The aim of this study was to evaluate the effects of three different kinds of oligosaccharides (a fructo-oligosaccharide (FOS) formulation consisting of 95% FOS (FOS95); a galacto-oligosaccharide (GOS) formulation consisting of 90% GOS (GOS90) and an isomalto-oligosaccharide (IMO) formulation consisting of 90% IMO (IMO90)) at dosages of 0.8, 4 g per d per kg bw and 8 g per d per kg bw on the composition and activity of the microbiota in the gut of mice with constipation induced by loperamide. Oligosaccharides were intragastrically administered to specific pathogen-free BALB/c mice once per day for 17 days. Feces were collected during a feeding trial and subjected to 16S rDNA amplicon analysis. Constipation indices, changes in gut microbiota and metabolic activity were measured to evaluate the effects of the oligosaccharides. The results show that oligosaccharides treated constipation by increasing both the water content of the feces and the small intestinal transit rate. The dosage required to treat constipation was different for different oligosaccharides. High-dose GOS90 was the most effective in relieving constipation, followed by medium-dose FOS95 and IMO90. The fecal samples were investigated after the oligosaccharide treatment. All three oligosaccharides increased the ratio of acetic acid and decreased the ratio of propionic and butyric acids in the feces. The increase in the ratio of acetic acid and the concentration of butyric acid were found to have relatively larger effects on constipation. After treatment with oligosaccharides, the gut microbiotas of the mice were dominated by Firmicutes, Bacteroidetes and Actinobacteria. At the genus level, oligosaccharide treatment increased the levels of Lactobacillus and Bifidobacterium and decreased the levels of Odoribacter, Alistipes and Bacteroides. In conclusion, our results demonstrate that oligosaccharides administered as a dietary supplement increase the water content of feces, reduce intestinal transit time, modulate the composition of the gut microbiota and increase the concentration of short-chain fatty acids in the feces of mice with constipation.

Constipation is one of the most common gastrointestinal complaints worldwide. The aim of this study was to determine whether edible bifidobacteria (Bifidobacterium longum, B. infantis, B. animalis, B. bifidum, B. adolescentis or B. breve) exhibit interspecies differences in alleviating constipation induced by loperamide in BALB/c mice and to analyse the main reasons for the interspecies differences. BALB/c mice were given bifidobacteria by gavage once per day for 8 days. The primary outcome measures, which included related constipation indicators, and the secondary outcome measures, which included changes in the concentration of short-chain fatty acids in faeces and changes in the faecal flora, were used to evaluate the therapeutic effects of the edible bifidobacteria on constipation. The findings show that the six species of Bifidobacterium differed in their ability to relieve constipation. B. longum, B. infantis and B. bifidum were the most effective in relieving constipation, B. adolescentis and B. breve were partially effective and B. animalis was not effective. Furthermore, edible Bifidobacterium treated constipation by increasing the abundance of Lactobacillus and decreasing the abundance of Alistipes, Odoribacter and Clostridium. Higher concentrations of short-chain fatty acids were found in the faecal samples from the edible Bifidobacterium treatment groups. Meanwhile, an increased concentration of acetic acid could alleviate constipation. In conclusion, edible bifidobacteria exhibit interspecies differences in the alleviation of constipation. Meanwhile, bifidobacteria improved constipation symptoms by increasing the concentration of acetic acid and the relative abundance of Lactobacillus and reducing the content of Alistipes, Odoribacter and Clostridium.

The method of α-glucosidase inhibitory activity could be effectively used to screen potential hypoglycaemic products and Lact. plantarum CCFM0236 might be a promising therapeutic agent for ameliorating type 2 diabetes.

Type 2 diabetes is a metabolic syndrome characterized by insulin resistance and relative insulin deficiency. In this study, the anti-diabetic effects of live and dead multi-strain probiotics were explored and compared in a high-fat and streptozotocin-induced model of type 2 diabetes in mice. Either live or dead probiotics were daily administered orally to the mice over 10 weeks. Both live and dead multi-strain probiotics reduced HbA1C and leptin levels, improved glucose tolerance, and protected against the impairment of the pancreas, while the live probiotic showed a greater ability to reduce fasting and postprandial blood glucose levels. In addition, the live multi-strain probiotic exerted the beneficial effect of ameliorating insulin resistance. This effect was associated with the gut microbiota, butyrate production, and the inflammatory response, and was more effective for the live probiotic than the dead probiotic. These findings showed that the viable probiotic more effectively relieved hypoglycemic symptoms in the host by ameliorating insulin resistance. Furthermore, a pathway related to insulin resistance, i.e., the gut microbiota-butyrate-inflammatory axis, provided a promising rationale for further research into preventing or treating type 2 diabetes.

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