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Research · Gut & microbiome

Stool transplant improves peanut tolerance in trial

LongevityWatch editors · August 7, 2026 · 1 min

Peanut allergy affects millions worldwide and has no real cure. New results from an early clinical study suggest that a fecal transplant, transferring gut bacteria from a healthy donor, may improve tolerance to peanuts.

In a Phase 1 trial, six participants with peanut allergy received fecal microbiome transplants (FMT) via capsules. Up to four months after the treatment, they showed improved tolerance to small peanut exposures. The results were published in the journal Science Translational Medicine.

The gut microbiome as an immune trainer

The logic behind the treatment is that the composition of gut bacteria partly determines how the immune system responds to food proteins. In people with allergies, the microbiome may be disrupted. By transferring bacteria from a donor, researchers aim to restore that balance and retrain the immune system.

According to the researchers, the initial findings are encouraging, but the study is too small to draw conclusions about efficacy. Only six people participated. A larger, controlled trial is needed to determine whether FMT works durably for food allergies.

What this says about the microbiome and aging

The gut microbiome plays a recognised role in immune function and the regulation of inflammation. As we age, the composition of gut bacteria shifts, contributing to what researchers call inflammaging: a low-grade, chronic inflammatory state that accelerates aging. Therapies that shape the microbiome are therefore relevant beyond allergy patients alone. They connect to a broader question about how gut bacteria influence health in later life.

This study is preliminary and limited in scale. But it illustrates the growing importance of the gut microbiome as a therapeutic target, beyond the classical indications for FMT such as Clostridioides difficile infections.

Read the original article

Search terms: fecal microbiome transplantation food allergy, gut microbiome immune regulation, inflammaging gut flora

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