(P04-049-24) Influence of Blackcurrant Anthocyanins on Fecal Short Chain Fatty Acids and Their Associations With Bone Health in Peri- and Early Postmenopausal Women

Objectives: The aim of the present study was to assess the effects of blackcurrant (BC) anthocyanins on fecal short chain fatty acid (SCFA) concentrations and explore the associations of six-month changes in fecal SCFAs with changes in bone mineral density (BMD) and biomarkers of bone metabolism.

Methods: Fecal and blood samples from a pilot randomized controlled clinical trial were collected from peri- and early postmenopausal women aged 45-60 years. Thirty-seven eligible women were randomized into one of three treatment groups including: (1) Control (placebo), (2) Low BC (392 mg BC/day) or (3) High BC (784 mg BC/day) for six months. For SCFA analysis, fecal samples were prepared for GC-MS and analyzed using Agilent GC-MSD. BMD was measured via dual energy x-ray absorptiometry and all biomarkers of bone metabolism were measure via ELISAs. Fecal samples were normalized by sample-specific normalization using sample weight on MetaboAnalyst and all statistical analyses were conducted using SAS v9.4.

Results: Isobutyric acid (IBUT; p < .01) and caproic acid (CAP; p < .05) were significantly decreased from baseline to 6 months in the control group while acetic acid (ACE; p = 0.069), butyric acid (BUT; p = 0.071), and heptanoic acid (HEP; p = 0.064) were marginally significantly increased in the high BC group at 6 months compared to control and low BC groups. IBUT and CAP positively correlated with BMD (r=0.35, p < .05 and 0.35, p < .05, respectively). VAL was marginally positively correlated with IGF-1 (r=0.35, p = 0.052) and both VAL and BUT with osteoprotegrin (r=0.36, p < .05 and r=0.40, p < .05, respectively), a bone regulatory factor  that protects bone from excessive resorption. Additionally, IVAL was positively correlated with bone alkaline phosphatase (r=0.34, p < .05), a biomarker of bone formation.

Conclusions: The findings suggest that BC anthocyanins may exert bone protective effects through stimulating SCFA production in the gut. Correlations found between fecal SCFAs, bone mass, and biomarkers of bone metabolism suggest BC may play a role in the interplay between diet with gut and bone health and bone related outcomes in peri- and early postmenopausal women.

Funding Sources: This research was funded by the USDA NIFA Seed Grant to Dr. Ock K. Chun. We thank Just The Berries Ltd. for providing the blackcurrant extract.