Involvement of the vagus nerve and hepatic gene expression in serum adiponectin concentrations in mice.

Several humoral factors, such as adiponectin and urate, have been suggested to affect metabolic syndromes. Previously, we reported a reduction in blood adiponectin concentrations after a high-fructose diet partially via the vagus nerve in rats. Although a lithogenic diet (LD), i.e., supplementation of a normal control diet (CT) with 0.6% cholesterol and 0.2% sodium cholate, reduced blood adiponectin concentrations, the involvement of the vagus nerve in this mechanism remains unclear. To estimate the involvement of the vagus nerve in the regulation of blood adiponectin concentrations using an LD, male imprinting control region mice that had been vagotomized (HVx) or only laparotomized (Sham) were administered a CT or an LD for 10 weeks. Serum adiponectin concentrations in the Sham-LD, HVx-CT, and HVx-LD groups were reduced by half compared with the Sham-CT group. The hepatic mRNA levels of fibroblast growth factor 21 (Fgf21), which reportedly stimulates adiponectin secretion from white adipose tissue, were lower in the LD groups compared with the CT groups. HepG2 hepatoma cells showed that various bile acids reduced the mRNA expression of FGF21. Moreover, the LD increased serum urate concentrations and reduced hepatic expressions of the acyl-CoA oxidase 1 (Acox1) mRNA and glucokinase, suggesting insufficient regeneration of ATP from AMP. In conclusion, serum adiponectin concentration may be regulated via the vagus nerve in normal mice, whereas a reduction of hepatic Fgf21 mRNA by bile acids may also lower serum adiponectin levels. Moreover, the LD may promote hepatic AMP accumulation and subsequently increase the serum urate concentration in mice.

Beneficial health effects of polyphenols metabolized by fermentation.

High daily intake of polyphenol-rich meal in some countries could be regarded as a healthy meal. However, the knowledge about the bioavailability and functionality of the exiting amounts of polyphenol into the large intestine needs to be elucidated, particularly the beneficial health effects and its fermentation characteristics during fermentation. Thus, this review focuses on the influence of polyphenols metabolized by fermentation and elucidates their health attributes. Besides, it also summarized the potential benefits of polyphenols and discussed the need for further research to fully understand the health attributes of polyphenols.

Combined effects of BARLEYmax and cocoa polyphenols on colonic microbiota and bacterial metabolites in vitro.

BARLEYmax, a barley variety, and cocoa polyphenols (CPPs) have been reported to affect bacterial metabolites in the colon. This study aimed to evaluate the combined effects of BARLEYmax and CPPs supplementation on fecal microbiota in vitro using pig feces for 48 h. The relative abundances of the family Clostridiaceae and the genus Clostridium and ammonia-nitrogen production were decreased by both BARLEYmax and CPP supplementation, and there was a positive correlation between their abundances and the ammonia-nitrogen concentration. Although acetate and n-butyrate production was decreased by CPP supplementation, their concentrations were maintained at a higher level in the BARLEYmax + CPP group than in the cellulose (control) and cellulose + CPP groups. Therefore, this study demonstrated that a combination of BARLEYmax and CPPs may be beneficial in maintaining higher short-chain fatty acid production and the elimination of potentially harmful factors. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-00959-z.

Purple Sweet Potato Polyphenols Differentially Influence the Microbial Composition Depending on the Fermentability of Dietary Fiber in a Mixed Culture of Swine Fecal Bacteria.

The prevalence of many chronic diseases which have been associated with poor nutrition may be reduced by the positive modulation of colonic microbiota. In this study, we assess the effects of purple sweet potato polyphenols (PSP) in a mixed culture of swine fecal bacteria during in vitro colonic fermentation using pig colonic digest. Jar fermenters were used to conduct a small scale in vitro colonic fermentation experiments under the anaerobic condition for 48 h. Jar fermenters were assigned to one of the following groups: Cellulose, cellulose + PSP, inulin, and inulin + PSP. The present study revealed that the polyphenolic content of purple sweet potato could modulate the colonic microbiota by differentially increasing the population of beneficial bacteria and decreasing the pathogenic bacteria depending on cellulose and inulin. Accordingly, PSP might be a material conducive for improving the conditions for the fermentation of partly-fermentable dietary fiber. Besides, PSP was also responsible for the drastic reduction of putrefactive products, especially p-cresol to a significant level. Our results suggest that PSP could alter the microbial composition depending upon the fermentability of dietary fiber and has the potential to maintain a stable and healthy colonic environment that will ultimately alleviate chronic diseases development and confer health benefits to the host.

Ultrastructural changes in colonic epithelial cells in a rat model of inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a global, chronic intractable disease. The functions of drugs and food components have been evaluated in models of IBD induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). Here, we used transmission (TEM) and osmium-maceration scanning (SEM) electron microscopy to evaluate the ultrastructure of colonic epithelial cells in rat models of IBD induced by TNBS. Histological evaluation revealed that the intestinal crypts in the most regions of the IBD-model colons were deformed and we classified them as having high cell migration rates (HMIG). The remaining regions in the intestinal crypts retained a relatively normal structure and we classified them as having low cell migration rates (LMIG). Osmium-maceration SEM revealed the mucosal fluid flowing in spaces without secretory granules in crypt goblet cells of both HMIG and LMIG regions, indicating the depletion of goblet cell mucin that is found in patients with IBD. The Golgi apparatus in absorptive cells was stacked and curled in both regions. Osmium-maceration SEM showed membrane network structures resembling endoplasmic reticulum that were large and expanded in absorptive cells with HMIG rather than with LMIG regions in IBD-model colons. These findings indicated that endoplasmic reticulum stress is associated with susceptibility to IBD and that the effects of various agents can be evaluated according to endoplasmic reticulum stress revealed by using electron microscopy in models of IBD induced by TNBS.

Safety and efficacy of adzuki bean extract in subjects with moderate to high LDL-C: a randomized trial.

The safety and efficacy of polyphenol-containing adzuki bean extract on lipid metabolism were evaluated in human subjects in an 8-week, randomized, double-blind, placebo-controlled, parallel intervention study. No adverse effects were observed in the participants receiving adzuki bean extract. The adzuki bean group showed a significant increase in the ΔHDL-C concentration compared with the placebo group after 4 weeks of intervention (3.76 ± 7.79 mg/dL vs. -0.08 ± 6.03 mg/dL), respectively, and both groups showed reduced ∆HDL-C concentrations, with the adzuki bean extract group showing a return to the baseline levels (0.36 ± 5.36 mg/dL) and the placebo group showing a decrease to below the baseline levels (-3.17 ± 7.79 mg/dL) at week 8. This short-term study represents the first step in establishing the practicality, safety, and plausibility of HDL-C maintaining effects of adzuki bean extract in human subjects.

Effect of a combination of inulin and polyphenol-containing adzuki bean extract on intestinal fermentation in vitro and in vivo.

The effect of a combination of inulin (INU) and polyphenol-containing adzuki bean extract (AE) on intestinal fermentation was examined in vitro using fermenters for 48 h and in vivo using rats for 28 d. The total short-chain fatty acid concentrations in the fermenters were decreased by a combination of INU and AE, but the concentration in the INU + AE group was higher than the cellulose (CEL) and CEL + AE groups. The cecal propionate concentration was increased by a combination of INU and AE compared with their single supplement. The ammonia-nitrogen concentration in the fermenters and rat cecum was decreased by INU and AE. Cecal mucin levels were increased by INU and AE respectively. Therefore, our observations suggested that the combination of INU and AE might be a material of functional food that includes several healthy effects through intestinal fermentation.

Detection of replication-competent adenoviruses spiked into recombinant adenovirus vector products by infectivity PCR.

The presence of replication-competent adenovirus (RCA) in clinical lots of adenovirus vectors raises a variety of safety concerns. To detect RCA in adenovirus vector products, the cell culture/cytopathic effect (CPE) method has generally been preferred. However, it is difficult to evaluate the amount of RCA clearly and quantitatively by this method. In addition, the cell culture/CPE method requires large-scale cell culturing and a substantial amount of time. For the purpose of establishing a method to detect RCA more sensitively and rapidly, we developed the infectivity PCR, a hybrid method that combines the infectivity assay and quantitative PCR. This method allows RCA to be quantified by real-time quantitative PCR using primers and a probe designed for E1 DNA. By infectivity PCR, 1 pfu of RCA spiked into 10(9) particles of adenovirus vectors could be detected. In contrast, CPE was observed in the cells infected with 10(4) pfu of RCA spiked into 10(9) particles of adenovirus vectors. The glass-beads method was suitable for extracting DNA rapidly from the RCA-infected cells. These results showed that infectivity PCR combined with the glass-beads-based DNA extraction method was useful for the detection of RCA in adenovirus vector products.