The Nutritional Efficacy of Chlorella Supplementation Depends on the Individual Gut Environment: A Randomised Control Study.

Yuichiro Nishimoto,Shinnosuke Murakami,Yuka Mori,Yuya Nakamura,Takuji Yamada,Masaki Ito,Tatsuhiro Nomaguchi,Shinji Fukuda,Masaki Fujishima

doi:10.3389/fnut.2021.648073

Abstract

Recent studies have accumulated evidence that the intestinal environment is strongly correlated with host diet, which influences host health. A number of dietary products whose mechanisms of influence operate via the gut microbiota have been revealed, but they are still limited. Here, we investigated the dietary influence of Chlorella, a green alga commercially available as a dietary supplement. A randomised, double-blind, placebo-controlled crossover trial including 40 Japanese participants with constipation was performed. In this study, the primary outcome and secondary outcome were set as defecation frequency and blood folate level, respectively. In both outcomes, no significant differences were detected compared to the control intake. Therefore, we analysed the gut microbiome, gut metabolome, and blood parameters in an integrated manner as an exploratory analysis. We revealed that the consumption of Chlorella increased the level of several dicarboxylic acids in faeces. Furthermore, the analysis showed that individuals with low concentrations of faecal propionate showed an increase in propionate concentration upon Chlorella intake. In addition, increasing blood folate levels were negatively correlated with defecation frequency at baseline. Our study suggested that the effect of Chlorella consumption varies among individuals depending on their intestinal environment, which illustrates the importance of stratified dietary management based on the intestinal environment in individuals.

Highlights

Chlorella is a genus that belongs to the class Chlorophyceae and consists of mostly green algae living in freshwater
No significant differences in defecation frequency or blood folate level were observed between timepoints C3 and T3
There was a significant difference observed between C1 and C3, which correspond to times before and after control supplement intake, respectively

Summary

INTRODUCTION

Chlorella is a genus that belongs to the class Chlorophyceae and consists of mostly green algae living in freshwater. Rat studies have reported that Chlorella intake improved blood lipid profiles, which was correlated with gut microbiota alteration [3, 10]. The gut microbiota is known to differ between rodents and humans [11]; the effect of Chlorella intake into the intestinal environment in humans could differ from that in rats. A previous study reported that there are inter-individual differences in the response to Chlorella intake [12]; while the study focused on genetic differences among consumers, individual differences in the intestinal environment were not considered. The intestinal environment differs among human individuals [13] In this interventional study, we recruited participants with a tendency for constipation to evaluate their responses to Chlorella intake. This study focused on their bowel movement, blood parameters and intestinal environment analysed by a metabologenomics approach which is an integrated approach of 16S rRNA gene-based microbiome and mass spectrometry-based metabolome analyses

RESULT

DISCUSSION

Ethics Approval

Findings

ETHICS STATEMENT