#5 Lactobacillus acidophilus: effects on the pharmacokinetics of marbofloxacin in rats

Background : Probiotics are currently produced commercially and widely used for improving human and animal health. They modulate the gut environment through secretion and production of different molecules and enzymes. Hence, they play a major role in changing the pharmacokinetics of an orally administered drug. Purpose : To determine the effect of Lactobacillus acidophilus (KCTC 3140) on the pharmacokinetics of marbofloxacin. Materials and Methods : Five male and five female 8-week old healthy Sprague Dawley rats were treated with 10 9 CFU/ml of L. acidophilus daily for seven days via the intra-gastric route.  Marbofloxacin (20 mg/kg) was administered orally at the beginning and the end of the experiment. The plasma concentration of marbofloxacin was measured using high performance liquid chromatography (HPLC). Results : The area under the curve (AUC) of marbofloxacin declined from 5.78 µg.h/ml to 2.57 µg.h/ml after treatment with L. acidophilus. Similarly, the maximum plasma concentration (C max ) of the drug decreased from 2.4 µg/ml to 1.2 µg/ml and the T max increased from 0.54 to 0.73 h. The elimination half-lives of marbofloxacin before and after treatment with L. acidophilus were 1.19 h and 0.69 h, respectively. The study was conducted by separating the male and female rats; no significant difference was observed between the sexes. Conclusion : The treatment of rats with L. acidophilus decreased the plasma AUC and C max after oral administration of marbofloxacin. Hence, studying the interaction of a probiotic with an antibiotic drug is essential prior to co-administration of the probiotic with the oral antibiotic.