Shiyi Ou

Continuously Ingesting Fructooligosaccharide Can't Maintain Rats’ Gut Bifidobacterium at a High Level

UNLABELLEDnFructooligosaccharide (FOS) has been reported to increase Lactobacillus and Bifidobacterium populations in animal and human gut. Hence, it has been utilized to regulate the balance of gut microbiota. In this study, we compared the effects of high-FOS (HFOS) diet on normal and obese rats gut Lactobacillus and Bifidobacterium, with high-soybean-fibers (HSF) diet as control. The results showed that the level of Bifidobacterium population substantially increased at week 4 in groups of rats fed the HFOS diet (P < 0.05), but significantly reduced to a small level at week 8 (P < 0.05); the abundance of Lactobacillus was increased in normal rats (P < 0.05), but decreased in obese rats (P < 0.05). The HSF diet did not promote the growth of Lactobacillus and Bifidobacterium in rats gut. The findings suggested that Bifidobacterium population could not be maintained at a high level when the rats continuously ingested the HFOS diet for 8 wk; additionally, Lactobacillus population could adapt to a relatively stable level with the consumption of HFOS diet.nnnPRACTICAL APPLICATIONnFructooligosaccharide (FOS) is one of the most popular prebiotics, and it is widely used in infant formulas, which is aiming to increase the growth of probiotics like Lactobacillus and Bifidobacterium. This study discovered new growth rhythm of Bifidobacterium based on a high-FOS diet. The growth of Bifidobacterium was first promoted but receded in the end. This finding is highly instructive and meaningful for the application of fructooligosaccharide in probiotic or prebiotic food.

Feruloylated Oligosaccharides from Maize Bran Modulated the Gut Microbiota in Rats

Corn bran is a byproduct produced from corn milling; it is rich in ferulic acid and hemicellulose. In this research, the effects of feruloylated oligosaccharides (FOs) from maize bran on the microbial diversity and profiles in rat feces were investigated through 16S rRNA sequencing. FOs significantly increased bacterial richness and diversity compared with the control and xylooligosaccharides (XOS) alone. In comparison with the control group and the group administrated with XOS, FOs orally administered at 300xa0mg/kg increased OTU in feces by 57.0 and 24.8xa0%, and Chao value by 93.4 and 37.6xa0%, respectively. FOs also influenced obesity- and diabetes-associated bacteria. Oral administration of FOs at 300xa0mg/kg decreased the ratio of Firmicutes to Bacteroidetes from 477.7:1 to 55.1:1; greatly increased the reads of bacteria that were previously found resistant against diabetes in rats, such as Actinobacteria, Bacteroides, and Lactobacillus; whereas decreased diabetes-prone bacteria, such as Clostridium and Firmicutes.

Different Flavonoids Can Shape Unique Gut Microbiota Profile In Vitro.

The impact of flavonoidsxa0hasxa0been discussed on the relative viability of bacterial groups in human microbiota. This study was aimed to compare the modulation of various flavonoids, including quercetin, catechin and puerarin, on gut microbiota culture in vitro, and analyze the interactions between bacterial species using fructo-oligosaccharide (FOS) as carbon source under the stress of flavonoids. Three plant flavonoids, quercetin, catechin, and puerarin, were added into multispecies culture to ferment for 24 h, respectively. The bacterial 16S rDNA amplicons were sequenced, and the composition of microbiota community was analyzed. The results revealed that the tested flavonoids, quercetin, catechin, and puerarin, presented different activities of regulating gut microbiota; flavonoid aglycones, but not glycosides, may inhibit growth of certain species. Quercetin and catechin shaped unique biological webs. Bifidobacterium spp. was the center of the biological web constructed in this study.

Lean rats gained more body weight than obese ones from a high-fibre diet

There is controversy over previous findings that a high ratio of Firmicutes to Bacteriodetes helps obese animals harvest energy from the diet. To further investigate the relationship between microbial composition and energy harvest, microbial adaptation to diet and time should be considered. In this study, lean and obese rats were successfully induced with low-fat and high-fat diets. An 8-week high soyabean fibre (HSF)-containing diet was then fed to investigate the interaction between the diet and the rats gut microbiota, as well as their influence on rats growth. Rats body weight (BW) was recorded weekly; their plasma lipids and their gut microbiota at week 11, 15 and 19 were analysed. After the consumption of the HSF diet, BW of lean rats increased significantly (P<0·05), but no significant alteration in BW was found in obese rats. The average content of plasma cholesterol was lowered and that of TAG was upgraded in both the groups when fed the HSF diet. There was no significant difference observed at each period between lean and obese rats. In the group of lean rats, the diversity of gut microbiota was elevated strongly (P<0·01), and bacteria from phylum Firmicutes and Bacteroidetes were both increased largely (P<0·01); however, the bacterial diversity and composition in obese rats were less altered after the HSF diet control. In conclusion, the increased Firmicutes and Bacteriodetes might relate to lean rats higher BW gain; obese microbiota could not help the hosts harvest more energy from the HSF diet.

Enhanced swelling and multiple-responsive properties of gelatin/sodium alginate hydrogels by the addition of carboxymethyl cellulose isolated from pineapple peel

AbstractnNatural polymers hydrogels were prepared by solution blending of gelatin, sodium alginate and carboxymethyl cellulose isolated from pineapple peel, and cross-linking with CaCl2 and glutaraldehyde solutions. The prepared hydrogels were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and field emission scanning electron microscope. The swelling behaviors and responsiveness to pH, salt and electric field were also investigated. The swelling dynamic mechanism of hydrogels agreed well with the Fickian diffusion and Schott’s pseudo second order models. The addition of carboxymethyl cellulose enhanced the swelling ability of the hydrogels in the selected mediums and sensitivities to pH, salt and electric field. The electric response of the hydrogels showed pH-dependent, ionic strength-dependent and electric voltage-dependent. This multiple-responsive characteristic of the prepared hydrogels was conducive to application as potential biomaterials such as microsensors, actuators, artificial muscles and drug delivery systems.

Angiotensin‐I‐Converting Enzyme Inhibitory Activities and In Vivo Antihypertensive Effects of Sardine Protein Hydrolysate

In our previous study, an antihypertensive protein hydrolysate was prepared from sardine. This study aimed to investigate the composition of sardine protein hydrolysate (SPH) and its in vivo antihypertensive effect. SPH was separated sequentially with ultrafiltration and size exclusion chromatography. Fractions with high angiotensin-I-converting enzyme (ACE) inhibitory activity were further analyzed with RP-HPLC and amino acids analysis. Then, SPH was individually oral administrated to spontaneously hypertensive rats (SHR) and normotensive wistar kyoto rats (WKY) for 4 wk. After treatment, the systolic blood pressure (SBP), organxa0index, oxidative status, serum ACE activity, and serum angiotensin-II (ANG-II) of all the rats were determined. According to the separation and analysis results, 3 main fractions with high ACE-inhibitory activity were obtained with different amino acids composition. The animal experiments results showed that SPH could significantly reduce SBP (P < 0.05 or P < 0.01) within 4 h after a single oral administration. After a chronic oral administration, a steady state of SBP in SHR rats was attained. The heart weight index and left ventricular weight index were significantly reduced (P < 0.05) in SPH-treated SHR rats. The malonyldialdehyde (MDA) levels in organs and serum, serum ACE activity, and serum ANG-II concentration in SPH-treated SHR rats were significantly lowered (P < 0.05 or P < 0.01) as compared to their controls. Meanwhile there was no significant effect (P > 0.05) on those parameters in WKY rats. These results indicate that SPH can decrease blood pressure in SHR rats and not in WKY rats.

Hydrolysis of Dicaffeoylquinic Acids from Ilex kudingcha Happens in the Colon by Intestinal Microbiota

Monocaffeoylquinic acids (mono-CQAs) can be hydrolyzed or metabolized by pancreatin, intestinal brush border esterase, and microbiota in the colon. Data about the conversion of dicaffeoylquinic acids (diCQAs) in digestion are scarce. The diCQA-rich fraction including 3,4-, 3,5-, and 4,5-diCQAs was prepared from Ilex kudingcha, and the conversion in simulated gastricintestine was investigated. Artificial saliva, gastric and pancreatic fluids, Caco-2 monolayer cells, and anaerobic fermentation model were utilized to mimic digestions of the oral cavity, stomach, small intestine, and colon in vitro. The results revealed that diCQAs remained intact in simulated saliva, gastric, and pancreatic fluids and within Caco-2 cells. In anaerobic fermentation with human fecal slurry, diCQAs were hydrolyzed to mono-CQAs and caffeic acid, which were further metabolized to caffeic acid and dihydrocaffeic acid, respectively. The hydrolysis of diCQAs depended on the chemical structures, carbohydrates in the culture medium, and microbial compositions. Our research demonstrated that hydrolysis of diCQAs happened in the colon by intestinal microbiota.

Modulating Effects of Dicaffeoylquinic Acids from Ilex kudingcha on Intestinal Microecology in Vitro

Dietary polyphenols have been considered as novel prebiotics, and polyphenols could exert their functions through modulating intestinal microbiota. The diverse bioactivities of kudingcha could derive from its phenolic compounds, but the effects of dicaffeoylquinic acids (diCQAs) from Ilex kudingcha on intestinal microbiota have not been investigated. In the present study, high-throughput sequencing and anaerobic fermentation in vitro were utilized to investigate the microecology-modulating function of I. kudingcha diCQAs. As a result, diCQAs raised the diversity and exhibited a more considerable impact than a carbon source on the microbial profile. DiCQAs increased the relative abundances of Alistipes, Bacteroides, Bifidobacterium, Butyricimonas, Clostridium sensu stricto, Escherichia/Shigella, Parasutterella, Romboutsia, Oscillibacter, Veillonella, Phascolarctobacterium, Lachnospiracea incertae sedis, Gemmiger, Streptococcus, and Haemophilus and decreased the relative abundances of Ruminococcus, Anaerostipes, Dialister, Megasphaera, Megamonas, and Prevotella. DiCQAs also affected the generation of short-chain fatty acids through microbiota. The contents of acetic and lactic acids were raised, while the production of propionic and butyric acids was reduced. Conclusively, diCQAs from I. kudingcha had significant modulating effects on intestinal microbiota in vitro, which might be the fundamental of diCQAs exerting their bioactivities.

Combinative effect of sardine peptides and quercetin alleviates hypertension through inhibition of angiotensin I converting enzyme activity and inflammation

Hypertension had relation to angiotensin I converting enzyme (ACE) activity and inflammation. In our previous research, sardine peptides (SP) with ACE inhibitory activity were prepared. However, the combinative effect of SP and quercetin (QC) on hypertension alleviation was still unknown. In the present study, the antihypertensive effect of SP and QC was discovered and the optimal proportion of SP and QC (v/v=8:2, with 20.00mg/mL of SP and 12.99μg/mL of QC for their original concentrations) was screened on ACE activity inhibition in vitro. And the in vivo experiment supported it by indicating that the mixture reduced the systolic blood pressure, heart, left ventricular and kidney weight and their corresponding indices, serum ACE activity, angiotensin-II (ANG-II) and tumor necrosis factor-α (TNF-α) (in high dose) concentration in SHR rats. Besides, the mixture also lowers NO, TNF-α andinterleukin-6 (IL-6) concentration significantly in vitro. Hence, the combinative effect of SP and QC in optimal proportion had stronger inhibition on ACE activity than SP or QC alone, and could alleviate hypertension through inhibition of ACE activity and inflammation.

Catechin supplemented in a FOS diet induces weight loss by altering cecal microbiota and gene expression of colonic epithelial cells

Our previous study showed that catechin controlled rats body weights and changed gut microbiota composition when supplemented into a high-fructo-oligosaccharide (FOS) diet. This experiment is devised to further confirm the relationship between specific bacteria in the colon and body weight gain, and to investigate how specific bacteria impact body weight by changing the expression of colonic epithelial cells. Forty obese rats were divided into four groups: three catechin-supplemented groups with a high-FOS diet (100, 400, and 700 mg kg-1 d-1 catechin, orally administered) and one group with a high-FOS diet only. Food consumption and body weights were recorded each week. After one month of treatment, rats cecal content and colonic epithelial cells were individually collected and analyzed with MiSeq and gene expression profiling techniques, respectively. Results identified some specific bacteria at the genus level-including the increased Parabacteroides sp., Prevotella sp., Robinsoniella sp., [Ruminococcus], Phascolarctobacterium sp. and an unknown genus of YS2, and the decreased Lachnospira sp., Oscillospira sp., Ruminococcus sp., an unknown genus of Peptococcaceae and an unknown genus of Clostridiales in rats cecum-and eight genes-including one downregulated Pla2g2a and seven upregulated genes: Apoa1, Apoa4, Aabr07073400.1, Fabp4, Pik3r5, Dgat2 and Ptgs2 of colonic epithelial cells-that were due to the consumption of catechin. Consequently, various biological functions in connection with energy metabolism in colonic epithelial cells were altered, including fat digestion and absorption and the regulation of lipolysis in adipocytes. In conclusion, catechin induces host weight loss by altering gut microbiota and gene expression and function in colonic epithelial cells.