The overuse of antibiotics occurs due to the mistaken widespread belief that they are beneficial for a broad array of conditions and because many physicians are willing to prescribe antibiotics if patients ask for the medication, a new study suggests.

In children, improper antibiotic use can alter the microbiome while their immunological, metabolic and neural systems are developing, suggests the study published in the journal BioEssays. And, in adults, there is increasing evidence that antibiotics may enhance risk for metabolic and neoplastic diseases, including diabetes, kidney stones and growths in the colon and rectum that can lead to cancer. The global use of antibiotics between 2000 and 2015 increased 39 percent, with a 77 percent increase in low- and middle-income countries, said lead author Martin Blaser from the Rutgers University in the US.

Antibiotic overuse is when antibiotics are used when they are not needed. Antibiotics are one of the great advances in medicine. But overprescribing them has led to resistant bacteria that are harder to treat. For the study, the research team reviewed more than 200 peer-reviewed studies to examine the causes behind antibiotic overuse, which can lead harmful bacteria to become drug-resistant and cause harmful effects on the microbiome, the collection of beneficial germs that live in and on our bodies. Studies in the US, UK and China found numerous online pharmacies selling antibiotics without a prescription. This is also a major problem in Iow- to middle-income countries, where 60 percent of antibiotics are sold without prescription, often by untrained medical practitioners.

The researchers said that clinicians need to be better educated about the long-term effects on the microbiome and learn about better ways to speak with their patients about antibiotic risks and benefits. They also need to improve their communication about the consequences of antibiotic treatment and identify alternatives.