Department of Integrative Pharmacology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan.
Mie University Zebrafish Drug Screening Center, Tsu, Mie, 514-8507, Japan.
Sci Rep. 2021 Jul 5;11(1):13384. doi: 10.1038/s41598-021-92459-7.
Rhamnan sulphate (RS), a sulphated polysaccharide from Monostroma nitidum, possesses several biological properties that help in treating diseases such as viral infection, thrombosis, and obesity. In the present study, we first administered RS (0.25 mg/g food volume) orally to high-fat diet-treated mice for 4 weeks. RS increased the faecal volume and calorie excretion with decreased plasma lipids, which was in accordance with the results of our previous zebrafish study. Notably, as the excretion amount by RS increased in the mice, we hypothesised that RS could decrease the chance of constipation in mice and also in human subjects because RS is considered as a dietary fibre. We administrated RS (100 mg/day) to subjects with low defaecation frequencies (3-5 times/week) for 2 weeks in double-blind placebo-controlled manner. As a result, RS administration significantly increased the frequency of dejection without any side effects, although no effect was observed on the body weight and blood lipids. Moreover, we performed 16s rRNA-seq analysis of the gut microbiota in these subjects. Metagenomics profiling using PICRUSt revealed functional alternation of the KEGG pathways, which could be involved in the therapeutic effect of RS for constipation.
岩藻半乳聚糖（RS）是一种来源于绿藻的硫酸化多糖，具有多种生物特性，可用于治疗病毒感染、血栓和肥胖等疾病。在本研究中，我们首先将 RS（0.25mg/g 食物量）通过口服给予高脂饮食处理的小鼠 4 周。RS 增加了粪便量和热量排泄，同时降低了血浆脂质，这与我们之前的斑马鱼研究结果一致。值得注意的是，由于 RS 在小鼠体内的排泄量增加，我们假设 RS 可以降低小鼠和人类发生便秘的几率，因为 RS 被认为是一种膳食纤维。我们以双盲安慰剂对照的方式给低排便频率（每周 3-5 次）的受试者每天服用 RS（100mg），持续 2 周。结果显示，RS 给药可显著增加排便频率，且无任何副作用，尽管对体重和血脂没有影响。此外，我们对这些受试者的肠道微生物组进行了 16s rRNA-seq 分析。基于 PICRUSt 的宏基因组分析显示，KEGG 途径的功能发生了改变，这可能与 RS 治疗便秘的疗效有关。
