Despite the beneficial actions of antibiotics against bacterial infections, the use of antibiotics is a crucial etiological factor influencing microbial dysbiosis-associated adverse outcomes in human health. Based on the assumption that gut microbial dysbiosis can provoke behavioral or psychological disorders, the present study evaluated anxiety-linked behavioral changes in a mouse model of streptomycin-induced dysbiosis. Measuring anxiety-like behavior using the light-dark box and elevated plus maze tests indicated that streptomycin treatment caused acute anxiety in mice. As an intervention for dysbiosis-associated distress, the probiotic strain Escherichia coli Nissle 1917 (EcN) was evaluated for its effects on streptomycin-induced behavioral changes in mice. EcN supplementation persistently ameliorated anxiety responses in mice with streptomycin-induced dysbiosis. As an outcome of anxiety, body weight changes were marginally affected by antibiotic treatment. However, mice supplemented with EcN displayed acute retardation of body weight gain, since EcN is known to reduce food intake and increase energy expenditure. Taken together, EcN treatment prominently counteracted streptomycin-induced anxiety in mice, with the metabolically beneficial retardation of body weight gain. The present model simulates psychological disorders in antibiotic users. As a promising intervention, EcN treatment can facilitate psychological relief under conditions of dysbiotic stress by blocking the pathologic gut-brain circuit.
Keywords: antibiotics; anxiety; probiotics; streptomycin.