The protective effects of Levilactobacillus brevis FZU0713 on lipid metabolism and intestinal microbiota in hyperlipidemic rats

Levilactobacillus brevis FZU0713, a potential probiotic previously isolated from the traditional brewing process of Hongqu rice wine, may have the beneficial effects on improving lipid metabolism. This study aimed to evaluate the in vivo protective effects and possible mechanism of L. brevis FZU0713 on the disturbance of lipid metabolism in hyperlipidemic rats fed a high-fat diet(HFD). Results showed that oral administration of L. brevis FZU0713 could significantly inhibit obesity, ameliorate the lipid metabolism disorder, including serum/liver biochemical parameters and hepatic oxidative stress in HFD-fed rats. Histopathological result also indicated that dietary intervention of L. brevis FZU0713 could reduce the accumulation of lipid droplets in liver induced by 8 weeks HFD feeding. Furthermore, L. brevis FZU0713 intervention significantly increased the fecal levels of short-chain fatty acids(SCFAs, including acetate, propionate, butyrate, isobutyrate, valerate and isovalerate)in HFD-fed rats, which may be closely related to the changes of intestinal microbial composition and metabolic function. Intestinal microbiota profiling by 16S rRNA gene sequencing revealed that L. brevis FZU0713 intervention significantly altered the relative abundance of Coprococcus, Butyricicoccus, Intestinimonas, Lachnospiraceae FCS020 group, Ruminococcaceae_NK4A214 group, Ruminococcaceae_UCG-005 and UCG-014 at genus levels. Based on Spearman's rank correlation coefficient, serum and liver lipid metabolism related biochemical parameters were positively correlated with genera Ruminococcus, Pediococcus and Lachnospiraceae, but negatively correlated with genera Pseudoflavonifractor, Butyricicoccus and Intestinimonas. Furthermore, liver metabolomics analysis demonstrated that L. brevis FZU0713 had a significant regulatory effect on the composition of liver metabolites in hyperlipidemic rats, especially the levels of some important biomarkers involved in the metabolic pathways of arachidonic acid metabolism, primary bile acid biosynthesis, amino sugar and nucleotide sugar metabolism, taurine and hypotaurine metabolism, biosynthesis of unsaturated fatty acid, fructose and mannose metabolism, tyrosine metabolism, etc. Additionally, oral administration of L. brevis FZU0713 significantly regulated the mR NA levels of liver genes(including Acat2, Acox1, Hmgcr, Cd36, Srebp-1c and Cyp7a1)involved in lipid metabolism and bile acid homeostasis. In conclusion, our findings provide the evidence that L. brevis FZU0713 has the potential to improve disturbance of lipid metabolism by regulating intestinal microflora and liver metabonomic profile. Therefore, L. brevis FZU0713 may be used as a potential probiotic strain to produce functional food to prevent hyperlipidemia.

Relation of tea ingestion to salivary redox and flow rate in healthy subjects

The biochemistry of human saliva can be altered by food intake.The benefits of tea drinking were extensively studied but the influence of tea ingestion on human saliva has not been revealed.The work aimed to investigate the immediate and delayed effect of vine tea,oolong tea and black tea intake on certain salivary biochemistry and flow rate.The saliva samples of healthy subjects were collected before,after and 30 min after tea ingestion.The chemical compositions and antioxidant capacity of tea samples were analyzed to correlate with salivary parameters.Principal component analysis indicated that the effects of vine tea consumption were dominated by increasing salivary flow rate(SFR),production rate of total protein(TPC),thiol(SH),malondialdehyde,catalase activity and antioxidant capacity(FRAP)in saliva.The antioxidant profile of studied tea samples(FRAP,polyphenols,flavonoids)was positively correlated with salivary SFR,TPC,SH and FRAP but negatively correlated with salivary uric acid concentration in saliva.

Hypothesis review:The direct interaction of food nanoparticles with the lymphatic system

Besides digestion and assimilation,there are other modes of direct interaction between food and human body.As it is known,the mucosal layer of the digestive tract interfaces with food after the digestion process.It has been demonstrated to uptake the micro-and nanoparticles via mucosa-associated lymphatic tissues(MALT).On the other hand,food is a typical polydisperse system and contains micro-and nanoparticles with different sizes and properties.Accordingly,it is hypothesized that food nanoparticles can directly interact with MALT and more specifically with the support of the preliminary experimental data from our research,that antioxidant nanoparticles can interact with the lymphatic vessels.This kind of interaction would be of great physiological importance.The confirmation of the hypothesis will establish a significant and novel approach to understand food system and provide answers to currently incomprehensible phenomena such as the biological functions of phytochemicals with low bioavailability.©2012 Production and hosting by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.