Historically, researchers in the gut microbiome have deemed the composition of the microbiome as being adult by the age of two. However, recent studies have contradicted this, demonstrating statistically significant differences in the microbiome even through childhood and adolescence. This difference is important in the field of microbiome research, particularly in studies examining this relationship with weight, because even though there have been significant associations between the gut microbiome and weight, they have been largely studied in adults. The freshman year of college is an interesting time to study this relationship in younger populations, due to the lifestyle changes that make them vulnerable to weight gain. This study included N=139 participants, a majority female (N=97, 69.8%), white (N=59, 42.4%), and non-Hispanic (N=89, 64%). Participants were only included in this analysis if they gave 2 or more fecal samples over the 4 timepoint study. Samples were sequenced using the Illumina MiSeq instrument after polymerase chain reaction (PCR) amplification was performed on the V4 region of the 16S rRNA gene sequence. Statistical analysis was performed using the longitudinal plugin of QIIME2. Results demonstrate that low abundance features seemed to drive a majority of the differences in variability between those who maintained their weight over the course of the study and those who gained weight. This was demonstrated through many significant Unweighted UniFrac results with corresponding nonsignificant Weighted UniFrac data. This study demonstrated that changes in lower abundance features may have driven the significant differences in weight status in this study. This study emphasized the importance of low abundance features and how this relates to changes in weight status during a period of major lifestyle changes. Further work is needed to confirm these findings and explore how gut microbes change in free-living individuals gaining weight over time.

Food insecurity and childhood obesity are both major public health concerns in the United States of America. Research has not found a definite relationship between childhood obesity and food insecurity to date, with conflicting results being found due to differences in sample sizes and protocol for measuring key variables. Preschoolers (children aged 2-5 years) are a population of particular interest as there tends to be improved health behaviors and greater adaptability to change at this period of growth and development. This study aims to evaluate if there is a relationship between food insecurity and childhood obesity with diet quality as a mediator among preschoolers in the Phoenix area. A secondary data analysis from participants (n=154) from the SAGE (Sustainability via Active Garden Education) research project was used to evaluate food insecurity status, diet quality components (kcal, saturated fat, added sugars, and servings of juice, fruits, and vegetables), and anthropometrics (waist circumference and BMI percentile). No significant associations between food insecurity status, diet quality components, and anthropometric data were found. There was an increased rate of food insecurity and childhood overweight/obesity in this sample compared to state and national averages. Further research of high quality is necessary to determine whether a relationship exists between childhood obesity and food insecurity exists and in what context. Additionally, practice and policy will need to be implemented to decrease rates of food insecurity and childhood obesity among Phoenix preschoolers.

Vinegar is gaining popularity as a natural and proven treatment for common diseases and conditions ranging from high blood pressure to diabetes. While the evidence to support the benefits of vinegar is growing, few studies have considered possible negative consequences. One concern relates to the effect of vinegar on saliva pH and dental erosion. The aim of this study is to explore this relationship as well as unsubstantiated claims that vinegar, although acidic, has an alkalizing effect on the overall body, specifically looking at its effect on resting saliva pH. Healthy adults aged 18-45 were recruited for this trial. Twenty-two participants completed this eight-week, parallel-arm, randomized, double blinded study that looked at the effect that regular consumption of red wine vinegar (two tablespoons taken two times per day before a meal) had on resting salivary pH and dental erosion compared to a control (low dosage vinegar pill taken two times a day before a meal). Resting saliva pH was measured at home using the pH20H application and pH strips at week 0 and 8 of the trial. Erosion was noted using the Basic Erosive Wear Examination (BEWE) by a registered dental hygienist at week 1 and 8 of trial. Results indicate no mean difference in resting salivary pH in either treatment group after eight weeks (p value, 0.49). However, there was a statistical significant mean difference in dental erosion between the VIN and CON group (p value, 0.05). Statistical significance in dental erosion, typically a gradual process, in just eight weeks is a significant finding and warrants concern about long time use of vinegar and dental health. Further exploration into this relationship is needed.

Since 1975, the prevalence of obesity has nearly tripled around the world. In 2016, 39% of adults, or 1.9 billion people, were considered overweight, and 13% of adults, or 650 million people, were considered obese. Furthermore, Cardiovascular disease remains to be the leading cause of death for adults in the United States, with 655,000 people dying from related conditions and consequences each year. Including fiber in one’s dietary regimen has been shown to greatly improve health outcomes in regards to these two areas of health. However, not much literature is available on the effects of corn-based fiber, especially detailing the individual components of the grain itself. The purpose of this preliminary study was to test the differences in influence on both LDL-cholesterol and triglycerides between treatments based on whole-grain corn flour, refined corn flour, and 50% refined corn flour + 50% corn bran derived from whole grain cornmeal (excellent fiber) in healthy overweight (BMI ≥ 25.0 kg/m2) adults (ages 18 - 70) with high LDL cholesterol (LDL ≥ 120mg/dL). 20 participants, ages 18 - 64 (10 males, 10 females) were involved. Data was derived from blood draws taken before and after each of the three treatments as well as before and after each treatment’s wash out periods. A general linear model was used to assess the effect of corn products on circulating concentrations of LDL-cholesterol and triglycerides. From the model, it was found that the whole-grain corn flour and the 50% refined corn flour + 50% corn bran drive from whole grain cornmeal treatments produced a higher, similar benefit in reductions in LDL-cholesterol. However, the whole grain flour, refined flour, and bran-based fiber treatments did not influence the triglyceride levels of the participants throughout this study. Further research is needed to elucidate the effects of these fiber items on cardiometabolic disease markers in the long-term as well as with a larger sample size.

The various health benefits of vinegar ingestion have been studied extensively in the<br/>literature. Moreover, emerging research suggests vinegar may also have an effect on mental<br/>health. Beneficial effects of certain diets on mood have been reported, however, the mechanisms<br/>are unknown. The current study aimed to determine if vinegar ingestion positively affects mood<br/>state in healthy young adults. This was a randomized, single blinded controlled trial consisting of<br/>25 subjects. Participants were randomly assigned to either the vinegar group (consumed 2<br/>tablespoons of liquid vinegar diluted in one cup water twice daily with meals) or the control<br/>group (consumed one vinegar pill daily with a meal), and the intervention lasted 4 weeks.<br/>Subjects completed mood questionnaires pre- and post-intervention. Results showed a significant<br/>improvement in CES-D and POMS-Depression scores for the vinegar group compared to the<br/>control. This study suggests that vinegar ingestion may improve depressive symptoms in healthy<br/>young adults.

The Human Gut Microbiome (GM) modulates a variety of structural, metabolic, and protective functions to benefit the host. A few recent studies also support the role of the gut microbiome in the regulation of bone health. The relationship between GM and bone health was analyzed based on the data collected from a group of twenty-three adolescent boys and girls who participated in a controlled feeding study, during which two different doses (0 g/d fiber and 12 g/d fiber) of Soluble Corn Fiber (SCF) were added to their diet. This analysis was performed by predicting measures of Bone Mineral Density (BMD) and Bone Mineral Content (BMC) which are indicators of bone strength, using the GM sequence of proportions of 178 microbes collected from 23 subjects, by building a machine learning regression model. The model developed was evaluated by calculating performance metrics such as Root Mean Squared Error, Pearson’s correlation coefficient, and Spearman’s rank correlation coefficient, using cross-validation. A noticeable correlation was observed between the GM and bone health, and it was observed that the overall prediction correlation was higher with SCF intervention (r ~ 0.51). The genera of microbes that played an important role in this relationship were identified. Eubacterium (g), Bacteroides (g), Megamonas (g), Acetivibrio (g), Faecalibacterium (g), and Paraprevotella (g) were some of the microbes that showed an increase in proportion with SCF intervention.

First year college students have been identified as a vulnerable population for weight gain and the onset of overweight and obesity. Research regarding the gut microbiome has identified differences in the microbial composition of overweight and obese individuals compared to normal weight individuals. Dietary components like dietary fibers, act as prebiotics, or fermentable substrate, that the gut microbiota use for metabolic functions including the production of short-chain fatty acids. The objective of this longitudinal, observational study was to assess changes in the gut microbiota over time in relation to changes in fiber consumption in healthy college students at a large a southwestern university (n=137). Anthropometric and fecal samples were collected at the beginning and end of the fall and spring semesters between August 2015 and May 2016. Both alpha, within sample, diversity and beta, between sample, diversity of participant gut microbes were assessed longitudinally using non-parametric pairwise (pre-post) comparisons and linear mixed effect (LME) models which also adjusted for covariates and accounted for time as a random effect. Alpha and beta diversity were also explored using LME first difference metrics and LME first distance metrics, respectively, to understand rates of change over time in microbial richness/phylogeny and community structure. Pre-post comparisons of Shannon Diversity and Faith’s PD were not significantly different within participant groups of fiber change (Shannon diversity, p=0.96 and Faith’s PD, p=0.66). Beta diversity pairwise comparisons also did not differ by fiber consumption groups (Unweighted UniFrac p=0.182 and Bray Curtis p=0.657). Similarly, none of the LME models suggested significant associations between dietary fiber consumption and metrics of alpha and beta diversity. Overall, data from this study indicates that small changes in fiber consumption among a free-living population did not have an impact on gut microbial richness, phylogeny or community structure. This may have been due to the low intake (~15 g/d) of fiber. Further study is needed to fully elucidate the role that fiber plays in the diversity and composition of the gut microbiota, especially when delivered from a variety of food sources rather than fiber supplements.

Obesity is highly prevalence in United States. Obesity can be seen as a positive energy balance, especially a positive fat balance. This may be due in part to how the human body uses energy sources. When a person overconsumes a meal that contains high amounts of both carbohydrate and fat, carbohydrate will stimulate its own oxidation and suppress fat oxidation. This can result in a positive fat balance, which could eventually lead to obesity. Also, it has been shown that after consuming a meal endothelial function is frequently impaired for several hours during the postprandial period. Long-term endothelial dysfunction is a major cause of different types of cardiovascular disease. Exercise has been shown to stimulate fat oxidation and, when performed the day before meal ingestion, precondition arteries by enhancing endothelial function in the basal state. However, the acute effect of exercise on postprandial period is unknown. The purpose of this study is to examine the effect of high intensity interval exercise (HIIE) on the substrate oxidation and endothelial function in the postprandial period after consumption of “meal” consisting of a sugar-sweetened beverage (SSB) and a candy bar (480 kcal; ~75% sugar). Five subjects (4 males, 1 female; age=25yr, BMI=25 kg/m2) completed two conditions in random order: 1) no exercise control; 2) high-intensity interval exercise on a cycle ergometer: alternating 1-min intervals at 90-95% HRmax separated by 1-min of active recovery at 50W, for a duration sufficient to expend ~480 kcal. Endothelial function was measured by flow-mediated dilation (FMD) at baseline, and at 1, 2 and 4 hours postprandial. Substrate oxidation was measured by indirect calorimetry during the entire first hour postprandial and then during the last 20 min of hours 2-5 postprandial. Absolute postprandial fat oxidation (g/5 hours) was higher in HIIE (exercise: 5.47 ± 9.97, control: -9.78 ± 3.80; p<0.011). Absolute postprandial carbohydrate oxidation (g/5 hours) was higher in control group (control: 27.79 ± 6.20, exercise: -1.48 ± 7.75; p<0.019). Therefore, these results show that HIIE results in greater fat oxidation during the postprandial period in comparison to a no-exercise control condition. For FMD, there was no significant difference between groups, and no group x time interaction. However, there was a significant time effect (p<0.046), with both groups demonstrating a reduction in FMD during the postprandial period. FMD in the control condition decreased from 12% to 7.5% during the first 2 hours postprandial, and from 11.4% to 7.3% in the HIIE condition. These results indicate that HIIE performed 1 hour prior to ingestion of a SSB and candy bar does not prevent postprandial endothelial dysfunction.

More than 200 hikers are rescued annually in the greater Phoenix area. This study

examined the impact of hiking in hot (HOT), dry temperatures versus moderate (MOD)

temperatures on dietary intake behaviors as well as markers of heat stress. Twelve

recreational mountain hikers climbed “A” Mountain four consecutive times (4-miles) on

a HOT day (WBGT=31.6 °C) and again on a MOD day (WBGT= 19.0 °C). Simulated

food and fluid behavior allowed participants to bring what they normally would for a 4-

mile hike and to consume both ad libitum. The following heat stress indicators (mean

difference; p-value), were all significantly higher on the HOT hike compared to the MOD

hike: average core temperature (0.6 °C; p=0.002), average rating of perceived exertion

(2.6; p=0.005), sweat rate (0.54; p=0.01), and fluid consumption (753; p<0.001). On the

HOT hike, 42% of the participants brought enough fluids to meet their individual

calculated fluid needs, however less than 20% actually consumed enough to meet those

needs. On the MOD hike, 56% of participants brought enough fluids to meet their needs,

but only 33% actually consumed enough to meet them. Morning-after USG samples

≥1.020 indicating dehydration on an individual level showed 75% of hikers after the

HOT hike and 67% after the MOD hike were unable to compensate for fluids lost during

the previous day’s hike. Furthermore, participant food intake was low with only three

hikers consuming food on the hot hike, an average of 33.2g of food. No food was

consumed on the MOD hike. These results demonstrate that hikers did not consume

enough fluids to meet their needs while hiking, especially in the heat. They also show

heat stress negatively affected hiker’s physiological and performance measures. Future

recommendations should address food and fluid consumption while hiking in the heat.

College students are a niche of young adults, characterized by abnormal sleeping habits and inactive lifestyles. Many students entering college are as young as 18 years old and graduate by 22 years old, a window of time in which their bones are still accruing mineral. The purpose of this cross-sectional study was to determine whether sleep patterns and physical activity observed in college students (N= 52) 18-25 years old at Arizona State University influenced bone biomarkers, osteocalcin (OC) and N-terminal telopeptide of type 1 collagen (NTX-1) concentrations. Students completed various dietary and health history questionnaires including the International Physical Activity Questionnaire short form. Students wore an actigraphy watch for 7 consecutive nights to record sleep events including total sleep time, sleep onset latency and wake after sleep onset. Total sleep time had a significant, negative correlation with OC (r = -0.298, p-value =0.036) while sleep onset latency had a significant, positive correlation with NTX-1 serum concentration (r = 0.293, p-value = 0.037). Despite correlational findings, only sleep percent was found to be significant (beta coefficient = 0.271 p-value = 0.788) among all the sleep components assessed, after adjusting for gender, race, BMI and calcium intake in multivariate regression models. Physical activity alone was not associated with either bone biomarker. Physical activity*sleep onset latency interactions were significantly correlated with osteocalcin (r = 0.308, p-value =0.006) and NTX-1 (r = 0.286, p-value = 0.042) serum concentrations. Sleep percent*physical activity interactions were significantly correlated with osteocalcin (r = 0.280, p-value = 0.049) but not with NTX-1 serum concentrations. Interaction effects were no longer significant after adjusting for covariates in the regression models. While sleep percent was a significant component in the regression model for NTX-1, it was not clinically significant. Overall, sleep patterns and physical activity did not explain OC and NTX-1 serum concentrations in college students 18-25 years old. Future studies may need to consider objective physical activity devices including accelerometers to measure activity levels. At this time, college students should review sleep and physical activity recommendations to ensure optimal healthy habits are practiced.