## 4 Results
### Inclusion and Exclusion Criteria
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Reference** & **Species** & \
\begin{tabular}{c} **Type, Size, and Period of** \\ **Exposure to Plastic** \\ \end{tabular} &
\begin{tabular}{c} **Mode of Exposure and** \\ **Dose** \\ \end{tabular} & **Results** \\ \hline
[127] & \begin{tabular}{c} Mice, \\ C57 male, with \\ induced acute colitis \\ \end{tabular} & \begin{tabular}{c} PS MPs, \\ size 5 \(\upmu\)m, for 28 days \\ \end{tabular} & \
\begin{tabular}{c} Drinking water: \\ 500 \(\upmu\)g/L \\ \end{tabular} &
\begin{tabular}{c} Mice exhibited enhanced inflammation, \\ increased hepatic lipid peroxidation, promoted \\ adipocyte differentiation, and hepatic \\ metabolic disorder. \\ \end{tabular} \\ \hline
[129] & \begin{tabular}{c} Mice, \\ male, C57/BL6 \\ \end{tabular} & \begin{tabular}{c} PS MPs, \\ size 5 \(\upmu\)m \\ \end{tabular} & \
\begin{tabular}{c} Oral gavage \\ 500 \(\upmu\)g/L \\ \end{tabular} &
\begin{tabular}{c} Increased expression of inflammatory factors \\ (TNF-x, IL- \(\upbeta\), and IFN-\(\upgamma\)) and intestinal \\ immune imbalance. \\ Exposure to PS MPs induced histopathological \\ damage in colonic mucosa. \\ \end{tabular} \\ \hline
[130] & \begin{tabular}{c} Mice, \\ ICR \\ \end{tabular} & \begin{tabular}{c} Polyethylene microplastics \\ size 10-50 \(\upmu\)m, \\ 1. Single oral dose toxicity \\ study, 14 days; 2. Repeated oral dose \\ toxicity study, 28 days \\ \end{tabular} & \
\begin{tabular}{c} Oral gavage \\ 500, 1000, and \\ 2000 mg/kg/day \\ \end{tabular} &
\begin{tabular}{c} In the toxicity experiments with a single oral \\ dose, there were no changes. \\ For the repeated oral dose toxicity study, the \\ histopathological examination revealed \\ granulomatous inflammation in the lungs and \\ MPs in the lungs, stomach, duodenum, ileum, \\ and serum. \\ \end{tabular} \\ \hline
[131] & \begin{tabular}{c} Mice, \\ C57 BL/6 \\ \end{tabular} & \begin{tabular}{c} Polypropylene (PP) MPs, \\ size 8 and 70 m, \\ for 28 days \\ \end{tabular} & \
\begin{tabular}{c} Oral gavage \\ 1, 10, and 100 mg/kg/d \\ \end{tabular} &
\begin{tabular}{c} Damage to tight junctions of the colon and \\ decreased expression of ion transporters, \\ intestinal mucus, and secretion. \\ Induced colonic apoptosis and damage to the \\ intestinal barrier through oxidative stress and \\ TLR4/NF-kB inflammation. \\ \end{tabular} \\ \hline
[132] & \begin{tabular}{c} Rats \\ ( juvenile) \\ \end{tabular} & \begin{tabular}{c} Polyethylene terephthalate \\ (PET MPs), \\ size 85 \(\upmu\)m, for 14 days \\ \end{tabular} & \
\begin{tabular}{c} Oral gavage \\ 1.4 mg/kg, 35 mg/kg, and \\ 125 mg/kg \\ \end{tabular} &
\begin{tabular}{c} Decreased rate of body weight gain and organ \\ indices of the kidney, heart, and ovaries. \\ Nephrotoxicity caused by disturbances of \\ serum blood urea nitrogen (BUN), creatinine \\ (CRE), and pro-inflammatory mediators IL-1b, \\ IL-6, and \\ TNF-a. \\ \end{tabular} \\ \hline
[133] & \begin{tabular}{c} Rats \\ (Wistar, male) \\ \end{tabular} & \begin{tabular}{c} Polyethylene terephthalate \\ (PET MPs), \\ size 85 \(\upmu\)m, for 14 days \\ \end{tabular} & \
\begin{tabular}{c} Oral gavage \\ 1.4 mg/kg, 35 mg/kg, and \\ 125 mg/kg \\ \end{tabular} &
\begin{tabular}{c} Lack of clinical signs of toxicity. \\ Changes in specific markers of liver, cardiac, \\ and renal function. \\ Increased levels of oxidative stress indicators. \\ \end{tabular} \\ \hline
[134] & \begin{tabular}{c} Pigs, 8 wk old \\ \end{tabular} & \begin{tabular}{c} PET (maximum size \\ 300 \(\upmu\)m), 28 days \\ \end{tabular} & \
\begin{tabular}{c} Oral feed \\ 0.1 g/day, \\ 1 g/day, \\ 28 days \\ \end{tabular} &
\begin{tabular}{c} Alterations in the enteric nervous system and \\ the histological structure \\ Changes were more pronounced in \\ the group of animals receiving microplastics at \\ a dose of 1 g/day than in the group receiving \\ 0.1 g/day. \\ \end{tabular} \\ \hline
[135] & \begin{tabular}{c} Mice, C57 BL/6/male \\ 1, or 5 \(\upmu\)m, for 28 days \\ \end{tabular} & \begin{tabular}{c} Polystyrene MPs, size 0.2, \\ Dose: 1 mg/kg body \\ weight daily \\ \end{tabular} & \begin{tabular}{c} Oral gavage \\ \end{tabular} & \
\begin{tabular}{c} Oral gavage \\ \end{tabular} &
\begin{tabular}{c} Increased expression of pro-inflammatory cytokines. \\ Increased intestinal permeability and decreased \\ mucus secretion. \\ At 5 \(\upmu\)m size, PS damage was more severe than \\ at 0.2 and 1 \(\upmu\)m. \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}