Mood disturbance, but not overall diet quality, is associated with fecal microbiome diversity in free-living adults

ABSTRACT

Objectives

To investigate the gut-brain axis, we explored the relationships among mood disturbance (MD), diet quality (DQ), and fecal microbiota in free-living adults.

Methods

A cross-sectional analysis was conducted with data from 75 healthy adults enrolled in two studies. Anthropometrics, 16s rRNA gene sequencing of fecal microbes, DQ as assessed by Healthy Eating Index-2015 (HEI), and MD determined by Profile of Mood States (POMS) were included. Alpha-diversity and DQ differences were explored between low (n = 37) and high MD (n = 38) groups. Spearman correlations were used to investigate relationships between alpha-diversity, DQ, and POMS subscales. Moderation analysis explored the effect of HEI score on the relationship between MD and alpha-diversity.

Results

Participants were mostly white (67%), 54.5 years old (±11.8), and overweight (28.5 ± 6.5 kg/m²). Shannon and Simpson indices indicate higher alpha-diversity in participants with low MD compared to high MD (p = 0.004 and p = 0.008, respectively). Simpson and Shannon indices were correlated with subscale of anger (rho = −0.303, p = 0.011; rho = −0.265, p = 0.027, respectively)and total MD (rho = −0.404, p = 0.001; rho = −0.357, p = 0.002, respectively). Refined grains were associated with fatigue and tension subscales (rho = 0.428, p < 0.001; rho = 0.302, p = 0.014, respectively). DQ did not significantly moderate the relationship between alpha-diversity and mood disturbance (F(7, 53) = 2.00, p = 0.072, R² = 0.209). Shannon index was a significant predictor of MD (b = −4.39, t(53) = −2.55, p = 0.014), but total HEI score and the interaction (Shannon index*HEI score) were not significant.

Discussion

Greater bacterial diversity was associated with lower MD, and DQ was associated with various mood state subscales in this sample of adults.

KEYWORDS:

• Gut microbiome
• alpha diversity
• mood disturbance
• diet quality
• profile of mood states

Acknowledgements

The authors would like to thank the study participants for their contributions and for making these studies possible.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, ADF, upon reasonable request.

Additional information

Funding

The Peanut Protein Supplementation study was funded by The Peanut Institute (TPI, Albany, GA, USA). TPI did not have a role in study design or analysis. Microbiome analysis was conducted by the Microbiome Resource at the University of Alabama at Birmingham, supported by the following: School of Medicine, Comprehensive Cancer Center [P30AR050948], Center for AIDS Research [5P30AI027767], Center for Clinical Translational Science [UL1TR000165, UL1TR001417], and Heflin Center for Genomic Sciences.