Pilot Study: Blueberries Modify Gut Microbiome in Older Adults With Mild Depression
Preliminary findings warrant additional studies into the relationship between blueberries, the gut microbiome, and mood in older adults.
A new pilot study has found that older, sedentary adults who consumed blueberries daily showed a greater, more consistent reduction in depressive symptoms, paired with minor changes in markers of gut microbial enzymes.
While there were no statistically significant differences in changes in depressive symptoms between the test and placebo groups, the preliminary data warrant additional research to investigate the link between blueberries, the gut microbiome, and mood in older adults.
“Fiber and anthocyanins in blueberries have potential to modify the gut microbiome and metabolites that are relevant to depression in older adults,” said lead author Courtney L. Millar, PhD, assistant scientist II at Hebrew SeniorLife’s Hinda and Arthur Marcus Institute for Aging Research and assistant professor of medicine at Beth Israel Deaconess Medical Center and Harvard Medical School. “Our objective was to preliminarily determine the effect of blueberry consumption on the gut microbiome, metabolites, and depressive symptoms.”
Study design
Sedentary adults 65 years and older with mild depressive symptoms were enrolled in a randomized, double-blind, parallel-arm, placebo-controlled pilot study. Participants consumed 48 grams per day of blueberry powder (approximately two cups of fresh berries) or a matched placebo powder for three months. Metagenomic sequencing measured the abundance of gut microbiota species and genes, liquid chromatography/mass spectrometry evaluated gut-derived fecal short-chain fatty acids, and validated questionnaires evaluated depressive symptoms before and after the intervention.
Study participants
Eighteen participants, predominantly female and white, completed the intervention (placebo group, n = 8; mean age: 75 ± 6; blueberry group, n = 10; mean age: 71 ± 4).
Measures of gut microbe species abundance, MetaCyc pathways, and short-chain fatty acid metabolites did not change. There were statistically significant differences in the gene abundance of several enzyme commissions of the gut microbiome within the blueberry group — including EC 3.6.3.31 Polyamine Transporting ATPase, which is involved in the production of the neurotransmitter, gamma-aminobutyric acid (GABA).
The study, “A pilot study of daily blueberry intake modulates the gut microbiota enzyme commissions in older, sedentary adults with mild depressive symptoms,” was published in the Journal of Nutrition, Health and Aging.
Other contributors included:
Mohit P. Chopra, MD, Deanna and Sidney Wolk Center for Memory Health, Hebrew SeniorLife, Department of Psychiatry, UMass Chan Medical School; Xochitl Morgan, PhD, Department of Biostatistics, Harvard T.H. Chan School of Public Health; Emily A. Green, PhD, Harvard T.H. Chan School of Public Health; Alex Wolfe, Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife; Kerry A. Pierce, Broad Institute of MIT and Harvard; Lidan Gao, PhD, Department of Nutritional Sciences, University of Connecticut; Christopher N. Blesso, PhD, Department of Nutritional Sciences, University of Connecticut; Alyssa B. Dufour, PhD, Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School; Douglas P. Kiel, MD, MPH, Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Harvard Medical School, Beth Israel Deaconess Medical Center; Lewis A. Lipsitz, MD, Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Professor of Medicine, Harvard Medical School.
About Hebrew SeniorLife
Hebrew SeniorLife is a national leader working to create a world where aging is defined by possibility, not limitation. We care for more than 4,500 older adults each day across seven campuses throughout Greater Boston, and offer support for families in the aging journey. Our services include in-home care, outpatient therapies, an outpatient memory clinic, short- and long-term inpatient care, hospice, independent and assisted living, and affordable housing with services. We conduct influential research on aging at our Hinda and Arthur Marcus Institute for Aging Research, which has a grant portfolio of $87 million, and train future health care workers at the Lunder CareForce Institute. Hebrew SeniorLife is a Harvard Medical School affiliate. Follow us on our blog, Facebook, Instagram, and LinkedIn.
About the Hinda and Arthur Marcus Institute for Aging Research
Scientists at the Marcus Institute seek to transform the human experience of aging by conducting research that will ensure a life of health, dignity, and productivity into advanced age. The Marcus Institute carries out rigorous studies that discover the mechanisms of age-related disease and disability; lead to the prevention, treatment, and cure of disease; advance the standard of care for older people; and inform public decision-making.
