How Differences in the Composition of Microorganisms in the Soil Affect the Microorganisms in the Human Gut, Through the Vegetables That Grow in it: a Process Pilot Study With Healthy Participants (HUMANITAS)
29 de julio de 2026 actualizado por: Pieter Maljaars, Leiden University Medical Center
The Effect of Soil Biodiversity on Human Gut Microbiome: a Process Pilot Study (The HUMANITAS Study)
There are two objectives for this clinical trial.
The first is to test whether, with the current logistics and study setup it is possible to perform the study well and see where there might be bottlenecks we couldn't predict.
The second objective is to investigate the relation between the composition of the microorganisms in the soil, the crops that grow in that soil, and the human gut.
During the study participants will drink three vegetable smoothies a day, for two periods of one week.
The only difference between the two periods is whether the vegetables come from a farm with a low diversity of microorganisms in the soil or a high diversity.
Participants will be asked to give blood samples and turn in fecal samples before and after each period.
Descripción general del estudio
Estado
Aún no reclutando
Condiciones
Intervención / Tratamiento
Descripción detallada
This randomized, double-blind, crossover pilot study will be used to assess the feasibility of logistics including vegetable delivery and preparation of the intervention product by the participants themselves. Besides feasibility, we will aim to identify live bacteria and fungi present in the intervention product (smoothies) and trace these back in stool samples.
The gut microbiome is also called the "second genome" to which many protective and life-supporting functions have been externalized. It orchestrates the crosstalk between our own cells and environmental metagenome. Diet and food choices can modulate gut microbiome species and functional diversity, but the mechanisms by which this occurs are unclear. The nutritional quality of crops, the crop microbiome and the soil microbiome may therefore all be involved.
Ten participants will be randomized in a cross-over design, with each participant drinking three 150 mL vegetable smoothies per day for two separate intervention weeks (HiDi vs LoDi soil origin, randomized 1 : 1). During the first week, smoothies will be prepared with the vegetables derived from microbiome-enriched soil (HiDi) or microbiome-impoverished soil (LoDi). Vegetables, a blender, and detailed instructions to prepare the smoothies on-site will be delivered to the participant. Each participant is asked to keep a diary (in the form of a daily Castor questionnaire), with special attention to dietary habits and intake. Furthermore, before and after this specified diet week, blood and stool samples will be collected. After a washout period of two weeks, participants will be offered identical meals in a crossover design.
Tipo de estudio
Intervencionista
Inscripción (Estimado)
10
Fase
- No aplica
Contactos y Ubicaciones
Esta sección proporciona los datos de contacto de quienes realizan el estudio e información sobre dónde se lleva a cabo este estudio.
Estudio Contacto
- Nombre: Jeroen Maljaars, MD, PhD
- Número de teléfono: +31 71 526 3575
- Correo electrónico: P.W.J.Maljaars@lumc.nl
Copia de seguridad de contactos de estudio
- Nombre: Maarten Tushuizen, MD, PhD
- Número de teléfono: +31 71 526 9111
- Correo electrónico: M.E.Tushuizen@lumc.nl
Ubicaciones de estudio
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South Holland
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Leiden, South Holland, Países Bajos, 2333ZA
- Leids Universitair Medisch Centrum
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Contacto:
- Jeroen Maljaars, MD, PhD
- Número de teléfono: +31 71 526 9111
- Correo electrónico: P.W.J.Maljaars@lumc.nl
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Investigador principal:
- Jeroen Maljaars, MD, PhD
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Criterios de participación
Los investigadores buscan personas que se ajusten a una determinada descripción, denominada criterio de elegibilidad. Algunos ejemplos de estos criterios son el estado de salud general de una persona o tratamientos previos.
Criterio de elegibilidad
Edades elegibles para estudiar
- Adulto
- Adulto Mayor
Acepta Voluntarios Saludables
Sí
Descripción
Inclusion Criteria:
- Aged 18 to 70 years
- Written informed consent
- Inhabitant of Leiden
Exclusion Criteria:
- Any documented causes of chronic disease
- Suspicion of or present excessive alcohol use defined as >2 units/day (>14/week)
- Recent use (<3 months) of antibiotics
- Any known food allergy or restriction, or following a vegan/vegetarian diet
- Use of possible drugs interfering microbiota or recent (< 3 months) changes in dosages
- A psychiatric, addictive or any other disorder that compromises the participants ability to understand the study content and to give written informed consent for participation in the study
Plan de estudios
Esta sección proporciona detalles del plan de estudio, incluido cómo está diseñado el estudio y qué mide el estudio.
¿Cómo está diseñado el estudio?
Detalles de diseño
- Propósito principal: Prevención
- Asignación: Aleatorizado
- Modelo Intervencionista: Asignación cruzada
- Enmascaramiento: Triple
Armas e Intervenciones
Grupo de participantes/brazo |
Intervención / Tratamiento |
|---|---|
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Comparador activo: Crops derived from Low followed by High diversity soil
Participants will be given vegetables, originating from low- or high-microbial diversity soil, to prepare smoothies with.
In this arm participants start with vegetables from a low diversity soil, after a washout period of two weeks they will receive vegetables from a high diversity soil.
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Vegetable smoothie prepared with crops grown in low-microbial diversity soil
Vegetable smoothie prepared with crops grown in high-microbial diversity soil
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Comparador activo: Crops derived from High followed by Low diversity soil
Participants will be given vegetables, originating from low- or high-microbial diversity soil, to prepare smoothies with.
In this arm participants start with vegetables from a high diversity soil, after a washout period of two weeks they will receive vegetables from a low diversity soil.
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Vegetable smoothie prepared with crops grown in low-microbial diversity soil
Vegetable smoothie prepared with crops grown in high-microbial diversity soil
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¿Qué mide el estudio?
Medidas de resultado primarias
Medida de resultado |
Medida Descripción |
Periodo de tiempo |
|---|---|---|
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Feasibility of logistics of the study protocol: Deliveries
Periodo de tiempo: From start enrollment to the end of treatment at 4 weeks
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The percentage of successful deliveries to the participants in the pre-agreed time window.
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From start enrollment to the end of treatment at 4 weeks
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Feasibility of logistics of the study protocol: Preparation of the intervention product
Periodo de tiempo: From the start of the treatment period until the end at 4 weeks
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Using the Daily diary (Castor questionnaire), successful preparation of the intervention product is assessed.
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From the start of the treatment period until the end at 4 weeks
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Feasibility of logistics of the study protocol: Recruitment rate
Periodo de tiempo: From the start of recruitment until the start of the study
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Number of recruited participants per month until the start of the study.
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From the start of recruitment until the start of the study
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Tracing back life microorganisms from the smoothie in stool samples
Periodo de tiempo: Day 1, Day 7, Day 22, and Day 28
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Life bacteria present in the smoothies will be cultured and sequenced to then compare to feces samples of participants
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Day 1, Day 7, Day 22, and Day 28
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Medidas de resultado secundarias
Medida de resultado |
Medida Descripción |
Periodo de tiempo |
|---|---|---|
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Participant compliance to the study protocol
Periodo de tiempo: From start enrolment until the end of treatment at the end of 4 weeks
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Compliance with the protocol will be assessed through the daily lifestyle diary (in the form of a Castor questionnaire).
Which will capture the number of consumed smoothies (≥95.2%) and number of consumed smoothies at the correct time window (≥80%).
As well whether the duration and time of exercise (≥80%), duration and time of nighttime sleeping period (≥80%), timing and content of main meals (≥80%) between the two periods are comparable.
For each of the parameters the compliance threshold is indicated above.
Based on these parameters we will get a percentage of participants that were compliant.
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From start enrolment until the end of treatment at the end of 4 weeks
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Shifts in gut microbiome composition
Periodo de tiempo: Baseline, Day 8, Day 21, and Day 29
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Metagenomics will be performed on feces samples from participants to get an compositional view of the gut microbiome.
Samples will be taken at baseline, Day 8, Day 21, and Day 29
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Baseline, Day 8, Day 21, and Day 29
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Sample completeness
Periodo de tiempo: From start of treatment to the end of treatment at 4 weeks
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percentage of complete sampling sets
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From start of treatment to the end of treatment at 4 weeks
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Asses willingness of participants to create their own intervention product
Periodo de tiempo: From start treatment to end of treatment at 4 weeks
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Using the Daily diary (Castor questionnaire), the participants are required to fill in their opinion on creating their own intervention product on a daily basis.
This is measured on a 10 point scale, with 1 being equal to never wanting to do it again and 10 being equal to enjoying it.
There is also an optional open question where participants can justify their answer.
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From start treatment to end of treatment at 4 weeks
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Differences in phytonutrient levels in serum
Periodo de tiempo: Baseline, Day 8, Day 21, and Day 29
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After confirmation of significant changes in gut microbiome composition, phytonutrient levels will be measured in serum.
Serum will be collected at Baseline, Day 8, Day 21, and Day 29
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Baseline, Day 8, Day 21, and Day 29
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Colaboradores e Investigadores
Aquí es donde encontrará personas y organizaciones involucradas en este estudio.
Patrocinador
Colaboradores
Publicaciones y enlaces útiles
La persona responsable de ingresar información sobre el estudio proporciona voluntariamente estas publicaciones. Estos pueden ser sobre cualquier cosa relacionada con el estudio.
Publicaciones Generales
- David LA, Maurice CF, Carmody RN, Gootenberg DB, Button JE, Wolfe BE, Ling AV, Devlin AS, Varma Y, Fischbach MA, Biddinger SB, Dutton RJ, Turnbaugh PJ. Diet rapidly and reproducibly alters the human gut microbiome. Nature. 2014 Jan 23;505(7484):559-63. doi: 10.1038/nature12820. Epub 2013 Dec 11.
- Albenberg LG, Wu GD. Diet and the intestinal microbiome: associations, functions, and implications for health and disease. Gastroenterology. 2014 May;146(6):1564-72. doi: 10.1053/j.gastro.2014.01.058. Epub 2014 Feb 4.
- Henao-Mejia J, Elinav E, Jin C, Hao L, Mehal WZ, Strowig T, Thaiss CA, Kau AL, Eisenbarth SC, Jurczak MJ, Camporez JP, Shulman GI, Gordon JI, Hoffman HM, Flavell RA. Inflammasome-mediated dysbiosis regulates progression of NAFLD and obesity. Nature. 2012 Feb 1;482(7384):179-85. doi: 10.1038/nature10809.
- Clemente JC, Ursell LK, Parfrey LW, Knight R. The impact of the gut microbiota on human health: an integrative view. Cell. 2012 Mar 16;148(6):1258-70. doi: 10.1016/j.cell.2012.01.035.
- Turnbaugh PJ, Backhed F, Fulton L, Gordon JI. Diet-induced obesity is linked to marked but reversible alterations in the mouse distal gut microbiome. Cell Host Microbe. 2008 Apr 17;3(4):213-23. doi: 10.1016/j.chom.2008.02.015.
- Julious, S.A. (2005), Sample size of 12 per group rule of thumb for a pilot study. Pharmaceut. Statist., 4: 287-291. https://doi.org/10.1002/pst.185
- Sanna S, van Zuydam NR, Mahajan A, Kurilshikov A, Vich Vila A, Vosa U, Mujagic Z, Masclee AAM, Jonkers DMAE, Oosting M, Joosten LAB, Netea MG, Franke L, Zhernakova A, Fu J, Wijmenga C, McCarthy MI. Causal relationships among the gut microbiome, short-chain fatty acids and metabolic diseases. Nat Genet. 2019 Apr;51(4):600-605. doi: 10.1038/s41588-019-0350-x. Epub 2019 Feb 18.
- Hirt H. Healthy soils for healthy plants for healthy humans: How beneficial microbes in the soil, food and gut are interconnected and how agriculture can contribute to human health. EMBO Rep. 2020 Aug 5;21(8):e51069. doi: 10.15252/embr.202051069. Epub 2020 Jul 31.
- Blum WEH, Zechmeister-Boltenstern S, Keiblinger KM. Does Soil Contribute to the Human Gut Microbiome? Microorganisms. 2019 Aug 23;7(9):287. doi: 10.3390/microorganisms7090287.
- Fierer N. Embracing the unknown: disentangling the complexities of the soil microbiome. Nat Rev Microbiol. 2017 Oct;15(10):579-590. doi: 10.1038/nrmicro.2017.87. Epub 2017 Aug 21.
- Leeming ER, Louca P, Gibson R, Menni C, Spector TD, Le Roy CI. The complexities of the diet-microbiome relationship: advances and perspectives. Genome Med. 2021 Jan 20;13(1):10. doi: 10.1186/s13073-020-00813-7.
- Johnson AJ, Zheng JJ, Kang JW, Saboe A, Knights D, Zivkovic AM. A Guide to Diet-Microbiome Study Design. Front Nutr. 2020 Jun 12;7:79. doi: 10.3389/fnut.2020.00079. eCollection 2020.
Fechas de registro del estudio
Estas fechas rastrean el progreso del registro del estudio y los envíos de resultados resumidos a ClinicalTrials.gov. Los registros del estudio y los resultados informados son revisados por la Biblioteca Nacional de Medicina (NLM) para asegurarse de que cumplan con los estándares de control de calidad específicos antes de publicarlos en el sitio web público.
Fechas importantes del estudio
Inicio del estudio (Estimado)
1 de agosto de 2026
Finalización primaria (Estimado)
1 de septiembre de 2026
Finalización del estudio (Estimado)
1 de septiembre de 2026
Fechas de registro del estudio
Enviado por primera vez
16 de julio de 2026
Primero enviado que cumplió con los criterios de control de calidad
29 de julio de 2026
Publicado por primera vez (Actual)
3 de agosto de 2026
Actualizaciones de registros de estudio
Última actualización publicada (Actual)
3 de agosto de 2026
Última actualización enviada que cumplió con los criterios de control de calidad
29 de julio de 2026
Última verificación
1 de julio de 2026
Más información
Términos relacionados con este estudio
Palabras clave
Otros números de identificación del estudio
- NL-010026
Plan de datos de participantes individuales (IPD)
¿Planea compartir datos de participantes individuales (IPD)?
SÍ
Descripción del plan IPD
Metagenomic sequencing data from feces and pythonutrient levels in serum (if available)
Marco de tiempo para compartir IPD
Beginning 1 month after publication with no end date
Tipo de información de apoyo para compartir IPD
- PROTOCOLO DE ESTUDIO
- CÓDIGO_ANALÍTICO
Información sobre medicamentos y dispositivos, documentos del estudio
Estudia un producto farmacéutico regulado por la FDA de EE. UU.
No
Estudia un producto de dispositivo regulado por la FDA de EE. UU.
No
Esta información se obtuvo directamente del sitio web clinicaltrials.gov sin cambios. Si tiene alguna solicitud para cambiar, eliminar o actualizar los detalles de su estudio, comuníquese con register@clinicaltrials.gov. Tan pronto como se implemente un cambio en clinicaltrials.gov, también se actualizará automáticamente en nuestro sitio web. .