Influence of peanut consumption on the gut microbiome: A randomized clinical trial
Presenting author: Sang Nguyen, Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine
Co-authored by:
- Thi Du Chi Tran, Vietnam Colorectal Cancer and Polyps Research, Vinmec Healthcare System
- Thi Mo Tran, Vietnam Colorectal Cancer and Polyps Research, Vinmec Healthcare System
- Cong Wang, Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine
- Jie Wu, Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine
- Qiuyin Cai, Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine
- Fei Ye, Department of Biostatistics, Vanderbilt University Medical Center
- Xiao-Ou Shu, Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine
Abstract:
Background: Peanut consumption has been associated with cardiometabolic health, potentially through its influence on the gut microbiome. To test this hypothesis, we conducted a randomized clinical trial in Vietnam to evaluate whether peanut consumption alters gut microbiome communities.
Methods: One hundred individuals were included in this trial and randomly assigned to two groups: peanut intervention and control group. Fifty-one participants were provided with and asked to consume 50 grams of peanuts daily for 16 weeks while 49 controls maintained their usual dietary intake for 16 weeks. After excluding ten non-compliant participants, 41 participants (age: 54.8±8.5; 22 male and 19 female) from the peanut intervention group and 49 (age: 55.7±8.9; 23 male and 26 female) from the control group were included in the analysis. Stool samples were collected at baseline and on the last day of the 16-week follow-up using FOBT cards. DNA samples extracted by the DNeasy PowerSoil Kit and gut microbiota composition were measured by shotgun metagenomic sequencing. The gut microbiome was categorized into 50 species-level sub-communities using Latent Dirichlet Allocation. Associations of gut microbial diversity, sub-community structure, taxa abundance, and microbial metabolic pathways with peanut consumption were evaluated via mixed-effect linear regression models with adjustment for age, sex, and other legume intake. In addition, we examined associations of peanut consumption with overall species/ metabolic pathway stability (intra-individual difference) and dissimilarity (inter-individual difference), as well as the stability and dissimilarity of individual microbial taxa and metabolic pathways using the beta regression analysis.
Results: No significant changes were found in α-diversities (species and metabolic pathway Shannon indexes) within and between the intervention and control groups before and post-intervention. Similarly, peanut intervention was not associated with overall stability and dissimilarity of gut microbial species and metabolic pathways (p>0.05). However, peanut intervention was significantly associated with the enrichment of three species-level sub-communities, with Prevotella stercorea (18.6%), Prevotella copri (70.3%), and Prevotella copri (22.2%) being the top representative taxa (p<0.05). The log2 fold-changes (SE) were 2.63 (1.25), 3.65 (1.66), and 2.43 (1.20), respectively, comparing the intervention group with the control group. Peanut intervention was significantly associated with the increased stability of 16 species belonging to members of the family Lachnospiraceae, Oscillospiraceae, and Ruminococcaceae as well as a microbial metabolic pathway involved in Nitrate reduction V (p<0.05; FDR <0.2). Moreover, peanut intervention was significantly associated with a reduced dissimilarity of the genus Lachnospira and 26 microbial metabolic pathways such as superpathways of fatty acids biosynthesis, fatty acid β-oxidation I, and fatty acid β-oxidation IV (p<0.05; FDR <0.2).
Conclusion: This trial showed that a 16-week peanut intervention leads to an enrichment of species-level sub-communities, with a dominant representation of Prevotella species, as well as the short-term stability of bacteria known to play an important role in human health.