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Methylmalonic acidemia
Published in William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop, Atlas of Inherited Metabolic Diseases, 2020
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop
Propionic acid is synthesized by intestinal bacteria, and this may be an important source of propionate and methylmalonate in these patients [110]. Treatment with neomycin or metronidazole may reduce levels of propionic and MMAs in body fluids [108–110]. Doses of metronidazole have ranged from 10 to 20 mg/kg per day and have been divided into three doses. Neomycin has been used in a dose of 50 mg/kg. Other antibiotics, such as bacitracin, paromycin, clindamycin, or vancomycin, may be useful in acute situations. Lincomycin was not effective [110]. In our experience, intermittent antibacterial therapy has been useful, suggesting that clonal populations of propionate-forming bacteria may be intermittently present in some patients. An effect of antibiotic treatment on metabolite accumulation may be especially useful during a crisis of metabolic decompensation. A sudden increase in MMA excretion unaccompanied by dietary change or stimulus for catabolism may suggest a bacterial source and an argument for neomycin or metronidazole.
Effect of Short-Chain Fatty Acids Produced by Probiotics
Published in Marcela Albuquerque Cavalcanti de Albuquerque, Alejandra de Moreno de LeBlanc, Jean Guy LeBlanc, Raquel Bedani, Lactic Acid Bacteria, 2020
Milena Fernandes da Silva, Meire dos Santos Falcão de Lima, Attilio Converti
In bacteria, propionate formation meets two needs, namely the disposal of excess reducing power mainly in the form of NADH, and the synthesis of ATP (Hoyles and Wallace 2010). Propionate, which is metabolized in the human colon in less extent than butyrate, seems to impact favourably on cholesterol level, unlike acetate. Moreover, it has been reported that propionate may favour colonocyte proliferation and differentiation, albeit less efficiently than butyrate (Roy et al. 2006). Both propionate and butyrate seem to suppress appetite, prevent diet-induced obesity and enhance insulin sensitivity (Pessione et al. 2015).
Nutrition and the Microbiome—Implications for Autism Spectrum Disorder
Published in David Perlmutter, The Microbiome and the Brain, 2019
Kirsten Berding, Sharon Donovan
SCFAs like acetate, propionate, and butyrate are the end-products of microbial fermentation in the colon and have the potential to confer health benefits to their host, including weight control, balancing lipid profiles, and improving colon health.35 SCFAs are rapidly absorbed in the large intestine and can be detected in the blood.36 Once in the blood, SCFAs can cross the blood–brain barrier (BBB) via monocarboxylic acid transporters or through passive diffusion, where they can impact nervous system physiology and cause developmental delay or seizures.37,38 Likewise, SCFAs could also interact with G protein-coupled membrane receptors (GPR), such as GPR-41, -43, or -109, triggering the activation of gene expression of pathways implicated in ASD, including neurotransmitter systems (e.g., serotonergic/cholinergic system), neuronal cell adhesion molecules, inflammation, oxidative stress, lipid metabolism, and mitochondrial function.39 In animal studies, propionate has been shown to cause brain events similar to those observed in individuals with ASD, and intraventricular administration of propionate provoked ASD-like behaviors in animals, including repetitive interests and impaired social interactions.39–41
The double-edged sword of probiotic supplementation on gut microbiota structure in Helicobacter pylori management
Published in Gut Microbes, 2022
Ali Nabavi-Rad, Amir Sadeghi, Hamid Asadzadeh Aghdaei, Abbas Yadegar, Sinéad Marian Smith, Mohammad Reza Zali
The interaction between H. pylori infection and SCFA is far from being fully elucidated, yet the reduction of SCFA has been reported in the feces of H. pylori-infected mice.111 Specifically, butyrate promotes intestinal barrier function via activating AMP-activated protein kinase (AMPK) or inhibiting claudin-2 production to stimulate the expression of tight junction proteins.40 Through the G protein-coupled receptor 4 (GPR4) and mammalian target of rapamycin (mTOR)/signal transducer and activator of transcription 3 (STAT3) signaling pathway, butyrate promotes AMPs expression in epithelial cells. SCFAs might lead to NLR family pyrin domain containing 3 (NLRP3) inflammasome activation by GPR4 receptor inducing IL-18 secretion from the epithelium. GPR109A is a surface receptor on DCs and macrophages that detects butyrate and further induces the development of regulatory T cells (Treg) and prevents the proliferation of T helper 17 (Th17) cells.112 Moreover, butyrate can suppress the production of iNOS, TNF-α, IL-6, MCP-1, and IFN-γ by inhibiting NF-κB activation.113 On the other hand, propionate downregulates the production of pro-inflammatory cytokines including IL-4, IL-5, and IL-17A, and stimulates Treg cells to release the anti-inflammatory cytokine IL-10. In LPS-activated monocytes, propionate is reported to inhibit TNF-α and iNOS expression.45 It is also suggested that the interaction of SCFAs with DCs elevates retinoic acid (RA) production and consequently increases IgA secretion by B cells in lamina propria.114
Use of inhaled corticosteroids on an intermittent or as-needed basis in pediatric asthma: a systematic review of the literature
Published in Journal of Asthma, 2022
Carlos E. Rodriguez-Martinez,, Monica P. Sossa-Briceño,, Luis Garcia-Marcos,
Ducharme et al. examined the efficacy and safety of preemptive treatment with high-dose fluticasone in reducing the severity of recurrent virus-induced wheezing in 129 children 1–6 years old with three or more wheezing episodes in their lifetime triggered by URTIs and with no intercurrent symptoms or suspected allergy. The children were randomly assigned to receive 750 μg of fluticasone propionate or a placebo twice daily, beginning at the onset of an URTI and continuing for a maximum of 10 days, over a period of 6–12 months. Over a median period of 40 weeks, 8% of upper respiratory tract infections in the fluticasone group led to treatment with rescue systemic corticosteroids, as compared with 18% in the placebo group (odds ratio [OR], 0.49; 95% CI, 0.30–0.83). Treatment with fluticasone was also associated with a smaller gain in height and weight (20).
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