# Systemic Effects of Oral Antibiotics in Mice: A Combined Physiological and Molecular Approach

## TL;DR

This study explores how amoxicillin and tetracycline affect mice's weight, food intake, and immune responses, finding that these effects may be due to microbiota disruption and immune signaling.

## Contribution

The study introduces a combined physiological and molecular approach to understand antibiotic effects, revealing sex-specific responses and potential immunomodulatory mechanisms.

## Key findings

- Both antibiotics reduced weight gain and food efficiency in mice with sex-specific effects.
- Tetracycline showed strong binding to TLR2, suggesting possible immunomodulatory action.
- Metabolic effects are likely due to microbiota disruption, not direct receptor engagement.

## Abstract

This study investigates the systemic effects of amoxicillin and tetracycline on healthy Mus musculus (Swiss albino) mice, focusing on food intake, body weight, and hematological parameters. Over a 14-day oral treatment period, both antibiotics significantly reduced weight gain and food efficiency, with sex-specific variations: tetracycline had stronger metabolic effects in males, while amoxicillin was more impactful in females. To explore underlying mechanisms, molecular docking and MM-GBSA analyses were performed on PPAR-γ and TLR2–TIRAP complexes. Both antibiotics showed negligible binding to PPAR-γ, suggesting their metabolic effects are not receptor-mediated. In contrast, tetracycline exhibited strong and stable binding to TLR2 (ΔGbind = −27.87 kcal/mol), supported by extensive hydrogen bonding, implying potential immunomodulatory action. These findings suggest that antibiotic-induced metabolic and immune alterations are more likely driven by microbiota disruption and innate immune signaling, rather than direct metabolic receptor engagement.