The different effects of psyllium husk and orlistat on weight control, the amelioration of hypercholesterolemia and non-alcohol fatty liver disease in obese mice induced by a high-fat diet.

Obesity is a widespread medical problem, for which many drugs have been developed, each with its own limitations. Orlistat, a lipase inhibitor, functions as a fat absorption blocker and is a widely used over-the-counter drug in China. Psyllium husk, in contrast, is a food source rich in dietary fibre and is beneficial for weight loss because it reduces appetite. Here, it was investigated how psyllium husk treatments affect mice with a high-fat diet (HFD)-induced obesity, using obesity-related indices, metabolism indices, and gut microbiota, compared to orlistat treatments. Orlistat had a greater effect on weight loss, whereas psyllium husk had a greater effect at reducing serum and liver cholesterol and triglyceride levels. Treatments had similar effects on controlling the body fat rate, the expression level of farnesoid X receptor, sterol 27-hydroxylase and oxysterol 7-hydroxylase (CYP7B1) in the liver, and the regulation of major bile acids such as cholic acid, chenodeoxycholic acid, deoxycholic acid, and lithocholic acid in faecal content. However, the expression of CYP7A1 in the liver and the structures of faecal bile acids were different between the two drugs. Furthermore, although they also had similar effects on the gut microbiota at the phylum level, there were differences at the genus level for Roseburia, Bacteroides, Faecalibacterium, Coprobacillus, and Akkernansia, which led to the difference in the serum lipopolysaccharide (LPS) level. Orlistat increased the food intake of the obese mice that were fed a HFD, which led to an increase in water intake, serum triglyceride levels, and lower glucose tolerance. Although orlistat is considered a suitable drug for weight loss, psyllium husk is a comparatively more cost-effective choice for ameliorating hypercholesterolemia and non-alcoholic fatty liver disease caused by a HFD.

The different effects of Chinese Herb Solid Drink and lactulose on gut microbiota in rats with slow transit constipation induced by compound diphenoxylate.

Slow transit constipation (STC) has become an epidemic medical problem. There are several kinds of drugs for constipation; however, each drug has its limitations. The gut microbiota has a close relationship with STC. Lactulose is an effective drug for constipation because it is a kind of bulking laxative and microbioecologic, and it relieves the syndromes of STC. We found that the Chinese Herb Solid Drink (CHSD), which contains medicine food homologous materials such as psyllium husk, sweetalmond, semen sesami nigrum, and hemp seed, has a similar effect on relieving constipation as lactulose, although it has different effects on the gut microbiota. We investigated the mechanisms of CHSD in rats with STC, induced by diphenoxylate, via constipation index and enzyme linked immunosorbent assay (ELISA) analyses using serum and 16S rDNA amplicon and gas chromatography-mass spectroscopy (GC-MS). CHSD enhanced the relative abundance of some types of gut microbiota, such as Blautia, Ruminococcus, Roseburia, Coprococcus, Lachnospira, and Phascolarctobacterium, while lactulose enhanced the relative abundance of Blautia, Phascolarctobacterium, Eubacterium, and Akkernansia in diphenoxylate-induced STC rats. Both CHSD and lactulose enhanced the level of short-chain fatty acids in the faeces of rats; however, the composition of those were different between the two drugs. From the perspective of the gut neuroendocrine system, both CHSD and lactulose could elevate neurotransmitters, such as motilin (MTL) and substance P (SP), which promote intestinal peristalsis and reduce the expression of vasoactive intestinal peptide, which inhibits intestinal peristalsis in the serum of STC rats. CHSD could elevate gastrin expression, which also promoted intestinal peristalsis in serum, while lactulose did not have this effect. Our findings suggest that CHSD may be an effective and safe therapeutic choice for STC.