• The Role of Antibiotics in Gut and Brain Microbiota Axis
  • Fatemeh Sadat Shojaeddin,1 Ava Behrouzi,2,*
    1. Bachelor’s student. Department of Microbiology, Faculty of Modern Science and Technologies, Tehran Medical Science, Islamic Azad University, Tehran
    2. Assistant Professor, Department of Microbiology, Faculty of Advanced Science and Technology, Tehran Medical Science, Islamic Azad University, Tehran, Iran


  • Introduction: The human body contains trillions of microbes that are thought to influence and regulate the host's physiology. Most of the microbes in the human digestive system are known as gut microbiota. Anatomically, the gut has a complex, two-way relationship with the central nervous system (CNS) that is called the gut-brain axis, which interacts in both health and disease. The communication between gut microbiota and the brain is diverse and occurs via various routes, including the autonomic nervous system, the vagus nerve, the enteric nervous system, neurotransmitters and the immune system. The levels of neurotransmitters and their precursors produced in the gut may also be influenced by the levels of these substances present in the brain. Additionally, neurotransmitters can be generated by bacteria, apart from being sourced from food metabolism. For example, Escherichia coli has been observed to release dopamine, serotonin, and noradrenaline, while Lactobacilli are known to produce serotonin, GABA, acetylcholine, and histamine, which may influence host brain function. If the amount of gut microbiome change, the host will have to use Antibiotics, which are known to disrupt the intestinal microbial community. Recent studies have indicated that the administration of antibiotics can induce changes in the gut microbiota, which may subsequently result in impairments in object recognition memory and altered expression of brain-derived neurotropic factor (BDNF) in the hippocampus during adulthood. It has been demonstrated that early-life antibiotic exposure is associated with an increased risk for psychiatric disorders. Furthermore, a recent clinical study has indicated that infants who have received intravenous antibiotics after delivery exhibit altered auditory processing and recognition memory responses, thereby supporting the importance of the microbiota-gut-brain axis in humans during early life. Additionally, there is evidence that links autism spectrum disorder, a neurodevelopmental condition, to gut microbiota-brain axis dysfunction.
  • Methods: A comprehensive literature review was conducted to identify studies investigating the role of antibiotics in gut and brain microbiota axis. Electronic databases were searched using relevant keywords, and studies published between 2024 and 2019 were included. The review encompassed in vitro studies, animal models, and clinical trials to provide a comprehensive understanding of the topic.
  • Results: A review of the literature reveals that the administration of antibiotics to laboratory animals has been shown to influence a number of behaviors including sociability and anxiety. For instance, a 11-day exposure to an antibiotic cocktail resulted in the disruption of object recognition memory in adult male mice.
  • Conclusion: The bidirectional interaction between the microbiota and the brain has been designated the microbiota-gut-brain axis. The investigation of how gut microbes influence the communication between the gut and the brain has constituted a significant research topic over the past decade. The role of antibiotics in the gut-brain axis is currently under investigation, despite the continued reliance on these agents as a cornerstone of therapy in numerous conditions. While antibiotics are undoubtedly a crucial therapeutic option, their prolonged use has been linked to adverse effects on both the microbiome and brain functions. These effects have been observed in the context of disrupted object recognition memory as well as psychiatric disorders. Nevertheless, in order to circumvent potential adverse effects on the central nervous system, it is advised to limit the use of antibiotics. Their administration must be conducted under the supervision of a qualified medical practitioner. Additionally, modifying one's dietary habits and lifestyle can potentially mitigate the risk of developing cognitive and psychiatric disorders.
  • Keywords: gut-brain axis; gut microbiome; antibiotics ;brain functions