells (T8 cells and M1-subtype macrophage) -Disturb pro-inflammatory cytokinase (IL-2, IL-6, TNF-α, and IFN-γ) -Oxidative stress to immune cells	[42]
C57BL/6 mice	PE-MPs	Size: No data Concentration: 6, 60, and 600 µg/day	Age: early exposure Exposure: 5 weeks	-Decrease the percentage of Th17 and Treg cells among CD4+ cells -Induce inflammation and higher TLR4, AP-1, and IRF5 expression -Induce intestinal dysbacteriosis and inflammation	[22]
Mice (Mus musculus)	PE-MPs	Size: 45–53 µm Concentration: –	Age: 5 weeks Exposure: 30 days	-Dysfunction of the intestinal epithelial barrier -Alteration of gut microbiota, which leads to abnormal immune response -Change in genera of important microbes that are essential for energy metabolism and immune function (e.g., Butyricimonas, Lactobacillus, and Ruminococcus)	[37]
Wistar rats	BPA (plastic additives)	Size: 45–53 µm Concentration: 250 µg/kg/day	Age: postnatal Exposure: day 5 of pregnancy to day 21 postnatal	-Decrease in the production of specific antibodies -Downregulate Th2 cytokines (IL-4, IL-5, and IL-13), and upregulate Th1 cytokines (IFN-γ and TNF-α) -Affect the performance of immune response during adult life -Abnormal cytokine and antibody production	[63]