Effects of Consuming Red Meat on the Gut Microbiota in Young Adults

Not Applicable

Completed

• Conditions: Diet Modification
• Interventions: Other: Controlled processed red meat diet; Other: Controlled Lacto-ovo vegetarian diet; Other: Controlled Unprocessed red meat diet

• Registration Number: NCT03885544
• Lead Sponsor: Purdue University

Brief Summary

The purpose of this study is to assess the impact of consuming unprocessed and processed red meat on gut microbiota in young healthy adults in a cross-over, randomized controlled feeding trial.

Detailed Description

The purpose of this study is to assess the impact of consuming processed and unprocessed red meat on gut microbiota in young healthy adults in a cross-over, randomized controlled feeding trial. The hypothesis is that compared to consuming a meat-free lacto-ovo vegetarian (LOV) diet, (1) consuming the LOV diet with unprocessed red meat or processed red meat (omnivorous diet) will shift the gut microbiota with greater abundance of the bacteria Lactobacillus and other SCFA producers such as Clostridium XIVa, and no increase of pathogenic bacteria. The concentration of SCFA in stools will also increase in subjects consuming the unprocessed red meat diet. Compared to consuming a meat-free lacto-ovo vegetarian (LOV) diet, (2) consuming the LOV diet with processed beef and pork (omnivorous diet) will result in a comparable shift in gut microbiota as unprocessed red meat, except for greater abundance of taxa Erysipelotrichaceae and lower abundance of Lachnospiraceae.

Study Timeline

• Study Start: 2018-01-09
• Study First Submitted: 2018-03-27
• Study First Submitted QC: 2019-03-19
• Study First Posted: 2019-03-21
• Primary Completion: 2020-03-23
• Study Completion: 2020-03-23
• Status Verified: 2020-07
• Last Update Submitted: 2020-07-10
• Last Update Posted: 2020-07-14

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 23

Inclusion Criteria

• male or female,
• 20-35 years old,
• BMI 20.0-29.9 kg/m2,
• fasting serum total cholesterol <240 mg/dL, low-density lipoprotein cholesterol <160 mg/dL, triglycerides <400 mg/dL, and glucose <110 mg/dL;
• systolic/diastolic blood pressure <140/90 mmHg;
• body weight stable for 3 months prior (±3 kg); stable physical activity regimen 3 months prior;
• medication use stable for 6 months prior and not using medications or supplements known to impact gut function;
• on-smoking; not drinking more than 2 alcoholic drinks per day;
• non-diabetic,
• no history of gastrointestinal disorders, surgeries or cancers;
• non-pregnant and not lactating.
• Participants must be willing and able to consume the prescribed diets (lacto-ovo vegetarian and omnivorous).

Exclusion Criteria

• male or female < 20->35 years old,
• BMI <20.0- >29.9 kg/m2,
• fasting serum total cholesterol >240 mg/dL, low-density lipoprotein cholesterol >160 mg/dL, triglycerides >400 mg/dL, and glucose >110 mg/dL;
• systolic/diastolic blood pressure >140/90 mmHg;
• body weight stable for <3 months prior (±3 kg);
• stable physical activity regimen < 3 months prior;
• medication use unstable for 6 months prior and using medications or supplements known to impact gut function;
• smoking;
• drinking more than 2 alcoholic drinks per day;
• diabetic,
• history of gastrointestinal disorders, GI surgeries or GI cancers;
• pregnant or lactating.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Controlled processed red meat diet	Controlled processed red meat diet	Subjects will be randomized and assigned into an intervention to consume the controlled lacto-ovo vegetarian diet with processed red meat for 3 weeks.
Controlled lacto-ovo vegetarian diet	Controlled Lacto-ovo vegetarian diet	Subjects will be randomized and assigned into an intervention to consume the controlled lacto-ovo vegetarian diet without red meat for 3 weeks.
Controlled unprocessed red meat diet	Controlled Unprocessed red meat diet	Subjects will be randomized and assigned into an intervention to consume the controlled lacto-ovo vegetarian diet with unprocessed red meat for 3 weeks.

Primary Outcome Measures

Name	Time	Method
Changes in gut microbiota composition	21 months. Stool samples will be obtained at the end of study weeks 3, 4, 7, 8, 11, 12, 15, 16, 19, 20, 23, and 24, which correspond to before and during the last 2 weeks of the three 3-wk controlled diet periods.	The hypothesis is that compared to consuming a meat-free lacto-ovo vegetarian (LOV) diet, (1) consuming the LOV diet with unprocessed red meat or processed red meat (omnivorous diet) will shift the gut microbiota with greater abundance of the bacteria Lactobacillus and other SCFA producers such as Clostridium XIVa, and no increase of pathogenic bacteria. Compared to consuming a meat-free lacto-ovo vegetarian (LOV) diet, (2) consuming the LOV diet with processed beef and pork (omnivorous diet) will result in a comparable shift in gut microbiota as unprocessed red meat, except for greater abundance of taxa Erysipelotrichaceae and lower abundance of Lachnospiraceae.
Concentrations of short chain fatty acids (SCFA)	21 months. Stool samples will be obtained at the end of study weeks 3, 4, 7, 8, 11, 12, 15, 16, 19, 20, 23, and 24, which correspond to before and during the last 2 weeks of the three 3-wk controlled diet periods.	The hypothesis is that compared to consuming a meat-free lacto-ovo vegetarian (LOV) diet, the concentration of SCFA in stools will also increase in subjects consuming the unprocessed or processed red meat diet.

Trial Locations

Locations (1)

Purdue University; 🇺🇸 West Lafayette, Indiana, United States