Objective To study the effect of intervention of probiotics on gastrointestinal function and expression of AQP4 in rats during exhaustive exercise. Methods Forty male SD rats were randomly divided into quiet control group (NC), exercise control group (ME), quiet medication group (NCY) and exercise medication group (MEY). The exercise control group and the exercise medication group were subjected to exhaustive training for 6 weeks: the running speed was 19. 3 m/ min, the slope was 5°, the training was once a day, 6 d/ week for 6 weeks. Probiotics in concentration of 107 CFU/ mL was gavaged 10. 0 mL/ (kg/ d) in the quiet medication group and exercise medication group. After 6 weeks of exhaustive training, the activities of serum gastrointestinal hormones ghrelin, PYY, CCK, GLP -1, MTL and GAS were measured. . The expression of AQP4 was detected by RT?PCR and western blot. Results The contents of serum ghrelin and PYY were significantly higher in the ME group than those in the NC group ( P < 0. 01). The contents of intestinal CCK, GLP -1, MTL and GAS in the ME group were significantly lower than those in the NC group ( P < 0. 01). The serum ghrelin and PYY were lower in the NCY group than in the ME group ( P < 0. 01), while the contents of intestinal CCK, GLP -1, MTL and GAS in the NCY group were higher than those in the ME group ( P < 0. 01). The serum ghrelin in the MEY group was higher than that in the NC group ( P < 0. 05) and lower than that in the ME group ( P < 0. 01). The PYY in the MEY group was lower than that in the ME group ( P < 0. 05). The serum CCK was lower in the MEYgroup than that in the NC group ( P < 0. 05) and higher than that in the ME group ( P < 0. 05). The serum GLP -1, MTL and GAS in the MEY group were higher than those in the ME group ( P < 0. 01). The expression of AQP4 mRNA and protein in the gastrointestinal tissue of the ME group were lower than those in the NC group ( P < 0. 01 or P < 0. 05). The expression of AQP4 mRNA and protein in the NCY and MEY groups were higher than those in the ME group ( P < 0. 01 or P < 0. 05). Conclusions Exhaustive exercise causes changes in gastrointestinal hormone levels and increase of AQP4 expression in rats. Probiotics may be involved in the gastrointestinal hormone secretion and water metabolic process.