The differences were attributed to significant changes in the gut microbiome, with recorded changes in faecal propionate and gamma aminobutyric acid (GABA) metabolite levels in the YM administered group.
In addition, treated participants were found to show improvements in gut health symptoms, reporting increased defecation frequency and stool volume.
“To our knowledge, this is the first report of the beneficial effects of prebiotics on objective sleep quality,” the Japanese researchers wrote in the journal Nutrients. “Our findings imply that YM may be a useful prebiotic for improving some aspects of gut health and sleep quality.”
Gut-brain axis
The importance of the gut microbiota for an array of health areas has been increasingly understood over recent years due to the production of hundreds of bioactive metabolites from food by the bacterial species. As a result, the microbiome plays a vital role in functions such as host immunity maturation, vitamin synthesis and the degradation of dietary fibres.
Imbalances in the gut microbiome can have significant effects on both physical and mental health areas, and thus, its maintenance is critical to prevent adversities.
There has been significant interest in administering prebiotics as one approach to maintaining a healthy gut environment. Specifically, in vitro and in vivo studies have reported that YM increases the growth of Bacteroides.
Recent evidence continues to support the potential link between the gut and sleep health, with research highlighting the reduction in sleep quality following gut dysbiosis. Thus, the present study sought to assess the effects of YM administration on gut health and sleep quality.
Study details
The researchers conducted a double-blind, randomised controlled trial utilising 40 healthy participants between the ages of 20 and 64 years with discomfort in defecation. Subjects were randomly allocated to receive either YM or a placebo for an administration period of four weeks. Defecation habits were self-reported, and sleep electroencephalogram (EEG) recordings and faecal samples were analysed.
The researchers reported that the YM group had significantly increased frequencies of defection and stool volumes when compared with the placebo group. In addition, following the full period of treatment, the YM group had significantly increased durations of non-REM sleep stage 3 (the deep sleep stage) as well as total time in bed.
Metabolomics analysis revealed 20 metabolite differences between the YM and placebo group, with changes in faecal propionate and GABA.
The findings suggest that YM intakes may improve areas of gut health as well as certain parameters of sleep quality; a finding that the researchers hypothesise results from elevated faecal propionate and GABA levels.
Regarding the improved gut symptoms observed in the study, the researchers explained: “It can be speculated that YM-degrading microorganisms produce propionate in the gut, and the subsequent increase in intestinal propionate levels enhances gut motility.”
They called for further research to fully prove the demonstrated effect of YM supplementation and clarify the underlying mechanisms of action.
Source: Nutrients
doi: doi.org/10.3390/nu16010141
“Effects of Prebiotic Yeast Mannan on Gut Health and Sleep Quality in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study”
Authors: Reiko Tanihiro et al.