Synbiotic to Attenuate Resorption of the Skeleton (STARS): Design and Participant Recruitment of a Randomized, Double-Blind, Placebo-Controlled Trial to Test the Efficacy of SBD111 Medical Food in Older Women

Authors:
  • EOEvelyn O’NEill
    Evelyn O’NEill
  • CTCatherine Tolland
    Catherine Tolland
  • TTThomas Travison
    Thomas Travison
  • KSKarl Singer
    Karl Singer
  • MCMark R. Charbonneau
    Mark R. Charbonneau
  • DED. Davidson Easson
    D. Davidson Easson
  • PJPaul Jacques
    Paul Jacques
  • GTGerardo V. Toledo
    Gerardo V. Toledo
  • CRClifford J. Rosen
    Clifford J. Rosen
  • ESEric M. Schott
    Eric M. Schott
  • DKDouglas Kiel
    Douglas Kiel
Preprint
Publisher website
Google Scholar
Abstract
Osteoporosis and related fractures pose a costly public health challenge. Primary prevention of bone loss is largely limited to non-pharmacologic options without consistent guidelines. Prior studies have demonstrated that modification of the gut microbiome can influence bone homeostasis. The Synbiotic To Attenuate Resorption of the Skeleton (STARS) trial aimed to evaluate the efficacy, safety, and mechanistic effects of daily intake of SBD111, a fruit and vegetable-derived synbiotic medical food on the skeleton, gut microbiome, and inflammation biomarkers in women aged ≥60 years. This 18-month, investigator-initiated, single-site, randomized, double-blind, placebo-controlled trial had an enrollment goal of 220 women, a primary endpoint of proportionate change in lumbar spine bone mineral density (BMD) relative to baseline, and secondary outcomes including Quantitative Computed Tomography derived volumetric BMD and vertebral compressive strength, gut microbiome function, and bone and inflammatory biomarkers. Recruitment approaches included simultaneous digital and traditional methods beginning August 2024. As of July 2025, there were 42 enrolled participants (32 via digital, 10 via traditional); baseline demographics, eligibility, and enrollment rates were similar across recruitment strategies. Digital recruitment achieved over three times faster enrollment (2.9 vs. 0.9 enrollments/month) and was nearly 10 times more staff-efficient (0.05 vs. 0.48 cumulative weekly full-time equivalent) despite greater cost per enrollment ($548 vs. $173). These findings demonstrate the feasibility and efficiency of digital recruitment of older adults, offering valuable insights for future nutrition and microbiome clinical trials. The STARS trial is positioned to provide high-quality evidence for skeletal health maintenance in older women using SBD111.