ABSTRACT
Aging can cause degenerative changes in the function of multiple tissues and organs in the body. Gastrointestinal diseases and intestinal dysfunction are very common in the elderly people. The purpose of this study is to explore the effect of the total extract of Astragalus membranaceus (Fisch.) Bge. on intestinal function and gut microbiota homeostasis in natural aging mice, which will provide clues for further mechanism study. The natural aging mice model is established and animal experiments follow the regulations of the Animal Ethics Committee of Nanjing University of Traditional Chinese Medicine. The overall health of the mice was evaluated by the "frailty index" scoring method. The intestinal absorption and transport function were measured by detecting intestinal glucose absorption capacity, transport time, lipase and amylase activities of aging mice. Intestinal inflammation was assessed by detecting inflammatory cytokines by enzyme-linked immunosorbent assay (ELISA). The pathological changes in the intestines of aging mice were tested by hematoxylin-eosin (H&E) staining and alizarin blue (AB) staining. The qRT-PCR method was used to explore the gene transcription level related with the proliferation and differentiation of intestinal stem cells. Microbiota analysis based on 16S rDNA were used to evaluate the composition of gut microbiota. The results showed that Astragalus had a tendency to reduce the "frailty index" of aging mice, but did not show a significant difference. In some indicators of aging phenotype, Astragalus has the most significant effect on hair loss and physical fitness. In terms of intestinal function, Astragalus could increase intestinal glucose absorption capacity, shorten intestinal transportation time and promote lipase secretion in aging mice. The levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) in the aging intestinal tissue were reduced after Astragalus administration. Astragalus also ameliorated the pathological degeneration of the intestinal tissue of aging mice by increasing the length of small intestinal villi, the thickness of colonic mucosa and goblet cell number. In addition, Astragalus elevated the expression of genes associated with the proliferation and differentiation in jejunum and modulated gut microbiota, especially restoring the abundance of Lachnospiraceae. Taken together, the above research results demonstrate the total extract of Astragalus as a key factor improving the intestinal function and gut microbiota homeostasis of aging mice.
ABSTRACT
The purpose of this research is to study the effect of small molecule compound piceatannol (PIC) on host inflammation in adenine induced chronic kidney disease (CKD) mice, and then to explore its mechanism based on the regulation of gut microbiota. All procedures were approved by the Institutional Animal Care and Use Committee of the Nanjing University of Chinese Medicine. The level of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) was detected by enzyme linked immunosorbent assay (ELISA); UPLC-TQ/MS technology was used to monitor the level of proinflammatory uremic toxin indoxyl sulfate (IS) and p-cresol sulfate (PCS); the expression of occludin was tested by Western blot; in vitro anaerobic culture of gut bacteria was used to produce indole; the abundance of gut microbiota was evaluated by 16S rDNA sequencing. The results showed that PIC had no effect on inflammatory infiltration in kidney tissue of CKD mice, but could decrease IL-6 level in blood and IL-6/TNF-α level in colon tissue. PIC did not improve intestinal occludin protein expression in CKD mice; while it could significantly reduce the levels of IS and PCS in blood and liver of CKD mice. Further mechanism studies showed that PIC could inhibit the synthesis of IS precursor indole in gut bacteria. Moreover, PIC could decrease the abundance of gut bacteria which producing uremic toxin, such as reducing the abundance of indole and p-cresol producing gut bacteria. In conclusion, PIC could regulate gut microbiota and inhibit the synthesis of uremic toxin precursor, thereafter reducing the accumulation of IS and PCS in vivo, ultimately relieving the inflammation of CKD mice.
ABSTRACT
Hepatic encephalopathy is a common metabolic neuropsychiatric syndrome in the development of end-stage liver disease. Since the concept of intestinal-liver-brain axis was proposed, the relationship between the pathogenesis of hepatic encephalopathy and the gut microbiota has been a hot research topic. In recent years, studies have confirmed that gut microbiota is involved in and affects various pathological processes of hepatic encephalopathy. This article combines the latest research progress at home and abroad to elaborate on the research status of regulating gut microbiota and thus interfering with the pathological process of hepatic encephalopathy, hoping to provide new ideas and methods for the intervention of hepatic encephalopathy based on the regulation of gut microbiota.
ABSTRACT
Chronic kidney disease (CKD) is a serious chronic disease with high incidence, poor prognosis, and a variety of complications. Indoxyl-sulfate (IS) and p-cresol sulfate (PCS) are two typical gut-derived uremic toxins, which are produced by the co-metabolism of intestinal microbes and the host. With the progression of CKD, gut-derived uremic toxins such as IS and PCS accumulate in patients with CKD and thereafter accelerate the progression of CKD. Gut microbiota is closely related with CKD, and targeting gut microbiota to regulate gut-derived uremic toxins synthesis and metabolic pathways may be a promising strategy to delay the progression of CKD. In this paper, the relationship between gut microbiota, gut-derived uremic toxins, and CKD was analyzed, and the strategy to delay the progression of CKD by targeting gut microbiota and uremic toxins metabolism pathway was proposed.