A cross-sectional study observing the association of psychosocial stress and dietary intake with gut microbiota genera and alpha diversity among a young adult cohort of black and white women in Birmingham, Alabama

Background

The relationships between psychosocial stress and diet with gut microbiota composition and diversity deserve ongoing investigation. The primary aim of this study was to examine the associations of psychosocial stress measures and dietary variables with gut microbiota genera abundance and alpha diversity among young adult, black and white females. The secondary aim was to explore mediators of psychosocial stress and gut microbiota diversity and abundance.

Methods

Data on 60 females who self-identified as African American (AA; n = 29) or European American (EA; n = 31) aged 21-45 years were included. Cortisol was measured in hair and saliva, and 16S analysis of stool samples were conducted. Discrimination experiences (recent and lifetime), perceived stress, and depression were evaluated based on validated instruments. Spearman correlations were performed to evaluate the influence of psychosocial stressors, cortisol measures, and dietary variables on gut microbiota genus abundance and alpha diversity measured by amplicon sequence variant(ASV) count. Mediation analyses assessed the mediating role of select dietary variables and cortisol measures on the associations between psychosocial stress, Alistipes and Blautia abundance, and ASV count.

Results

AA females were found to have significantly lower ASV count and Blautia abundance. Results for the spearman correlations assessing the influence of psychosocial stress and dietary variables on gut microbiota abundance and ASV count were varied. Finally, diet nor cortisol was found to partially or fully mediate the associations between subjective stress measures, ASV count, and Alistipes and Blautia abundance.

Conclusion

In this cross-sectional study, AA females had lower alpha diversity and Blautia abundance compared to EA females. Some psychosocial stressors and dietary variables were found to be correlated with ASV count and few gut microbiota genera. Larger scale studies are needed to explore the relationships among psychosocial stress, diet and the gut microbiome.

The Mediterranean Diet in the Stroke Belt: A Cross-sectional Study on Adherence and Perceived Knowledge, Barriers, and Benefits (P18-066-19)

Objectives

The Mediterranean diet (MD) is recommended by the current Dietary Guidelines for Americans, yet little is known about the diet in the US, particularly in areas of high chronic disease. Thus, we investigated MD adherence and perceived benefits and barriers to consumption of the MD in the US Stroke Belt.

Methods

A survey containing 44 validated MD knowledge, barriers, and benefits (KBB) questions, a validated 14-question MD adherence screener, 7 questions based on the Precaution Adoption Model (stages of change), and 7 demographic/anthropometric questions was distributed systematically to US residents using Amazon Mechanical Turk. Responses from the Stroke Belt (SB; n = 304), California (CA; n = 489), and all other US states (OtherUS; n = 439) were obtained. The CA group served as the reference group. A linear model was used to assess KBB question scores in the groups (Model 1), adjusted for sex and age (Model 2), and all other demographic variables (Model 3). Multivariable linear regression analysis was used to assess the differences in total MD adherence scores between the groups adjusted for all covariates. Simple logistic regression for having heard of the MD with demographic variables was examined. Statistical analyses were conducted in R v3.5.2.

Results

Barriers on MD knowledge, convenience, sensory factors, and health and familiarity with the MD diet were significantly greater in the SB group, but not the OtherUS group, in all models (P < 0.05). Weight loss was found to be a significantly greater benefit in the SB group in all models (P < 0.05). For each point increase in MD adherence, a reduction in 0.32 and 0.48 points (P < 0.05) was observed in the SB and otherUS groups, respectively. In the full cohort, the odds for participants having heard of the MD prior to taking the survey significantly increased 12.50 times (95%CI, 2.56–226) for 65–74 year olds. The odds were also significantly increased (OR 1.68; 95%CI, 1.13–2.47 and OR 2.47; 95%CI, 1.45–4.32) for those with Bachelor's and Master's or professional degrees, respectively, while no significant differences were found with sex or race.

Conclusions

Our results identify key barriers and benefits of the MD in the SB which can inform targeted MD intervention studies.

Funding Sources

USDA Hatch Funding Program (MWG) and Haggard Family Annual Award in Nutrition and Dietetics (OJ).

Abstract P5-15-03: Withdrawn

This abstract was withdrawn by the authors.