Studies on the effect of the gut microflora on dietary nitrogen digestibility in pigs

1984 ◽  
Vol 1984 ◽  
pp. 59-59
Author(s):  
B. Ratcliffe ◽  
A.G. Low
Keyword(s):  
Amino Acids ◽  
Preliminary Report ◽  
Gut Microflora ◽  
Reliable Measure ◽  
Germ Free ◽  
Miniature Pigs ◽  
Dietary Nitrogen ◽  
Dietary Amino Acids ◽  
General Recognition ◽  
Dietary Origin

Proteins which escape digestion and absorption in the small intestine of the pig are extensively metabolized by the microbial flora of the large intestine. It is known that bacterial enzymes are potentially capable of catabolizing all amino acids (Michel, 1966). Furthermore, it has been shown that virtually all soluble protein or amino acids introduced into the caecum are rapidly metabolized, absorbed (presumably as ammonia, amines etc.) and the nitrogen (N) derived from them is rapidly excreted as urea (Zebrowska, 1973). This has led to the general recognition that the amino acid composition is not a reliable measure of undigested dietary amino acids in pigs. It has been estimated that only 6% of faecal N is of undigested dietary origin, while the remainder is of bacterial or endogenous origin (Low, Sambrook & Yoshimoto, 1978). It was therefore of interest to estimate which proportions of faecal N derived from a barley-soya diet, are of either bacterial, endogenous or undigested dietary origin. We have used germ-free or conventional miniature pigs for this work because they are small enough to be kept in our isolators for periods of up to 20 weeks. It is emphasised that this is a preliminary report on our first efforts at raising miniature pigs under germ-free conditions.

Gastrointestinal Interaction between Dietary Amino Acids and Gut Microbiota: With Special Emphasis on Host Nutrition

2020 ◽  
Vol 21 (8) ◽  
pp. 785-798 ◽  
Author(s):  
Abedin Abdallah ◽  
Evera Elemba ◽  
Qingzhen Zhong ◽  
Zewei Sun
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Immune System ◽  
Gut Microbiota ◽  
Short Chain Fatty Acids ◽  
Nutrition And Health ◽  
Nitrogenous Compounds ◽  
Dietary Amino Acids ◽  
Host Nutrition ◽  
Chain Fatty Acids

The gastrointestinal tract (GIT) of humans and animals is host to a complex community of different microorganisms whose activities significantly influence host nutrition and health through enhanced metabolic capabilities, protection against pathogens, and regulation of the gastrointestinal development and immune system. New molecular technologies and concepts have revealed distinct interactions between the gut microbiota and dietary amino acids (AAs) especially in relation to AA metabolism and utilization in resident bacteria in the digestive tract, and these interactions may play significant roles in host nutrition and health as well as the efficiency of dietary AA supplementation. After the protein is digested and AAs and peptides are absorbed in the small intestine, significant levels of endogenous and exogenous nitrogenous compounds enter the large intestine through the ileocaecal junction. Once they move in the colonic lumen, these compounds are not markedly absorbed by the large intestinal mucosa, but undergo intense proteolysis by colonic microbiota leading to the release of peptides and AAs and result in the production of numerous bacterial metabolites such as ammonia, amines, short-chain fatty acids (SCFAs), branched-chain fatty acids (BCFAs), hydrogen sulfide, organic acids, and phenols. These metabolites influence various signaling pathways in epithelial cells, regulate the mucosal immune system in the host, and modulate gene expression of bacteria which results in the synthesis of enzymes associated with AA metabolism. This review aims to summarize the current literature relating to how the interactions between dietary amino acids and gut microbiota may promote host nutrition and health.

10 THE ROLE OF DIETARY L-SERINE IN THE REGULATION OF INTESTINAL MUCUS BARRIER DURING INFLAMMATION

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S42-S42
Author(s):  
Kohei Sugihara ◽  
Nobuhiko Kamada
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gut Microbiota ◽  
Control Diet ◽  
Bacterial Strains ◽  
Germ Free ◽  
Intestinal Mucus ◽  
Gnotobiotic Mice ◽  
Mucus Barrier

Abstract Background Recent accumulating evidence suggests that amino acids have crucial roles in the maintenance of intestinal homeostasis. In inflammatory bowel disease (IBD), amino acid metabolism is changed in both host and the gut microbiota. Among amino acids, L-serine plays a central role in several metabolic processes that are essential for the growth and survival of both mammalian and bacterial cells. However, the role of L-serine in intestinal homeostasis and IBD remains incompletely understood. In this study, we investigated the effect of dietary L-serine on intestinal inflammation in a murine model of colitis. Methods Specific pathogen-free (SPF) mice were fed either a control diet (amino acid-based diet) or an L-serine-deficient diet (SDD). Colitis was induced by the treatment of dextran sodium sulfate (DSS). The gut microbiome was analyzed by 16S rRNA sequencing. We also evaluate the effect of dietary L-serine in germ-free mice and gnotobiotic mice that were colonized by a consortium of non-mucolytic bacterial strains or the consortium plus mucolytic bacterial strains. Results We found that the SDD exacerbated experimental colitis in SPF mice. However, the severity of colitis in SDD-fed mice was comparable to control diet-fed mice in germ-free condition, suggesting that the gut microbiota is required for exacerbation of colitis caused by the restriction of dietary L-serine. The gut microbiome analysis revealed that dietary L-serine restriction fosters the blooms of a mucus-degrading bacterium Akkermansia muciniphila and adherent-invasive Escherichia coli in the inflamed gut. Consistent with the expansion of mucolytic bacteria, SDD-fed mice showed a loss of the intestinal mucus layer. Dysfunction of the mucus barrier resulted in increased intestinal permeability, thereby leading to bacterial translocation to the intestinal mucosa, which subsequently increased the severity of colitis. The increased intestinal permeability and subsequent bacterial translocation were observed in SDD-fed gnotobiotic mice that colonized by mucolytic bacteria. In contrast, dietary L-serine restriction did not alter intestinal barrier integrity in gnotobiotic mice that colonized only by non-mucolytic bacteria. Conclusion Our results suggest that dietary L-serine regulates the integrity of the intestinal mucus barrier during inflammation by limiting the expansion of mucus degrading bacteria.

Important impacts of intestinal bacteria on utilization of dietary amino acids in pigs

Amino Acids ◽  
2014 ◽  
Vol 46 (11) ◽  
pp. 2489-2501 ◽  
Author(s):  
Yu-Xiang Yang ◽  
Zhao-Lai Dai ◽  
Wei-Yun Zhu
Keyword(s):  
Amino Acids ◽  
Intestinal Bacteria ◽  
Dietary Amino Acids

scholarly journals High-coverage metabolomics uncovers microbiota-driven biochemical landscape of interorgan transport and gut-brain communication in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yunjia Lai ◽  
Chih-Wei Liu ◽  
Yifei Yang ◽  
Yun-Chung Hsiao ◽  
Hongyu Ru ◽  
...  
Keyword(s):  
Amino Acids ◽  
Brain Function ◽  
Aromatic Amino Acids ◽  
Indoxyl Sulfate ◽  
Future Research ◽  
High Coverage ◽  
Microbial Ecosystem ◽  
Germ Free ◽  
Host Metabolism ◽  
Gender Specific

AbstractThe mammalian gut harbors a complex and dynamic microbial ecosystem: the microbiota. While emerging studies support that microbiota regulates brain function with a few molecular cues suggested, the overall biochemical landscape of the “microbiota-gut-brain axis” remains largely unclear. Here we use high-coverage metabolomics to comparatively profile feces, blood sera, and cerebral cortical brain tissues of germ-free C57BL/6 mice and their age-matched conventionally raised counterparts. Results revealed for all three matrices metabolomic signatures owing to microbiota, yielding hundreds of identified metabolites including 533 altered for feces, 231 for sera, and 58 for brain with numerous significantly enriched pathways involving aromatic amino acids and neurotransmitters. Multicompartmental comparative analyses single out microbiota-derived metabolites potentially implicated in interorgan transport and the gut-brain axis, as exemplified by indoxyl sulfate and trimethylamine-N-oxide. Gender-specific characteristics of these landscapes are discussed. Our findings may be valuable for future research probing microbial influences on host metabolism and gut-brain communication.

Dietary Amino Acids and Mood

2011 ◽  
pp. 565-576
Author(s):  
Reeta Rintamäki ◽  
Timo Partonen
Keyword(s):  
Amino Acids ◽  
Dietary Amino Acids
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