An antimicrobial peptide of the cathelicidin family that provides innate immune defense by killing pathogens and modulating inflammation and wound healing.
Koppen. Bruce C BC; Mulder. Patrick P G PPG; de Boer. Leonie L; Riool. Martijn M; Drijfhout. Jan W J...
Researchers found that the natural antimicrobial peptide LL‑37 (and lab‑made versions inspired by it) works much better at killing Staphylococcus aureus, especially when paired with the antibiotic teicoplanin. This combo also breaks down tough bacterial biofilms, but it didn’t help against Staph epidermidis.
The study measured the natural antibacterial peptide LL‑37 in older people with sepsis and found that it spikes early in the illness but falls as the condition gets worse. Lower LL‑37 levels around day 7 were linked to higher severity scores and a greater chance of dying within 28 days.
The study shows that the normal prion protein (PRNP) may act like an antimicrobial peptide, similar to LL‑37, by fighting viruses and binding harmful amyloid‑β, but it can also be hijacked by viruses like HSV‑1. This is mostly basic science and doesn’t give any direct tips for supplementing or dosing.
In rats with COPD‑like lung damage caused by cigarette smoke and bacterial toxin, giving the natural peptide LL‑37 together with a steroid inhaler (budesonide) made the steroid work better. LL‑37 boosted a protein called HDAC2 that helps steroids reduce inflammation and lowered activity of a signaling pathway (PI3K/Akt) that normally makes steroids less effective.
McHugh. Brian J BJ; Wang. Rongling R; Li. Hsin-Ni HN; Beaumont. Paula E PE; Kells. Rebekah R; Steven...
The study shows that the natural peptide LL‑37 can get inside lung cells infected with the tough bacteria Pseudomonas aeruginosa and then act like a fire alarm, turning on an immune alarm system (the NLRP3 inflammasome). This triggers the release of inflammatory signals (IL‑1β, IL‑18), kills the infected cells in a controlled way, and calls in neutrophils to help clear the infection.
Scientists tested citron essential oil on human skin cells in the lab and found it lowered several inflammation‑related proteins that are linked to rosacea, suggesting the oil could help calm rosacea symptoms, though the study was only done in cell cultures, not people.
In people with bronchiectasis, the natural antimicrobial peptide LL‑37 is found in higher amounts in the lungs, especially in those who get frequent flare‑ups and have worse lung function. Higher LL‑37 (and lower levels of another peptide, SLPI) predicts quicker and more frequent worsening of the disease.
Anders. Emma E; Dahl. Sara S; Svensson. Daniel D; Nilsson. Bengt-Olof BO
LL-37, a natural antimicrobial peptide, can kill bone‑building cells (osteoblasts) and make their membranes leaky, and it does this even when the cells don’t take the peptide inside through the usual clathrin pathway. Blocking that uptake route cuts how much peptide gets inside but doesn’t stop the damage, meaning the harmful effect happens outside the cell.
Shurko. James F JF; Galega. Ralph S RS; Li. Chuxi C; Lee. Grace C GC
Researchers tested the natural antimicrobial peptide LL-37 and two shorter versions (LL-13 and LL-17) against tough Staph infections. When mixed with the antibiotic vancomycin, the short peptides helped kill vancomycin‑resistant strains and even made them sensitive to the drug again. They also stopped the bacteria from forming protective biofilm layers.
Researchers tested three short versions of the human peptide LL-37 and found that one called P38 kills drug‑resistant E. coli very well while not harming human cells. It works by punching holes in the bacterial membrane, and computer models show it sticks strongly to the outer layer of Gram‑negative bacteria. The study is still in the lab stage, but it points to P38 as a promising candidate for future infection treatments.
The study shows that a part of the bacteria’s control system (CovS phosphatase) is needed for group A strep to survive attacks by the human antimicrobial peptide LL‑37. When this bacterial function is disabled, the bugs are far less able to cause skin infections, colonize the throat, or survive immune cells, and they become much more sensitive to LL‑37.
Spencer. John J JJ; Pitts. Rowan E RE; Pearson. Rachel A RA; King. Lauren B LB
The study shows that two natural antimicrobial peptides, especially the marsupial peptide WAM‑1, can kill drug‑resistant Acinetobacter bacteria in lab tests and work better when combined with regular antibiotics, but this is still early‑stage research and not a ready‑to‑use treatment for everyday health hacks.
Babikir. Ibrahim H IH; Abugroun. Elsir A EA; Bilal. Naser Eldin NE; Alghasham. Abdullah Ali AA; Abda...
People with urinary tract infections have higher levels of the natural antimicrobial peptide LL-37 in both blood and urine, and the amount rises with infection severity, so measuring LL-37 could help spot a UTI.
LL-37, a natural antimicrobial peptide, can change how mast cells display immune sensors (TLRs), making them better at spotting germs, and it also triggers inflammation signals and reactive oxygen species.
LL-37 is a natural peptide that helps immune cells sense stray DNA, but when it gets chemically altered by PAD enzymes (a process called citrullination), it can no longer bind DNA or trigger those immune cells, which may lower the risk of auto‑immune flare‑ups. The study shows the more parts of LL-37 that are citrullinated, the weaker its effect, and that swapping certain building blocks can protect its activity.
Dolkar. Tsetan T; Trinidad. Celestine M CM; Nelson. Kelly C KC; Amaria. Rodabe N RN; Nagarajan. Priy...
A case report shows that injecting the immune‑boosting peptide LL‑37 into melanoma tumors can shrink the cancer but may cause serious skin problems like wart‑like bumps and blistering after about a month and a half. The skin issues went away once the injections stopped.
LL-37 is a natural peptide that our bodies make in skin, gut, lungs and other surfaces to kill microbes and fine‑tune inflammation. It’s produced by skin cells, gut lining, immune cells and changes its activity depending on the tissue and the local microbes.
The paper explains that psoriasis, a skin disease, is driven by an immune pathway involving IL-17. A natural protein called LL-37, which some people think about using for its antimicrobial benefits, can act as a trigger for this pathway in people with a certain genetic background, potentially worsening or causing psoriasis.
Zhao. Lin L; Tan. Shuai S; Zhang. Hai H; Liu. Peng P; Tan. Yu-Zhu YZ; Li. Jia-Chuan JC; Jia. Da D; S...
Astragalus polysaccharides (APS) can boost the body's own antimicrobial peptide LL‑37 in airway cells, leading to stronger antibacterial effects in lab dishes, but this is only shown in cell cultures, not in people.
People with high cholesterol have more of the immune peptide LL‑37 in their blood, and taking a common cholesterol drug (atorvastatin) brings those levels down. The study also found that higher LL‑37 is linked to higher good‑cholesterol (HDL).