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Micronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Vitamin B2 or riboflavin is an essential vitamin of group B. It is a water-soluble, yellow-orange organic compound and is heat stable. Riboflavin is the central component of the coenzymes: flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), and acts as a co-factor in numerous enzymatic reactions. It is therefore important for energy production, enzyme function, and normal protein, fatty acid and amino acid synthesis (3, 9, 33, 37–38). It mediates the transfer of electrons in biological oxidation-reduction reactions. It is also involved in the metabolism of folate, vitamin B12, vitamin B6, and other vitamins. It also helps to maintain the integrity of mucous membranes, skin, the eyes and nervous system (38). The role of riboflavin has also been credited in the prevention of a wide array of health diseases like migraine, anemia, cancer, hyperglycemia, hypertension, diabetes mellitus, and oxidative stress, directly or indirectly (38). A deficiency of riboflavin named ariboflavinosis is manifested in swollen tongue, skin eruption, and eye irritation (3, 33, 37–38). Riboflavin deficiency has profound effects on iron absorption, metabolism of tryptophan, mitochondrial dysfunction, the gastrointestinal tract, brain dysfunction, and metabolism of other vitamins (38). Although riboflavin is involved in all areas of metabolism, and deficiency is widespread on a global scale, deficiency is not fatal (33). Riboflavin deficiency is usually associated with other vitamin B complex deficiencies; isolated riboflavin deficiency is rare (3, 33).
The lymphoreticular system and bone marrow
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
Deficiency of these two vitamins leads to megaloblastic anaemia. Each has an important role in the synthesis of RNA and DNA, and in the metabolism of some amino acids (synthesis of methionine and breakdown of homocystine). This explains why deficiency of either or both has effects on tissues other than the bone marrow, most notably the central nervous system (see Chapter 12).
Protein and amino acids
Published in Jay R Hoffman, Dietary Supplementation in Sport and Exercise, 2019
The key metabolic systems involved in maintaining body protein and amino acid homeostasis are protein synthesis and degradation, amino acid oxidation and urea production and amino acid synthesis in regard to the nutritionally-dispensable amino acids. The EAAs, particularly leucine, play a role in MPS by initiating translation. The initiation step, unlike the elongation and termination steps, plays a major source of regulation following acute hyperaminoacidemia. Amino acid concentrations are not the only nutritional regulator of translation; rather hormonal factors are significantly involved in regulating anabolic drive. Conversely, muscle protein content is determined by the relative rate of MPB, which is regulated by ubiquitination and amino acid oxidation.
A pilot study on the relationship between Lactobacillus, Bifidibactrium counts and inflammatory factors following exercise training
Published in Archives of Physiology and Biochemistry, 2023
Molanouri Shamsi Mahdieh, Jalali Maryam, Bakhshi Bita, Fazel Neda, Mokhtarzade Motahare, Bahroudi Mahboobeh, Quinn LeBris S, Sadeghi Kalani Behrooz
Although possible mechanisms by which exercise can modulate gut bacteria are not well understood, there are several candidates for this effect especially in obesity. Some studies have suggested exercise training is an effective method to modify gut microbiota in relation to the obesity situation (Evans et al. 2014, Allen et al. 2018). Changes in the composition of the microbiome following an active lifestyle are associated with increases in short-chain fatty acids [SCFAs] such as n-butyrate, which are the end products of bacterial fermentation in the intestines (Perrin et al. 2001). Also, it has been shown that gut microbial pathways for amino acid synthesis and carbohydrate metabolism are changed in athletes, who also had greater faecal SCFA concentrations (Barton et al. 2018). SCFAs can modulate host energy balance, and lead to increased nutrient availability (Samuel et al. 2008). It is possible that changes in some metabolites associated with microbiomes such as SCFAs are part of the mechanisms involved in weight loss and energy balance in the present study.
Toxicity of the herbicides used on herbicide-tolerant crops, and societal consequences of their use in France
Published in Drug and Chemical Toxicology, 2022
In Arabidopsis thaliana, up-regulated genes are those encoding enzymes involved in the metabolization of herbicides such as cytochrome P450 (CYP), GST and UDP glycosyl transferases (UGT), and allowing detoxification such as ATP-binding cassette (ABC) transporters and multidrug resistance (MRP) and toxin extrusion (MATE) protein families, and the iron superoxide dismutase Fe-SOD genes (FSD). Also up-regulated genes comprise those encoding ribosome associated proteins or protein synthesis initiation factors (eIF4A, eIF4E and eIF5), and some involved in amino acid synthesis. The mitochondrial function is also impacted since the genes encoding mitochondrial genes alternative oxidases ATAOX1a and ATAOX1b, along with two mitochondrial NADH dehydrogenases, NDB2 and NDB4 are up-regulated. Down-regulated genes are those involved in cell wall biosynthesis, along with genes involved in the neutralization of the oxidative stress such as those encoding copper-zinc superoxide dismutases Cu/ZnSOD (CSD), ascorbate peroxidases (APX), and glutathione peroxidases (GPX).
Probiotic-directed modulation of gut microbiota is basal microbiome dependent
Published in Gut Microbes, 2020
Qiangchuan Hou, Feiyan Zhao, Wenjun Liu, Ruirui Lv, Wei Wei Thwe Khine, Jia Han, Zhihong Sun, Yuan-Kun Lee, Heping Zhang
Functional analysis showed that there were significant differences between the two enterotypes in many metabolic modules. For example, three modules related to lipopolysaccharide metabolism were significantly more abundant in PF enterotypes than FB enterotypes, while many pathways related to human essential amino acid synthesis were significantly higher in FB enterotypes than PF enterotypes. Lipopolysaccharides are components of the cell membranes of gram-negative bacteria, and gut microbiota-derived lipopolysaccharides and systemic endotoxemia are involved in the onset and progression of atherosclerosis, inflammatory bowel disease, obesity and related metabolic diseases, and nonalcoholic steatohepatitis.52–54 Essential amino acids are those amino acids that cannot be synthesized by the human body, or cannot be synthesized at a speed that meets requirements and must be provided from external sources. A lack of essential amino acids leads to a series of problems including metabolic disorders and a decline in immune resistance.55 Considering that the biosynthesis pathway for lipopolysaccharide was enriched in PF enterotypes and various modules related to the synthesis of essential amino acids were enriched in FB enterotypes, we speculate that the composition of gut microbiota of FB enterotypes may be more beneficial to the health of adults. After LCZ consumption, the enterotype of many adults changed from PF to FB with a significant decrease in abundance of the lipopolysaccharide biosynthesis module in both enterotypes confirms the probiotic effect of LCZ.