- As of 2020, an increase in the number of people with mental health problems was reported.
- Research published in PNAS highlights that antidepressants contribute to the resistance of bacteria to multiple antibiotics.
- It is estimated that by 2050 antimicrobial resistance will be the leading cause of mortality worldwide.
Today it is common to hear in university environments that both students and professors take antidepressants. This situation increased in the general population derived from the Covid-19 pandemic up to 25%. On the other hand, the use of these drugs in recent years has generated a public and medical debate due to the fact that their intake has become widespread. Depression is a mental illness considered a “silent pandemic”, which currently affects 5% of the world’s population.
What does the scientific evidence say?
On January 23, 2023, the journal Proceedings of National Science (PNAS) published a research paper led by Jianhua Guo from the University of Queensland in Brisbane, Australia, which unites two of the topics of high interest in chemical and medical sciences: Antibiotic resistance and antidepressant use.
He Dr. Miguel Beltran GarciaResearch Professor at the Autonomous University of Guadalajara (UAG), mentions that the study highlights that antidepressants contribute to the resistance of bacteria to multiple antibiotics. The study was based on the hypothesis that antidepressants accumulate in a high concentration in the colon, eliminate microbes from the digestive tract and on results published by the same group in 2018, where the antidepressant fluoxetine caused mutations in the Escherichia coli bacteria that increased their Antibiotic Resistance (AR).
In the new study carried out during 60 days of exposure, sertraline and duloxetine were the antidepressants that most significantly induced AR in the number of bacterial cells, in a time ranging from 5 to 10 days of exposure. The RA persisted in the following 33 generations of the bacterium. Antioxidant genes, genes coding for expulsion pumps of toxic substances, as well as some other stress biomarker genes were associated with persistence and resistance to antibiotics.
Also, the study reports that antidepressants cause chromosome mutations in bacteria, due to the production of reactive oxygen species (“ROS”) commonly called free radicals.
Another outstanding result was the conjugation of plasmids (a small DNA molecule found in bacteria and some other microscopic organisms) between bacterial cells in no more than 10 minutes of contact resulting from exposure to antidepressants, which hypothetically Increases Horizontal Gene Transfer (THG) with abilities to resist the drugs that medicine uses to combat them.
In THG, bacteria share plasmids, transposons, and other mobile genetic elements that offer them opportunities to survive in aggressive environments. Beyond the spectacular results presented in PNAS, a point of debate is whether the antidepressant causes the mutations of the bacteria in the colon (in situ). Because, in assays, mutations occur under aerobic conditions (in the presence of oxygen), where “ROS” are formed.
In conditions of absence of oxygen (anaerobic), the number of bacterial mutants with RA drops drastically, proving that reactive oxygen is the cause, so from my point of view as a possible patient this gives us a breather, since in the colon, anaerobic conditions predominate, that is, there is no free oxygen.
However, as a scientist, the published results raise some questions for me that need to be explored almost immediately, including these:
a) Is the percentage of antibiotic resistance and persistence genes expressed in the microbial communities that inhabit the colon in antidepressant users high?
b) If the answer to the previous question is positive, then, what is the mechanism that causes mutations in bacteria in the colon (in situ) without free oxygen? Are colon cells free to undergo mutations?
c) What are the levels of antidepressants contained in the feces of consumers?, and if the levels of expression of resistance genes in bacteria change once they are excreted in feces from the intestine when they come into contact with the air.
All responses to be positive are dangerous in any sense; especially the last one, because animals and humans will be exposed to this fecal matter, so we will be in contact with resistant bacteria.
The exposure of bacteria to antibiotics has increased quantitatively
“RA” occurs due to the intensive use of antibiotics for the treatment of human infections, but its use has been extended to the cosmetic, veterinary and agricultural industries. Now, in terms of the spread of RA, consider sewage, tourism, and trade, factors that globally move antibiotic-resistant bacteria and their resistance genes at unprecedented speed between continents, perhaps as much as the same speed at which a virus can spread.
RA, without a doubt, is an announced disaster that puts human health in check. Experts mention that by the year 2050, both resistance to antibiotics and supermicrobes that cause infections will be the cause of death of 10 million people.
New information on this subject should call our attention, where resistance to antibiotics is a silent threat that will affect our lives in a short time, if it has not already done so.
Also read:
The 5 most dangerous superbugs in the world: They are all resistant to current antibiotics
Antimicrobial resistance: 9 out of 10 viral infections are unjustly treated with antibiotics
Why is antibiotic resistance generated?