Los Angeles: Though antibiotics are essential for fighting bacterial infection, they may also make the body more prone to infection and diarrhoea, a new study has warned.
Exactly how the resident "good" microbes in the gut protect against pathogens, such as Salmonella, and how antibiotic treatments foster growth of disease-causing microbes have been poorly understood, scientists said. Now, researchers from the University of California studied a mouse model and identified the chain of events that occur within the gut lumen after antibiotic treatment that allow "bad" bugs to flourish.
The finding has profound implications, expanding the current view of how microbes interact with each other at the gut surface and informing the development of new strategies to prevent the side effects of antibiotic treatment, researchers said. The process begins with antibiotics depleting "good" bacteria in the gut, including those that breakdown fibre from vegetables to create butyrate, an essential organic acid that cells lining the large intestine need as an energy source to absorb water, they said.
The reduced ability to metabolise fibre prevents these cells from consuming oxygen, increasing oxygen levels in the gut lumen that favour the growth of Salmonella, researchers said. "Unlike Clostridia and other beneficial microbes in the gut, which grow anaerobically, or in the complete absence of oxygen, Salmonella flourished in the newly created oxygen-rich micro environment after antibiotic treatment," said Andreas Baumler from University of California.
"In essence, antibiotics enabled pathogens in the gut to breathe," said Baumler.
The findings were published in the journal Cell Host Microbe.