Most people who have sat with San Pedro (Huachuma) or Ayahuasca will tell you something shifted. Not just emotionally, not just psychologically, but in the body itself. Something biological. A settling. A clearing. Something that felt structural in a way that's hard to put into words.
New research is beginning to put words to it.
A case study published in December 2025 in the Journal of Restorative Medicine by researchers at the Helfgott Research Institute at the National University of Natural Medicine looked at something that most plant medicine research hasn't measured: what happens to the gut microbiome before and after Huachuma and Ayahuasca ceremonies.
The study is early and small. It's a case study, not a clinical trial. It is worth naming for the question it asks about what these medicines do in the body.
What the Research Measured
Participants in the study sat with both Huachuma (San Pedro) and Ayahuasca in ceremonial settings. Before and after each ceremony, researchers looked at gut microbiome composition.
The question behind it is whether ceremony has any relationship to the microbial landscape of the gut.
It is a single, small case study. It does not establish cause and effect.
Why This Matters Beyond the Ceremony
This study matters because it asks whether what happens in ceremony extends beyond the brain, into the gut.
This research looks at a parallel story happening below the stomach. The gut isn't just processing food. It's in constant conversation with the brain, influencing mood, threat perception, inflammatory tone, and the capacity for genuine connection. Many people who have sat in ceremony describe feeling that conversation, even if they couldn't name it. The body settling. The chest loosening. Something releasing that wasn't psychological.
If the microbial landscape does shift, it may help explain something that has always been hard to articulate after ceremony: the feeling that whatever changed, it changed all the way through.
What This Means for How We Think About Preparation
If microbial shifts are part of what happens in ceremony, then dietary preparation isn't just spiritual practice. It may also be microbiome preparation. And that changes how seriously we should take it.
Most protocols include dietary guidance in the days before ceremony. This has always been framed as energetic or spiritual preparation. And it is. But it may also be creating conditions in the gut that influence how the medicine lands. The two explanations aren't in conflict. They may be describing the same thing from different angles.
At Ananda Lodge, preparation is one of the things we take most seriously. Every guest begins working with our team weeks before they arrive, not as a formality, but because we believe the container you build before ceremony shapes everything that happens inside it. This research adds a biological question to that belief, and we find it humbling.
Two Medicines, Two Lineages
Huachuma and Ayahuasca are medicines with distinct lineages, distinct ceremonial containers, and experiences that feel fundamentally different from each other. The study looked at both.
Huachuma, the Illuminator, a cactus of the Andes, is known for its grounded, embodied, heart-opening quality. A long day in presence. Clarity arriving slowly and staying. In traditional Andean-Amazonian ceremony sequencing, Huachuma opens the heart center first, creating the conditions for what comes next.
Ayahuasca, the Path Opener, held within the Shipibo tradition, moves differently: it travels to the root of a pattern, personal and ancestral, where understanding alone hasn't reached. In that sequencing, it goes into mind and shadow work from a heart that Huachuma has already softened. Then Huachuma returns to close the container, grounding everything that moved.
Whatever these medicines are doing at the level of consciousness, emotion, and spirit, research is beginning to ask what they may also be doing at the level of biology.
Frequently Asked Questions
What did the 2025 study on plant medicine and the gut microbiome look at?
A December 2025 case study published in the Journal of Restorative Medicine looked at the gut microbiome before and after Huachuma and Ayahuasca ceremonies. It is a single, small case study.
What is the gut-brain axis and why does it matter for plant medicine?
The gut-brain axis is the bidirectional communication system between the digestive system and the brain. The gut microbiome is thought to influence mood, inflammation, threat perception, and social behavior. That may help explain why plant medicine experiences can feel biological as well as psychological.
Is this research definitive?
No. The 2025 study is a case study, meaning it is early and small in scale. It is not a clinical trial and does not establish cause and effect. It does, however, open an important line of inquiry that deserves further investigation.
How are Huachuma and Ayahuasca different from each other?
Huachuma (San Pedro) is a cactus with roots in Andean tradition, known for producing a long, embodied, heart-centered experience focused on clarity and connection. Ayahuasca is a brew used in Amazonian traditions, particularly by the Shipibo, known for traveling to the root of a pattern, personal and ancestral. Each teaches differently, and none more deeply than another. They are distinct medicines with distinct ceremonial lineages.