Journal of Exercise & Organ Cross Talk

Abstract This study investigated the effects of high-intensity interval training (HIIT) and a multi-strain probiotic mixture, on the intestinal expression of FXR and PPAR-γ in a rat model of type 2 diabetes mellitus (T2DM). Forty male Wistar rats were randomly assigned to five groups (n=8): Healthy Control (HC), Diabetic Control (DC), Diabetic+HIIT (DH), Diabetic+Probiotic (DP), and Diabetic+HIIT+Probiotic (DHP). T2DM was induced via a single intraperitoneal injection of nicotinamide (95 mg/kg) followed by streptozotocin (STZ, 55 mg/kg). The HIIT protocol was performed on a rodent treadmill for 8 weeks (5 sessions/week). The probiotic mixture (Lactobacillus rhamnosus GG, Lactobacillus casei, Lactobacillus reuteri; 1×10¹⁰ CFU/mL each) was administered daily via oral gavage. Diabetes induction significantly downregulated the intestinal expression of both FXR and PPAR-γ compared to healthy controls (p<0.001). HIIT and probiotic interventions, individually, significantly increased the expression of both nuclear receptors compared to the diabetic control group (p<0.001). Notably, the combined HIIT and probiotic intervention (DHP) produced the highest expression levels of FXR and PPAR-γ, which were significantly greater than either intervention alone (p<0.01) and restored FXR expression to levels comparable to healthy controls. Both HIIT and multi-strain probiotic supplementation effectively upregulate the intestinal expression of FXR and PPAR-γ in diabetic rats, with the combination exerting a synergistic effect. These findings identify a novel mechanism by which lifestyle interventions may restore intestinal metabolic function and inter-organ communication in T2DM, highlighting the therapeutic potential of targeting the gut through combined exercise and probiotic strategies.

Abstract The aim of this study was the effect of endurance exercise and probiotic supplement enriched with amino acid leucine and vitamin D on the gut-muscle axis in aged male rats. For this purpose, 25 male Wistar rats (5 rats in each group) in two age groups of 8 to 12 weeks (young) and 18 to 24 months (elderly) were randomly divided into 5 equal groups of old control (OC), young control (YC), endurance exercise (OE), supplement group (OS) and endurance exercise plus supplement (OES) were divided. The results showed that 8 weeks of endurance training (three times a week) and supplemental oral gavage (5 times a week) caused a significant change in postbiotics (decrease of indoxyl sulfate (IXS) and increase of Short-chain fatty acids (SCFAs)). The role of OS in reducing IXS was more prominent than OE and OES variables; of course, the synergistic effect of OES (P=0.000), caused a greater improvement in the amount of SCFA. Also, Administering the supplement alone and at rest (without exercise) could not cause a significant increase in VO_2max (P=0.449). But, the effect of exercise on increasing VO_2max index was more effective than OS and even OES. Eventually, the independent variables made a significant difference on the Villus height (VH) (except for the OS group) and number of goblet cells (GC) compared to the OC group (P<0.05).