Fig. 6

Lactobacillus or indole propionic acid attenuates PND by restoring intestinal barrier function in aged mice. A Flow chart of the experiment indicates the pretreatment of Lactobacillus or IPA in aged mice before surgery and the detection time of each cognitive behavior. B Swimming path diagrams of the aged mice with different treatment in the MWM test on postoperative day 12 and day 13. C Latency to find the platform in the MWM test from 8 to 12 days after surgery of the aged mice. D The retention time in the platform quadrant in the MWM test in the 13th day after surgery of the aged mice. E Freezing time in the fear conditioning test in the 16th day after surgery of the aged mice. F Novel object exploration index in novel object recognition in the 19th day after surgery of the aged mice. G Representative images of immunofluorescence staining of the tight junction protein ZO-1, Cluadin-1, and Occludin in colon tissues of the aged mice with different treatment. H Correlation with G, the fluorescence intensity of ZO-1, Cluadin-1, and Occludin in the mouse colon tissues was calculated. I Representative images of immunohistochemical staining of the tight junction protein ZO-1, Cluadin-1, and Occludin in ileum tissues of the aged mice with different treatment. J Correlation with I, the mean IOD/area of ZO-1, Cluadin-1, and Occludin in the mouse ileum tissues was calculated. K Immunohistochemical staining was used to detect the expression level of IL-17a and IL-22 in ileum tissues of the aged mice with different treatment. L Correlation with K, the mean IOD/area of IL-17a and IL-22 in ileum was calculated. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001