Gut probiotics to lower high blood phenylalanine in inherited metabolic disorders

Microbiota-based probiotics to treat inborn errors in metabolism

NIH-funded research Stanford University · NIH-11261166

Natural gut bacteria are being used to lower high blood phenylalanine in people with phenylketonuria.

Quick facts

Grant typeR01 grant
Study typeNIH-funded research
Funding institutionStanford University NIH-funded
Lab location1 site (Stanford, United States)
Project IDNIH-11261166 on NIH RePORTER

What this research studies

This project looks for natural gut bacteria that can break down phenylalanine, the amino acid that builds up in phenylketonuria. Researchers will search bacterial genomes and measure gene activity and metabolites to identify pathways that consume phenylalanine. Promising microbes will be tested by introducing them into germ-free mice that model phenylketonuria to see whether blood phenylalanine levels fall. The longer-term aim is to develop probiotic strains that could one day be given to people to help control harmful blood amino acids.

Who could benefit from this research

Good fit: People with phenylketonuria or related inborn errors causing elevated blood phenylalanine would be the primary candidates for this approach.

Not a fit: People without amino-acid metabolic disorders or whose condition cannot be managed by microbial breakdown of the problematic metabolite are unlikely to benefit.

Why it matters

Potential benefit: If successful, this work could lead to probiotic treatments that lower blood phenylalanine and reduce complications of phenylketonuria and similar inborn errors of metabolism.

How similar studies have performed: Engineered bacteria have shown promise in preclinical and some early clinical work for lowering toxic metabolites, but using native, non-genetically modified gut strains for PKU is a newer strategy.

Where this research is happening

Stanford, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.