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The effects of waxy barley on defecation, sleep, mental health, and quality of life: a randomized double-blind parallel-group comparison study

Honda M, Minato-Inokawa S, Matsuura K, Ito A, Nitta Y, Kimura D, Yoshikawa Y

Journal of physiological anthropology, 2025

68 participants · 2 citations

Abstract

Background: Dietary fiber (DF) is beneficial for preventing constipation, and the metabolites produced by gut microbiota fermentation are suggested to positively influence on depression and sleep. Additionally, constipation has been reported to affect mental health and health-related quality of life (HRQoL). This study aimed to increase DF intake and examined its effects on daily DF and β-G consumption using two types of waxy barley (WB), rich in DF with varying β-glucan (β-G) content. Additionally, this study examined the effects of WB consumption on defecation, sleep, mental health, and HRQoL.

Methods: A randomized double-blind parallel-group comparison study was conducted on 68 young Japanese women, using Kirarimochi (Group K) as common WB cultivar and Fukumi Fiber (Group F) as high-β-G WB cultivar. Participants consumed WB rice for 4 weeks, targeting 3 g/day of β-G (48 g/day of WB). We estimated the intake of WB and DF including β-G from the daily records. Defecation was evaluated through daily records and Rome IV criteria-based surveys. Sleep, mental health, and HRQoL were evaluated using PSQI-J, J-PHQ-9, and SF-36, respectively.

Results: Both groups consumed about 40 g/day of WB. DF and β-G intakes from barley were 6.3 g/2.5 g in Group K and 10.7 g/4.3 g in Group F. Regarding defecation, both groups showed increases defecation days, defecation frequency and stool amount, with no differences between groups. Regarding sleep, Group F showed a decrease (improvement) in the…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 68 participants or records.

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