AUG 22, 2017 1:28 PM PDT

As If Superbugs Weren't Bad Enough, Here's Another Reason Not to Overuse Antibiotics

WRITTEN BY: Kara Marker

Ever since penicillin was discovered in 1928, bacteria have been fighting back against every single antibiotic we develop. Unfortunately, we’re helping bacteria become resistant by being careless with the use of antibiotic drugs, and a recent study from the University of Virginia shows that in addition to creating superbugs, the overuse of antibiotics is hurting the immune system’s ability to fight pathogens.


An Entamoeba histolytica cyst in a micrograph stained with chlorazol black. Credit: CDC/ Dr. George Healy

Contributions to Antibiotic Resistance

When you’re given a prescription for antibiotics to treat a bacterial infection, your doctor always stresses the importance of taking all of the pills, even if you start to feel better. If you don’t kill all of the bacteria, the infection could return, and only the strongest and most resilient bacteria would be the ones surviving and multiplying. For the same reason, it’s important for doctors not to over-prescribe antibiotics and to limit the use of antibiotics in commercial agriculture.

Now, there’s another reason to use antibiotics carefully and appropriately.

While studying amebic colitis and gut microbiome, the population of healthy bacteria living in parts of the body like the gastrointestinal (GI) tract, researchers found that a reduction in the diversity of gut microbes due to excessive or inappropriate antibiotic use impairs the ability of immune cells called neutrophils to respond to pathogenic threats in the body.

Neutrophils: vital first-responders

Neutrophils lead the attack when pathogens enter the body. They absorb and digest pathogens, a process called phagocytosis. "We found that antibiotic disruption of the natural microbes in the gut prevented this from happening properly, leaving the gut susceptible to severe infection,” explained Virginia’s Koji Watanabe, PhD.

Watanabe and the other researchers were studying amebic colitis, a disorder of the GI tract most common in underdeveloped countries. The disease is caused by a protozoan parasite called Entamoeba histolytica. There are approximately 40 million cases of amebic colitis reported worldwide every year. The parasite attaches to the lining of the digestive tract, poking holes in the tissue to travel to and infect other parts of the body.

During a study in Bangladesh slums, researchers collected stool samples from children. Those with the most severe cases of the amebic colitis were also the ones with the least diverse gut microbiomes. Later, in mice models, researchers saw that antibiotic-directed disturbances in the gut microbiome reduced neutrophil activity to the point where neutrophils wouldn’t respond to the immune messenger chemicals signaling an infection. Additionally, the intestinal barrier that separates the GI tract from the rest of the body was “compromised.”

This is another important reason not to use antibiotics unless they are clearly needed," explained Bill Petri, MD, PhD, chief of the Division of Infectious Diseases at the University of Virginia. "Unwise use of antibiotics not only increases the risk of multi-drug resistant bacteria and the risk of C. difficile infection but also impairs white blood cell function."

The present study was published in the journal PLOS Pathogens.

Sources: University of Virginia Health System, PubMed Health, The Internet Journal of Advanced Nursing Practice, National Academies Press

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog:
You May Also Like
JUN 30, 2019
JUN 30, 2019
Opioid Addiction Comes With Increased Risk Of Infection
Public health officials have put decades of work into the battle against infectious diseases. Now, this progress is at risk of being dismantled. A recent s...
AUG 13, 2019
Health & Medicine
AUG 13, 2019
Blood-Brain Barrier Impairment and Its Role in Alzheimer's Disease
In healthy people, the blood-brain barrier (BBB), which is fromed by brain endothelial cells, strictly controls the entrance of harmful materials into...
OCT 19, 2019
OCT 19, 2019
Autism May be Linked to an Immune Disorder
Until now, diagnosis for autism spectrum disorder have relied on behavioral assessments looking for symptoms including poor social and communication skills...
NOV 19, 2019
NOV 19, 2019
Ketogenic Diet Appears to Help Protect Against the Flu
The ketogenic diet forces the body to use stored fat as fuel instead of carbohydrates; the fat gets broken down into ketone bodies....
DEC 16, 2019
Drug Discovery & Development
DEC 16, 2019
Vaccine To Protect Against The Zika Virus
Scientists at The University of Texas Medical Branch at Galveston present for the first time how a single high dose vaccine can protect a pregnant mouse al...
JAN 08, 2020
Cell & Molecular Biology
JAN 08, 2020
In a First, Scientists Generate Early Human Immune Cells in the Lab
Now we know more about the early stages of the human immune system....
Loading Comments...