Antibiotics Once? Your Gut May Stay Resistant for Years
Antimicrobial resistance (AMR) has become a major global health threat, causing millions of deaths each year. A new study by researchers from Stanford University, USA, sheds light on how even brief antibiotic use can lead to lasting resistance in the human gut.
Focus on Ciprofloxacin and Its Effects
The researchers specifically studied ciprofloxacin, a commonly prescribed antibiotic used to treat infections in various body parts. They found that even short-term use of ciprofloxacin can cause bacteria in the gut to develop resistance, which can last for more than 10 weeks.
Importantly, resistance did not occur in just one type of bacteria. Instead, it appeared independently across different bacterial species in the gut.
Study Approach: Moving Beyond Lab Tests
Until now, most studies on AMR relied heavily on laboratory experiments and animal models. However, this new research, published in the journal Nature, involved 60 healthy human volunteers, providing real-world insights.
Each participant received a 500 mg dose of ciprofloxacin, taken twice a day for five days. The researchers then collected stool samples and used advanced computational tools to reconstruct 5,665 bacterial genomes, identifying over 2.3 million genetic variations.
Key Findings: How Resistance Emerges and Persists
Among the bacterial populations studied, 513 showed mutations in the gyrA gene, which is known to be associated with resistance to fluoroquinolone antibiotics like ciprofloxacin. Fluoroquinolones work by disrupting bacterial DNA replication, ultimately killing the bacteria.
However, the study revealed that:
- Around 10% of bacteria that were initially sensitive developed resistance through genetic mutations.
- Many mutations arose independently within individual participants.
- The resistance persisted beyond 10 weeks and, in some cases, was predicted to last up to a year.
Factors Influencing Resistance
Interestingly, resistance was more likely to occur in bacterial populations that were abundant before the antibiotic treatment. These bacteria also showed significant decreases in their numbers during ciprofloxacin exposure, suggesting that stress from the drug may encourage the development of mutations.
Conclusion
The researchers highlighted that even short-term exposure to antibiotics like ciprofloxacin can drive long-lasting resistance in gut bacteria. Furthermore, the study shows that the human gut is a powerful environment where bacterial resistance can evolve rapidly.
Understanding the genetic and ecological factors that influence resistance is critical. This knowledge can help develop strategies to manage antibiotic use more wisely and prevent the further spread of AMR.
Source: Inputs from various media Sources
Priya Bairagi
Reviewed by Dr Aarti Nehra (MBBS, MMST)
I’m a pharmacist with a strong background in health sciences. I hold a BSc from Delhi University and a pharmacy degree from PDM University. I write articles and daily health news while interviewing doctors to bring you the latest insights. In my free time, you’ll find me at the gym or lost in a sci-fi novel.
