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Protein-Distinct Macronutrient-Equivalent Diet 1

Effect of a Pulse-based USDA-diet on Gut Microbial Metabolites and Biomarkers of Healthspan: A 18-week Randomized Controlled Crossover Feeding Study in Older Adults

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05577858
Acronym
PRODMED1
Enrollment
76
Registered
2022-10-13
Start date
2022-11-15
Completion date
2023-12-20
Last updated
2026-09-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Lifestyle

Brief summary

Plant-based diets are naturally low in Methionine (Met), and also low in precursor molecules (e.g L-carnitine, choline, betaine, etc.) producing microbiota-mediated proatherogenic TMAO. Among plant proteins, pulses are rich in micronutrients, and dietary fibers, making them ideal for microbiome-stimulating, nutrient-dense, healthful dietary patterns. However, daily pulse intake remains low at 8% in America despite recommendations by DGA, a resource to guide health promotion across communities. A significant body of preclinical data, waiting to be translated to humans, suggests that dietary Met restriction can trigger beneficial metabolic and anti-inflammatory adaptations leading to improved chronic health and longevity. The central hypothesis is that a pulse-protein-based healthy diet can be simultaneously equivalent to omnivorous diets in protein content and yet naturally lower in Met and TMAO to improve glycemic control, body composition, and immunometabolic flexibility to reduce the risk of chronic diseases and improve healthspan. The goal is to systematically elucidate for the first time the effects of a lacto-vegetarian feeding pattern with pulses as the primary protein source on a comprehensive panel of \ 500 traditional and next-generation biomarkers of health, and assess the role of the gut microbiota in mediating such effects. We also aim to interrogate the potential concern about the lower bioavailability of non-heme iron from pulses.

Interventions

OTHERMeat based

Omnivorous diet following dietary guidelines

OTHERPulse based

Lacto-ovo-vegetarian pulse-based diet following dietary guidelines

Sponsors

South Dakota State University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Caregiver, Outcomes Assessor)

Masking description

Blinding will be implemented to the extent possible. A researcher, unaware of the study goals and not involved with downstream data analyses will use a 1:1 block randomization to allocate participants to the diets in the first arm. Food service personnel (care provider) will not be aware of study goals and allocations. Metabolomic assays will be run in a blinded manner.

Eligibility

Sex/Gender
ALL
Age
60 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Generally good health status based on routine physical in the past 12 months, current healthy status * Normal HbA1C, not underweight * Age 60 years or more, all races, both sexes and all education level * Do not have any special dietary requirements and willing to consume vegetarian diet * Willingness to comply with the study protocol, including on-site meal consumption and sample/data collection.

Exclusion criteria

* Probiotic, long-term antibiotic, and tobacco/drug/alcohol use * Not on any special diet within 3 months of recruitment * Impaired kidney functions * Active history of cancer, diabetes, heart, liver, and kidney diseases * Major gastrointestinal disorders in the past 3 months * History of heart attacks or stroke * Unable to meet in-person visit requirements for dining, picking up meals, and tests * Any mental health condition that would affect the ability to provide written informed consent. * If they had not had a routine health checkup during the 12 months prior to recruitment. * If they were unwilling to abstain from taking certain nutritional supplements, alcohol, or non-study foods during the study period.

Design outcomes

Primary

MeasureTime frameDescription
Ferritin16 weeksMicroplate assay
Concentration of TMAO in blood16 weeksUsing LC/MS based method method
Fasting blood glucose concentration in blood16 weeksUsing Glucometer

Secondary

MeasureTime frameDescription
Body weight in kilograms16 weeksMeasurement
Concentration of CRP in blood16 weeksMicroplate assay
Gut microbiota composition and diversity16 weeks16S rRNA gene sequencing
Fat and lean mass in kg using DXA for body composition measures16 weeksDEXA scan
Concentration of sulfur containing amino acids in blood16 weeksLC/MS based method
Digestible indispensable amino acid score using different amino acid concentrations16 weeksUsing standard equation
Concentration of IGF-1 in blood16 weeksUsing Microplate assay kit
Concentration of IGF-BP3 in blood16 weeksUsing Microplate assay kit
Concentration of Fasting insulin in blood16 weeksUsing Microplate assay kit
Peak heights of several complex lipids panel using metabolomics technique16 weeksLC/MS based assay
Concentration Short-chain fatty acid panel in stool16 weeksusing LC/MS based assay
Peak heights of several Biogenic amines panel using metabolomics technique16 weeksusing LC/MS based assay
Muscle strength using Isokinetic muscle testing16 weeksBiodex ergometer
Balance assessment using balance16 weeksMechanography
Grip force per kg mass16 weeksusing Dynamometer
Blood pressure in mm Hg16 weeksUpper arm cuff

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORMoul Dey, Ph.D.

South Dakota State University

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 18, 2026