Meat-based Versus Pesco-vegetarian Diet and Colorectal Cancer

Summary

Colorectal cancer (CRC) is strongly affected by diet, with red and processed meat increasing risk. To understand the role of microbiome in this phenomenon and to identify specific microbiome/metabolomics profiles associated with CRC risk, will be studied: 1) healthy volunteers fed for 3 months with: a high-CRC risk diet (meat-based MBD), a normalized CRC risk diet (MBD plus alpha-tocopherol, MBD-T), a low-CRC risk diet (pesco-vegetarian, PVD). At the beginning and at the end of the intervention, gut microbiome profiles (metagenomics and metabolomics), and CRC biomarkers (genotoxicity, cytotoxicity, peroxidation in faecal water; lipid/glycemic indexes, inflammatory cytokines, oxidative stress), 2) Colon carcinogenesis: the same diets will be fed (3 months) to carcinogen-induced rats or to Pirc rats, mutated in Apc, the key gene in CRC; faecal microbiome profiles, will be correlated to carcinogenesis measuring preneoplastic lesions, colon tumours, and faecal and blood CRC biomarkers as in humans; 3) To further elucidate the mechanisms underlying the effect of different microbiomes in determining CRC risk, faeces from rats fed the experimental diets will be transplanted into carcinogen-induced germ-free rats, measuring how microbiome changes correlate with metabolome and disease outcomes. The results will provide fundamental insight in the role of microbiome in determining the effect of the diet, in particular red/processed meat intake, on CRC risk

Conditions

• Nutrition Aspect of Cancer
• Diet Modification
• Cancer of Colon

Interventions

BEHAVIORAL

Meat-based diet

Diet including 4 servings per week of red meat (1 serving = 150 g), 3 servings per week of processed meat (1 serving = 50 g), and 1 servings per week of poultry (1 serving = 150 g), for a total amount of 900 g per week of meat.

DIETARY_SUPPLEMENT

Meat-based diet supplemented with alpha-tocopherol (MBD-T)

Dietary intervention like the MBD with supplementation of alpha-tocopherol at a dosage of 100 mg/die. Available evidence suggests that alpha-tocopherol may help prevent colon cancer by decreasing the formation of mutagens arising from the oxidation of faecal lipids, by decreasing oxidative stress in the epithelial cells of the colon and by molecular mechanisms that influence cell death, cell cycle and transcriptional events (Pierre 2013, Bastide 2016, Bastide 2017, Diallo 2016). It is important to note that 200 mg/day of tocopherol was administered to 20,000 women for 10 years without side effects (Lee et al.,2005).

BEHAVIORAL

Pesco-vegetarian diet

Diet excluding fresh and processed meat, poultry but including 3 servings per week of any type of fish, excluding shellfish (1 serving = 150 g), for a total amount of 450 g per week. Diet will contain other sources of proteins (e.g. eggs, dairy, legumes/beans). There is suggestive evidence that fish and vegetable consumption has protective effects against CRC (Vieira et al., 2017).

Sponsors & Collaborators

• Azienda Ospedaliero-Universitaria Careggi

  lead OTHER

Principal Investigators

• Alessandro Casini, MD · University of Florence

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

50 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2019-06-01

Primary Completion

2019-12-31

Completion

2021-04-30

Countries

• Italy

Study Locations