Dozens of new natural antibiotics have been found in the human body

Antibiotic-resistant bacteria have become a major threat to health, not only in the past but also in the decades to come. But now, scientists have discovered that new antibiotics may have been inside our bodies for a long time. Researchers at the University of Pennsylvania used a "search" algorithm to find dozens of potential antibacterial peptides lurking in the human body.

Essentially, as bacteria develop more and more resistance to drugs, previously treatable infections become dangerous again. In fact, it is predicted that these "superbugs" could cause 10 million deaths a year by 2050. With our last line of defense starting to fail, scientists Scientists are searching for new medicines in many places, including things like green tea, breast milk, rattlesnake venom, frog skin, mushrooms and even platypus milk.

Staphylococcus aureus is one of the bacteria that newly discovered antibacterial peptides are effective against.

In a new study, researchers tried to find new antibacterial peptides (AMPs) in the human body. Peptides are essentially a long chain of amino acids produced by the body with the effect of biosynthesis of proteins.

Just like when you use the search function to find specific words or phrases in a document, they used an algorithm to find peptides with antimicrobial properties in the human proteome. The proteome is likened to a complete library of proteins produced in the body.

The team started by scanning the proteome for peptides that share characteristics common to all AMPs - namely, being between 8 and 50 amino acids in length, carrying a positive charge, and containing both hydrophobic and hydrophilic fragments water. This search returned 2,603 ​​hits, and interestingly, they had no connection to the immune system, leading the team to call them "encoded peptides".

The researchers then selected 55 of these peptides and tested their effectiveness against eight well-known pathogenic bacteria, including E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus . Infections with these bacteria are often acquired in the hospital and can be dangerous and difficult to treat.

"We found that 63.6% of these 55 encoded peptides had antibacterial activity," said lead researcher César de la Fuente. "Interestingly, these peptides not only fight infections with some of the most harmful bacteria in the world, they also target the gut and skin symbionts that benefit us. I speculate that this may be indicative of a microbiome-regulating role, which these peptides may also possess."

AMPs work even better when grouped with other AMPs from the same area of ​​the body, with their antibacterial power being enhanced 100-fold. In tests on mice, the team found that the new AMPs worked as well as existing antibiotics, and did not cause any signs of toxicity.

Further testing will examine whether these encoded peptides influence bacteria to develop resistance. And the results also look promising.

"What we discovered is that these encoded molecules attack bacteria by permeating through their outer membrane, an organ that is indispensable for survival," says De la Fuente: "Permeability These extremely damaging membranes would require large amounts of energy and many generations of mutations to confer resistance in bacteria, suggesting that these newly discovered peptides are good candidates for sustainable antibiotics. ."

According to the researchers, the new discovery could not only lead to new natural antibiotics to combat the growing threat of superbugs, but the technique used to find them could also help uncover potential molecules with therapeutic potential for other diseases.

The study was published in the journal Nature Biomedical Engineering .