Search

Emerging effects of tryptophan pathway metabolites and intestinal microbiota on metabolism and intestinal function. 10.1007/s00726-021-03064-x. 34468872 4 Gasaly N, Gotteland M. Interference of dietary polyphenols with potentially toxic amino acid metabolites derived from the colonic microbiota. References 1 Armand L, Fofana M, Couturier-Becavin K, Andriamihaja M, Blachier F. Dual effects of the tryptophan-derived bacterial metabolite indole on colonic epithelial cell metabolism and physiology: comparison with its co-metabolite indoxyl sulfate. [Extracted from the article]

Supplementation with whey and other dietary protein, mainly associated with exercise training, has been proposed to be beneficial for the elderly to gain and maintain lean body mass and improve health parameters. The main objective of this review is to examine the evidence provided by the scientific literature indicating benefit from such supplementation and to define the likely best strategy of protein uptake for optimal objectified results in the elderly. Overall, it appears that an intake of approximately 0.4 g protein/kg BW per meal thus representing 1.2-1.6 g protein/kg BW/day may be recommended taking into account potential anabolic resistance. The losses of the skeletal muscle mass contribute to lower the capacity to perform activities in daily living, emphasizing that an optimal protein consumption may represent an important parameter to preserve independence and contribute to health status. However, it is worth noting that the maximal intake of protein with no adverse effect is not known, and that high levels of protein intake is associated with increased transfer of protein to the colon with potential deleterious effects. Thus, it is important to examine in each individual case the benefit that can be expected from supplementation with whey protein, taking into account the usual protein dietary intake. [ABSTRACT FROM AUTHOR]

The present review focuses on the physiological functions of glutamate-glutamine exchange involving placental amino acid transport and umbilical amino acid uptake in mammals (particularly in sows), with special emphasis on the associated regulating mechanisms. Glutamate plus glutamine are among the most abundant and the most utilized amino acids in fetus during late gestation. During pregnancy, amino acids, notably as precursors of macromolecules including proteins and nucleotides are involved in fetal development and growth. Amino acid concentrations in fetus are generally higher than in the mother. Among amino acids, the transport and metabolism of glutamate and glutamine during fetal development exhibit characteristics that clearly emphasize the importance of the interaction between the placenta and the fetal liver. Glutamate is quite remarkable among amino acids, which originate from the placenta, and is cleared from fetal plasma. In addition, the flux of glutamate through the placenta from the fetal plasma is highly correlated with the umbilical glutamate delivery rate. Glutamine plays a central role in fetal carbon and nitrogen metabolism and exhibits one of the highest fetal/maternal plasma ratio among all amino acids in human and other mammals. Glutamate is taken up by placenta from the fetal circulation and then converted to glutamine before being released back into the fetal circulation. Works are required on the glutamate-glutamine metabolism during late pregnancy in physiological and pathophysiological situations since such works may help to improve fetal growth and development both in humans and other mammals. Indeed, glutamine supplementation appears to ameliorate fetal growth retardation in sows and reduces preweaning mortality of piglets. [ABSTRACT FROM AUTHOR]

Dietary glutamate is extensively oxidized in enterocytes during its trans-cellular journey from the intestinal lumen to the blood. This corresponds to high energy requirement for the absorptive function and renewal of the epithelium. Excitatory amino acid carrier 1 (EAAC1) is known to be the major transporter of glutamate in the intestine. The present study was conducted in Huanjiang mini-piglets which represent a valuable agronomical model for pig production and also extrapolation to human intestinal physiology in order: (i) to determine the amino acid sequence of EAAC1; (ii) to measure the ontogenic expression profiles of jejunal EAAC1 during the suckling period and (iii) to evaluate the influence of low body weight at birth on the expression of EAAC1. For such a purpose, we cloned EAAC1 from Huanjiang mini-pig and used real-time RT-PCR method and Western blotting analysis. Our results show that EAAC1 in the mini-pig encoded a predicted 524-AA protein with eight putative trans-membrane domains. The expression in mRNA and protein of EAAC1 in jejunum was increasing from birth up to 14 days of age and then decreased at 21 days. Piglets with small BW had lower jejunal EAAC1 protein content between birth and after 7 days suckling. These findings indicate that the expression of the EAAC1 in jejunum is much depending on the stage of piglet development and that low BW at birth is associated with lower expression of this carrier in the early suckling period. Then, it can be hypothesized that lower expression of the intestinal glutamate carrier may decrease the availability of glutamate to enterocytes, thus challenging the optimal absorptive function of the small intestine and normal mucosal growth. [ABSTRACT FROM AUTHOR]

Placental vascular formation and blood flow are crucial for fetal survival, growth and development, and arginine regulates vascular development and function. This study determined the effects of dietary arginine or N-carbamylglutamate (NCG) supplementation during late gestation of sows on the microRNAs, vascular endothelial growth factor A (VEGFA) and endothelial nitric oxide synthase (eNOS) expression in umbilical vein. Twenty-seven landrace × large white sows at day (d) 90 of gestation were assigned randomly to three groups and fed the following diets: a control diet and the control diet supplemented with 1.0% l-arginine or 0.10% NCG. Umbilical vein of fetuses with body weight around 2.0 kg (oversized), 1.5 kg (normal) and 0.6 kg (intrauterine growth restriction, IUGR) were obtained immediately after farrowing for miR-15b, miR-16, miR-221, miR-222, VEGFA and eNOS real-time PCR analysis. Compared with the control diets, dietary Arg or NCG supplementation enhanced the reproductive performance of sows, significantly increased ( P < 0.05) plasma arginine and decreased plasma VEGF and eNOS ( P < 0.05). The miR-15b expression in the umbilical vein was higher ( P < 0.05) in the NCG-supplemented group than in the control group. There was a trend in that the miR-222 expression in the umbilical vein of the oversized fetuses was higher (0.05 < P < 0.1) than in the normal and IUGR fetuses. The expression of eNOS in both Arg-supplemented and NCG-supplemented group were lower ( P < 0.05) than in the control group. The expression of VEGFA was higher ( P < 0.05) in the NCG-supplemented group than in the Arg-supplemented and the control group. Meanwhile, the expression of VEGFA of the oversized fetuses was higher ( P < 0.05) than the normal and IUGR fetuses. In conclusion, this study demonstrated that dietary Arg or NCG supplementation may affect microRNAs (miR-15b, miR-222) targeting VEGFA and eNOS gene expressions in umbilical vein, so as to regulate the function and volume of the umbilical vein, provide more nutrients and oxygen from the maternal to the fetus tissue for fetal development and survival, and enhance the reproductive performance of sows. [ABSTRACT FROM AUTHOR]

Calbindin- d 28K expression in insulin-producing tumoral cells of the RINm5F line was assessed by Western-blot and high pressure liquid chromatography. Western blot analysis demonstrated the presence in RINm5F cell homogenates of a protein recognized by a specific polyclonal antibody against chick calbindin. Proteins with apparent molecular weights (mol wt) of 44, 47, 56, and 85 kD were also recognized by the antiserum in RINm5F cell extract, but not in normal rat islet extract. HPLC heat-resistant protein extract from RINm5F cell homogenates revealed three calbindin positive peaks: a major peak with a retention time (20.5 min) identical to that found in a rat cerebellar extract and two minor peaks with shorter retention times. The calbindin content of RINm5F cells was apparently unaffected after 9 d culture in a medium supplemented with 10% calf serum pretreated with dextran-charcoal to remove 1,25-dihydroxyvitamin D. [ABSTRACT FROM AUTHOR]

This study explored the effect of dietary xylo-oligosaccharide (XOS) supplementation on the gut microbial composition and activity in pigs of different ages. Eighty pigs with an average body weight (BW) of 30 kg were randomly divided into eight groups: A control group, a group that received antibiotic treatment, and six groups fed diets supplemented with 100, 250, and 500 g/t XOS, of which three groups were in the growing period (GP, 30–65 kg BW) and three groups in the growing and fattening period (GFP, 30–100 kg BW). At the end of the experiment, the intestinal contents were sampled for analyses of gut microbiota and bacterial metabolites including short-chain fatty acids (SCFAs) and bioamines. The results showed that 100 g/t XOS supplementation during the GFP significantly reduced the relative abundances of presumably pathogenic bacteria (Proteobacteria and Citrobacter), but enhanced the relative abundances of likely beneficial bacteria (Firmicutes and Lactobacillus). However, XOS supplementation during the GP showed little effect on the gut microbiota when pigs were killed at 100 kg BW. Meanwhile, 100 g/t XOS supplementation during the GFP decreased the level of 1,7-heptane diamine and increased the acetic acid, straight-chain fatty acids, and total SCFAs concentrations in the intestinal contents. Statistical analysis showed that both the dose and exposure time to XOS supplementation affected the microbial communities. In summary, 100 g/t XOS supplementation during the GFP modified the gut microbiota composition and metabolic activity. Possible consequences of such changes for the host are discussed. [ABSTRACT FROM AUTHOR]

Gut microbiota positively contribute to livestock nutrition and metabolism. The manipulation of these microbes may improve animal health. Some feed additives improve livestock health and metabolism by regulating gut microbiota composition and activity. We fed hybrid pigs diets supplemented with 0% (control), 5% (treat 1), 10% (treat 2), or 15% (treat 3) fermented Mao-tai lees (FML) for 90 days. Short-chain fatty acids (SCFAs), bioamines, and microbial communities found in colonic contents were analyzed to investigate microbiota composition and metabolic profiles. Concentrations of straight-chain fatty acids (e.g., acetate, propionate, and butyrate) and tyramine increased with FML supplementation content. Contrary to the minor effects of 5% and 10% FML on gut microbiota, 15% FML influenced beta diversity (Jaccard or Bray-Curtis dissimilarity) but not alpha diversity (number of operational taxonomic units and Shannon diversity) of pig gut microbial communities compared to the control group. Notably, 15% FML animals were characterized by a higher abundance of potentially beneficial bacteria (Lactobacillus and Akkermansia) but lower abundances of potential pathogens (Escherichia). Numerous genes associated with metabolism (e.g., starch, sucrose, and sulfur-compounds metabolism) showed a higher relative abundance in the 15% FML than in the control group. Additionally, most Phascolarctobacterium, Treponema, Prevotella, and Faecalibacterium bacterial markers in the 15% FML group were positively correlated with straight-chain fatty acid concentrations, suggesting that these bacteria are likely associated with SCFA production. Taken together, our findings demonstrate the beneficial effects of 15% FML on fermentation of undigested compounds and gut microbiota composition in the colon. Thus, 15% FML supplementation in pig feed may possibly represent a way to optimize pig colon health for livestock farming. [ABSTRACT FROM AUTHOR]