J, Burd N, Holscher H, Khan N. Dietary Xanthophyll and Choline Intake Interactively Influence Cognitive Flexibility in Middle-Adulthood

Objectives

Consumption and biomarker status of the xanthophyll-carotenoids lutein + zeaxanthin and the dietary component choline have been linked to benefits in cognition. However, knowledge on the interactive influence of these dietary components on cognition is sparse. We examined associations between dietary and bio-markers of lutein + zeaxanthin, choline, and cognitive flexibility among adults with overweight and obesity.

Methods

80 adults with overweight and obesity completed 7-day diet records, venous blood draws, heterochromatic flicker photometry for assessment of macular pigmentation (MPOD), the Kaufman Brief Intelligence Test–2 (IQ), and a Switch task of cognitive flexibility while undergoing electroencephalographic recording (ERP). Multiplicative interaction terms were calculated to assess interactive capabilities. Hierarchical linear regressions controlling for age, body mass index, sex, annual household income, and IQ were utilized to assess independent and interactive contributions of dietary and metabolite data on Switch task outcomes.

Results

Dietary intake of lutein + zeaxanthin and choline were correlated with serum lutein concentrations (r = 0.42, P < 0.01, r = 0.35, P < 0.01) but not with plasma choline metabolites nor MPOD. Higher intakes of lutein + zeaxanthin and choline were associated interactively, but not independently, with faster reaction time (RT; β = −0.29, P = 0.01). Plasma phosphatidylcholine (PC) concentrations were associated with accuracy in Switch trials (β = 0.28, P = 0.01), while no other biomarkers were associated with cognitive outcomes. Dietary intake and biomarker data were not related to the N2 nor P3 ERP components.

Conclusions

Individuals with greater intake of lutein + zeaxanthin and choline exhibited faster RT during a cognitive flexibility task. Circulating PC was associated with higher response accuracy. These benefits were evident without differences in the N2 or P3 components, suggesting alternative neural benefits of xanthophyll and choline consumption on cognitive function.

Funding Sources

Funds were provided by the Hass Avocado Board, the Department of Kinesiology and Community Health at the University of Illinois, and the USDA National Institute of Food and Agriculture, Hatch project 1,009,249.

The Impact of Fresh Hass Avocado on the Fecal Metabolome Among Adults with Overweight and Obesity: A Randomized, Controlled Trial

Objectives

Avocados are nutrient-rich fruits that have been recently linked to beneficial alterations to the gastrointestinal microbiota. However, previous research on shifts in the fecal metabolome with avocado intake has largely been conducted in in vitro or preclinical models and little is known about their metabolomic impact in human subjects.

Methods

Adult participants (n = 109) 25–45 years of age with BMI ≥ 25.0 kg/m2 were enrolled in an investigator-blinded, parallel arm, randomized, controlled trial. Participants consumed isocaloric meals with or without fresh Hass avocado once daily for 12-weeks and reported ≥ 80% meal consumption over the intervention period. Untargeted fecal metabolites were quantified in a subsample of participants (n = 48) using gas chromatography mass spectroscopy and were normalized by sample weight. Kruskal-Wallis tests and false discovery rate type I error correction were conducted and orthogonal partial least squares discriminant analysis (OPLS-DA) was used to predict treatment group by fecal metabolite concentrations (RStudio, version 3.6.2).

Results

A total of 292 metabolites were identified at intervention follow-up. Of these, three metabolites differed significantly between treatment groups. Fecal concentrations of lanosterol (P = 0.0004, q = 0.04) and the fatty alcohols hexadecanol (P = 0.001, q = 0.04) and octadecanol (P = 0.001, q = 0.04), were greater in the group consuming avocado as compared to control. Seventeen additional metabolites, including nine fecal lipids, two fat soluble vitamin derivatives, and three monosaccharides/disaccharides differed at P < 0.05 but did not meet the q < 0.05 threshold. Treatment group assignment was predicted correctly in 70% of cases (R2 = 72%, Q2 = 33%) using the trained OPLS-DA model.

Conclusions

Fresh Hass avocado intake increased fecal lipid and sterol concentrations among healthy adults with overweight and obesity, demonstrating diet-related modifications to the fecal metabolome.

Funding Sources

Support for this research was provided by the Hass Avocado Board, the USDA National Institute of Food and Agriculture, Hatch project 1009249, and the USDA National Institute of Food and Agriculture AFRI Predoctoral Fellowship, project 2018–07785.

Evaluating the application of the dual path platform VetTB test for badgers (Meles meles) in the test and vaccinate or remove (TVR) wildlife research intervention project in Northern Ireland

European badgers (Meles meles) are accepted as a wildlife reservoir host for Mycobacterium bovis, which causes bovine tuberculosis (bTB) in the British Isles. The objective of this study was to evaluate the use of Dual Path Platform (DPP) VetTB test (Chembio Diagnostic Systems Inc., Medford, NY, USA) within a Test and Vaccinate or Remove (TVR) wildlife research intervention project. Blood samples were collected from 456 individual badgers, trapped in 2015 and 2016, and tested in the field with DPP VetTB test using whole blood. Additionally, whole blood and serum samples were taken to the laboratory for further DPP VetTB testing and for gamma interferon (IFN-γ) testing. Swabs were taken from the oropharynx and trachea and submitted for bacteriological culture as were swabs from wounds, if present. Field DPP VetTB test positive badgers were euthanised and underwent post-mortem examination and bTB confirmatory testing. The results demonstrated that the test performed as well in the field using whole blood as DPP Vet TB tests in the laboratory using sera or whole blood, and as well as other established tests for M. bovis. Visual assessment of the DPP VetTB test using serum under laboratory conditions showed a high degree of consistency between raters. Using a relative gold standard (parallel interpretation of IFN-γ assay and oropharyngeal/tracheal sample/culture), sensitivity estimates for the DPP VetTB test using sera and whole blood were 0.5 (95%CI 0.34-0.66) and 0.42 (95%CI 0.24-0.66), respectively. Specificity estimates were 0.95 (95%CI 0.93-0.97) for sera and 0.89 (95%CI 0.86-0.92) for whole blood. Parallel interpretation of Band 1 (MPB83) and Band 2 (CFP-10/ESAT-6) of the DPP VetTB test was not superior to interpretation of Band 1 only. The results give confidence in the reliability and reproducibility of the DPP VetTB test for badgers under field conditions and therefore it is considered appropriate for use in a badger bTB control campaign.

Core Size does not Affect Blinking Behavior of Dye-Doped Ag@SiO2 Core-Shell Nanoparticles for Super-Resolution Microscopy

Dye-doped nanoparticles have been investigated as bright, luminescent labels for super-resolution microscopy via localization methods. One key factor in super-resolution is the size of the luminescent label, which in some cases results in a frame shift between the label target and the label itself. Ag@SiO₂ core–shell nanoparticles, doped with organic fluorophores, have shown promise as super-resolution labels. One key aspect of these nanoparticles is that they blink under certain conditions, allowing super-resolution localization with a single excitation source in aqueous solution. In this work, we investigated the effects of both the Ag core and the silica (SiO₂) shell on the self-blinking properties of these nanoparticles. Both core size and shell thickness were manipulated by altering the reaction time to determine core and shell effects on photoblinking. Size and shell thickness were investigated individually under both dry and hydrated conditions and were then doped with a 1 mM solution of Rhodamine 110 for analysis. We observed that the cores themselves are weakly luminescent and are responsible for the blinking observed in the fully-synthesized metal-enhanced fluorescence nanoparticles. There was no statistically significant difference in photoblinking behavior—both intensity and duty cycle—with decreasing core size. This observation was used to synthesize smaller nanoparticles ranging from approximately 93 nm to 110 nm as measured using dynamic light scattering. The blinking particles were localized via super-resolution microscopy and show single particle self-blinking behavior. As the core size did not impact blinking performance or intensity, the nanoparticles can instead be tuned for optimal size without sacrificing luminescence properties.

Dye-doped nanoparticles have been investigated as bright, luminescent labels for super-resolution microscopy via localization methods.

Comparison of manual and semi-automatic registration in augmented reality image-guided liver surgery: a clinical feasibility study

BACKGROUND

The laparoscopic approach to liver resection may reduce morbidity and hospital stay. However, uptake has been slow due to concerns about patient safety and oncological radicality. Image guidance systems may improve patient safety by enabling 3D visualisation of critical intra- and extrahepatic structures. Current systems suffer from non-intuitive visualisation and a complicated setup process. A novel image guidance system (SmartLiver), offering augmented reality visualisation and semi-automatic registration has been developed to address these issues. A clinical feasibility study evaluated the performance and usability of SmartLiver with either manual or semi-automatic registration.

METHODS

Intraoperative image guidance data were recorded and analysed in patients undergoing laparoscopic liver resection or cancer staging. Stereoscopic surface reconstruction and iterative closest point matching facilitated semi-automatic registration. The primary endpoint was defined as successful registration as determined by the operating surgeon. Secondary endpoints were system usability as assessed by a surgeon questionnaire and comparison of manual vs. semi-automatic registration accuracy. Since SmartLiver is still in development no attempt was made to evaluate its impact on perioperative outcomes.

RESULTS

The primary endpoint was achieved in 16 out of 18 patients. Initially semi-automatic registration failed because the IGS could not distinguish the liver surface from surrounding structures. Implementation of a deep learning algorithm enabled the IGS to overcome this issue and facilitate semi-automatic registration. Mean registration accuracy was 10.9 ± 4.2 mm (manual) vs. 13.9 ± 4.4 mm (semi-automatic) (Mean difference - 3 mm; p = 0.158). Surgeon feedback was positive about IGS handling and improved intraoperative orientation but also highlighted the need for a simpler setup process and better integration with laparoscopic ultrasound.

CONCLUSION

The technical feasibility of using SmartLiver intraoperatively has been demonstrated. With further improvements semi-automatic registration may enhance user friendliness and workflow of SmartLiver. Manual and semi-automatic registration accuracy were comparable but evaluation on a larger patient cohort is required to confirm these findings.

Longitudinal dynamics of herd-level Mycobacterium bovis MLVA type surveillance in cattle in Northern Ireland 2003-2016

Investigating genetically-structured diversity in pathogen populations over time is important to better understand disease maintenance and spread. Herd-level surveillance of Mycobacterium bovis genotypes (multi-locus VNTR analysis types, MLVA types) from all culture-confirmed bovine tuberculosis (TB) herd cases was undertaken in Northern Ireland (NI), generating an unparalleled, longitudinal, population-level 14-year survey for this pathogen. Across this population, 295 genetically-distinct M. bovis MLVA types were identified in the 19,717 M. bovis isolates surveyed. Of these, the most frequent was MLVA type 002 (23.0%); 151 MLVA types were represented more than once, in groups ranging from 2 to 4438 isolates. Only 23 MLVA types were isolated in all 14 years. Investigating inter-annual frequency of M. bovis MLVA types, examples of statistically-significant expansions (MLVA types 002, 004, 006, 009 and 027), contractions (MLVA types 001, 007 and 011) and maintenance (MLVA types 003 and 005) were disclosed, during a period of fluctuating bovine TB herd-level incidence at the NI scale. The fixed period frequency distribution of MLVA types remained highly right-skewed. Novel VNTR copy number variant MLVA types (N = 242; an average of 17 per annum) were identified throughout the survey. The MLVA type distribution in the landscape was not random; MLVA types showed statistically-significant geographical localization and strong spatial associations with Divisional Veterinary Office (DVO) regions. There was also evidence of differential risk of particular MLVA types across breeds (Holstein/Friesian vs. other), age-class, and sex and some evidence of an association between the number of animals testing positive for bovine TB during the disclosing test and particular MLVA types, although there was substantial variation.

A Profile of the SAIL Databank on the UK Secure Research Platform

BACKGROUND

The Secure Anonymised Information Linkage (SAIL) Databank is a national data safe haven of de identified datasets principally about the population of Wales, made available in anonymised form to researchers across the world. It was established to enable the vast arrays of data collected about individuals in the course of health and other public service delivery to be made available to answer important questions that could not otherwise be addressed without prohibitive effort. The SAIL Databank is the bedrock of other funded centres relying on the data for research.

APPROACH

SAIL is a data repository surrounded by a suite of physical, technical and procedural control measures embodying a proportionate privacy-by-design governance model, informed by public engagement, to safeguard the data and facilitate data utility. SAIL operates on the UK Secure Research Platform (SeRP), which is a customisable technology and analysis platform. Researchers access anonymised data via this secure research environment, from which results can be released following scrutiny for disclosure risk. SAIL data are being used in multiple research areas to evaluate the impact of health and social exposures and policy interventions.

DISCUSSION

Lessons learned and their applications include: managing evolving legislative and regulatory requirements; employing multiple, tiered security mechanisms; working hard to increase analytical capacity efficiency; and developing a multi-faceted programme of public engagement. Further work includes: incorporating new data types; enabling alternative means of data access; and developing further efficiencies across our operations.

CONCLUSION

SAIL represents an ongoing programme of work to develop and maintain an extensive, whole population data resource for research. Its privacy-by-design model and UK SeRP technology have received international acclaim, and we continually endeavour to demonstrate trustworthiness to support data provider assurance and public acceptability in data use. We strive for further improvement and continue a mutual learning process with our contemporaries in this rapidly developing field.

Evaluation of the BAX® System for Detection of Salmonella in Selected Foods: Collaborative Study

A multilaboratory study was conducted to compare the automated BAX® System to the standard cultural methods for detection of Salmonella in selected foods. Five food types—frankfurters, raw ground beef, mozzarella cheese, raw frozen tilapia fish, and orange juice—at 3 inoculation levels, were analyzed by each method. A sixth food type, raw ground chicken, was tested using 3 naturally contaminated lots. A total of 16 laboratories representing government and industry participated. In this study, 1386 samples were analyzed, of which 1188 were paired samples and 198 were unpaired samples. Of the 1188 paired samples, 461 were positive by both methods and 404 were negative by both methods. Thirty-seven samples were positive by the BAX System but negative by the standard reference method, and 11 samples were positive by standard cultural method and negative by the BAX System. Of the 198 unpaired samples, 106 were positive by the BAX System and 60 were positive by the standard cultural method. A Chi square analysis of each of the 6 food types, at the 3 inoculation levels tested, was performed. For all foods, the BAX System demonstrated results comparable to those of the standard reference methods based on the Chi square results.

Modulation and study of photoblinking behavior in dye doped silver-silica core-shell nanoparticles for localization super-resolution microscopy

Blinking of fluorescent nanoparticles is a compelling phenomenon with widely debated mechanisms. The ability to inhibit or control blinking is important for applications in the field of optical, semiconductor and fluorescent imaging. Self-blinking nanomaterials are also attractive labels for localization-based super-resolution microscopy. In this work, we have synthesized silver core silica nanoparticles (Ag@SiO2) doped with Rhodamine 110 and studied the parameters that affect blinking. We found that under nitrogen rich conditions the nanoparticles shifted towards higher duty cycles. Also, it was found that hydrated nanoparticles showed a less drastic response to nitrogen rich conditions as compared to dried nanoparticles, indicating that surrounding matrix played a role in the response of nanoparticles to molecular oxygen. Further, the blinking is not a multi-body phenomena, super-resolution localization combined with intensity histogram analysis confirmed that single particles are emitting.

Dietary Patterns and Metabolic Syndrome Among Adults with Overweight and Obesity (FS18-03-19)

Objectives

Metabolic syndrome (MetS) is a cluster of risk factors that are highly correlated with obesity, cardiovascular disease, and type 2 diabetes. Studies suggest that a Western diet high in fat, red meat, and added sugar is predictive of MetS, but connections between dietary patterns high in fruits, vegetables and seafoods, such as the Mediterranean diet, with this condition remain under-investigated. We aimed to assess the relation of Western and Mediterranean diet patterns with MetS among overweight or obese adults.

Methods

Adults (n = 151, 25–45y) with body mass index ≥25.0 kg/m2 were included in this study. MetS was evaluated using International Diabetes Federation guidelines. Waist circumference was measured with inelastic tape. Lipid and glucose concentrations were assessed with a chemical analyzer. Blood pressure was evaluated with an automatic blood pressure monitor. Habitual diet was evaluated with the National Cancer Institute's Diet History Questionnaire II (DHQII, Past Year with Portion Size). Diet variables were selected from the Food Patterns Equivalents Database. Statistical analyses included Mann-Whitney U tests and principal component analysis (PCA).

Results

MetS was present among 30% of the sample. Meat (P = 0.03) and added sugar (P = 0.04) intakes were greater among those with MetS, while seafood (P = 0.03) and alcohol (P = 0.02) were lower. Four components comprising 64% of dietary pattern variation included: 1) High in starchy vegetables, meat, and cheese; 2) High in non-starchy vegetables, seafood, and alcohol; 3) High in milk and added sugar but low in vegetables; and 4) High in alcohol and sodium, but low in protein and vegetables. PCA biplot grouped by prevalence of MetS indicated that seafood and non-starchy vegetables were inversely related to MetS, whereas meat, starchy vegetables, cheese, milk, added sugar, and sodium were positively correlated with MetS.

Conclusions

A Western diet pattern high in meat, starchy vegetables, dairy, sodium, and added sugar was related to MetS, while a Mediterranean diet pattern characterized by seafood, non-starchy vegetables, and moderate alcohol was protective against MetS. These findings highlight the links between dietary habits and MetS among adults with overweight or obesity.

Funding Sources

The Hass Avocado Board and the USDA National Institute of Food and Agriculture, Hatch project 1009249.

Genetic Variants in Lipid Metabolism Pathways Interact with Diet to Influence Blood Lipid Concentrations in Adults with Overweight and Obesity (P15-015-19)

Objectives

There is substantial controversy regarding the role of saturated (SFA) and unsaturated fat intake for optimal cardiometabolic health due to the heterogeneity of blood lipid changes in clinical trials. This variance may be due to genetic differences. Studying physiologically relevant variants can elucidate the mechanisms between genotype and metabolism. The objective of this study was to determine relationships between genetic variation, fat intake, and blood lipid concentrations.

Methods

DNA, blood lipid concentrations (total cholesterol, high-density lipoprotein cholesterol [HDL], and triglycerides [TG]), and 7-day diet records were obtained from 87 adults (25–45 years) with overweight or obesity. Resting energy expenditure (REE) was measured using indirect calorimetry and used to determine implausible intake using a modified Goldberg method (kilocalories/REE). Genetic variants included 22 single nucleotide polymorphisms (SNPs) from genes in lipid metabolism pathways. Variants were analyzed with dietary fat intake (total fat, SFA, monounsaturated fat [MUFA], and polyunsaturated fat) via regression analyses.

Results

Nine SNPs (ANGPTL3 rs10889337, ANGPTL4 rs7255436, APOE rs1044250, CETP rs5882, FADS1 rs174548 and rs174550, LPL rs13702 and rs328, PPARG rs12639162) were associated with one or more blood lipid traits. Two significant diet-gene interactions were detected: the interaction of total fat intake and LPL rs13702 was associated with HDL concentrations (P = 0.01), and the interaction of MUFA intake and CETP rs5882 was associated with TG concentrations (P = 0.01). Carriers of the minor allele that reported higher total fat intake exhibited higher HDL concentrations, while minor allele carriers with higher MUFA intake exhibited lower TG concentrations.

Conclusions

Interactions between diet and genes in lipid metabolism pathways were predictors of blood lipid concentrations in adults. Fat intake may not affect blood lipid concentrations uniformly across all individuals. Therefore, personalized diet recommendations for chronic disease prevention are warranted.

Funding Sources

Support is provided by the Hass Avocado Board, the Division of Nutritional Sciences at the University of Illinois at Urbana-Champaign, the USDA National Institute of Food and Agriculture Hatch Project, and the Agriculture and Food Research Initiative.

Supporting Tables, Images and/or Graphs

Associations Between Serum Lutein and Human Gut Microbiota (P02-004-19)

Objectives

Lutein is a carotenoid found in green leafy vegetables, avocados, and eggs, and is purported to have protective effects against age-related macular degeneration (AMD) as well as benefits for visual and cognitive health. Recent studies have indicated significant variation in serum lutein among individuals and that gastrointestinal (GI) microbial profile may potentially contribute to lutein status. However, the extent to which the GI microbiota contribute to lutein is unclear. The current study aimed to determine GI microbial predictors of serum lutein in a healthy young adult population.

Methods

Among adults ages 25–45 years (N = 105), venous blood was collected following a 10-hour fast. Serum lutein was determined using HPLC. Fecal DNA was extracted and the V4 region of the 16S rRNA gene was amplified. Amplicon sequence variants were assigned using the GreenGenes 13-8 database and DADA2, followed by analysis in QIIME2 and LDA Effect Size (LEfSe). Participants underwent DXA scan for whole body % fat (%Fat) and completed a 7-day food record to assess lutein consumption. Demographic information on participant's age and sex was also assessed and included in the statistical models.

Results

Four genera (Dialister, Ruminococcus, Gemmiger, and Phascolarctobacterium) and two species (Bacteroides eggerthii, Ruminococcus torques) were different between individuals in the highest and lowest quartiles of serum lutein. The genera Ruminococcus (Rho = −0.24, P = 0.02) and Phascolarctobacterium (Rho = −0.21, P = 0.03) and species R. torques (Rho = −0.35, P < 0.001) were inversely related to serum lutein. Linear regression modelling, adjusted for age, sex, %Fat, and dietary lutein, revealed that R. torques was the only significant predictor of serum lutein concentrations, accounting for 8.4% of the variance.

Conclusions

Our results reveal that individuals with lower serum lutein concentrations have a higher relative abundance of R. torques than those with higher lutein concentrations. As R. torques has been shown to be elevated in those with AMD, it is possible the relationship between this microbe and lutein is evident earlier in adulthood. However, further dietary intervention trials are warranted to clarify the relations among R. torques and serum lutein concentrations.

Funding Sources

This work was supported by funds provided by the Department of Kinesiology and Community Health at the University of Illinois and the USDA National Institute of Food and Agriculture, Hatch Project 1009249. Partial support was also provided by the Hass Avocado Board.

Lean Body Mass, but Not Fat Mass, Is Associated with Hippocampal Memory Performance (P14-011-19)

Objectives

A converging body of evidence indicates elevated weight status is inversely related to memory forms that disproportionately rely on the hippocampus. However, much of this work has relied on BMI, resulting in a limited understanding of the impact of body composition on memory performance. Accordingly, this study investigated the influence of soft tissue compartments (i.e., lean and fat mass) on hippocampal-dependent memory function. Using a mnemonic discrimination task, we examined lure discrimination, a measure of hippocampal memory ability. It was anticipated that lean body mass would relate positively, and fat mass negatively to lure discrimination ability.

Methods

Participants included 216 individuals (134 females) between the ages of 25 and 46 years. Participants provided demographic information such as sex, age, and income. Dual energy x-ray absorptiometry (DXA) was used to assess height-adjusted lean and fat mass (LMI and FMI, respectively). Lure discrimination, the ability to correctly identify objects similar to those seen during encoding, was assessed using the Mnemonic Similarity Task (MST). Bivariate correlations were conducted to determine demographic predictors of task performance. Subsequently, a linear regression model controlling for significant predictors was used to determine LMI and FMI influence on lure discrimination.

Results

Preliminary data analysis showed a positive correlation between BMI and MST performance. Follow-up bivariate correlations revealed an underlying positive association between LMI and lure discrimination (r = .153, P = .029), while FMI and lure discrimination were not significantly associated (r = .087, P = .218). A linear regression model controlling for age and income showed LMI accounted for a significant proportion of variance in lure discrimination (R2 = .070, P = .002), adjusting for demographic variables.

Conclusions

These findings indicate that while BMI is related to lure discrimination, this effect appears to be driven by LMI, but not FMI. Future studies are warranted to determine the impact of changes in lean mass on hippocampal memory performance.

Funding Sources

Funding provided by the Department of Kinesiology and Community Health at the University of Illinois and the USDA National Institute of Food and Agriculture, Hatch Project 1009249. Partial support provided by the Hass Avocado Board.

Effects of Avocado Consumption on Gastrointestinal Microbial Metabolite Concentrations and Taxa Abundances: A Randomized, Controlled Trial (OR23-07-19)

Objectives

Avocados are rich in dietary fiber and monounsaturated fatty acids, nutrients that have been independently connected with metabolic health benefits and changes to the gastrointestinal (GI) microbiota. However, little is known regarding the impact of avocado consumption on GI microbial community composition and microbially-derived metabolites, particularly among adults with overweight or obesity.

Methods

Adults (n = 160) between 25–45 years of age with BMI ≥ 25.0 kg/m2 were enrolled in an investigator-blinded, parallel arm, randomized, controlled trial. Participants consumed isocaloric meals with or without fresh Hass avocado once daily for 12-weeks. Compliance was evaluated with daily self-report records. Fecal microbially-derived metabolites, including acetate, propionate, butyrate, isovalerate, valerate, and isobutyrate were quantified using gas chromatography mass spectroscopy on a dry matter basis. Following fecal DNA extraction, microbial analyses were conducted by sequencing the V4 region of the 16S rRNA gene. Sequence data were analyzed using DADA2 and QIIME version 2. Per protocol (PP; >80% meal consumption) and intent-to-treat (ITT) approaches were applied and generalized linear mixed models were assessed for treatment, time, and treatment by time interactions in SAS version 9.4.

Results

The intervention was completed by 88% (n = 140) of participants, average meal compliance among both groups was 90%, and 83% (n = 132) of participants met PP criteria. Microbiota analyses were completed for 156 ITT and 109 PP participants, respectively. ITT time by treatment analyses indicated that compared to control, avocado consumption increased acetate (P < 0.01) and total short-chain fatty acid (SCFA; P = 0.02) concentrations and increased the relative abundances of Faecalibacterium (P = 0.01). PP time by treatment analyses revealed that avocado consumption increased acetate concentrations (P < 0.01), increased the relative abundances of Lachnospira (P = 0.04), and trended to increase Faecalibacterium (P = 0.08).

Conclusions

Fresh Hass avocado intake increased the relative abundances of microbes capable of fiber fermentation and SCFA production among adults with overweight or obesity, providing valuable evidence for the impact of this nutrient dense food on the GI microbiota.

Funding Sources

Support for this research was provided by the Hass Avocado Board and the USDA National Institute of Food and Agriculture, Hatch project 1009249.

Interplay Between Systemic Inflammation, Visceral Fat, and Cognitive Control in People with Excess Fat Mass (OR32-06-19)

Objectives

Excess fat mass has been associated with poorer cognitive function. Elevated visceral adiposity (VAT) has also been associated with cardiometabolic risk factors including chronic systemic low-grade inflammation. Whereas the cognitive implications of inflammation have been extensively studied in preclinical models, the influence of inflammatory cytokines on human cognition is unclear. Thus, this study aimed to investigate the relations among VAT, inflammatory cytokines and cognitive control. We hypothesized that elevated VAT and inflammation would be related to poorer performance during a cognitive control task.

Methods

Participants between 25–45 years (N = 77 48 females) with overweight/obesity (BMI ≥ 25 kg/m2) underwent a DXA scan to quantify VAT. A Flanker Task was used to assess cognitive control while Event-Related Potentials were recorded. Following an overnight fast, blood was collected to quantify plasma C-reactive protein (CRP) and Interleukin-6 (IL-6) concentrations using ELISAs. Spearman's correlations were used to analyze relations using a 1-tailed approach.

Results

Greater VAT was related to lower congruent (r = −.19, P = .05) and incongruent trial accuracy (r = −.26, P = .01), as well as lower congruent P3 peak amplitude (r = −.23, P = .02) and slower latency (r = .37, P < .001). Similarly, elevated CRP and IL-6 were associated with poorer congruent (rCRP = −.22 pCRP = .03; rIL6 = −.20 pIL6 = .03), and incongruent (rCRP = −.33 pCRP = .002; rIL6 = −.32 pIL6 = .002) accuracy. Additionally, CRP was related to slower incongruent P3 peak latency (r = .22, P = .02). Partial correlations controlling for CRP and IL-6 showed that VAT was no longer associated with cognitive performance (all p's > 0.07); however, the association between VAT and P3 peak amplitude (r = −.26, P = .01) and latency (r = .35, P = .001) persisted even following adjustment for CRP and IL-6.

Conclusions

This work replicates previous research indicating that VAT is related to poorer attentional abilities; however, we extend the literature by elucidating the role of low-grade inflammation as a contributing factor in this relationship in adults with excess fat mass.

Funding Sources

This work was supported by funds provided by the Dept of Kinesiology & Community Health at UIUC & the USDA National Institute of Food and Agriculture, Hatch Project 1009249. Partial support provided by the Hass Avocado Board.

Effects of a 12-week Avocado Randomized-controlled Trial on Cognitive Function and Lutein Status Among Adults with Overweight and Obesity (OR05-01-19)

Objectives

Overweight and obesity affect over two-thirds of the US population. This is concerning, as excess adiposity increases risk for dementia in later life. Thus, it is important to elucidate dietary approaches that benefit cognition. Lutein is a xanthophyll carotenoid thought to impact cognitive function. Daily consumption of avocado has been shown to improve cognitive function and lutein status but it is not clear whether these benefits extend to populations with overweight and obesity. Thus, we evaluated the influence of daily avocado consumption on cognitive function, serum lutein concentrations, and retinal xanthophyll status among adults with overweight and obesity using a randomized-controlled study.

Methods

Adults (N = 72, 25–45 years, 31 males) with overweight or obesity (BMI 25 kg/m2) were randomized to an intervention group (N = 38) that received a daily meal with one avocado or a control group (N = 34) that received an isocaloric meal without avocado for 12 weeks. Fasting serum lutein concentrations were evaluated through high-performance liquid chromatography. Macular pigment optical density (MPOD) was assessed through heterochromatic flicker photometry. Selective attention was assessed by a modified Flanker task.

Results

Group by time interactions were seen for serum lutein concentrations (P = 0.002) and flanker accuracy (P = 0.006) whereby the intervention group exhibited a more substantial increase in serum lutein concentrations (0.04 ug/ml; 95% CI, 0.02 to 0.06) and overall task accuracy (2.4%; 95% CI, 0.4 to 4.5). However, there was no relationship between task performance and changes in serum lutein concentration (P = 0.23), nor changes in MPOD.

Conclusions

Daily consumption of a meal containing avocado improved selective attention and serum lutein concentrations among adults with overweight and obesity. The cognitive benefits of avocado consumption were apparent even prior to changes in retinal lutein status. Given that avocados are comprised of a variety of nutrients, additional work is necessary to determine non-carotenoid dependent mechanisms by which avocados may impact cognitive function.

Funding Sources

This work was supported by funds from the Hass Avocado Board, the Department of Kinesiology and Community Health at the University of Illinois, and the USDA National Institute of Food and Agriculture, Hatch project 1009249.

Effects of Avocado Consumption on Abdominal Adiposity and Glucose Tolerance: Findings from the Persea Americana for Total Health (PATH) Randomized Controlled Trial (P21-005-19)

Objectives

Over 35% of adults have elevated abdominal obesity. This is concerning because abdominal obesity increases risk for type 2 diabetes. Therefore, dietary interventions with the potential to prevent abdominal obesity and its metabolic consequences have gained increasing importance. Habitual intake of the Hass avocado (Persea Americana) has been cross-sectionally linked to lower abdominal obesity; however, the effects of regular avocado consumption for abdominal adiposity and glycemic measures are unknown. Accordingly, we conducted a single-blind, randomized, controlled trial examining the effects of daily avocado consumption on abdominal adiposity and oral glucose tolerance (OGTT).

Methods

111 adults (65 females) between 25 and 45y with overweight or obesity (BMI >= 25 kg/m2) were randomized to an intervention group (N = 54) that received a daily meal with one fresh avocado or a control group (N = 57) that received an isocaloric meal without avocado for 3 months. DXA was used to assess abdominal fat distribution changes, calculated as the ratio of visceral adipose tissue to subcutaneous abdominal tissue (VS Ratio) and an OGTT was conducted following an overnight fast.

Results

A group by time effect (P = 0.04) was observed whereby the intervention group exhibited a reduction in the VS Ratio (0.02; 95% CI, 0.0003 to 0.04) whereas there was no change in the control group (0.003; 95% CI, −0.02 to 0.01). Changes in the VS ratio were driven by a reduction in visceral adipose tissue among intervention participants (28.3 g; 95% CI, 3.4 to 53.3). Avocado consumption did not affect the Matsuda Insulin Sensitivity Index (P = 0.28), Glucose AUC (P = 0.37), or Insulin AUC (P = 0.09). However, there was a group by time effect (P = 0.005) whereby the control group exhibited an increase in insulin concentration at 120 m (21.9 µU/ml; 95% CI, 3.3 to 40.5) whereas there was no change in the intervention group (6.1 µU/ml; 95% CI, −4.4 to 16.5).

Conclusions

Inclusion of one fresh avocado per day over 3 months had abdominal adiposity lowering effects. However, the effects for oral glucose tolerance were limited to insulin secretion 2 h postprandial. Our results demonstrate that avocados have beneficial effects on fat distribution while maintaining insulin sensitivity over time among adults with overweight and obesity.

Funding Sources

This work was supported by funds provided by the Hass Avocado Board. Partial support was also provided by the Department of Kinesiology and Community Health at the University of Illinois and the USDA National Institute of Food and Agriculture, Hatch project 1009249.

TM3-4 The effect of acetazolamide on intracranial pressure: primary study with prolonged continuous intracranial pressure monitoring

Objectives

Acetazolamide has frequently been used as a first-line treatment for idiopathic Intracranial Hypertension (IIH) and other disorders which lead to a non-acute rise in intracranial pressure (ICP). The effect of acetazolamide has been observed through lumbar puncture, however the effect of acetazolamide on ICP has not been studied in continuous ICP measurement.

Design

A retrospective study of a prospectively built ICP database

Subjects

All patients with continuous ICP monitoring demonstrating 24 hours on and 24 hours off acetazolamide were included in the study.

Methods

Patients median ICP and median pulse amplitude over 24 hour monitoring period on and off Diamox was assessed.

Results

12 patients (9F, 3M) underwent ICP monitoring with data collected during the same admission. 8 patients had IIH, 1 Chiari Malformation, 3 new diagnostic ICP procedures. 10 patients saw a reduction in ICP while on acetazolamide. Overall, patients experienced a Median reduction of 1.14 mmHg (Mean 1.16 mmHg, Range 4.24 to −4.445 mmHg). Patients (n9) who were on ≥1 g of acetazolamide per day experienced a median reduction in ICP of 1.595 mmHg (Mean 1.91 mmHg, Range 4.24–0.5 mmHg).

Conclusions

Our data suggests acetazolamide can reduce ICP quickly following commencement, however this reduction was relatively small. The effect seems greater with a higher dose. Larger numbers of patients are required to gain a greater understanding into the significance of acetazolamide on ICP, particularly the affect at larger doses.

P102 Shunting slit ventricles: a comparison of the parieto-occipital vs frontal approach

Objectives

Slit ventricles can be a challenging target during shunt catheter insertion. Traditionally, the frontal approach has been considered optimal. At this centre, routine use of electromagnetic (EM) stereotatic guidance (StealthTM, Medtronic) has enabled a parieto-occipital burr hole approach to the frontal horns. We compare shunt placement and revisions required for patients with slit ventricles who had shunts inserted via a parieto-occipital (P-O) approach vs. frontal shunt.

Design

Retrospective cohort.

Subjects

Patients with slit ventricles and a ventricular shunt inserted using EM guidance between 2012–2018.

Methods

Slit ventricles were defined as <3 mm (widest). Outcome measures included placement accuary and survival using Kaplan-Meier curve.

Results

82 patients (77F:5M) aged 34.9±10.8 years (mean ±SD) had shunts inserted for IIH (n=63), chiari/syrinx (n=8), congenital hydrocephalus (n=10), pseudomeningocoele (n=1). 35 had primary P-O shunts and 46 had frontal shunts. Overall, 94% of cases had the catheter tip sitting in the frontal horn. The P-O approach was just as accurate as the frontal approach. Eight P-O shunts and 9 frontal shunts required revision over a 60 month periods. There was no significant different in shunt survival between the two approaches (p=0.99).

Conclusions

EM guided placement has enabled the P-O approach to be as safe and with equivalent survival to frontal approach. The accuracy of shunt placement between the two approaches was equivocal.

Controlled release of microencapsulated docosahexaenoic acid (DHA) by spray-drying processing

The omega-3-fatty acid, docosahexaenoic acid (DHA) 22:6 n-3, is an important food component for the visual and brain development of infants. In this study two approaches have been explored for the encapsulation of DHA in the pH dependant polymer hydroxyl-propyl-methyl-cellulose-acetate-succinate (HPMCAS). In the first approach Direct Spray Drying (DSD) was implemented for the microencapsulation of DHA/HPMCAS organic solutions, whilst in the second approach solid lipid nanoparticle (SLN) dispersions of DHA, were first produced by high-pressure homogenization, prior to being spray dried in HPMCAS aqueous solutions. The DSD approach resulted in significantly higher quantities of DHA being encapsulated, at 2.09 g/100 g compared to 0.60 g/100 g in the spray-dried SLNs. The DHA stability increased with the direct spray-drying approach. Release studies of DHA in the direct sprayed dried samples revealed a lag time for 2 h in acidic media followed by rapid release in phosphate buffer (pH 6.8).