Researchers are warning that frequent consumption of antibiotics weakens the body's immunity by killing useful stomach bacteria.
According to a new study published in the PLOS pathogens journal, scientists found that the long-term consumption of these medicines reduces varieties of good stomach bugs.
This then causes immune cells naturally present in the gut - known as neutrophils - to be less effective in warding off infections.
It also weakens protection barriers in the intestines thus making it easy for disease causing bugs to invade the stomach.
Dr Koji Watanabe, one of the study’s researchers from the University of Virginia (UVA) School Of Medicine, said neutrophils provide the first line of defence against foreign pathogens invading the body.
However, he noted that antibiotic disruption of natural bacteria in the stomach hampers this defence mechanism hence leaving the gut susceptible to severe infection.
"I think the take-home is that this is another important reason not to use antibiotics unless they are clearly needed," said Dr Bill Petri, lead researcher and head of UVA's Division of Infectious Diseases.
He added that unwise use of antibiotics increases the risk of multi-drug resistant bacteria whilst impairing the function of white blood cells that help the body to fight infections.
The study was conducted in Bangladesh and appears in the August issue of PLOS Pathogens journal.
The researchers analysed stool samples collected from children living in one of the country’s urban slums.
Most of the kids were found to suffer from a common stomach infection known as amoebiasis that is caused by amoeba bacteria.
However, the severity of the disease was found to be highest among those that had less diversity of good bacteria in the gut.
In the second stage of the research, the scientists then used lab mice to determine how the decrease in natural intestinal bacteria might be worsening the ailment.
They found that antibiotics disrupted natural bacteria in the mice’s stomach which reduced the ‘strength’ of disease fighting immune cells (neutrophils).
This then left the gut insufficiently protected from bugs that cause amoebiasis, a disease whose symptoms include abdominal pain, plain or bloody diarrhoea.