Effects of a Low-Carbohydrate, High-Protein Diet on Gut Microbiome Composition in Insulin-Resistant Individuals With Chronic Spinal Cord Injury: Preliminary Results From a Randomized Controlled Trial.

OBJECTIVE: To evaluate the effect of a low-carbohydrate, high-protein (LC/HP) diet that includes healthy dietary components (eg, lean meat, whole grains, fruits and vegetables, fiber, etc) on the gut microbiome composition in individuals with chronic spinal cord injury (SCI). DESIGN: A single-center randomized parallel controlled trial. SETTING: Research University. PARTICIPANTS: Adult participants with chronic SCI (N=19, 3 years or more after the injury, C2-L2, American Spinal Injury Association Impairment Scale A-D). Participants were insulin resistant and had not received antibiotics within 4 weeks before enrolling in the study. INTERVENTIONS: Participants were randomized to the LC/HP diet group (40% energy from carbohydrates, 30% energy from protein, and 30% energy from fat and met dietary guideline recommendations) or the control group for 8 weeks. Participants assigned to the LC/HP group were provided with all meals delivered weekly to their homes. Participants assigned to the control group were asked to continue their usual diet. MAIN OUTCOME MEASURES: Stool samples were collected at baseline and the end of week 8. The gut microbiome 16S ribosomal RNA V4 region was sequenced, and gut microbiome diversity and taxonomical abundance were computed using the QIIME2 suite. RESULTS: Participants in the LC/HP group had significant changes in alpha-diversity (reduced operational taxonomic unit and Faith's phylogenetic diversity) and beta-diversity (unweighted UniFrac), while no significant differences were observed among participants in the control group after the intervention. Moreover, several taxa changed differently over time between groups, including increased Bacteroides thetaiotaomicron, Coprococcus 3, Fusicatenibacter, Tannerellaceae, and decreased Tyzzerella, Phascolarctobacterium, Romboutsia, Clostridium sensu stricto 1, Hungatella, Ruminococcus gauvreauii, family XI, and Bacillales among participants in the diet group, while these taxa did not change in the control group. CONCLUSIONS: An LC/HP diet with healthy dietary components improved gut microbiome composition in individuals with SCI, including increased bacteria implicated in fiber metabolism and reduced bacteria communities linked to cardiometabolic disorders.

Gut Microbiome Composition and Serum Metabolome Profile Among Individuals With Spinal Cord Injury and Normal Glucose Tolerance or Prediabetes/Type 2 Diabetes.

OBJECTIVE: To compare the gut microbiome composition and serum metabolome profile among individuals with spinal cord injury (SCI) and normal glucose tolerance (NGT) or prediabetes/type 2 diabetes (preDM/T2D). DESIGN: Cross-sectional design. SETTING: Research university. PARTICIPANTS: A total of 25 adults (N=25) with SCI were included in the analysis and categorized as NGT (n=16) or preDM/T2D (n=9) based on their glucose concentration at minute 120 during a 75-g oral glucose tolerance test. The American Diabetes Association diagnosis guideline was used for grouping participants. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: A stool sample was collected and used to assess the gut microbiome composition (alpha and beta diversity, microbial abundance) via the 16s ribosomal RNA sequencing technique. A fasting serum sample was used for liquid chromatography-mass spectrometry-based untargeted metabolomics analysis, the results from which reflect the relative quantity of metabolites detected and identified. Gut microbiome and metabolomics data were analyzed by the Quantitative Insights into Microbial Ecology 2 and Metaboanalyst platforms, respectively. RESULTS: Gut microbiome alpha diversity (Pielou's evenness index, Shannon's index) and beta diversity (weighted UniFrac distances) differed between groups. Compared with participants with NGT, participants with preDM/T2D had less evenness in microbial communities. In particular, those with preDM/T2D had a lower abundance of the Clostridiales order and higher abundance of the Akkermansia genus, as well as higher serum levels of gut-derived metabolites, including indoxyl sulfate and phenylacetylglutamine (P < .05 for all). CONCLUSIONS: Our results provide evidence for altered gut microbiome composition and dysregulation of gut-derived metabolites in participants with SCI and preDM/T2D. Both indoxyl sulfate and phenylacetylglutamine have been implicated in the development of cardiovascular diseases in the able-bodied population. These findings may inform future investigations in the field of SCI and cardiometabolic health.

Limited Association between the Total Healthy Eating Index-2015 Score and Cardiovascular Risk Factors in Individuals with Long-Standing Spinal Cord Injury: An Exploratory Study: An Exploratory Study.

BACKGROUND: The healthy eating index-2015 (HEI-2015) reflects diet quality in reference to the 2015-2020 Dietary Guidelines for Americans (DGA). Little is known regarding its application in individuals with chronic spinal cord injury (SCI). OBJECTIVE: To explore the relationship between diet quality as assessed by the HEI-2015 and cardiovascular risk factors among individuals with chronic SCI. DESIGN: This is a cross-sectional analysis of baseline data collected from August 2017 through November 2019 for an interventional study that evaluates the effects of a high-protein/low-carbohydrate diet on cardiovascular risk factors in individuals with chronic SCI at the University of Alabama at Birmingham. PARTICIPANTS/SETTING: Twenty-four free-living adults with SCI (mean age, 45 ± 12 y; 8F/16M, level of injury: nine cervical, 15 thoracic; mean duration of injury: 20 ± 13 y) were included. MAIN OUTCOME MEASURES: Participants underwent a 2-hour oral glucose tolerance test (OGTT) and a dual-energy x-ray absorptiometry scan. Dietary intake was assessed by three, 24-hour multiple-pass dietary recalls to calculate the HEI-2015 using the simple HEI scoring algorithm method. DATA ANALYSIS: Multiple linear regression analyses were performed to predict indices of lipid metabolism and glucose homeostasis and C-reactive protein (CRP) from the HEI-2015. Principal component analysis was used to reduce the number of covariates (level of injury, sex, and body fat percentage). RESULTS: On average, participants' diets were of low quality (HEI-2015, 47.2 ± 10.8). The regression models for fasting glucose (FG), cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and CRP had moderate to large effect sizes (adjusted R2 ≥ 13%), suggesting good explanatory abilities of the predictors. Small or limited effect sizes were observed for glucose tolerance, fasting insulin, triglycerides, and Matsuda index (adjusted R2 < 13%). The HEI-2015 accounted for a moderate amount of variation in FG (partial omega-squared, ωP2 = 13%). Each 10-point HEI-2015 score increase was associated with a 3.3-mg/dL decrease in FG concentrations. The HEI-2015 accounted for a limited amount of variation in other indices (ωP2 < 5%). CONCLUSIONS: Among participants with SCI, higher conformance to the 2015-2020 DGA was 1) moderately associated with better FG homeostasis; and 2) trivially associated with other cardiovascular risk factors. Because of the small sample size, these conclusions cannot be extrapolated beyond the study sample. Future larger studies are warranted to better understand the relationship between diet quality and cardiovascular disease risks in this population.

Ketogenic regimens for acute neurotraumatic events.

Dietary modification would be the most translatable, cost-efficient, and, likely, the safest approach available that can reduce the reliance on pharmaceutical treatments for treating acute or chronic neurological disorders. A wide variety of evidence suggests that the ketogenic diet (KD) could have beneficial effects in acute traumatic events, such as spinal cord injury and traumatic brain injury. Review of existing human and animal studies revealed that KD can improve motor neuro-recovery, gray matter sparing, pain thresholds, and neuroinflammation and decrease depression. Although the exact mechanism by which the KD provides neuroprotection is not fully understood, its effects on cellular energetics, mitochondria function and inflammation are likely to have a role.

Mapping Quantitative Trait Loci Associated With Resistance to Aflatoxin Accumulation in Maize Inbred Mp719.

Aflatoxins are carcinogenic and toxic compounds produced principally by fungal species Aspergillus flavus (Link: Fries) and A. parasiticus (Speare), which are common contaminants of food and feed. Aflatoxins can be found at dangerously high levels and can readily contaminate pre-harvest maize (Zea mays L.) grain. Sources of resistance to aflatoxin accumulation in maize have been identified, however, the highly quantitative nature and complex inheritance of this trait have limited the introgression of aflatoxin accumulation resistance into agronomically desirable lines. Mapping of quantitative trait loci (QTL) was performed on a bi-parental population comprised of 241 F2:3 families derived from the cross of inbred lines Mp705 (susceptible) × Mp719 (resistant). The mapping population was phenotyped in replicated field trials in three environments for resistance to aflatoxin accumulation under artificial inoculation with an A. flavus spore suspension. The genetic linkage map was constructed with 1,276 single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) molecular markers covering a total genetic distance of 1,642 cM across all ten maize chromosomes. Multiple interval mapping revealed that majority of the aflatoxin-reducing alleles and the source for the larger effect QTL identified in this study were contributed from Mp719, the resistant parent. Two QTL identified on chromosome 1 (bin 1.06-1.07) and chromosome 3 (bin 3.09) were the most stable across different environments and when combined, explained 24.6% of the total phenotypic variance across all three environments. Results from the study showed that these chromosomal regions harbor important QTL for influencing aflatoxin accumulation, which is consistent with previous reports with other different mapping populations. These stable QTL were the most promising for controlling aflatoxin accumulation in maize grain. Identifying beneficial alleles derived from Mp719 and closely linked molecular markers through QTL analysis for implementation of MAS could accelerate breeding efforts to reduce aflatoxin accumulation in maize.

A Histological Study of Aspergillus flavus Colonization of Wound Inoculated Maize Kernels of Resistant and Susceptible Maize Hybrids in the Field.

Aspergillus flavus colonization in developing kernels of maize single-cross hybrids resistant (Mp313E × Mp717) and susceptible (GA209 × T173) to aflatoxin accumulation was determined in the field over three growing seasons (2012-2014). Plants were hand pollinated, and individual kernels were inoculated with a needle dipped in a suspension of A. flavus conidia 21 days after pollination. Kernels were harvested at 1- to 2-day intervals from 1 to 21 days after inoculation (DAI). Kernels were placed in FAA fixative, dehydrated, embedded in paraffin, sectioned, and stained with toluidine blue. Kernels were also collected additional kernels for aflatoxin analyses in 2013 and 2014. At 2 DAI, A. flavus hyphae were observed among endosperm cells in the susceptible hybrid, but colonization of the endosperm in the resistant hybrid was limited to the wound site of the resistant hybrid. Sections of the scutellum of the susceptible hybrid were colonized by A. flavus by 5 DAI. Fungal growth was slower in the resistant hybrid compared to the susceptible hybrid. By 10 DAI, A. flavus had colonized a large section of the embryo in the susceptible hybrid; whereas in the resistant hybrid, approximately half of the endosperm had been colonized and very few cells in the embryo were colonized. Fungal colonization in some of the kernels of the resistant hybrid was slowed in the aleurone layer or at the endosperm-scutellum interface. In wounded kernels with intact aleurone layers, the fungus spread around the kernel between the pericarp and aleurone layer with minimal colonization of the endosperm. Aflatoxin B1 was first detected in susceptible kernel tissues 8 DAI in 2013 (14 µg/kg) and 2014 (18 µg/kg). The resistant hybrid had significantly lower levels of aflatoxin accumulation compared to the susceptible hybrid at harvests 10, 21, and 28 DAI in 2013, and 20 and 24 DAI in 2014. Our study found differential A. flavus colonization of susceptible and resistant kernel tissues, and that the aleurone and the outer layer of the scutellum slowed the rate of colonization by A. flavus.

Genome-Wide Association and Metabolic Pathway Analysis of Corn Earworm Resistance in Maize.

Maize ( L.) is a staple crop of economic, industrial, and food security importance. Damage to the growing ears by corn earworm [ (Boddie)] is a major economic burden and increases secondary fungal infections and mycotoxin levels. To identify biochemical pathways associated with native resistance mechanisms, a genome-wide association analysis was performed, followed by pathway analysis using a gene-set enrichment-based approach. The gene-set enrichment exposed the cumulative effects of genes in pathways to identify those that contributed the most to resistance. Single nucleotide polymorphism-trait associations were linked to genes including transcription factors, protein kinases, hormone-responsive proteins, hydrolases, pectinases, xylogluconases, and the flavonol synthase gene (in the maysin biosynthesis pathway). The most significantly associated metabolic pathways identified included those that modified cell wall components, especially homogalacturonan, wax esters, and fatty acids; those involved in antibiosis, especially 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), flavonoids, and phenolics; and those involved in plant growth, including N uptake and energy production. The pathways identified in this study, and especially the cell wall-associated pathways, identified here for the first time, provide clues to resistance mechanisms that could guide the identification of new resistant ideotypes and candidate genes for creation of resistant maize germplasm via selection of natural variants or gene editing.

Who Needs a Pediatric Intensive Care Unit After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis?

BACKGROUND: Hypotensive events (HEs) following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) can lead to delayed neurologic postoperative deficits (DNPD). This study aimed to determine the incidence of HEs (mean arterial pressure [MAP] <60 mmHg) after PSF for AIS and identify predictors for HEs. METHODS: Medical records of 99 consecutive patients who had PSF for AIS were retrospectively reviewed (2011-2013). Perioperative data were collected. Patients were divided into two groups based on MAP readings by an arterial line in the pediatric intensive care unit immediately postoperatively into postoperative day one: Group 1 (MAP ≥60 mmHg) and Group 2 (multiple occurrences of MAPs <60 mmHg). Mean values were compared using the independent t test. Multiple logistic regression was used to estimate the association of preoperative and intraoperative parameters with multiple HEs. RESULTS: Group 1 had 68 patients (68.7%) and Group 2 had 31 patients (31.3%). None of the compared parameters were associated significantly with multiple HE. However, patients who did not exhibit HEs within the first four hours postoperatively remained stable throughout the rest of the postoperative period. Only those with HEs in the first four hours experienced subsequent HEs in the first 24 hours. There were no DNPD or other major complications. CONCLUSION: Results showed that the incidence of HEs after PSF in AIS can be as high as 31.3%. We did not find any significant risk factors. Although DNPD after PSF is a rare complication and we had none in this series, we suggest that these patients with multiple HEs may be at risk for DNPD as a result of hypotension and potential for cord ischemia. Therefore, all patients after PSF should be monitored in a pediatric intensive care unit-type environment or postanesthesia recovery room initially. If stable for, at least, the initial four hours, then patients should be good candidates for a less intensive environment. LEVEL OF EVIDENCE: Level 3.

A recent review of non-biological remediation of aflatoxin-contaminated crops.

Aflatoxins are highly toxic, mutagenic, teratogenic and carcinogenic compounds produced predominantly as secondary metabolites by certain species of fungi belonging to the Aspergillus genus. Owing to the significant health risks and economic impacts associated with the presence of aflatoxins in agricultural commodities, a considerable amount of research has been directed at finding methods to prevent toxicity. This review compiles the recent literature of methods for the detoxification and management of aflatoxin in post-harvest agricultural crops using non-biological remediation.

Screw Versus Hybrid Constructs for Flexible Thoracic Curves in Adolescent Idiopathic Scoliosis: A Prospective, Randomized Study.

STUDY DESIGN: Prospective, computer-randomized design. OBJECTIVE: Compare screw and hybrid constructs in flexible, thoracic curves for adolescent idiopathic scoliosis (AIS) in a prospective randomized fashion. SUMMARY OF BACKGROUND: The consensus in scientific literature is that all-screw constructs correct AIS better than hooks in the lumbar and in large, stiff thoracic curves. However, debate continues whether all-screw constructs outperform hybrid constructs in small, flexible thoracic AIS. To our knowledge, this is the first prospective, randomized scoliosis study that examines measures of correction and patient satisfaction with the Scoliosis Research Society-30 (SRS-30) questionnaire. METHODS: A total of 45 enrolled AIS patients with flexible, thoracic curves were given an identification number with an associated computer-generated randomization to the hybrid (n = 22) or screw group (n = 23). The treating surgeon received the randomization 2-3 days before surgery. Data including major Cobb (MC), truncal rotation (TR), rib index (RI), secondary curve (SC), and SRS-30 questionnaire were collected preoperatively and postoperatively at 4 weeks and 3, 6, 12, and 24 months. RESULTS: Thirty-seven patients in the hybrid (n = 18) and screw (n = 19) groups completed the study with a mean follow-up of 26 months (range, 24-49 months). Hybrid versus screw group means for preoperative, postoperative, and final follow-up were: MC 58° ± 8° versus 55° ± 6°, 18° ± 8° versus 15° ± 7°, and 23°± 8° versus 14° ± 6°; TR 14° ± 6° versus 16° ± 4°, 10° ± 5° versus 7° ± 3°, and 11° ± 5° versus 7° ± 4°; RI 3.0° ± 1.2° versus 3.4° ± 1.4°, 2.5° ± 0.7° versus 1.8° ± 0.6°, and 2.5° ± 0.8° versus 2.0° ± 0.5°; SC 35° ± 13° versus 31° ± 8°, 13° ± 11° versus 7° ± 9°, and 13° ± 12° versus 7° ± 7°; and SRS-30 3.9 ± 0.2 versus 3.9 ± 0.2, 4.1 ± 0.4 versus 4.0 ± 0.3, and 4.1 ± 0.3 versus 4.0 ± 0.2. CONCLUSIONS: Intergroup preoperative and early postoperative values were comparable (p > .05). At final follow-up, owing to loss of correction in the hybrid group, differences in MC (9°; p = .000), RI (0.54; p = .016), and TR (4°; p = .039) correction were statistically significant as SC trended toward significance (6°; p = .052). All-screw constructs outperformed hybrid constructs, especially over time. No differences in SRS-30 scores occurred between groups.