# Princeton study: plant proteins Prif resist digestion and reach the colon to feed gut bacteria

- Published: 2026-11-10 14:50 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: Prif proteins, plant-resistant indigestible proteins, gut microbiota, dietary fibre, p-cresol sulfate, indole-3-lactate, Nature Metabolism, isotope labelling, Princeton University
- URL: https://realtech.media/news/rt-9e36c65d538c6031246fc3df_princeton_study_plant/

**Researchers at Princeton University describe plant proteins that survive the stomach and feed colon bacteria; most data come from lab and animal models.**

![Princeton study: plant proteins Prif resist digestion and reach the colon to feed gut bacteria](https://realtech.media/media/2026/11/9e7664e6bec29528.jpg)
*pravda.ru*

Researchers at Princeton University (USA) have described a group of plant proteins that resist breakdown in the stomach and reach the large intestine. The work was published in Proceedings of the National Academy of Sciences (PNAS), as reported by pravda.ru [1]. The authors call these compounds Prif, from "plant-resistant indigestible proteins" [1].

Fibre has traditionally been considered the key component of a plant-based diet for gut health. Humans cannot digest it themselves, but it serves as a nutrient medium for beneficial microbes [1]. The new study indicates that certain plant proteins also play an important role [1].

## Prif proteins and gut bacteria

In the large intestine, Prif proteins become fuel for bacteria. Interacting with fibre, they change how the microbiota behaves [1]. When there is not enough fibre in the gut, bacteria begin to consume the mucus layer that protects the intestinal wall. This produces potentially harmful phenolic metabolites, for example p-cresol sulfate [1].

When fibre and Prif proteins are present, microbial activity is directed toward processing these substances instead of breaking down the protective mucus. According to the report, this supports the production of metabolites linked to maintaining a healthy weight and general well-being [1].

## Metabolites the body makes itself

A second study, published in Nature Metabolism, challenged the view that many metabolites linked to immunity and inflammation are produced only by gut bacteria [1]. Using isotope labelling, the researchers traced the path of molecules in mice and humans [1]. Mammalian cells turned out to be capable of producing some compounds on their own, including indole-3-lactate and indole-3-acetate, which had previously been attributed solely to the microbiota [1].

Even when antibiotics, which substantially reduce the bacterial population of the gut, were given, blood levels of many important metabolites remained high. This is presented as confirmation of their own origin [1].

The scientists note that when developing therapeutic diets or probiotics, it matters to consider not only microbes but also how food components interact with the body's own systems. They also suggest that information on Prif content may in future appear on food packaging alongside fibre data [1]. Most of the data were obtained in laboratory conditions and in animal models, and confirming the long-term effect of these mechanisms on human health will require additional clinical studies [1].

## Sources

1. [pravda.ru](https://www.pravda.ru/news/health/2440219-new-science-plant-diet-metabolism)

---

Source: RealTech, realtech.media — https://realtech.media/news/rt-9e36c65d538c6031246fc3df_princeton_study_plant/