A synbiotic mixture augmented the efficacy of doxepin, venlafaxine, and fluvoxamine in mice model of depression

INTRODUCTION: Currently available antidepressant drugs have notable downsides; in addition to their side effects and slow onset of action their moderate efficacy in some individuals, may influence compliance. Previous literature has shown that probiotics may have antidepressant effects. Introducing complementary medicine in order to augment the efficacy of therapeutic doses of antidepressant drugs seems to be very important. Therefore the effect of adding a synbiotic cocktail in drinking water was assessed in mice model of despair following administrating three antidepressant drugs belonging to different classes.
METHODS: The marble burring test (MBT), and forced swimming test (FST) were used as animal model of obsessive behavior and despair. The synbiotic cocktail was administered in mice drinking water (6.25×106 CFU) for 14 days and the tests were performed on the days 7 and 14 thirty minutes after injecting the lowest dose of doxepin (1 mg/kg), venlafaxine (15 mg/kg), and fluvoxamine (15 mg/kg).
RESULTS: After 7 days of the synbiotic ingestion immobility time decreased in FST for doxepin (92 sec ± 5.5) and venlafaxine (17.3 sec ± 2.5) compared to their control group (drinking water) but fluvoxamine could decrease immobility time after 14 days of ingesting the synbiotic (70 sec ± 7.5). The synbiotic cocktail pre-administration improved the MBT test response for venlafaxine, while it did not change the results for the other two drugs.
DISCUSSION AND CONCLUSION: Adding synbiotic to drinking water improved the efficacy of discrete antidepressant drugs particularly during the FST. Probiotics could be useful complementary medicine for drug resistant depressed individuals.