Increased Production of Short-Chain Fatty Acids in Microbacteria Fermentation Treated by Fullerenols

Fullerenol nanoparticles were found to significantly modulate the gut microbiota and selectively enrich the short-chain fatty acids (SCFAs) production by adjusting the gut microbacteria in mice models. In this research, we screened the C. butyricum from seven strains and investigated the interactions and mechanism between the C. butyricum and fullerenol NPs in vitro fermentation. The results shows that fullerenol NPs increased the amounts of acetate and butyrate of C. butyricum without significant bacteria growth in the complete medium. The activities of the butyryl-CoA: acetate CoA transferase (BUT), which are the main pathway to produce butyrate, were reduced while the activities of the butyrate kinase (BUK) were enhanced simultaneously. Surprisingly, fullerenol NPs promoted the growth of C. butyricum and L. lactis in low glucose medium, but they could not be direct carbon source in the culture. Moreover, when cocultured with C. butyricum and the bifidobacterial strains in fullerenols, the biomass and acetate production of C. butyricum were markedly increased while butyrate was decreased significantly.

Characterization of a butyrate kinase from Desulfovibrio vulgaris str. Hildenborough

ABSTRACT Short and branched chain fatty acid kinases participate in both bacterial anabolic and catabolic processes, including fermentation, through the reversible, ATP-dependent synthesis of acyl phosphates. This study reports biochemical properties of a predicted butyrate kinase from Desulfovibrio vulgaris str. Hildenborough (DvBuk) expressed heterologously and purified from Escherichia coli. Gel filtration chromatography indicates purified DvBuk is active as a dimer. The optimum temperature and pH for DvBuk activity is 44°C and 7.5, respectively. The enzyme displays enhanced thermal stability in the presence of substrates as observed for similar enzymes. Measurement of kcat and KM for various substrates reveals DvBuk exhibits the highest catalytic efficiencies for butyrate, valerate and isobutyrate. In particular, these measurements reveal this enzyme's apparent high affinity for C4 fatty acids relative to other butyrate kinases. These results have implications on structure and function relationships within the ASKHA superfamily of phosphotransferases, particularly regarding the acyl binding pocket, as well as potential physiological roles for this enzyme in Desulfovibrio vulgaris str. Hildenborough.

Modulation of Gut-Brain Axis Improves Microbiome, Metabolism, and Mood

Objective: There is a close bidirectional relationship between overweight/obesity and depression, which may be largely modified through the microbiome and the gut-brain axis. Previous research has shown targeted weight loss effects and anti-depressive benefits of diets high in fiber and phytonutrients and low in sugar and processed foods. Thus, our objective was to determine changes in parameters common to both obesity and depression (e.g., microbiome balance, metabolic biomarkers, and psychological mood state) following a coordinated supplementation regimen combining probiotics, prebiotics, and phytonutrients (“phytobiotics”).Methods: Thirty-three (33) healthy subjects participated in a 6-week supplementation trial (Amare “Project b3”) containing a targeted blend of probiotics, prebiotics, and phytobiotics. Microbiome balance was assessed in fecal samples using a novel PCR-based analysis (BiomeTracker) that has previously compared favorably to 16S sequencing. Biomarkers, including blood lipids, glucose, cortisol, and butyrate kinase, were assessed as indicators of effects on cardiovascular, inflammatory, and energy metabolism. Psychological mood state was assessed using the validated Profile of Mood States survey (POMS) to generate scores for Global Mood State and six sub-scales (Depression, Tension, Fatigue, Anger, Confusion, and Vigor).Results: Following supplementation, there was a significant increase in populations of “good” bacteria (+8% Bifidobacterium, +33% Lactobacillus, +62% S. Thermophilus, +90% Akkermansia) as well as bacterial ratios associated with a healthier “obesity-resistant” metabolism (+6% composite score, -11% Firmicutes, +6% Bacteroidetes, -14% F/B ratio). Metabolites associated with stress and glycemic control improved post-supplementation (-11% cortisol; +89% butyrate kinase, -6% glucose), as did body fat (-2%) and blood lipids (-8% total cholesterol, -5% LDL, +3% HDL, -23% triglycerides, -7% TC/HDL). Psychological indices were significantly improved post-supplementation for both positive (+17% Global Mood; +23% Vigor) and negative mood states (-38% Depression; -41% Tension; -42% Fatigue; -31% Confusion; -39% Anger).Conclusions: These results demonstrate the close relationship between microbiome balance, systemic metabolism, and psychological parameters – and the utility of targeted supplementation to optimize gut-brain-axis balance for both improved metabolism and enhanced mental wellness.Keywords: Obesity; Depression; Anxiety; Stress; Probiotics; Prebiotics; Diet; Supplement

Effects of High Forage/Concentrate Diet on Volatile Fatty Acid Production and the Microorganisms Involved in VFA Production in Cow Rumen

The objectives of this study were to investigate the difference in the mechanism of VFAs production combined with macrogenome technology under different forage-to-concentrate ratios and sampling times. Six ruminally cannulated Holstein cows were used in a randomized complete block design. The high forage (HF) and high concentrate (HC) diets contained 70 and 35% dietary forage, respectively. The results showed that pH was affected by sampling time, at 4 h after feeding had lower value. Excepted for acetate, the VFAs was increased with forage decreased. Propionate formation via the succinic pathway, in which succinate CoA synthetase (EC 6.2.1.5) and propionyl CoA carboxylase (EC 2.8.3.1) were key enzymes, and significantly higher in HC treatment than in HF treatment, Selenomonas, Ruminobacter, Prevotella, and Clostridium were the main microorganism that encodes these key enzymes. Butyrate formation via the succinic pathway, in which phosphate butyryltransferase (EC 2.3.1.19), butyrate kinase (EC 2.7.2.7) and pyruvate ferredoxin oxidoreductase (EC 1.2.7.1) are the important enzymes, Prevotella and Bacteroides played important role in encodes these key enzymes. This research gave a further explanation on the metabolic pathways of VFAs, and microorganisms involved in VFAs production under different F:C ration, which could further reveal integrative information of rumen function.