Background
The effects of β-glucan on colitis mice are contradictory in previous reports. As a result, it is still unclear whether there is an anti-colitis effect in
Ganoderma lucidum
polysaccharide (GLP), which is mainly composed of β-glucan. Moreover, the association between GLP function and gut microbiota remains to be elucidated.
Objective
This study aimed to investigate whether GLP consumption improved rat dextran sodium sulfate (DSS)-induced colitis by regulating gut microbiota and altering colonic epithelial expression.
Design
The disease activity index (DAI) scores and the cecal short chain fatty acid (SCFA) levels of DSS-induced colitis rats fed with a GLP diet (Group GLP,
n
= 6) and a control diet (Group Con,
n
= 6) were investigated and analyzed. Moreover, the profiles of gut microbiota and colonic epithelial expression were analyzed using metagenomics and transcriptomics.
Results
GLP consumption significantly lowered animal DAI scores by producing more SCFAs by increasing SCFA-producing bacteria such as
Ruminococcus_1
and reducing pathogens such as
Escherichia-Shigella
in both the small intestine and cecum of rat. Moreover, GLP consumption regulated 11 genes, including six upregulated (
Ccl5
,
Cd3e
,
Cd8a
,
Il21r
,
Lck
, and
Trbv
) and five downregulated (
Ccl3
,
Gro
,
Il11
,
Mhc2
, and
Ptgs
) genes enriched in six inflammation-related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, resulting in enhancement of immunity and reduction of inflammatory response and colonic cancer risk.
Conclusions
GLP consumption alleviated DSS-induced colitis and may have potential for ulcerative colitis relief.
Polyphenol compositions and concentrations in skins and seeds of five muscadine grapes (cv. "Noble", "Alachua", "Carlos", "Fry", and "Granny Val") cultivated in the United States (Tallahassee-Florida, TA-FL) and South China (Nanning-Guangxi, NN-GX and Pu'er-Yunnan, PE-YN) were investigated, using ultra performance liquid chromatography tandem triple quadrupole time-of-flight mass spectrometry (UPLC Triple TOF MS/MS). Fourteen ellagitannins were newly identified in these muscadine grapes. The grapes grown in NN-GX accumulated higher levels of ellagic acid, methyl brevifolin carboxylate, and ellagic acid glucoside in skins, and penta-O-galloyl-glucose in seeds. In PE-YN, more flavonols were detected in skins, and higher contents of flavan-3-ols, ellagic acid, and methyl gallate were identified in seeds. Abundant seed gallic acid and flavonols were found among the grapes grown in TA-FL. Based on principal component analysis (PCA) of 54 evaluation parameters, various cultivars grown in different locations could be grouped together and vice versa for the same cultivar cultivated in different regions. This is the result of the interaction between genotype and environmental conditions, which apparently influences the polyphenol synthesis and accumulation.
Obesity is a metabolic syndrome worldwide that causes many chronic diseases. Recently, we found an antiobesity effect of flaxseed polysaccharide (FP), but the mechanism remains to be elucidated. In this study, rats were first induced to develop obesity by being fed a high-fat diet. The obese rats were then fed a control diet, AIN-93M (group HFD), or a 10% FP diet (group FPD). The body weight, body fat, adipose tissue and liver sections, serous total triglycerides, levels of fasting blood glucose in serum, serous insulin, inflammatory cytokines in serum, and serous proteins within the leptin−neuropeptide Y (NPY) and AMP-activated protein kinase (AMPK) signaling pathway were determined and analyzed. FP intervention significantly reduced body weight and abdominal fat from 530 ± 16 g and 2.15% ± 0.30% in group HFD to 478 ± 10 g and 1.38% ± 0.48% in group FPD, respectively. This effect was achieved by removing leptin resistance possibly by inhibiting inflammation and recovering satiety through the significant downregulation of NPY and the upregulation of glucagon-like peptide 1. Adiponectin was then significantly upregulated probably via the gut−brain axis and further activated the AMPK signaling pathway to improve lipid metabolism including the improvement of lipolysis and fatty acid oxidation and the suppression of lipogenesis. This is the first report of the proposed antiobesity mechanism of FP, thereby providing a comprehensive understanding of nonstarch polysaccharides and obesity.
Both fructooligosaccharide (FOS) and polyphenols can be individually and directly transferred to the large intestine of mammals and are beneficial for human health as they reshape the composition of gut microbiota. The combination impact of FOS and polyphenols on rats' gut microbiota and the corresponding consequences on rats were investigated via MiSeq sequencing technique and bioinformatics. The results showed that the combination of different phenolic compounds and FOS displayed distinct impact on the host. The addition of catechin to a FOS diet inhibited Firmicutes and enhanced Bacteroidetes. Moreover, the content of each short chain fatty acid fluctuated in various groups because different unique bacterial species survived or were inhibited under three conditions. On the other aspects, the supplement of catechin controlled the body weight (BW), up-regulated serum leptin, induced more soluble carbohydrates and less soluble polysaccharides in feces, and inhibited or activated some specific genera. The inhibition of genera by catechin could be responsible for the degradation of carbohydrates in gut and the activation of genera might be keystones for the increment of serum leptin. The effect of consuming FOS and/or polyphenols on the health of hosts needs to be further explored.
Dietary fiber (DF) can be broken down into short-chain fatty acids (SCFAs) such as acetic, propionic and n-butyric acid by gut microbiota to obtain energy. Therefore, dietary fibers have effects on the balance of gut microbiota and the production of SCFAs. In the four-week feeding, mice were fed with four dietary fibers, including pectin, resistant starch (RS), fructo-oligosaccharide (FOS) and cellulose. The results showed that the mice body-weight gain was the smallest (7.0 ± 2.3 g) when the mixture of RS-FOS-cellulose was ingested, followed by the mixture of RS-cellulose (7.2 ± 3.5 g) and FOS-cellulose (8.3 ± 2.5 g). Ingestion of the mixture of pectin-FOS-cellulose, RS-FOS and RS-FOS-cellulose can respectively increase the diversity of the gut microbiota with 12, 11 and 11 terminal restriction fragments (TRFs) detected (digested by Hha I). The maximum amount of total SCFAs were produced by the mixture of FOS-cellulose (5.504 ± 0.029 μmol mL(-1)), followed by pectin-FOS-cellulose (3.893 ± 0.024 μmol mL(-1)) and pectin-RS-FOS-cellulose (3.309 ± 0.047 μmol mL(-1)). In conclusion, the addition of DFs (pectin, RS, FOS and cellulose), in single or mixture pattern, can exert different effects. An amount of 10.7% of single DF in the diet cannot be conducive to the balance of gut microbiota after ingestion for a long time, however, it can help with body weight loss like the mixtures of DFs in this study; FOS is a very important component in the mixture of DFs for both the balance of the gut microbiota and the production of SCFAs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.