Fig. 5

OCN administration increased fecal propionate levels in 6-OHDA-induced PD mice. a (Left panel) Metabolic pathway for acetate, propionate, and butyrate synthesis and corresponding KOs and genes are displayed. (Right panel) Bar plots of the RAs of K01847, K00634, K00929, and K00074, n = 7–12 per group. b Bar plots of comparing the fecal levels of acetate, propionate, and butyrate among groups. Data represent the mean ± SEM, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. c Heatmap shows correlations analysis between the fecal level of SCFAs and the RAs of f_S24-7, f_Rikenellaceae, f_Lachnospiraceae, and f_unclassified Clostridiales. Color key represents the correlation coefficients, *p < 0.05, ⁺p < 0.01. OCN-enriched taxa were marked in red color; depleted taxa were marked in blue. d Plots of correlation analysis between the fecal level of propionate and motor function. X-axis represented the values of open field test, cylinder test, and rotarod test; Y-axis represented the fecal propionate levels. K00656: pflD, formate C-acetyltransferase; K13788: pta, phosphate acetyltransferase; K00925: ackA, acetate kinase; K00626: Thl, acetyl-CoA C-acetyltransferase; K00074: Hbd, 3-hydroxybutyryl-CoA dehydrogenase; K00634: ptb, phosphate butyryltransferase; K00929: buk, butyrate kinase; K01034: but, acetate CoA-transferase alpha subunit; K01899: Sucla1, succinyl-CoA synthetase alpha subunit; K01847: Mut, methylmalonyl-CoA mutase; K11264: mmcD, methylmalonyl-CoA decarboxylase; K13923: pduL, phosphate propanoyltransferase; K00932: tdcD, propionate kinase; K01905: acdA, acetate-CoA ligase (ADP-forming) subunit alpha. The dosage of OCN was 4 μg/kg