## Results
### Moderator Analysis  
As high heterogeneity was observed, an additional moderator analysis had to be performed. Table 3 shows the results of a meta-ANOVA analysis of the probiotic administration effect by strain on TJP expression in the animal models. It revealed that _L. reuteri_ was the most effective probiotic in claudin and ZO-1 expression, and that prebiotics were most effective in occludin expression. After unification of \(\tau^{2}\) for the variance between subgroups, the Q statistics between groups (Q\({}_{\text{b}}\)) of the claudin, occludin, and ZO-1 were 346.83 (df = 20, \(p<0.0001\)), 369.17 (df = 25, \(p<0.0001\)), and 236.59 (df = 26, \(p<0.0001\)), respectively. In addition, the SMD of the medicine was lower than that of the probiotics, except for some probiotics in all TJPs. In the meta-regression test (Table 4), some items showed significance (\(p<0.05\)), such as _B. breve, B. fragilis, L. casei, L. johnsonii, L. rhamnus_, and _L. sakei_ in claudin, and prebiotics in occludin expression. On the other hand, there was no significance in the administration time and dosage (\(p>0.05\)). As a result, a significant regression model could not be obtained (R\({}^{2}\) = 0.00), which means that there is no explanatory power in the regression model. Figure 3: Forest plot for the effect size of probiotics administration on the mRNA expression of the tight junction protein by the random effects model. (**A**) claudin, (**B**) occludin, (**C**) ZO\(-1\), [23, 29, 33, 34, 35, 36, 37, 38, 39, 44, 46, 48, 49, 50, 53, 56, 59, 65, 66, 69]. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Item 1** & **Subgroup** & **Estimate** & **SE 3** & _p_**-Value 4** & **CI. Ib 5** & **CI. ub 6** & **R2 (\%)** \\ \hline \multirow{10}{*}{Claudin} & Intercept 2 & 12.3197 & 3.9377 & 0.0018 ** & 4.6020 & 20.0374 & \\  & _B. breve_ & \(-13.3197\) & 5.1349 & 0.0066 ** & \(-24.0091\) & \(-3.8806\) & \\  & _B. fragilis_ & \(-9.8015\) & 4.3794 & 0.0252 * & \(-18.3850\) & \(-1.2181\) & \\  & _B. infinitus_ & \(-4.3984\) & 5.5055 & 0.4243 & \(-15.1891\) & 6.3923 & \\  & _B. longun_ & \(-5.2956\) & 5.4295 & 0.3294 & \(-15.9372\) & 5.3459 & \\  & _B. subtilis_ & \(-11.0005\) & 5.1768 & 0.0336 * & \(-21.1469\) & \(-0.8541\) & \\  & _C. hutricum_ & \(-6.1354\) & 4.8116 & 0.2023 & \(-15.5660\) & 3.2952 & \\  & _L. casi_ & \(-12.7922\) & 4.5728 & 0.0052 ** & \(-21.7547\) & \(-3.8297\) & \\  & _L. jotinsoniti_ & \(-12.2498\) & 5.1128 & 0.0166 * & \(-22.2707\) & \(-2.2289\) & \\  & _L. lactis_ & \(-8.4080\) & 5.1461 & 0.1023 & \(-18.4943\) & 1.6783 & \\  & strain & _L. paracasi_ & \(-9.8159\) & 4.5881 & 0.0324 * & \(-18.8093\) & \(-0.8235\) & \\  & _L. plantarum_ & \(-5.8372\) & 4.1768 & 0.1623 & \(-14.0236\) & 2.3492 & \\  & _L. reuteri_ & \(14.9535\) & 7.9587 & 0.0603 & \(-0.6452\) & 30.5522 & \\  & _L. rhamnus_ & \(-10.1128\) & 4.2426 & 0.0171 * & \(-18.4282\) & \(-1.7974\) & \\  & _L. sakei_ & \(-16.1100\) & 4.6066 & 0.0005 ** & \(-25.1389\) & \(-7.0812\) & \\  & _Medicine_ & \(-14.0232\) & 4.3397 & 0.0012 ** & \(-25.2588\) & \(-5.5176\) & \\  & Mixed culture & \(-6.3576\) & 4.2563 & 0.1353 & \(-14.6998\) & 1.9845 & \\  & _Prebiotics_ & \(-7.7392\) & 5.2650 & 0.1416 & \(-18.0584\) & 2.5800 & \\  & _S. thermophiles_ & \(-10.1320\) & 5.1511 & 0.0492 * & \(-20.2279\) & \(-0.0361\) & \\  & _Sheuumella_ sp. & \(-0.8224\) & 5.6405 & 0.8841 & \(-11.8776\) & 10.2329 & \\  & Synbiotics & \(-2.9140\) & 4.8327 & 0.5465 & \(-12.3860\) & 6.5579 & \\ \hline \multirow{2}{*}{ \begin{tabular}{c} Administration \\ time \\ \end{tabular}  } & Intercept & 4.8498 & 2.0891 & 0.0203 & 0.7552 & 8.9445 & \\  & Day & 0.0207 & 0.0731 & 0.7775 & 0.1226 & 0.1640 & 0.00 \\ \hline \multirow{2}{*}{Dosage} & Intercept & \(-2.0531\) & 13.1000 & 0.8755 & \(-27.7285\) & 23.6223 & \\  & Dosage & 0.7001 & 1.4574 & 0.6310 & \(-2.1564\) & 3.5567 & \\ \hline \multirow{10}{*}{Ocoludin} & Intercept & 8.6724 & 3.3722 & 0.0101 * & 2.0631 & 15.2817 & \\  & _B. breve_ & \(-3.6635\) & 4.6024 & 0.4260 & \(-12.6841\) & 5.3571 & \\  & _B.