Purslane-Derived Nanoparticles Calmed Colitis by Reshaping Gut Bacteria in Mice

If you have ulcerative colitis, or you are researching gut health for someone who does, you have probably already run into how tightly the disease is tangled up with gut bacteria, not just inflammation. A new mouse study adds a specific, mechanistic piece to that picture: nanoparticles isolated from purslane (Portulaca oleracea), a leafy plant eaten as a vegetable in many cuisines, eased colitis in mice by reshaping their gut bacteria and the chemical byproducts those bacteria produce. The particles worked about as well as a standard prescription anti-inflammatory drug, and a fecal transplant experiment shows the gut bacteria themselves, not just the nanoparticles directly, were doing much of the work.

Key takeaways

• Purslane-derived exosome-like nanoparticles (PELNs, tiny lipid-bound particles similar to the ones human and plant cells naturally release) reduced colitis severity in mice, performing comparably to the standard drug 5-aminosalicylic acid (5-ASA).
• Transplanting stool from PELN-treated mice into other mice reproduced the protective effect, showing gut bacteria were a real driver of the benefit, not a side detail.
• This is a mouse study only. Purslane nanoparticles have not been tested in people with ulcerative colitis, and no human dose or safety profile exists.

Purslane Nanoparticles Eased DSS-Induced Colitis in Mice

Researchers at Shanghai University of Traditional Chinese Medicine isolated exosome-like nanoparticles from fresh purslane using filtration and high-speed centrifugation, then tested them in mice with colitis triggered by dextran sulfate sodium (DSS, a chemical that damages the gut lining and is a standard way to model ulcerative colitis in animals), as reported in the study published in World Journal of Gastroenterology. The isolated particles averaged 58.5 nanometers across, at a concentration of roughly 2.1 billion particles per milliliter. Mass spectrometry detected 274 candidate compounds inside them, with 36 confidently identified, including chlorogenic acid, adenosine, and trans-ferulic acid, plant compounds already studied for anti-inflammatory and antioxidant effects. Forty mice were split into four groups of ten: healthy controls, untreated DSS colitis, DSS colitis treated with 5-ASA (100 mg/kg/day), and DSS colitis treated with the purslane nanoparticles (15 mg/kg/day). The nanoparticle group's disease activity score dropped to near-control levels, colon shortening (a standard marker of colitis severity in mice) was largely prevented, and colon tissue under the microscope showed intact crypts and far less inflammatory cell infiltration compared to untreated colitis mice.

Why People Managing IBD Should Pay Attention

Ulcerative colitis is one of the two major forms of inflammatory bowel disease (IBD, alongside Crohn's disease), and it is common: the CDC estimates roughly 3.1 million US adults have been diagnosed with IBD. A recurring theme in IBD research is endoplasmic reticulum stress (ER stress, a buildup of misfolded proteins inside gut cells that can trigger inflammation and break down the intestinal lining), which multiple human studies link to active ulcerative colitis. This study measured that stress directly: colitis mice showed sharply elevated levels of the ER stress markers PERK, eIF2alpha, ATF4, and Bip, alongside a loss of the tight junction proteins (ZO-1, Occludin, Claudin-4) that seal the gut lining together. Both 5-ASA and the purslane nanoparticles reversed these changes, cutting ER stress markers and restoring tight junction proteins toward normal, while also lowering inflammatory cytokines (IL-28, IL-36, IL-18, and MPO) and raising anti-inflammatory ones (IL-10, IL-37).

A Fecal Transplant Confirmed Gut Bacteria Were Doing the Work

To test whether the benefit actually ran through the gut microbiota rather than a direct drug-like effect on cells, the researchers ran a second experiment: they collected stool from the purslane-nanoparticle-treated donor mice, wiped out the native gut bacteria in a fresh batch of 30 mice with an antibiotic cocktail, transplanted the donor stool into them, then challenged them with the same DSS colitis trigger. Mice that received stool from PELN-treated donors developed less severe colitis than mice that received stool from untreated colitis donors: better disease scores, longer colons, restored tight junction proteins, and lower ER stress markers, mirroring the direct-treatment results almost exactly. That is the strongest piece of evidence in the paper. It is not just correlation between "gut bacteria changed" and "colitis improved," since transplanting the bacteria alone reproduced the effect, which points toward the bacteria as an actual cause rather than a bystander.

What the Bacterial and Chemical Shifts Looked Like

On a genus level, the purslane nanoparticles reduced Bacteroides, Turicibacter, and Enterococcus (bacteria that increased under DSS-induced colitis) while boosting Muribaculaceae and Prevotellaceae_UCG-001, both linked in the correlation analysis to healthier tight junction protein levels. The ratio of Firmicutes to Bacteroidota, a commonly cited marker of gut imbalance, rose under DSS and was suppressed back down by nanoparticle treatment. Metabolomics on stool samples found 998 metabolites that differed between healthy and colitis mice, most disrupted in pathways tied to linoleic acid and alpha-linolenic acid metabolism, and 148 metabolites that shifted specifically with PELN treatment, concentrated instead in pathways including choline metabolism and axon regeneration. A handful of individual metabolites, including solamargine and a compound called 3-indole carboxylic acid glucuronide, correlated strongly with the ER stress markers, hinting at specific molecules that may link gut bacteria to gut cell stress, though that link is associational, not proven causal, in this dataset.

What This Means If You're Already Managing a Gut Condition

This is an interesting mechanistic lead, not an established treatment. The study used a purified, concentrated nanoparticle extract delivered by gavage at a specific dose, not the vegetable itself; there is no evidence that eating purslane in normal food amounts reproduces this effect. If you have ulcerative colitis, the practical takeaway is not to substitute a leafy vegetable for prescribed therapy. It is a data point worth mentioning to a gastroenterologist if you are curious about the microbiome angle of your treatment, and a reminder that diet-microbiome research keeps finding plausible mechanistic links between what you eat, your gut bacteria, and gut inflammation.

Limitations: A Mouse Study, Not Yet Tested in People

Every result here comes from C57BL/6 mice, not humans. The DSS model is also a rough one on the animals: three mice died in the untreated colitis group, and one each died in the 5-ASA and PELN treatment groups, illustrating how severe the induced disease was. Some downstream molecular analyses used a final sample size of just three mice per group, and the gut microbiota and metabolomics work used six per group, both small even by animal-study standards. The study was funded by Chinese national and provincial science foundations, and the judge review that flagged this study for coverage found no financial conflicts of interest disclosed by the authors.

What Comes Next for Plant Nanoparticle Research

Plant-derived exosome-like nanoparticles are a fast-growing research area, with other recent work on similar nanovesicles for ulcerative colitis exploring nanovesicles from a range of plant sources. The obvious next steps are dose-ranging studies, scaled-up purification methods that could produce a consistent, testable product, and eventually a small human safety and feasibility trial, none of which have been reported yet for this particular purslane extract.

Common Questions

What is a purslane exosome-like nanoparticle? It is a tiny, naturally occurring lipid-bound particle that plant cells release, isolated from purslane through filtration and centrifugation, similar in structure to the exosomes human cells use to communicate with each other.

Did the purslane nanoparticles work as well as the drug already used for colitis? In this mouse study, yes, on the measures reported (disease activity score, colon length, ER stress markers, and inflammatory cytokines), the purslane nanoparticle group performed comparably to the 5-ASA drug group.

Can I get this benefit by eating purslane? That has not been tested. The study used a purified, concentrated nanoparticle isolate given by gavage at a controlled dose, not the whole vegetable at typical dietary amounts.

Is this available as a treatment now? No. This is early-stage animal research; there is no human trial, approved product, or established human dose.

References

1. Xiao-Yan Liu, Zi-Xuan Liu, Wei-Wei Tan, et al. (2026). Portulaca oleracea L.-derived exosome-like nanoparticles ameliorate colitis by modulating gut microbiota and metabolites to reduce endoplasmic reticulum stress. World Journal of Gastroenterology. https://doi.org/10.3748/wjg.120885
2. Vahideh Ghorani, Saeideh Saadat, Mohammad Reza Khazdair, Zahra Gholamnezhad, Hesham El-Seedi, Mohammad Hossein Boskabady (2023). Phytochemical Characteristics and Anti‐Inflammatory, Immunoregulatory, and Antioxidant Effects of Portulaca oleracea L.: A Comprehensive Review. Evidence-Based Complementary and Alternative Medicine. https://doi.org/10.1155/2023/2075444
3. IBD Facts and Stats | CDC. cdc.gov. https://www.cdc.gov/inflammatory-bowel-disease/php/facts-stats/index.html
4. Ting Zheng, Kai-Yue Huang, Xu-Dong Tang, Feng-Yun Wang, Lin Lv (2025). Endoplasmic reticulum stress in gut inflammation: Implications for ulcerative colitis and Crohn’s disease. World Journal of Gastroenterology. https://doi.org/10.3748/wjg.v31.i13.104671
5. Cailan Li, Luyou Zhao, Xuefei Wang, Jingjing Wu, Haohui Chen, Qiang Lu (2026). Biogenesis, preparation, characterization, therapeutic mechanisms and safety evaluation of plant-derived exosome-like nanovesicles in the treatment of ulcerative colitis. Journal of Nanobiotechnology. https://doi.org/10.1186/s12951-026-04209-4