Branched-chain Fatty Acids Research Articles

Effects of dietary mangosteen peel powder and extract on the growth performance, meat quality and indicators for immunity, gut health and antioxidant activity in broiler chicks

The objective of this study was to evaluate the effects of dietary mangosteen peel preparations, either powdered (MspP) or ethanolic extract (MspE), on the growth performance, meat quality, immune response, gut health, serum biochemical profiles, and antioxidant activity of broiler chicks. A total of 480 day-old straight-run broiler chicks (Ross 308) were randomly placed into four treatments, with eight replicates of 12 chicks each, and subjected to one of the four experimental diets for 21 days. The corn and soybean meal-based diet was supplemented with 2% MspP (20 g per kg of diet) or 0.05% and 0.1% MspE (0.5 g and 1.0 g per kg of diet). Data were analyzed using analysis of variance, and post hoc comparisons of treatments were performed using Tukey's Honestly Significant Difference test. From days 0 to 21, dietary mangosteen peel preparations did not affect growth performance (body weight gain, feed intake, and feed conversion ratio), thigh meat and tibia characteristics, serum markers of innate immunity (interferon-r, interleukin-10, alpha-1-acid glycoprotein, and nitric oxide), and ileal morphology in broiler chicks (P > 0.05). Dietary mangosteen peel preparations increased the percentage of high-density lipoprotein cholesterol and decreased the relative concentrations of isobutyrate and branched-chain fatty acids in the cecal digesta compared with the control chickens. Notably, dietary mangosteen peel preparations altered the antioxidant characteristics of the serum, liver, and thigh meat. Dietary MspE increased glutathione peroxidase (P = 0.039) and catalase (P = 0.008) in the serum and catalase in the liver (P = 0.05) and thigh meat (P = 0.01) compared to the control group. In addition, dietary MspP increased catalase levels in thigh meat compared to those in the control diet-fed chickens (P = 0.01). The concentration of malondialdehyde, an indicator of lipid peroxidation, was lower in all chicks-fed diets containing mangosteen peel preparations; however, statistical significance was only noted in the serum samples (P < 0.0001). Collectively, our study shows that dietary mangosteen peel preparations are potent natural antioxidants that can be used as functional dietary additives to effectively mitigate oxidative stress in broiler chicks.

Insights into Protein and Amino Acid Metabolism of Thermoanaerobacter mathranii

Few investigations have been carried out into the members of the genus Thermoanerobacter for protein and amino acid metabolism compared to carbohydrates, mostly due to the intense interest in bioethanol and biohydrogen in recent decades. The present study investigates the biotechnological potential of Thermoanaerobacter mathranii (DSM 11426) in terms of its ability to produce high-energy alcohols from amino and fatty acids. End product formation from glucose (in the presence and absence of butyrate) as well as from selected proteins and amino acids were analyzed. T. mathranii did not degrade any of the proteins tested to a large extent but degraded several amino acids, namely serine and the branched-chain amino acids (leucine, isoleucine, valine) when cultivated in the presence of thiosulfate. The main end products from the branched-chain amino acids were a mixture of their corresponding branched-chain fatty acids and alcohols, with the strain producing a concentration of the corresponding branched-chain alcohol between 1.0 and 1.7 mM and 8.2–10.9 mM of the corresponding fatty acid. 13C2-labeled leucine revealed that the strains degraded the amino acid in the presence of thiosulfate, producing 3-methyl-1-butyrate, which was then used as an electron acceptor which led to the accumulation of 3-methyl-1-butanol. The strain is highly ethanologenic, producing more than 1.2 mol of ethanol per mol of glucose degraded. The strain was able to reduce volatile fatty acids during glucose fermentation to their corresponding alcohol, further suggesting this strain may be of greater biotechnological value beyond bioethanol production.

Caecal metabolomics of two divergently selected rabbit lines revealed microbial mechanisms correlated to intramuscular fat deposition.

The gastrointestinal microbiota plays a key role in the host physiology and health through a complex host-microbiota co-metabolism. Metabolites produced by microbial metabolism can travel through the bloodstream to reach distal organs and affect their function, ultimately influencing the development of relevant production traits such as meat quality. Meat quality is a complex trait made up of a number of characteristics and intramuscular fat content (IMF) is considered to be one of the most important parameters. In this study, 52 rabbits from two lines divergently selected for IMF (high-IMF (H) and low-IMF (L) lines) were used to perform an untargeted metabolomic analysis of their caecal content, with the aim to obtain information on genetically determined microbial metabolism related to IMF. A large, correlated response to selection was found in their caecal metabolome composition. Partial least squares discriminant analysis was used to identify the pathways differentiating the lines, which showed a classification accuracy of 99%. On the other hand, two linear partial least squares analyses were performed, one for each line, to extract evidence on the specific pathways associated with IMF deposition within each line, which showed predictive abilities (estimated using the Q2) of approximately 60%. The most relevant pathways differentiating the lines were those related to amino acids (aromatic, branched-chain and gamma-glutamyl), secondary bile acids, and purines. The higher content of secondary bile acids in the L-line was related to greater lipid absorption, while the differences found in purines suggested different fermentation activities, which could be related to greater nitrogen utilisation and energy efficiency in the L-line. The linear analyses showed that lipid metabolism had a greater relative importance for IMF deposition in the L-line, whereas a more complex microbial metabolism was associated in the H-line. The lysophospholipids and gamma-glutamyl amino acids were associated with IMF in both lines; the nucleotide and secondary bile acid metabolisms were mostly associated in the H-line; and the long-chain and branched-chain fatty acids were mostly associated in the L-line. A metabolic signature consisting of two secondary bile acids and two protein metabolites was found with 88% classification accuracy, pointing to the interaction between lipid absorption and protein metabolism as a relevant driver of the microbiome activity influencing IMF.

PREBIOTIC EFFICACY OF DEFATTED FENUGREEK SEED FLAKES (FENUFLAKESTM): A SHORT-TERM COLONIC SIMULATION STUDY

Objective: To investigate the prebiotic effects of defatted fenugreek seed flakes (Fenuflakes™) using a 48-hour colonic simulation model. Methods: Fecal samples from three healthy adult human donors were exposed to treatment conditions of blank (medium control), Fenuflakes, or inulin (fiber control). The effects on microbial fermentation (pH and gas production), metabolite production [Short Chain Fatty Acid (SCFAs), Branched-Chain Fatty Acid (BCFA), ammonium and lactate production], and microbial community composition were evaluated at 0, 6, 24, and 48 h. Results: In comparison to inulin, Fenuflakes demonstrated a significant reduction in gas production. Both inulin and Fenuflakes significantly increased beneficial SCFAs, but no significant change was observed in BCFA. Ammonium production increased upon Fenuflakes treatment due to a residual protein fraction reaching the colon, in contrast to inulin, which is in a protein-depleted state. The lactate levels significantly increased for Fenuflakes and inulin. The presence of Fenuflakes and inulin resulted in favorable fermentation by the colonic gut microbiota, indicating an increase in species enrichment and alpha diversity in the microbial community composition. Conclusion: Fenuflakes exhibit prebiotic potential by increasing SCFA and promoting the enrichment of several beneficial colonic bacteria while maintaining normal colonic pH and producing less gas than inulin.

Programming rumen microbiome development in calves with the anti-methanogenic compound 3-NOP

The aim of this study was to establish a distinctive rumen microbial and fermentation profile using the anti-methanogenic compound 3-NOP to assess dam effect, and nutritional intervention of the juvenile offspring on microbial structure and function of rumen up to 12 months of age, once the treatment was withdrawn. Forty-eight pregnant heifers (H) and their future offspring (C) were allocated to either Control (-) or 3-NOP (+) treatment resulting in four experimental groups: H+/C+, H+/C-, H-/C + and H-/C-. Animals were treated from 6 weeks prior to calving until weaning, with the offspring monitored until 12 months of age. Rumen fluid samples and methane measurements using the Greenfeed system were collected during the trial. Results supported the mode of action of the compound, with a shift in fermentation from acetate to propionate, increases in branched chain fatty acids and formic acid in the 3-NOP treated animals. Similar shifts in microbial populations occurred in 3-NOP treated animals with lower abundances of rumen methanogen populations, increases of bacterial groups Succiniclasticum spp, Candidatus Saccharimonas. Fibrobacter and the families Prevotellaceae and Succinivibrioacea. and the protozoa Entodinium. Early life intervention had an enduring impact on the rumen microbial structure of young animals up to 28 weeks post weaning, however the effect was diminished once 3-NOP was withdrawn. Interestingly, a group of young animals emitted significantly less methane (15%) than the animals that did not receive the treatment during their juvenile stage. Our results suggest a higher resemblance of the young calf microbiome to a low methane adult and that early life colonisation of the rumen persists through to later life with the pre-weaning microbiome comprising ~ 65% of the yearling animal. Further research needs to be performed to determine the timing and dose of 3-NOP for new-born calves that can sustain a reduction in methane emissions after the treatment is withdrawn, under extensive grazing or controlled conditions.

Effects of chicken slurry inclusion on apparent total tract macronutrient digestibility, palatability, and fecal characteristics, microbiota, and metabolites of healthy adult dogs.

"Premium" pet foods are often formulated with meat slurries. Meat slurries are believed to be of higher quality than rendered meals, but inadequate research has been performed to test how their inclusion affects palatability, digestibility, or indicators of gastrointestinal health. Therefore, the objectives of this study were to determine how chicken slurry inclusion affected the palatability and apparent total tract macronutrient digestibility (ATTD) of dog foods and to assess their effects on the fecal characteristics, metabolites, and microbiota of dogs. A replicated 3x3 Latin square design digestibility study was conducted using 9 healthy adult dogs (age = 5.44 ± 0.53 yr) to test diets containing 0% (control; CON), 8% (low inclusion; LOW), and 16% (high inclusion; HIGH) chicken slurry. The experiment comprised three 21-day experimental periods (14 days of adaptation, 5 days of total fecal collection (used for ATTD calculations), and 2 days of blood collection). On the first day of fecal collections, one fresh sample was collected for measurement of pH, dry matter (DM) content, fermentative metabolite concentrations, and microbiota populations. A 2-day palatability study (n=20 dogs) was also conducted to compare CON vs. HIGH. Data were analyzed statistically by Mixed Models using SAS 9.4, with P<0.05 being significant. In the palatability study, dogs were shown to prefer (P<0.05) the HIGH diet by a ratio of 2:1. In the digestibility study, fecal output, scores, pH, and DM percentage were not different among diets. The ATTD of protein was higher (P<0.05) for the HIGH diet (84.6%) than for the LOW (82.7%) or CON (82.6%) diets. The ATTD of other nutrients and energy were not different among diets (all over 80%). Fecal propionate, butyrate, and total short-chain fatty acid concentrations were higher (P<0.05) in dogs fed the LOW diet (122.0, 67.4, and 408.2 βmol/g, respectively) than those fed the HIGH diet (89.0, 46.9, and 338.2 βmol/g, respectively). The other fecal metabolites (acetate, branched-chain fatty acids, ammonia, phenol, and indole) were not different among treatments. Few changes to the fecal microbiota were noted. However, the relative abundance of fecal Fusobacterium was higher (P<0.05) in dogs fed the CON diet than those fed the HIGH diet (25.% vs. 20.0% relative abundance). In summary, chicken slurry inclusion improved palatability but had minimal effects on nutrient digestibility and fecal characteristics, metabolites, and microbiota.

CodY controls the SaeR/S two-component system by modulating branched-chain fatty acid synthesis in Staphylococcus aureus.

Staphylococcus aureus is a Gram-positive, opportunistic human pathogen that is a leading cause of skin and soft tissue infections and invasive disease worldwide. Virulence in this bacterium is tightly controlled by a network of regulatory factors. One such factor is the global regulatory protein CodY. CodY links branched-chain amino acid sufficiency to the production of surface-associated and secreted factors that facilitate immune evasion and subversion. Our previous work revealed that CodY regulates virulence factor gene expression indirectly in part by controlling the activity of the SaeRS two-component system (TCS). While this is correlated with an increase in membrane anteiso-15:0 and -17:0 branched-chain fatty acids (BCFAs) derived from isoleucine, the true mechanism of control has remained elusive. Herein, we report that CodY-dependent regulation of SaeS sensor kinase activity requires BCFA synthesis. During periods of nutrient sufficiency, BCFA synthesis and Sae TCS activity are kept relatively low by CodY-dependent repression of the ilv-leu operon and the isoleucine-specific permease gene brnQ2. In a codY null mutant, which simulates extreme nutrient limitation, de-repression of ilv-leu and brnQ2 directs the synthesis of enzymes in redundant de novo and import pathways to upregulate production of BCFA precursors. Overexpression of brnQ2, independent of CodY, is sufficient to increase membrane anteiso BCFAs, Sae-dependent promoter activity, and SaeR ~P levels. Our results further clarify the molecular mechanisms by which CodY controls virulence in S. aureus.IMPORTANCEExpression of bacterial virulence genes often correlates with the exhaustion of nutrients, but how the signaling of nutrient availability and the resulting physiological responses are coordinated is unclear. In S. aureus, CodY controls the activity of two major regulators of virulence-the Agr and Sae two-component systems (TCSs)-by unknown mechanisms. This work identifies a mechanism by which CodY controls the activity of the sensor kinase SaeS by modulating the levels of anteiso branched-chain amino acids that are incorporated into the membrane. Understanding the mechanism adds to our understanding of how bacterial physiology and metabolism are linked to virulence and underscores the role virulence in maintaining homeostasis. Understanding the mechanism also opens potential avenues for targeted therapeutic strategies against S. aureus infections.

Microbiota, metabolic profiles and immune biomarkers in infants receiving formula with added bovine milk fat globule membrane: a randomized, controlled trial.

Few studies have evaluated the effects of milk fat globule membrane (MFGM) on microbiota and immune markers in early infant nutrition. In this double-blind randomized study, infants (7-18 days of age) received either bovine milk-based infant formula (Control) or similar formula with an added source (5 g/L) of bovine MFGM (INV-MFGM) for 60 days. A reference group received mother's own human milk over the same period (HM). Oral and stool samples were collected (Baseline and Day 60) to evaluate microbiota, immune markers, and metabolites. At Day 60, stool bacterial diversity and richness were higher in formula groups vs HM, as were Bifidobacterium bifidum and B. catenulatum abundance. Compared to HM, stool pH was higher in Control, while acetate, propionate, isovalerate, and total short- and branched-chain fatty acids were higher in INV-MFGM. Butyrate and lactate increased for INV-MFGM from baseline to Day 60. No group differences in oral microbiota or immune markers (α- and β-defensin, calprotectin, or sIgA) were detected, although sIgA increased over time in all study groups. Added bovine MFGM in infant formula modulated stool microbiota and short- and branched-chain fatty acids compared to human milk; changes were modest relative to control formula. Overall, distinct patterns of stool metabolites and microbiota development were observed based on early nutrition. ClinicalTrials.gov, identifier NCT04059666.

Eight-Week Supplementation With Bifidobacterium lactis HN019 and Functional Constipation

Probiotic supplementation may improve bowel movements. However, large, properly designed studies are lacking. To evaluate the potential benefit of Bifidobacterium animalis subsp lactis HN019 on constipation, expressed as complete spontaneous bowel movements (CSBMs). This randomized triple-blind placebo-controlled clinical trial with 2 weeks of run-in and 8 weeks of intervention was conducted from December 25, 2020, to February 28, 2022, at 5 hospitals in Shanghai, China. Participants included healthy volunteers with functional constipation according to Rome III criteria, 18 to 70 years of age, and a body mass index (calculated as the weight in kilograms divided by the height in meters squared) of less than 30.0. Eligibility after the run-in phase required the randomized participants to have 3 or fewer CSBMs/wk. Data were analyzed from September 29, 2022, to March 23, 2023, and reported as intention to treat. Participants were randomized to receive probiotic (B lactis HN019, 7.0 × 109 colony forming units (CFU)/d in maltodextrin at the start of the study and 4.69 × 109 CFU/d at the end of the study or maltodextrin placebo once a day for 8 weeks. Primary outcome was change in CSBMs. Secondary outcomes included use of rescue medication, stool consistency, degree of straining for each bowel movement, abdominal pain, and bloating. Further, dietary habits and physical activity were recorded. Fecal samples were analyzed for moisture content, short-chain fatty acids, branched-chain fatty acids, microbiota composition, and calprotectin. Of the 283 individuals assessed for eligibility, 229 were randomized to either the placebo (n = 117) or the HN019 (n = 112) group. One participant in the placebo group discontinued due to COVID-19 restrictions. The 229 participants (194 [84.7% female) had a median age of 45 (38-52) years, mean (SD) BMI of 22.8 (2.5), and a mean (SD) of 0.77 (1.0) CSBM/wk. There was no difference in the change of weekly CSBMs from baseline to the end of study between the HN019 (least-square mean change, 0.80 [95% CI, 0.54-1.05]) and placebo (least-square mean change, 0.66 [95% CI, 0.41-0.90]) groups. Although probiotics have been reported to improve bowel function, this large, well-conducted randomized clinical trial did not confirm such results. Daily consumption of B lactis HN019 at the tested dose of 4.69 × 109 CFU did not outperform placebo to increase CSBMs. Chinese Clinical Trial Registry Identifier: ChiCTR2000029215.

Analysis of the correlation between human milk odd and branched chain fatty acid (OBCFA) and diet intake in different regions of China

Analysis of the correlation between human milk odd and branched chain fatty acid (OBCFA) and diet intake in different regions of China

Biodegradation and high-value utilization of waste cooking oil: Strategies and mechanisms for producing lipopeptide biosurfactants using Bacillus subtilis YZQ-2

This study explored the strategies and mechanisms of Bacillus subtilis YZQ-2 in producing lipopeptide biosurfactants using waste cooking oil (WCO) as a raw material. The optimal conditions achieved a WCO utilization rate of 75.88% and a biosurfactant yield of 0.30g/L at pH 6.0, 30°C, with 20g/L WCO and 5g/L yeast extract. GC-MS analysis of degradation products at different intervals elucidated the mechanism of WCO degradation. After 72hours of fermentation, a reduction in linoleic and palmitic acid levels indicated the completion of lipid hydrolysis and the continuation of β-oxidation. The biosurfactants, identified as lipopeptides (surfactin and fengycin), exhibited stability in alkaline environments (pH 7.0-11.0) and high-salt concentration (5-45g/L). Genomic and transcriptomic analyses of Bacillus subtilis YZQ-2 revealed genes associated with biosurfactant production, which were upregulated in the presence of WCO. The differential expression values (log2 fold change) were SrfAA 3.30, SrfAB 3.31, SrfAC 3.63, FenA 2.42, FenB 2.55, FenC 1.99, FenD 2.03 and FenE 2.29, respectively. The proposed biosynthesis pathway of lipopeptides begins with the hydrolysis of WCO by lipase into glycerol and fatty acids. The glycerol is then transformed into pyruvate through glycolysis, entering the Tricarboxylic Acid cycle. Additionally, pyruvate contributes to synthesizing amino acids and branched-chain fatty acids, which serve as precursors for lipopeptide synthesis. These findings underscore the potential of WCO as a sustainable feedstock for biosurfactant production.

Quantifying acyl-chain diversity in isobaric compound lipids containing monomethyl branched-chain fatty acids

Compound lipids comprise a diverse group of metabolites present in living systems, and metabolic- and environmentally-driven structural distinctions across this family is increasingly linked to biological function. However, methods for deconvoluting these often isobaric lipid species are lacking or require specialized instrumentation. Notably, acyl-chain diversity within cells may be influenced by nutritional states, metabolic dysregulation, or genetic alterations. Therefore, a reliable, validated method of quantifying structurally similar even-, odd-, and branched-chain acyl groups within intact compound lipids will be invaluable for gaining molecular insights into their biological functions. Here we demonstrate the chromatographic resolution of isobaric lipids containing distinct combinations of straight-chain and branched-chain acyl groups via ultra-high-pressure liquid chromatography (UHPLC)-mass spectrometry (MS) using a C30 liquid chromatography column. Using metabolically-engineered adipocytes lacking branched-keto acid dehydrogenase A (Bckdha), we validate this approach through a combination of fatty acid supplementation and metabolic tracing using monomethyl branched-chain fatty acids and valine. We observe resolution of numerous isobaric triacylglycerols and other compound lipids, demonstrating the resolving utility of this method. This approach adds to the toolbox for laboratories to quantify and characterize acyl chain diversity across the lipidome.

Effects of a Veterinary Gastrointestinal Low-Fat Diet on Fecal Characteristics, Metabolites, and Microbiota Concentrations of Adult Dogs Treated with Metronidazole.

Antibiotics are known to cause loose stools, disrupt the fecal microbiota, and alter fecal bile acid (BA) profiles of dogs. Recovery may be aided by diet, but little research has been conducted. The objective of this study was to determine how a veterinary low-fat diet affected the fecal characteristics, metabolites, BA, and microbiota of dogs receiving antibiotics. Twenty-four healthy adult dogs [7.38 ± 1.95 yr; 7.67 ± 0.76kg body weight (BW)] were used in an 8-wk completely randomized design study. During a 2-wk baseline, all dogs were fed a leading grocery brand dry kibble diet (GBD). Over the next 2wk, dogs were fed GBD and received metronidazole orally (20mg/kg BW twice daily). At wk 4, dogs were randomly allotted to one of two treatments [GBD or Blue Buffalo Natural Veterinary Diet GI Gastrointestinal Support Low-Fat (BB)] and fed for 4wk. Fecal scores were recorded daily and fresh fecal samples were collected at wk 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter content, and metabolite and BA concentrations. Fecal microbiota populations were analyzed by 16S rRNA gene amplicon sequencing and qPCR-based dysbiosis index (DI). All data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, testing for effects of treatment, time, and treatment*time and significance set at P<0.05. Metronidazole increased (P<0.0001) fecal scores (looser stools), reduced fecal short-chain fatty acid, branched-chain fatty acid, phenol, and indole concentrations, increased primary BA concentrations, and decreased secondary BA concentrations. Metronidazole also reduced fecal bacterial alpha diversity, altered the abundance of 58 bacterial genera, and increased DI. During antibiotic recovery, change in fecal pH, dry matter percentage, and metabolite and immunoglobulin A concentrations were altered (P<0.05) by diet. Fecal BA concentrations recovered quickly for all dogs. Change in lithocholic acid was affected (P<0.0001) by diet, but other BA were not. Recovery of over 25 bacterial genera was impacted by diet (P<0.05). While many bacterial taxa returned to baseline levels after 4wk, others did not fully recover. DI and bacterial alpha diversity measures recovered quickly for all dogs, but were not impacted by diet. In conclusion, metronidazole drastically altered the fecal microbiota and metabolites of dogs. While most variables returned to baseline by wk 8, diet may be used to aid in recovery.

Monomethyl Branched-Chain Fatty Acids Suppress M1 Macrophage Polarization via FABP4/PPAR-γ Signaling Pathway.

Monomethyl-branched chain fatty acids (mmBCFAs) are found in a variety of food sources and are of great interest due to their potent antiinflammatory properties. However, most of the current researches have concentrated on the relationship between mmBCFAs and intestinal inflammation, and there is a large gap in the biological mechanisms involved behind their antiinflammatory effects. The present study examines the role of mmBCFAs in modulating macrophage polarization. The results demonstrate that iso-C16:0 significantly inhibits macrophages M1 proinflammatory polarization through regulating FABP4/PPAR-γ pathway. Proteomics and molecular biology experiments verify that metabolic reprogramming is involved in the inhibition of M1 macrophage, referring to the upregulation of fatty acid oxidation, TCA cycle, and oxidative phosphorylation, as well as downregulation of glycolytic flux. In summary, this study offers a novel perspective on the antiinflammatory effects mediated by mmBCFAs.

Longitudinal changes of serum metabolomic profile after laparoscopic sleeve gastrectomy in obesity.

Bariatric surgery induces significant weight loss, increases insulin sensitivity, and improves dyslipidemia. As one of the most widely performed bariatric surgeries, laparoscopic sleeve gastrectomy (LSG) is thought to improve the metabolic profile along with weight loss. The objective of this study was to evaluate longitudinal changes in the serum metabolite levels after LSG and elucidate the underlying mechanisms of metabolic improvement. Clinical metabolic parameters and serum samples were collected preoperatively and at 1, 3, and 6 months postoperatively from nine patients with obesity undergoing LSG. Serum metabolites were measured using a non-targeted metabolic liquid chromatography-mass spectrometry method. During the 1, 3, and 6 months postoperative follow-up, the body mass index, HOMA-IR, and liver fat content showed a gradual descending trend. A total of 328 serum metabolites were detected, and 38 were differentially expressed. The up-regulated metabolites were mainly enriched in ketone body metabolism, alpha-linolenic acid and linoleic acid metabolism, pantothenate and CoA biosynthesis, glycerolipid metabolism, and fructose and mannose degradation, while the down-regulated metabolites were closely related to caffeine metabolism, oxidation of branched-chain fatty acids, glutamate metabolism, and homocysteine degradation. Notably, nine metabolites (oxoglutarate, 2-ketobutyric acid, succinic acid semialdehyde, phthalic acid, pantetheine, eicosapentaenoate, 3-hydroxybutanoate, oxamic acid, and dihydroxyfumarate) showed persistent differential expression at 1, 3, and 6 months follow-up. Some were found to be significantly associated with weight loss, insulin resistance improvement, and liver fat content reduction. This finding may provide a new perspective for revealing novel biomarkers and mechanisms of metabolic improvement in obesity and related comorbidities.

Interaction of Wheat Bran Particle Size and Stimbiotic Supplementation on Growth Performance and Gut Health Parameters in Broilers.

A 42-day study was conducted with 720-day-old Cobb male broiler chicks allocated to treatments in a 3 × 2 factorial, with the factors as wheat bran (WB) inclusion (no WB, 50 g/kg coarse WB, or 50 g/kg fine WB) and stimbiotic (STB) supplementation in corn-based diets. The inclusion of WB (p < 0.05) or STB supplementation (p < 0.05) increased the FCR and feed intake in the day 0-10 phase. During the day 0-28 phase, coarse-WB inclusion increased (p < 0.05) the FCR, compared to fine WB or diets without WB. In the day 0-42 phase, WB marginally decreased weight gain in diets without STB supplementation, but the STB-supplemented diet, weight gain was greater (p < 0.05) the diet with fine WB compared with diets with coarse WB. Fine-WB inclusion increased the ileal nitrogen and energy digestibility determined at day 18 compared to coarse WB or diets without WB. Supplementation with STB (p < 0.05) or fine WB (p < 0.05) inclusion increased the villi height compared to diets without STB supplementation or coarse WB, or the diet without WB. Coarse or fine WB decreased (p < 0.05) cecal branched-chain fatty acids compared to diets without WB. In conclusion, stimbiotic supplementation to fine WB improved the performance and nutrient digestibility of broilers compared to coarse WB with no effects on the caeca total SCFA concentration.

PSXI-29 Effects of Vitamin B6 supplementation on rumen fermentation and branched chain fatty acids content in vitro

Abstract Vitamin B6 promotes branched-chain amino acid aminotransferases in branched chain fatty acids (BCFA) synthesis pathways. This study aimed to investigate the effects of Vitamin B6 supplementation in total mixed ration on rumen fermentation characteristics and the rumen BCFA content in vitro. Treatments were set as dose response with 0, 3, 6, 12 and 24 mg/kg dry matter (DM) Vitamin B6. Each incubated with 75 mL of buffered rumen fluid and 0.5 g of fermentation substrate for 24 h at 39°C. Five replicate parallel fermentation flasks were prepared by each level of supplemented Vitamin B6, and incubation was repeated twice. Filtered fluid with Nylon bags were collected from each fermentation flask. The contents of volatile fatty acids (VFA) and BCFA were determined using an Agilent 6890N GC equipped with a flame ionization detector. All data were analyzed using the linear mixed model of nlme Package in R (version 4.3.1). Compared with the control group, the concentration of total branched chain volatile fatty acids, propionic acid, butyric acid, valeric acid, isobutyric acid and isovaleric acid at 3 mg/kg DM Vitamin B6 significantly decreased, while the ratio of acetic acid to propionic acid was significantly increased (P &amp;lt; 0.01). As the dose of Vitamin B6 increased, the concentrations of iso-C14:0, iso-C15:0, anteiso-C17:0 changed quadratically with greatest at 3 mg/kg DM Vitamin B6 (P &amp;lt; 0.05). Compared with the control group, the contents of iso-C13:0, iso-C14:0, iso-C15:0, anteiso-C15:0, anteiso-C17:0, iso, anteiso and BCFA at 3 mg/kg DM Vitamin B6 significantly increased (P &amp;lt; 0.01). The contents of total iso, anteiso and BCFA increased by 18.80 %, 35.37 % and 22.58 %, respectively, compared with the control. In summary, the results of this study indicated that 3 mg/kg DM Vitamin B6 had beneficial effects on increasing BCFA content than other groups.

Unusual polyunsaturated fatty acids in edible marine worms identified by covalent adduct chemical ionization mass spectrometry

Non-traditional seafood, such as spoon worms (Urechis unicinctus) and peanut worms (Sipunculus nudus), serves as both delicacies and potential solutions to the global food insecurity crisis. Despite being consumed primarily in parts of China, Korea, and Japan, the nutritional values especially the complex fatty acid compositions of these marine worms are difficult to characterize. To overcome this obstacle, we employed covalent adduct chemical ionization (CACI) tandem mass spectrometry for the de novo identification of their unusual polyunsaturated fatty acids (PUFA). Through this method, we identified several PUFA with polymethylene-interrupted (PMI) double bond configurations, including 22:3(7Z,13Z,16Z), a novel PUFA derived from sciadonic acid. U. unicinctus exhibits an exceptionally low n-6/n-3 PUFA ratio of 0.15, making it a potential functional food to counterbalance the n-6/n-3 imbalance in modern diets. S. nudus boasts notably high concentrations (∼3 %, wt/wt) of branched chain fatty acids (BCFA), exceeding typical levels found in dairy products.

Cow's Milk Bioactive Molecules in the Regulation of Glucose Homeostasis in Human and Animal Studies.

Obesity disrupts glucose metabolism, leading to insulin resistance (IR) and cardiometabolic diseases. Consumption of cow's milk and other dairy products may influence glucose metabolism. Within the complex matrix of cow's milk, various carbohydrates, lipids, and peptides act as bioactive molecules to alter human metabolism. Here, we summarize data from human studies and rodent experiments illustrating how these bioactive molecules regulate insulin and glucose homeostasis, supplemented with in vitro studies of the mechanisms behind their effects. Bioactive carbohydrates, including lactose, galactose, and oligosaccharides, generally reduce hyperglycemia, possibly by preventing gut microbiota dysbiosis. Milk-derived lipids of the milk fat globular membrane improve activation of insulin signaling pathways in animal trials but seem to have little impact on glycemia in human studies. However, other lipids produced by ruminants, including polar lipids, odd-chain, trans-, and branched-chain fatty acids, produce neutral or contradictory effects on glucose metabolism. Bioactive peptides derived from whey and casein may exert their effects both directly through their insulinotropic effects or renin-angiotensin-aldosterone system inhibition and indirectly by the regulation of incretin hormones. Overall, the results bolster many observational studies in humans and suggest that cow's milk intake reduces the risk of, and can perhaps be used in treating, metabolic disorders. However, the mechanisms of action for most bioactive compounds in milk are still largely undiscovered.

Structural insights into human ABCD3-mediated peroxisomal acyl-CoA translocation

Human ABC transporters ABCD1–3 are all localized on the peroxisomal membrane and participate in the β-oxidation of fatty acyl-CoAs, but they differ from each other in substrate specificity. The transport of branched-chain fatty acids from cytosol to peroxisome is specifically driven by ABCD3, dysfunction of which causes severe liver diseases such as hepatosplenomegaly. Here we report two cryogenic electron microscopy (cryo-EM) structures of ABCD3 bound to phytanoyl-CoA and ATP at resolutions of 2.9 Å and 3.2 Å, respectively. A pair of phytanoyl-CoA molecules were observed in ABCD3, each binding to one transmembrane domain (TMD), which is distinct from our previously reported structure of ABCD1, where each fatty acyl-CoA molecule strongly crosslinks two TMDs. Upon ATP binding, ABCD3 exhibits a conformation that is open towards the peroxisomal matrix, leaving two extra densities corresponding to two CoA molecules deeply embedded in the translocation cavity. Structural analysis combined with substrate-stimulated ATPase activity assays indicated that the present structures might represent two states of ABCD3 in the transport cycle. These findings advance our understanding of fatty acid oxidation and the molecular pathology of related diseases.