An antimicrobial peptide of the cathelicidin family that provides innate immune defense by killing pathogens and modulating inflammation and wound healing.
Dhaliwal. Winnie W; Shawa. Tamara T; Khanam. Moriam M; Jagatiya. Poonam P; Simuyandi. Michelo M; Ndu...
A study in Zambian adults found that taking a daily multi‑micronutrient pill didn’t change gut levels of the antimicrobial peptide LL‑37, but it did boost another peptide (HD5) in people who were underweight. During diarrhea, HD5 fell in the placebo group but stayed stable with the supplement. There’s no direct evidence here that LL‑37 supplementation helps gut health.
Cole. Jason N JN; Pence. Morgan A MA; von Köckritz-Blickwede. Maren M; Hollands. Andrew A; Gall...
The study shows that certain proteins on a dangerous strain of strep bacteria (M1 protein and its capsule) help it survive the body's defenses and make it resistant to the natural antimicrobial peptide LL‑37. This resistance is part of how the bacteria become more invasive.
The study looked at saliva from men who have sex with men who were exposed to HIV but stayed uninfected. It found higher levels of certain immune chemicals (CC-chemokines) linked to sexual behavior, but the peptide LL‑37 was not higher and didn’t seem to help block HIV. So there’s no clear action you can take with LL‑37 for HIV protection based on this work.
Researchers looked at the skin inside the ear canal and found that immune cells called mast cells and antimicrobial proteins like LL‑37 and β‑defensin‑1 are especially present in the ear’s wax‑producing glands. This suggests mast cells help release these natural antibiotics right where they can protect the ear from infections.
Naito. Mizue M; Frirdich. Emilisa E; Fields. Joshua A JA; Pryjma. Mark M; Li. Jianjun J; Cameron. An...
The study looked at how changes in a bacterial surface sugar layer affect the bacteria’s ability to form biofilms, survive stress, and cause disease, and it also tested the natural antimicrobial peptide LL‑37 against the bacteria. They found LL‑37 can kill the pathogen, but the bacteria’s surface changes only slightly alter how sensitive they are to it. The main take‑away is that LL‑37 has antibacterial activity, but the findings are specific to a gut bug and not directly useful for human supplement or health protocols.
Acar. B B; Simsek. G Güler GG; Oguztuzun. S S; Zaim. M M; Karasen. R Murat RM
Researchers examined ear‑canal itching and measured the antimicrobial peptide LL‑37. They found more inflammation than in healthy ears but no extra LL‑37, indicating the itching isn’t caused by dermatitis or LL‑37 deficiency.
Rodríguez-Martínez. Sandra S; Cancino-Diaz. Juan Carlos JC; Vargas-Zuñiga. Luis Marti...
The study shows that when human skin cells are made to produce more of the peptide LL‑37, they also make more of VEGF (a factor that promotes blood vessel growth) and c‑IAP‑2 (a protein that prevents cell death). This effect seems to involve the HIF‑1α pathway, but the work was done only in lab‑grown cells, not in people.
Coffelt. Seth B SB; Marini. Frank C FC; Watson. Keri K; Zwezdaryk. Kevin J KJ; Dembinski. Jennifer L...
The study shows that the natural peptide LL‑37, which is higher in some cancers, helps ovarian tumors grow by pulling in special stem‑like cells that make blood vessels and inflammation. Blocking LL‑37 in mice stopped these cells from entering the tumor and slowed its growth.
Tran-Winkler. Hien J HJ; Love. John F JF; Gryllos. Ioannis I; Wessels. Michael R MR
The study shows that the human antimicrobial peptide LL‑37 can act as a signal that makes certain strep bacteria more aggressive, while magnesium does the opposite. This signaling happens through a bacterial sensor called CsrS, which changes the bacteria’s gene activity and helps it switch from harmless to invasive.
Rinker. Sherri D SD; Trombley. Michael P MP; Gu. Xiaoping X; Fortney. Kate R KR; Bauer. Margaret E M...
The study shows that a bacterium called Haemophilus ducreyi becomes more vulnerable to the human antimicrobial peptide LL‑37 when a specific gene (mtrC) is removed. This gene is part of a transporter that helps the bacteria resist LL‑37 and certain beta‑defensins. The resistance involves multiple bacterial systems, so LL‑37’s killing power isn’t due to a single factor.
Senyürek. Ilknur I; Paulmann. Maren M; Sinnberg. Tobias T; Kalbacher. Hubert H; Deeg. Martin M;...
The study shows that natural skin peptides called DCD work differently from the well‑known peptide LL‑37 to kill Staph bacteria. DCD peptides kill bacteria over time, cause the bacterial membrane to lose its charge, and block the bacteria’s ability to make RNA and proteins, but they don’t punch holes in the membrane like LL‑37 does. They also stick only weakly to bacterial surface components.
Froehlich. Barbara J BJ; Bates. Christopher C; Scott. June R JR
The study found that a bacterial control system called CovRS lets group A strep keep growing when iron is scarce and when the human antimicrobial peptide LL‑37 is around, by turning on genes that bring in metals. This means the bacteria can partly resist LL‑37’s killing effect.
Zähner. Dorothea D; Zhou. Xiaoliu X; Chancey. Scott T ST; Pohl. Jan J; Shafer. William M WM; St...
The human antimicrobial peptide LL-37 can trigger a gene in Streptococcus pneumoniae that makes the bacteria resistant to macrolide antibiotics like erythromycin. This means that LL-37, instead of helping, might actually protect the bacteria against some antibiotics.
Seib. K L KL; Serruto. D D; Oriente. F F; Delany. I I; Adu-Bobie. J J; Veggi. D D; Aricò. B B;...
The study shows that a bacterial protein called factor H‑binding protein (fHBP) helps meningitis‑causing bacteria survive in human blood and resist the natural antimicrobial peptide LL‑37. Bacteria lacking this protein die quickly, while even low levels of fHBP protect them from LL‑37’s killing action.
The study shows that a skin protein called psoriasin shoots up a lot in eczema (atopic dermatitis) and when the skin barrier is damaged, but it doesn’t change the levels of the peptide LL‑37 that many biohackers track. This rise seems to help keep E. coli away, even though other antimicrobial proteins are lower in eczema skin.
Gambichler. Thilo T; Skrygan. Marina M; Tomi. Nordwig S NS; Othlinghaus. Nick N; Brockmeyer. Norbert...
The study looked at skin samples from people with eczema (atopic dermatitis), psoriasis, and healthy skin to see how much the body’s natural antimicrobial proteins, including LL‑37, are made. It found that LL‑37 levels weren’t higher in the disease groups, while other antimicrobial peptides were increased, especially different ones in eczema versus psoriasis.
Giesemann. Torsten T; Guttenberg. Gregor G; Aktories. Klaus K
The study found that certain human alpha‑defensins can block the harmful effects of Clostridium difficile toxin B, but the peptide LL‑37 does not work against this toxin. This means LL‑37 isn’t useful for protecting against C. difficile‑related gut damage.
Mason. Kevin M KM; Raffel. Forrest K FK; Ray. William C WC; Bakaletz. Lauren O LO
The study shows that a bacterial protein called SapA can bind both heme (an iron source) and several human antimicrobial peptides, including LL-37. When these peptides bind SapA, they can block heme uptake, suggesting the bacteria prioritize defending against the immune system over getting iron. This reveals a new way the bacteria hide from our immune defenses.
The paper explains that our bodies make a natural antibiotic called LL‑37, but the bacteria Staphylococcus aureus has tricks to dodge it. It’s mostly a scientific review, not a how‑to guide, so there’s little you can directly apply to personal health routines.
Kreuter. A A; Skrygan. M M; Gambichler. T T; Brockmeyer. N H NH; Stücker. M M; Herzler. C C; Po...
The study looked at antimicrobial peptides in HPV‑related anal skin lesions and found that LL‑37 levels stayed the same, while other peptides (hBD‑2 and hBD‑3) went up. There was no link between these peptide levels and the amount or type of HPV, and the results were the same in HIV‑positive and HIV‑negative men.