# Therapeutic bubble tea: Preventing the formation of uremic toxins with hydrogel immobilized microbes

> **NIH NIH R01** · UNIVERSITY OF WASHINGTON · 2022 · $475,802

## Abstract

Project summary
Each year over 100,000 Americans begin dialysis when their kidneys lose the capacity to remove
toxins from the blood and half of them die within five years. These high mortality rates are in part
due to the ineffectiveness of dialysis at removing protein-bound uremic toxins (PBUTs) such as
indoxyl sulfate and p-cresol sulfate, which would otherwise be removed by healthy kidneys.
Herein, we propose a non-invasive ingestible bubble tea to reduce the blood concentration of
PBUTs and improve the outcomes of patients with end stage kidney disease (ESKD).
In contrast to conventional treatments, which attempt to remove toxins from the blood by dialysis,
this research offers a radically different approach, which prevents the formation of toxins at their
origin. PBUTs are byproducts of gut microbial metabolism; indole and p-cresol originate in the
gut from fermentation of amino acids and both solutes are sulfonated in the liver to form the
PBUTs indoxyl sulfate and p-cresol sulfate. We propose a novel microbe enriched bubble tea
which will expand the capacity of the gut to degrade the uremic toxin (UT) precursors (indole and
p-cresol) and thereby prevent their sulfonation to toxic forms in the liver. The bubble components
will be engineered to remain tight in the stomach, hence protecting the hydrogel entrapped
microbes from low pH, and then swell at neutral pH in the small intestine and colon, allowing
UTs to diffuse into the hydrogel where the UT degrading microorganisms will deactivate them.
Finally, the bubble tea will be excreted intact without altering the natural gut microbiome. This
concept builds on the successful applications of microbe enriched hydrogels in bioengineering
and environmental engineering for drug delivery and wastewater treatment.
We will develop the bubble tea by first enriching novel indole and p-cresol degrading microbes
from the environment, second engineering specialized hydrogel carriers for the microbes, and
finally replicating their trip through the gut in well controlled bioreactor units. The substrate
profiles, pH gradients, and removal rates will be experimentally measured and mathematically
simulated to visualize spatial localization of bacteria and to determine UT degradation over time.
Delivering these hydrogels in a formulated bubble tea drink could improve the lives of chronic
kidney disease and ESKD patients by reducing the burden from uremic symptoms and
complications.

## Key facts

- **NIH application ID:** 10332134
- **Project number:** 1R01DK130815-01
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Mari-Karoliina Winkler
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $475,802
- **Award type:** 1
- **Project period:** 2022-01-01 → 2026-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10332134

## Citation

> US National Institutes of Health, RePORTER application 10332134, Therapeutic bubble tea: Preventing the formation of uremic toxins with hydrogel immobilized microbes (1R01DK130815-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10332134. Licensed CC0.

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