Botanicals and the Gut Microbiome
Namrita Lall in Medicinal Plants for Cosmetics, Health and Diseases, 2022
Hyper-nutrition is the increase in a body mass index due to an overload of nutrition and is associated with a cancer mortality rate that is much higher (Calle et al., 2003). The mechanism of action of the tumorigenesis through hyper-nutrition takes place through inflammation, accumulation of fat and resistance to insulin with hyperglycemia (Font-Burgada et al., 2016). Polysaccharides have the ability to promote the loss of weight and associate body-mass index and improvement of the dysbiosis that has occurred (Nguyen et al., 2016; Goffredo et al., 2016; Liu et al., 2019). The metabolites formed by polysaccharides, such as acetate and propionate, can be absorbed into the blood and contribute to weight management (Macfarlane and Macfarlane, 2011). Acetate seems to suppress an individual’s appetite and can increase the release of leptin from adipose tissues in mice (Xiong et al., 2004). Propionate lowers the synthesis of cholesterol, all indications of the positive outcome of a polysaccharide-enriched diet, and in this case, the potential lowering of a nutrition overload by lowering intake of food (Liu et al., 2019).
Emollient Esters and Oils
Randy Schueller, Perry Romanowski in Conditioning Agents for Hair and Skin, 2020
Hydrolytic stability is a major consideration for all esters. Possibly one of the reasons for the popularity of the isopropyl alcohol esters of fatty acids in preference to similar esters that can be made from a low-molecular-weight acid (such as propionic acid) and a fatty alcohol, is their improved hydrolytic stability. It is important to consider that when an ester such as isopropyl myristate does hydrolyze, the resulting products are isopropyl alcohol and myristic acid. However, when an ester such as myristyl propionate hydrolyzes, the resulting components are myristyl alcohol and propionic acid. In this example, isopropyl alcohol would have a much more agreeable odor than propionic acid. Additionally, the propionic acid will lower the product pH possibly to a point where it will be detrimental to the product or consumer.
Methylmalonic acidemia
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop in Atlas of Inherited Metabolic Diseases, 2020
A simplified test for the overall enzymatic block at the mutase step is to test the conversion by cultured fibroblasts of 14C-propionate to 14CO2 [84]. Assessment of 14C-MMA oxidation permits distinction of MMA from propionic acidemia. The extrapolation of this assay to the incorporation of 14C-propionate into acid precipitable material has simplified the procedure [85]. This has been employed in studies of complementation among the inherited methylmalonic acidemias. Patients responsive to B12 were promptly subfractioned into two complementation groups, designated Cbl A and Cbl B [60, 61, 86, 87]. The Cbl A variants synthesize adenosylcobalamin normally from 57Co-hydroxycobalamin and adenosine triphosphate (ATP) under reducing conditions [83]. In the Cbl B variants, adenosylcobalamin synthesis is defective under these conditions, and the defect has been shown to be in the adenosyltransferase [88, 89]. Patients with defects in cobalamin synthesis generally present later than those with apoenzyme defects, and most survive the illness once diagnosed. Among the Cbl A patients, a clinical response to B12 is regularly seen, while in Cbl B patients only half respond to B12 with a decrease in the amounts of MMA in body fluids, suggesting that there is a complete block in the unresponsive patients.
A double-blind, 377-subject randomized study identifies Ruminococcus, Coprococcus, Christensenella, and Collinsella as long-term potential key players in the modulation of the gut microbiome of lactose intolerant individuals by galacto-oligosaccharides
Published in Gut Microbes, 2021
M. A. Azcarate-Peril, J. Roach, A. Marsh, William D. Chey, William J. Sandborn, Andrew J. Ritter, Dennis A. Savaiano, T. R. Klaenhammer
Coprococcus catus was one major species that showed an overall significant increased abundance in correlation with treatment only. Our previous study did not specifically identify C. catus as increased by the treatment or subsequent period of dairy consumption;11 however, an Operational Taxonomic Unit (OTU) identified at the time at the family level only (Lachnospiraceae_2) was increased in response to GOS and dairy consumption. The genus Coprococcus (family Lachnospiraceae, phylum Firmicutes) contains three species (C. eutactus, C. catus and C. comes), which are not phylogenetically closely related.28C. catus produces butyrate and propionate, while C. eutactus and C. comes produce butyrate with formate or lactate, respectively. C. catus uses lactate to generate propionate via the acrylate pathway.29 The role of propionate in intestinal and overall health was only recently elucidated, with studies showing that propionate can lower serum cholesterol levels, lipogenesis, and carcinogenesis risk.30 Propionate also promotes secretion of the satiety-inducing hormones PYY and GLP-1 hormones in human colonic cells.31–34
The role of short-chain fatty acids in the interplay between gut microbiota and diet in cardio-metabolic health
Published in Gut Microbes, 2021
Ana Nogal, Ana M. Valdes, Cristina Menni
Propionate can be synthesized through three different biochemical pathways, namely succinate, acrylate, and propanediol pathway.83 In the succinate pathway, the primitive electron transfer chain using phosphoenolpyruvate (PEP) can be utilized to generate propionate.84 Specifically, PEP is carboxylated to oxalacetate, and then oxalacetate is sequentially converted into malate and fumarate. The latter accepts electrons from NADH using a fumarate reductase and a NADH dehydrogenase, which form a simple electron-transfer chain. The NADH dehydrogenase transport protons across the cell membrane. These protons are utilized for chemiosmotic ATP synthesis. Likewise, succinate is generated as a result of the fumarate reductase. When the carbon dioxide partial pressure is low, succinate is transformed to methylmalonate, which leads to propionate and carbon dioxide. The latter can be recycled for the PEP carboxylation, repeating the process. Bacteroidetes85 and several Firmicutes belonging to the Negativicutes class86 use this pathway for the propionate formation. Besides, acrylate pathway can be used to reduce lactate to propionate by a lactoyl-CoA dehydratase.80 This pathway is only present in a very reduced number of gut bacteria, including Coprococcus catus.83 Lastly, 1,2-propanediol can be formed from deoxy sugars such as rhamnose and fucose in the propanediol pathway. Likewise, 1,2-propanediol is sequentially converted into propionaldehyde and propionyl-CoA, which leads to the propionate formation.87Salmonella enterica serovar Typhimurium88 and R. inulinivorans89 are bacteria utilizing this pathway, just as Akkermansia municiphilla which appears to be the major propionate-producing species.90
Bacterial sulfidogenic community from the surface of technogenic materials in vitro: composition and biofilm formation
Published in Biofouling, 2023
Nataliia Tkachuk, Liubov Zelena
According to Bergey’s Manual of Systematic Bacteriology (Bergey’s Manual of Systematic Bacteriology 2009) the bacteria of isolated species C. propionicum are capable of significant hydrogen production (4 points on a scale from 0 to 4). Metabolic products of C. propionicum are propionate, isovalerate, isobutyrate, butyrate, small amounts of acetate, succinate, and sometimes lactate (Bergey’s Manual of Systematic Bacteriology 2009). It is known that bacteria of this species form ammonia and hydrogen sulfide. Thus, metabolic products of this species may act as substrates for SRB, and, moreover, are corrosive compounds (Andreyuk et al. 2005). Thus, organic acids may force a shift in the tendency for corrosion to occur. Trapping of acidic metabolites at the biofilm/metal interface leads to intensification of corrosion process. Acetic, formic and lactic acids are common metabolic by-products of acid-producing bacteria, but unfortunately the acids produced and their concentrations are rarely monitored under microbiologically influenced corrosion (MIC) conditions (Beech and Gaylarde 1999). At the same time, it is known that the acids produced by acid-producing bacteria serve as nutrients for SRB and it has been suggested that SRB proliferate at sites of corrosion due to the activities of acid-producing bacteria (Soracco et al. 1988). Nevertheless, today there is a misconception that acid-producing bacteria play only a minor role in MIC (Gu 2014). The possibility of a very high corrosion rate of MIC pits due to free organic acids (represented by acetic acid) and acid corrosion of pH through mechanical modeling is considered to show that biofilms of acid-forming bacteria are capable of very rapid pitting of MIC. The author notes that more efforts should be devoted to MIC by acid-producing bacteria instead of focusing too much on SRB (Gu 2014).
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