A peptide called KF6, isolated from a parasitic mushroom complex, effectively lowered blood pressure and reduced heart and kidney damage in spontaneously hypertensive rats by modulating the RAAS system and improving gut bacteria composition.
10 mg/kg for 5 weeksKF6 matched Captopril's dose while reducing blood pressure and protecting organs in hypertensive rats
What the researchers found
KF6 peptide administered at 10 mg/kg for 5 weeks to spontaneously hypertensive rats (SHRs) effectively lowered both diastolic blood pressure (DBP) and systolic blood pressure (SBP). The peptide decreased serum levels of ACE, angiotensinogen (AGT), aldosterone (ALD), and angiotensin II (ANG II).
Beyond blood pressure reduction, KF6 ameliorated cardiac and renal injury by inhibiting fibrosis, inflammation, and oxidative stress. Mechanistically, it inhibited the ACE-ANG II-AT1 axis while activating the protective ACE2-Ang(1-7)-MAS1L pathway in both the kidney and heart. The peptide also improved intestinal microbiota composition, increasing beneficial Prevotella and Phascolarctobacterium while decreasing potentially harmful Alistipes, Clostridium_IV, Nosocomiicoccus, and Allobaculum.
Why it matters
Hypertension affects over a billion people worldwide and is a leading cause of heart disease, kidney failure, and stroke. Current ACE inhibitor drugs like Captopril are effective but come with side effects. Food-derived bioactive peptides represent a potentially safer alternative for blood pressure management. This study is notable because KF6 not only lowered blood pressure but also addressed organ damage and gut health, suggesting a multi-targeted therapeutic approach that synthetic drugs typically don't provide.
How the study worked
Researchers administered the KF6 peptide orally at 10 mg/kg body weight to spontaneously hypertensive rats (SHRs) for 5 weeks, comparing it to Captopril at the same dose as a positive control. They measured blood pressure throughout the study and analyzed serum biomarkers of the renin-angiotensin-aldosterone system (RAAS). Heart and kidney tissues were examined for signs of fibrosis, inflammation, and oxidative stress. Gut microbiota composition was assessed to evaluate intestinal effects.
What this study cannot tell us
This study was conducted entirely in rats, so the results may not directly translate to humans. The spontaneously hypertensive rat model, while well-established, doesn't capture the full complexity of human hypertension. The study used only one dose level (10 mg/kg), so the optimal dose range is unknown. Long-term safety and efficacy beyond 5 weeks were not assessed. The gut microbiota changes were observational and the causal relationship between microbial shifts and blood pressure effects needs further investigation.
How to read the evidence
This is a preclinical animal study using a well-established hypertension model (SHRs). While the results are promising and the methodology is sound with appropriate positive controls, the findings have not been validated in human subjects, limiting the translational evidence.
When this study was published
Published in 2025, this is a very recent study reflecting current research trends in food-derived bioactive peptides and the gut-cardiovascular axis.
The bigger picture
This research fits into a growing field of food-derived bioactive peptides as functional alternatives or complements to pharmaceutical antihypertensives. The finding that KF6 modulates both RAAS pathways and gut microbiota adds to emerging evidence connecting gut health to cardiovascular outcomes. Mushroom-derived peptides are relatively underexplored compared to marine or milk-derived peptides, making this a noteworthy addition to the peptide research landscape.
Questions still open
- Would KF6 show similar antihypertensive effects in human clinical trials, and at what dose?
- How does the long-term safety profile of KF6 compare to established ACE inhibitors like Captopril?
- Is the gut microbiota modulation a direct mechanism of blood pressure reduction or a secondary effect?
Common questions
What is the KF6 peptide and where does it come from?
How does KF6 compare to conventional blood pressure medication?
Read the original research
A peptide from Boletus griseus-Hypomyces chrysospermus protects against hypertension and associated cardiac and renal damage through modulating RAAS and intestinal microbiota.
Journal of food science, 90(1), e17617
Citation
Huan, Pengtao; Sun, Liping; Chen, Shupeng; Zhong, Yujie; Zhuang, Yongliang. (2025). A peptide from Boletus griseus-Hypomyces chrysospermus protects against hypertension and associated cardiac and renal damage through modulating RAAS and intestinal microbiota.. Journal of food science, 90(1), e17617. https://doi.org/10.1111/1750-3841.17617