Establishing the Role of Dried Plums in the Prevention of Glucocorticoid Induced Osteoporosis in Mice

This research investigates whether dietary dried plums (prunes) can prevent glucocorticoid-induced osteoporosis (GIO) in a well-established mouse model and explores links between bone health and the gut microbiota. Chronic glucocorticoid (GC) therapy is a common clinical cause of secondary osteoporosis, producing trabecular bone loss and associated morbidity. Prior work has shown that GC treatment induces gut microbiota dysbiosis in mice and that the microbiota mechanistically contributes to GIO, suggesting the microbiome as a therapeutic target. Prunes, a dried fruit with prebiotic properties, have shown efficacy in treating primary, sex-steroid deficiency-related osteoporosis and are known to alter gut microbial composition in both rodents and humans. Building on these observations, McCabe and co-authors tested whether supplementing the diet with dried California prune powder could prevent GC-induced trabecular bone loss and modulate gut microbiota composition.

In the study, sixteen-week-old female C57BL/6J mice were treated subcutaneously with either placebo or a prednisolone pellet delivering chronic GC exposure for eight weeks. Mice were fed a standardized control diet or the same diet modified to include 5%, 15%, or 25% (w/w) dried prune powder. As expected, GC-treated mice developed significant trabecular bone loss in the distal femur. Notably, dietary prune supplementation at levels as low as 5% effectively prevented this GC-induced trabecular bone loss. Furthermore, higher prune doses showed dose-dependent improvements: GC-treated mice receiving 15% and 25% prune diets exhibited increasing trabecular bone volume fraction compared to GC treatment alone. In non-GC (placebo) mice, the highest supplementation level (25% DP) produced an approximately threefold increase in distal femur trabecular bone volume fraction, an unusually large bone response for a gut-targeted, natural dietary intervention in otherwise healthy animals.

Alongside bone outcomes, GC treatment and 25% prune supplementation induced pronounced shifts in gut microbiota composition. Several specific microbial changes were strongly associated with bone health metrics, reinforcing the link between gut microbial ecology and skeletal outcomes. The combined findings demonstrate that dietary prune supplementation can effectively prevent the detrimental effects of prolonged GC therapy on trabecular bone in female mice and that these skeletal benefits are strongly associated with, and perhaps mediated by, modifications of the gut microbiota.

This work positions dried plums as a promising, food-based intervention to counteract GC-associated bone loss, highlights the importance of the gut-bone axis in secondary osteoporosis, and provides a foundation for further mechanistic and translational research. The authors report no commercial or financial conflicts of interest, and the study contributes novel evidence that modest dietary supplementation with a natural prebiotic can yield substantial protective effects on trabecular bone during chronic glucocorticoid exposure.