Thanutchaporn Kumrungsee

Consumption of an acid protease derived from Aspergillus oryzae causes bifidogenic effect in rats

A marked elevation in the abundance of Bifidobacterium was found in the cecum of rats that were fed a high-fat diet supplemented with an Amano protease preparation (derived from Aspergillus oryzae). The protease preparation contains several digestive enzymes, including acid protease (AcP), alkaline protease, and amylase. We hypothesized that the elevation in the abundance of Bifidobacterium by Amano protease preparation is associated with the digestive enzymes involved in the protease preparation. To test this hypothesis, this study was conducted to investigate if such bifidogenic effect is because of the AcP. Rats were fed a high-fat diet containing purified AcP obtained from the Amano protease preparation for 2 weeks. The numbers of Bifidobacterium in the cecum and feces of rats were markedly elevated by the dietary supplementation of 1 g/kg Amano protease. Bifidobacterium numbers were unaffected by supplementation with purified AcP (0.096 g/kg) at the level equivalent to the AcP amount found in the 1-g/kg Amano protease diet. Bifidobacterium numbers in the cecum and feces, and lactate levels in the cecum were significantly (P<.05) elevated when rats were fed a diet containing 0.384 g/kg AcP (4-fold higher amount of AcP than that used in the 1-g/kg Amano protease diet). Thus, the bifidogenic effect of 1 g/kg Amano protease diet could not be explained by the AcP. However, intriguingly, supplemental AcP was found to cause a significant bifidogenic effect at the dose that is 4-fold higher than that used in the 1-g/kg Amano protease diet.

Time-course microarrays reveal early activation of the immune transcriptome in a choline-deficient mouse model of liver injury

Aims Choline‐deficient diet is extensively used as a model of nonalcoholic fatty liver disease (NAFLD). In this study, we explored genes in the liver for which the expression changed in response to the choline‐deficient (CD) diet. Main methods Male CD‐1 mice were divided into two groups and fed a CD diet with or without 0.2% choline bitartrate for one or three weeks. Hepatic levels of choline metabolites were analyzed by using liquid chromatography mass spectrometry and hepatic gene expression profiles were examined by DNA microarray analysis. Key findings The CD diet lowered liver choline metabolites after one week and exacerbated fatty liver between one and three weeks. We identified >300 genes whose expression was significantly altered in the livers of mice after consumption of this CD diet for one week and showed that liver gene expression profiles could be classified into six distinct groups. This study showed that STAT1 and interferon‐regulated genes was up‐regulated after the CD diet consumption and that the Stat1 mRNA level was negatively correlated with liver phosphatidylcholine level. Stat1 mRNA expression was actually up‐regulated in isolated hepatocytes from the mouse liver with the CD diet. Significance This study provides insight into the genomic effects of the CD diet through the Stat1 expression, which might be involved in NAFLD development.

Feeding of the water extract from Ganoderma lingzhi to rats modulates secondary bile acids, intestinal microflora, mucins, and propionate important to colon cancer

Consumption of reishi mushroom has been reported to prevent colon carcinogenesis in rodents, although the underlying mechanisms remain unclear. To investigate this effect, rats were fed a high-fat diet supplemented with 5% water extract from either the reishi mushroom (Ganoderma lingzhi) (WGL) or the auto-digested reishi G. lingzhi (AWGL) for three weeks. Both extracts markedly reduced fecal secondary bile acids, such as lithocholic acid and deoxycholic acid (colon carcinogens). These extracts reduced the numbers of Clostridium coccoides and Clostridium leptum (secondary bile acids-producing bacteria) in a per g of cecal digesta. Fecal mucins and cecal propionate were significantly elevated by both extracts, and fecal IgA was significantly elevated by WGL, but not by AWGL. These results suggest that the reishi extracts have an impact on colon luminal health by modulating secondary bile acids, microflora, mucins, and propionate that related to colon cancer. Water extract of Ganoderma lingzhi or reishi mushroom exhibited potential anti-colon cancer effect through modulating secondary bile acids, intestinal microflora, mucins, and propionate.

Gender Difference and Dietary Supplemental Vitamin B 6 : Impact on Colon Luminal Environment

Colon diseases can be affected by several factors such as gender difference and dietary supplemental vitamin B6 (B6). The nutritional status of B6 is affected by gender difference, leading us to hypothesize that gender difference affects colon luminal environment, which is dependent on B6 status. To investigate this hypothesis, we fed male and female rats a diet containing 1 mg, 7 mg, or 35 mg pyridoxine HCl/kg diet for 6 wk. We found significantly higher fecal mucin levels in female rats compared to those in male rats. Supplemental B6 significantly increased fecal mucins and was particularly profound in the female rats. The abundances of cecal and fecal Akkermansia muciniphila (mucin degrader) were unaffected. The fecal mucin levels were significantly correlated with colonic free threonine and serine and with gene expression of colon MUC16, implying that the combined effect of gender and dietary B6 on fecal mucins was mediated by the alteration in the levels of such amino acids and MUC16 expression. This study further showed the significant effects of gender difference on colonic free amino acids such as threonine, ornithine, asparagine/aspartate ratio, and glutamine/glutamate ratio, cecal and fecal Lactobacillus spp. levels, and colonic gene expressions of MUC16 and TLR8, the factors relating to colon health and diseases. Therefore, our findings suggest that gender difference and dietary B6 may have an impact on colon diseases by modulating these parameters.

Transgenic mice specifically expressing amphiregulin in white adipose tissue showed less adipose tissue mass

To determine adipocytokines that play a regulatory role during obesity development, we explored the genes that encode growth factors and investigated the physiological functions for adipose tissue development. Here, we isolated amphiregulin (Areg) gene whose expression was significantly up‐regulated in obese adipose tissues. Areg mRNA level was positively correlated with macrophage marker gene expression in adipose tissues in vivo. Unexpectedly, Areg transgenic mice showed less adipose tissue mass with increased mRNA expression levels of Tnf‐α and peroxisome proliferator‐activated receptor γ coactivator 1α (Pgc‐1α) and delayed white adipose tissue development during the convalescent stage in a dextran sodium sulfate‐induced colitis model. This study showed that Areg mRNA expression was significantly up‐regulated in obese adipose tissues and over‐expression of Areg in white adipose tissue caused less adipose tissue mass.

Increased intestinal ethanol following consumption of fructooligosaccharides in rats

Previous studies have suggested that ethanol is a fermentation product of microflora. However, it is unknown whether this ethanol production is elevated by intake of prebiotics. Prebiotics are considered to enhance the production of short-chain fatty acids (SCFAs) as a fermentation product of beneficial bacteria. In the present study, the effect of fructooligosaccharides (FOS) consumption on intestinal ethanol levels was investigated. Rats were fed a diet with or without 10% FOS for two weeks. Consequently, FOS intake significantly increased ethanol levels per gram of ileum and cecum digesta of the rats (3.5-fold and 1.9-fold, respectively, P<0.01). The numbers of cecum Bifidobacterium (producer of ethanol and lactate) were significantly increased by FOS intake (P<0.05) and correlated with the cecum ethanol levels per gram of cecum (r=0.626, P<0.05). FOS intake also led to a significant increase in the cecum levels of SCFAs, namely lactate, propionate and n-butyrate (P<0.05). Furthermore, ethanol levels were significantly correlated with lactate levels (r=0.691, P<0.01), but not with propionate or n-butyrate levels (r=0.449 and 0.493, respectively, P>0.05). The current study, to the best of our knowledge, is the first to indicate that FOS intake significantly increases the level of intestinal ethanol. Therefore, dietary FOS may affect the intestinal health status of animals by elevating their ethanol levels, without direct ethanol consumption.

TALEN-mediated targeted editing of the GDE5 gene suppresses fibroblastic cell proliferation

In this study, we investigated the physiological function of glycerophosphodiesterase 5 (GDE5) in the proliferation of NIH3T3 fibroblasts. We used transcription activator-like effector nuclease (TALEN) in NIH3T3 cells with an intron targeting-mediated GDE5 gene knockout. The heterozygously GDE5-targeted NIH3T3 fibroblasts were isolated and showed decreased cell proliferation and up-regulation of EGFR mRNA expression, indicating that GDE5 modulates fibroblastic cell proliferation.