Work

Pilot investigation of an oligosaccharide blend in adults with asthma – a double-blind, randomised, placebo-controlled, 4-arm crossover trial

Year: 2025

Type: article

Study designs: Randomized Controlled Trial, Clinical Trial

Abstract: Background and objective Soluble fibres can decrease airway inflammation and improve asthma control, though optimal dosing protocols have not been identified. The objective of this study was to examine the effect of multiple timing and dosing regimens of a soluble fibre supplement in symptomatic adults with asthma. Methods A randomised, double-blind, crossover trial was performed in adults with poorly controlled asthma. Subjects (n=35) received 4×2-week interventions with an oral oligosaccharide blend in random order [twice-daily 6g dose (HD2×6), once-daily 12g dose (HD12), once-daily 6g dose (LD), and placebo]. Outcomes: ACQ7 (primary outcome), lung function, airway hyper-responsiveness, sputum cell counts, plasma short-chain fatty acids (SCFA), sputum and blood gene expression, gastrointestinal symptoms. Results Asthma control was not significantly different following HD2×6 (-0.04 [-0.34, 0.25] (coefficient [95% C.I.]), p=0.79), HD12 (0.05 [-0.23, 0.33], p=0.73), or LD (-0.01 [-0.30, 0.27], p=0.93) compared to placebo. Following HD12, plasma total SCFA and plasma acetate increased compared to placebo. There were no significant changes in lung function, airway inflammation, or airway hyperresponsiveness following any intervention arm compared to placebo. Within-arm analysis showed a decrease in ACQ7 (Δ=-0.14 (-0.29, 0.14) [median (IQR)], p=0.03) and sputum eosinophils (Δ=-2.67 (-12.77, -0.20)×10 4 cells/mL [median (IQR)], p=0.03) following LD treatment. Conclusion Multiple 14-day soluble fibre supplementation dosing regimens did not change asthma control compared to placebo. Within-arm analysis showed an improvement in asthma control and eosinophilic airway inflammation following once-daily low-dose soluble fibre intervention. However, these findings should be interpreted with caution as changes were not statistically significant compared to placebo.

Source: Respiratory Medicine

DOI: 10.1016/j.rmed.2025.108474