Trial Outcomes & Findings for The Effect of Concord Grape Polyphenol-soy Protein Isolate Complex (GP-SPI) on Gut Microbiota (NCT NCT04018066)

NCT ID: NCT04018066

Last Updated: 2025-12-23

Results Overview

Evaluate the effect of nutritional supplementation with GP-SPI on gut microbiota composition by 16S rRNA amplicon sequencing and analysis

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

34 participants

Primary outcome timeframe

16S rRNA amplicon sequencing will be performed on samples collected at baseline (before intervention, day -5), after 5 days of SPI supplementation (day 0), and after 10 days of GP-SPI supplementation (day 10). Total time frame is 17 days.

Results posted on

2025-12-23

Participant Flow

34 participants were enrolled in the study based on inclusion/exclusion criteria. 4 participants withdrawn from the study, due to the following reasons: 3 started taking medications and 1 had scheduling conflicts. Of the remaining 30 participants that completed the study, 3 were excluded due to protocol deviations.

Participant milestones

Participant milestones
Measure
GP-SPI Intervention
Each participant consumed 20 g of soy protein isolate (SPI) twice per day for 5 days. After a one day break, participants then consumed 20 g of GP-SPI taken twice per day for 10 days. During the entire 17 day study period, participants abstained from an extensive list of PAC-rich foods. GP-SPI: grape polyphenol-soy protein isolate complex (GP-SPI)
Overall Study
STARTED
34
Overall Study
COMPLETED
30
Overall Study
NOT COMPLETED
4

Reasons for withdrawal

Reasons for withdrawal
Measure
GP-SPI Intervention
Each participant consumed 20 g of soy protein isolate (SPI) twice per day for 5 days. After a one day break, participants then consumed 20 g of GP-SPI taken twice per day for 10 days. During the entire 17 day study period, participants abstained from an extensive list of PAC-rich foods. GP-SPI: grape polyphenol-soy protein isolate complex (GP-SPI)
Overall Study
participants started taking medications during the study period
3
Overall Study
participant dropped out due to schedule conflicts.
1

Baseline Characteristics

The Effect of Concord Grape Polyphenol-soy Protein Isolate Complex (GP-SPI) on Gut Microbiota

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
GP-SPI Intervention
n=27 Participants
Each participant consumed 20 g of soy protein isolate (SPI) twice per day for 5 days. After a one day break, participants then consumed 20 g of GP-SPI taken twice per day for 10 days. During the entire 17 day study period, participants abstained from an extensive list of PAC-rich foods. GP-SPI: grape polyphenol-soy protein isolate complex (GP-SPI)
Age, Customized
Age
21.7 years
STANDARD_DEVIATION 3.5 • n=68 Participants
Sex: Female, Male
Female
16 Participants
n=68 Participants
Sex: Female, Male
Male
11 Participants
n=68 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
4 Participants
n=68 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
22 Participants
n=68 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
1 Participants
n=68 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=68 Participants
Race (NIH/OMB)
Asian
15 Participants
n=68 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=68 Participants
Race (NIH/OMB)
Black or African American
3 Participants
n=68 Participants
Race (NIH/OMB)
White
5 Participants
n=68 Participants
Race (NIH/OMB)
More than one race
1 Participants
n=68 Participants
Race (NIH/OMB)
Unknown or Not Reported
3 Participants
n=68 Participants
Region of Enrollment
United States
27 participants
n=68 Participants
Glucose
88.78 mg/dL
STANDARD_DEVIATION 6.25 • n=68 Participants
Blood urea nitrogen
12.81 mg/dL
STANDARD_DEVIATION 4.3 • n=68 Participants
Creatine
0.76 mg/dL
STANDARD_DEVIATION 0.19 • n=68 Participants
Calcium
9.82 mg/dL
STANDARD_DEVIATION 0.38 • n=68 Participants
Sodium
142.7 mmol/L
STANDARD_DEVIATION 2.28 • n=68 Participants
Potassium
4.83 mmol/L
STANDARD_DEVIATION 0.34 • n=68 Participants
Chloride
103.4 mmol/L
STANDARD_DEVIATION 2.8 • n=68 Participants
Total carbon dioxide
26.04 mmol/L
STANDARD_DEVIATION 1.72 • n=68 Participants
Anion gap
13.26 meq/L
STANDARD_DEVIATION 2.19 • n=68 Participants
Protein
7.38 g/dL
STANDARD_DEVIATION 0.37 • n=68 Participants
Albumin
4.83 g/dL
STANDARD_DEVIATION 0.34 • n=68 Participants
Bilirubin total
0.54 mg/dL
STANDARD_DEVIATION 0.26 • n=68 Participants
Alkaline phosphatase
68.56 IU/L
STANDARD_DEVIATION 15.19 • n=68 Participants
Alkaline transaminase
21.26 IU/L
STANDARD_DEVIATION 5.4 • n=68 Participants
Alanine transaminase
16.89 IU/L
STANDARD_DEVIATION 7.44 • n=68 Participants

PRIMARY outcome

Timeframe: 16S rRNA amplicon sequencing will be performed on samples collected at baseline (before intervention, day -5), after 5 days of SPI supplementation (day 0), and after 10 days of GP-SPI supplementation (day 10). Total time frame is 17 days.

Population: All 27 participant samples were analyzed.

Evaluate the effect of nutritional supplementation with GP-SPI on gut microbiota composition by 16S rRNA amplicon sequencing and analysis

Outcome measures

Outcome measures
Measure
GP-SPI Intervention
n=27 Participants
Each participant consumed 20 g of soy protein isolate (SPI) twice per day for 5 days. After a one day break, participants then consumed 20 g of GP-SPI taken twice per day for 10 days. During the entire 17 day study period, participants abstained from an extensive list of PAC-rich foods. GP-SPI: grape polyphenol-soy protein isolate complex (GP-SPI)
Gut Microbiota Composition
Actinobacteria (day 10), % relative abundance
8.1 percentage of bacterial phyla
Standard Deviation 5.6
Gut Microbiota Composition
Proteobacteria (day 10), % relative abundance
4.1 percentage of bacterial phyla
Standard Deviation 2.6
Gut Microbiota Composition
Tenericutes (day 10), % relative abundance
0.03 percentage of bacterial phyla
Standard Deviation 0.1
Gut Microbiota Composition
Bacteroidetes (day -5), % relative abundance
30 percentage of bacterial phyla
Standard Deviation 9.7
Gut Microbiota Composition
Verrucomicrobia (day -5), % relative abundance
0.04 percentage of bacterial phyla
Standard Deviation 0.1
Gut Microbiota Composition
Verrucomicrobia (day 10), % relative abundance
0.07 percentage of bacterial phyla
Standard Deviation 0.13
Gut Microbiota Composition
Actinobacteria (day -5), % relative abundance
7.3 percentage of bacterial phyla
Standard Deviation 5.3
Gut Microbiota Composition
Proteobacteria (day -5), % relative abundance
4 percentage of bacterial phyla
Standard Deviation 2.9
Gut Microbiota Composition
Tenericutes (day -5), % relative abundance
0.4 percentage of bacterial phyla
Standard Deviation 0.1
Gut Microbiota Composition
Firmicutes (day 0), % relative abundance
59.3 percentage of bacterial phyla
Standard Deviation 6.9
Gut Microbiota Composition
Bacteroidetes (day 0), % relative abundance
31.1 percentage of bacterial phyla
Standard Deviation 8.06
Gut Microbiota Composition
Verrucomicrobia (day 0), % relative abundance
0.04 percentage of bacterial phyla
Standard Deviation 0.09
Gut Microbiota Composition
Actinobacteria (day 0), % relative abundance
5.29 percentage of bacterial phyla
Standard Deviation 3.7
Gut Microbiota Composition
Proteobacteria (day 0), % relative abundance
3.66 percentage of bacterial phyla
Standard Deviation 2.66
Gut Microbiota Composition
Tenericutes (day 0), % relative abundance
0.009 percentage of bacterial phyla
Standard Deviation 0.05
Gut Microbiota Composition
Firmicutes (day 10), % relative abundance
54.3 percentage of bacterial phyla
Standard Deviation 8.9
Gut Microbiota Composition
Bacteroidetes (day 10), % relative abundance
33.44 percentage of bacterial phyla
Standard Deviation 10.4
Gut Microbiota Composition
Firmicutes (day -5), % relative abundance
58 percentage of bacterial phyla
Standard Deviation 10

SECONDARY outcome

Timeframe: Samples will be analyzed within one week of blood collection

Population: CMP data was measured for all 27 participants

Evaluate the effect of GP-SPI on kidney and liver health/function via CMP blood tests ALP, AST, ALT

Outcome measures

Outcome measures
Measure
GP-SPI Intervention
n=27 Participants
Each participant consumed 20 g of soy protein isolate (SPI) twice per day for 5 days. After a one day break, participants then consumed 20 g of GP-SPI taken twice per day for 10 days. During the entire 17 day study period, participants abstained from an extensive list of PAC-rich foods. GP-SPI: grape polyphenol-soy protein isolate complex (GP-SPI)
Comprehensive Metabolic Panel (CMP) Blood Test (ALP, AST, ALT)
Alkaline phosphatase
70.7 IU/L
Standard Deviation 16.79
Comprehensive Metabolic Panel (CMP) Blood Test (ALP, AST, ALT)
Aspartate transaminase (IU/L)
21.41 IU/L
Standard Deviation 5.6
Comprehensive Metabolic Panel (CMP) Blood Test (ALP, AST, ALT)
Alkaline transaminase
17.52 IU/L
Standard Deviation 8.59

SECONDARY outcome

Timeframe: Samples will be analyzed within one week of blood collection

Population: CMP data was measured for all 27 participants

Evaluate the effect of GP-SPI on kidney and liver health/function via CMP blood tests Measure glucose, blood urea nitrogen, creatine, calcium, bilirubin total

Outcome measures

Outcome measures
Measure
GP-SPI Intervention
n=27 Participants
Each participant consumed 20 g of soy protein isolate (SPI) twice per day for 5 days. After a one day break, participants then consumed 20 g of GP-SPI taken twice per day for 10 days. During the entire 17 day study period, participants abstained from an extensive list of PAC-rich foods. GP-SPI: grape polyphenol-soy protein isolate complex (GP-SPI)
Comprehensive Metabolic Panel (CMP) Blood Test (Glucose, Blood Urea Nitrogen, Creatine, Calcium, Bilirubin Total)
Glucose
85.96 mg/dL
Standard Deviation 6.79
Comprehensive Metabolic Panel (CMP) Blood Test (Glucose, Blood Urea Nitrogen, Creatine, Calcium, Bilirubin Total)
Blood urea nitrogen
14.81 mg/dL
Standard Deviation 3.28
Comprehensive Metabolic Panel (CMP) Blood Test (Glucose, Blood Urea Nitrogen, Creatine, Calcium, Bilirubin Total)
Creatine
0.76 mg/dL
Standard Deviation 0.18
Comprehensive Metabolic Panel (CMP) Blood Test (Glucose, Blood Urea Nitrogen, Creatine, Calcium, Bilirubin Total)
Calcium
9.64 mg/dL
Standard Deviation 0.53
Comprehensive Metabolic Panel (CMP) Blood Test (Glucose, Blood Urea Nitrogen, Creatine, Calcium, Bilirubin Total)
Bilirubin total
0.54 mg/dL
Standard Deviation 0.25

SECONDARY outcome

Timeframe: Samples will be analyzed within one week of blood collection

Population: CMP data was measured for all 27 participants

The Anion gap was measured for all 27 participants. The anion gap is a calculation of the difference between the amounts of some negatively charged electrolytes (such as chloride and bicarbonate) and the amount of positively charged electrolytes (such as sodium) in blood. The anion gap reveals whether blood has an imbalance of electrolytes, i.e., blood is too acidic or too basic.

Outcome measures

Outcome measures
Measure
GP-SPI Intervention
n=27 Participants
Each participant consumed 20 g of soy protein isolate (SPI) twice per day for 5 days. After a one day break, participants then consumed 20 g of GP-SPI taken twice per day for 10 days. During the entire 17 day study period, participants abstained from an extensive list of PAC-rich foods. GP-SPI: grape polyphenol-soy protein isolate complex (GP-SPI)
Comprehensive Metabolic Panel Blood Test (Anion Gap)
14.41 meq/L
Standard Deviation 1.9

SECONDARY outcome

Timeframe: Samples will be analyzed within one week of blood collection

Population: CMP data was measured for all 27 participants

For all 27 participants CMP measured four electrolytes: sodium, potassium, chloride, total carbon dioxide. Electrolytes are minerals that carry an electric charge when they are dissolved in a liquid. These electrolytes in blood control nerve and muscle function and maintain the acid-base balance (pH balance) of blood and water balance. Sodium: Most sodium comes from food, and kidneys help regulate body's sodium levels. Potassium: Potassium comes from food and is present in all tissues of body. Bicarbonate: Bicarbonate indicates the amount of carbon dioxide (CO₂) in blood. Chloride: Chloride functions along with sodium, potassium and bicarbonate to control many processes in the body.

Outcome measures

Outcome measures
Measure
GP-SPI Intervention
n=27 Participants
Each participant consumed 20 g of soy protein isolate (SPI) twice per day for 5 days. After a one day break, participants then consumed 20 g of GP-SPI taken twice per day for 10 days. During the entire 17 day study period, participants abstained from an extensive list of PAC-rich foods. GP-SPI: grape polyphenol-soy protein isolate complex (GP-SPI)
Comprehensive Metabolic Panel (CMP) Blood Test (Sodium, Potassium, Chloride, Total Carbon Dioxide)
Sodium
142.2 mmol/L
Standard Deviation 2.33
Comprehensive Metabolic Panel (CMP) Blood Test (Sodium, Potassium, Chloride, Total Carbon Dioxide)
Potassium
4.57 mmol/L
Standard Deviation 0.43
Comprehensive Metabolic Panel (CMP) Blood Test (Sodium, Potassium, Chloride, Total Carbon Dioxide)
Chloride
102.3 mmol/L
Standard Deviation 1.7
Comprehensive Metabolic Panel (CMP) Blood Test (Sodium, Potassium, Chloride, Total Carbon Dioxide)
Total carbon dioxide
25.51 mmol/L
Standard Deviation 1.69

SECONDARY outcome

Timeframe: Samples will be analyzed within one week of blood collection

Population: CMP data was measured for all 27 participants

Evaluate the effect of GP-SPI on kidney and liver health/function via CMP blood tests

Outcome measures

Outcome measures
Measure
GP-SPI Intervention
n=27 Participants
Each participant consumed 20 g of soy protein isolate (SPI) twice per day for 5 days. After a one day break, participants then consumed 20 g of GP-SPI taken twice per day for 10 days. During the entire 17 day study period, participants abstained from an extensive list of PAC-rich foods. GP-SPI: grape polyphenol-soy protein isolate complex (GP-SPI)
Comprehensive Metabolic Panel (CMP) Blood Test (Protein, Albumin)
Protein
7.37 g/dL
Standard Deviation 0.33
Comprehensive Metabolic Panel (CMP) Blood Test (Protein, Albumin)
Albumin
4.87 g/dL
Standard Deviation 0.29

SECONDARY outcome

Timeframe: De-identified samples will be processed and analyzed after all subjects complete the study and within 1 year.

Collect fecal, blood, and urine samples for a microbiome-wide association study (MWAS)

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Data will be deposited no later than within 1 year of the completion of the funded project period for the parent award or upon acceptance of the data for publication, or public disclosure of a submitted patent application

Enter de-identified study results into microbiome and metabolome nationwide data sharing database

Outcome measures

Outcome data not reported

Adverse Events

GP-SPI Intervention

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Diana Roopchand, Study Investigator

Rutgers, The State University of New Jersey

Phone: 8489320248

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place