Effect of soluble corn fiber supplementation for 1 year on bone mass in children and adolescents: results from the MetA-Bone randomized clinical trial.

Soluble corn fiber supplementation for 1 year resulted in significantly higher whole-body bone mineral content gain in girls compared to placebo.

• 1-year gain in whole-body BMC was 216.3 ± 138.3 g (18.8%) in girls receiving SCF versus 139.9 ± 84.0 g (12.9%) in girls receiving placebo (P < 0.05).
• Results were adjusted for age, Tanner stage, height velocity, weight velocity, lean mass velocity, fat mass velocity, and compliance.
• Similar results were found for BMD in girls.
• This effect was not observed in boys.
• This effect was not observed when calcium supplementation was added to SCF.

Among study completers, whole-body BMC and BMD significantly increased from baseline to 6 months and to 12 months across all participants.

• Analysis was conducted among completers (n = 151) out of 177 randomized participants.
• Bone mass was measured using dual-energy x-ray absorptiometry (DXA) at baseline, 6 months, and 12 months.
• Increases were statistically significant at both the 6-month and 12-month time points.
• These overall increases reflect normal bone accrual expected during childhood and adolescence.

Girls and boys in the study differed significantly in Tanner stage and body fat percentage at baseline, necessitating sex-stratified analyses.

• Girls had a significantly higher Tanner score (3.10 ± 1.20) than boys (2.30 ± 1.20; P < 0.001).
• Girls also had a significantly higher body fat percentage than boys (P < 0.05).
• These baseline differences were the basis for stratifying all results by sex.
• Participants were 9–14 years old and were required to have low habitual calcium intake.

The study recruited a mostly Hispanic, White, and healthy-weight population of children and adolescents with low habitual calcium intake.

• 213 participants were recruited, of whom 177 were randomized.
• Most participants were White (41.3%), Hispanic (69.5%), and of healthy weight (74.0%).
• Participants were healthy children and adolescents aged 9–14 years.
• Eligibility required usual low calcium intake, which was the target population for this intervention.

The trial used a four-arm design comparing SCF with or without calcium supplementation against placebo with or without calcium.

• Participants were randomly assigned to SCF (12 g/d) or placebo (maltodextrin, 12 mg/d), with or without calcium (calcium gluconate, 600 mg/d).
• The main comparison was SCF versus placebo; the secondary comparison involved adding or not adding calcium supplementation.
• The trial was registered at clinicaltrials.gov as NCT02916862.
• Duration of supplementation was 1 year.
• Statistical analyses included linear mixed-effects models and analysis of variance.

The addition of calcium supplementation to SCF did not produce the same bone mass benefit seen with SCF alone in girls.

• The significant effect of SCF on whole-body BMC and BMD in girls was not observed when calcium supplementation (600 mg/d) was added.
• This finding was described as part of the secondary comparison in the study design.
• The mechanism behind the attenuated effect with added calcium is not detailed in the abstract.
• The placebo comparator was maltodextrin (12 mg/d).

The authors conclude that the SCF-related improvement in bone mass acquisition in girls could have potential long-term benefits.

• The study hypothesized that SCF supplementation would result in higher bone mass, which was confirmed in girls but not boys.
• The authors note the effect 'could have potential long-term benefits on bone mass acquisition in girls.'
• Prebiotic fiber supplementation is known to increase calcium absorption, but prior long-term effects on bone mass in children were described as 'mixed.'
• The clinical significance relates to the fact that bone mass accumulated during childhood and adolescence affects long-term skeletal health.