A syrup containing L-arabinose and D-xylose appears superior to PEG-4000 as a bowel cleansing agent

Abstract

Adequate bowel cleansing is crucial for endoscopic diagnosis and treatment, and the recovery of gut microbiota after intestinal cleansing is also important. A hypertonic syrup predominantly comprising L-arabinose and D-xylose (20% xylo-oligosaccharides) can be extracted from the hemicellulose of corn husks and cobs. L-Arabinose and xylo-oligosaccharides have been reported to relieve constipation and improve the gut microbial environment. This study evaluated the bowel cleansing effect of the aforementioned syrup and its influence on the organism and intestinal microbiota after cleansing in comparison with polyethylene glycol-4000 (PEG-4000) in mice. Bowel cleansing was performed using syrup or PEG-4000 in C57BL/6J mice, and the effect of intestinal preparation and its influence on serum electrolytes and gut microbiota after bowel cleansing were evaluated. The volume of intestinal residual feces in the syrup group was significantly lower than that in the PEG-4000 group. Additionally, syrup disturbed serum electrolytes more mildly than PEG-4000. Alpha diversity in the gut microbiota was significantly higher in the syrup group than in the PEG-4000 group on the first day after bowel cleansing. However, no difference in beta diversity was observed between the two groups. Syrup increased the abundance of Bifidobacteria and Christensenella and decreased the abundance of Akkermansia in comparison with PEG-4000 on the first day after bowel cleansing. Thus, this syrup has potential clinical use as a bowel cleansing agent given the above effects, its benefits and safety, and better taste and acceptability.

Keywords: d-Xylose; l-Arabinose; Bowel cleansing; Intestinal microbiota; Polyethylene glycol-4000 (PEG-4000); Xylo-oligosaccharide (XOS).

Fig. 1

Main components of the syrup are l-arabinose and d-xylose. A Flowchart of the syrup production process. B Analysis of the composition of syrups by chromatographymass spectrometry (GCMS). C Analysis of xylo-oligosaccharide (XOS) in d-xylose by high-performance liquid chromatography (HPLC)

Fig. 2

Syrup exhibits a more pronounced bowel cleansing effect than polyethylene glycol-4000 (PEG-4000). Mice were randomly allocated to the following groups: control (n = 12; administered a normal diet and water), fasting (n = 12; fasted for 16 h), syrup (n = 14; five gavages with 250 μL of 20% syrup (v/v) at 30-min intervals, repeated after fasting for 12 h), and PEG-4000 (n = 14; five gavages with 250 μL of PEG-4000 (A, 2.625 g/L; B, 2.879 g/L) at 30-min intervals, repeated after fasting for 12 h). Food (but not water) was withdrawn from mice in the latter three groups 1 h before bowel cleansing. Mice were euthanized 1 h after the end of cleansing. A Entire small and large intestines. B Volume of residual feces in intestines. C Hematoxylin and eosin (H&E) staining of small and large intestinal tissues (40×). Data are expressed as mean ± standard error of the mean (SEM). ^*P < 0.05, ^**P < 0.01, ^***P < 0.001, and ^****P < 0.0001

Fig. 3

Syrup bowel cleansing resulted in milder serum electrolyte disturbance than polyethylene glycol-4000 (PEG-4000). Mice were randomly divided into the control (n = 6), fasting (n = 6), syrup (n = 8), and PEG-4000 groups (n = 8). The levels of serum electrolytes and plasma osmotic pressure are shown. Data are expressed as mean ± standard error of the mean (SEM). ^*P < 0.05, ^**P < 0.01, ^***P < 0.001, and ^****P < 0.0001

Fig. 4

Syrup bowel cleansing affected the intestinal microbiota community composition less than polyethylene glycol-4000 (PEG-4000). Freshly excreted feces were collected from mice in the syrup group and PEG-4000 group before bowel cleansing and on days 1 and 7 after bowel cleansing for 16S rRNA gene sequencing (n = 6 per group). A Flowchart of the mouse fecal 16S rRNA experiment. B, C The intestinal microbiota α diversity after using PEG-4000 and syrup for bowel cleansing. D, E The intestinal microbiota β diversity after using PEG-4000 and syrup for bowel cleansing. F, G The relative abundance of intestinal microbiota community composition at the phylum and genus levels

Fig. 5

Changes in intestinal microbiota at the phylum and genus levels after using polyethylene glycol-4000 (PEG-4000) and syrup for bowel cleansing. The changes in intestinal microbiota on the first day after bowel cleansing were shown. Data are expressed as mean ± standard error of the mean (SEM). ^*P < 0.05, ^**P < 0.01, ^***P < 0.001, and ^****P < 0.0001