Tiffany L. Weir

While polyphenol consumption is often associated with an increased abundance of beneficial microbes and decreased opportunistic pathogens, these relationships are not completely described for polyphenols consumed via habitual diet, including culinary herb and spice consumption. This analysis of the International Cohort on Lifestyle Determinants of Health (INCLD Health) cohort uses a dietary questionnaire and 16s microbiome data to examine relationships between habitual polyphenol consumption and gut microbiota in healthy adults (n = 96). In this exploratory analysis, microbial taxa, but not diversity measures, differed by levels of dietary polyphenol consumption. Taxa identified as exploratory biomarkers of daily polyphenol consumption (mg/day) included Lactobacillus, Bacteroides, Enterococcus, Eubacterium ventriosum group, Ruminococcus torques group, and Sutterella. Taxa identified as exploratory biomarkers of the frequency of polyphenol-weighted herb and spice use included Lachnospiraceae UCG-001, Lachnospiraceae UCG-004, Methanobrevibacter, Lachnoclostridium, and Lachnotalea. Several of the differentiating taxa carry out activities important for human health, although out of these taxa, those with previously described pro-inflammatory qualities in certain contexts displayed inverse relationships with polyphenol consumption. Our results suggest that higher quantities of habitual polyphenol consumption may support an intestinal environment where opportunistic and pro-inflammatory bacteria are represented in a lower relative abundance compared to those with less potentially virulent qualities.

Malnutrition and food insecurity remain high in rural Rwanda, where residents consume a low-diversity diet provided through subsistence farming. Agricultural interventions using kitchen gardens may improve diet diversity in some populations. However, little is known about their efficacy when developed using community-based participatory research in combination with nutrition education focused on the empowerment of women. The objective of this study was to develop and implement a kitchen garden and nutrition education intervention using a community-engaged model and examine its impact on household diet diversity and food security. Using a mixed methods community-level design, we assessed a 16-week intervention implemented in Cyanika, Rwanda. Stratified purposeful sampling was used to select women participants representing 42 households. Household diet diversity scores (HHDS) and hunger scores were calculated at the baseline, post-intervention and one-year follow-up. HDDS increased after intervention from a pre-intervention intake of 2.59 [1.3] food groups/day, to 4.85 [1.6] at four months post-intervention and at one year post-intervention, reaching 5.55 [1.3]. There were no significant changes in household hunger scores. Our results indicate that collaborative community-engaged nutrition-sensitive agricultural interventions can increase household diet diversity; however, future work should explore whether this type of intervention strategy can lead to sustained changes and impact nutritional adequacy in this population.