•Food deprived male rats and female rats (regardless of feeding status) display less passive avoidance behavior compared to ad libitum fed male rats.•Re-exposure to the shock-paired chamber activates ...prRp-positive noradrenergic neurons, but not GLP1-positive neurons, in the cNTS and activates neurons in the vlBNST.•Food deprivation prior to shock-paired chamber re-exposure reduces activation of prrp-positive noradrenergic neurons in the cNTS and neurons in the vlBNST.
Competing motivational drives coordinate behaviors essential for survival. For example, interoceptive feedback from the body during a state of negative energy balance serves to suppress anxiety-like behaviors and promote exploratory behaviors in rats. Results from past research suggest that this shift in motivated behavior is linked to reduced activation of specific neural populations within the caudal nucleus of the solitary tract (cNTS). However, the potential impact of metabolic state and the potential role of cNTS neurons on conditioned avoidance behaviors has not been examined. The present study investigated these questions in male and female rats, using a task in which rats learn to avoid a context (i.e., a darkened chamber) after it is paired with a single mild footshock. When rats later were tested for passive avoidance of the shock-paired chamber, male rats tested in an overnight food-deprived state and female rats (regardless of feeding status) displayed significantly less avoidance compared to male rats that were fed ad libitum prior to testing. Based on prior evidence that prolactin-releasing peptide (PrRP)-positive noradrenergic neurons and glucagon-like peptide 1 (GLP1)-positive neurons within the cNTS are particularly sensitive to metabolic state, we examined whether these neural populations are activated in conditioned rats after re-exposure to the shock-paired chamber, and whether neural activation is modulated by metabolic state. Compared to the control condition, chamber re-exposure activated PrRP+ noradrenergic neurons and also activated neurons within the anterior ventrolateral bed nucleus of the stria terminalis (vlBNST), which receives dense input from PrRP+ terminals, in both male and female rats when fed ad libitum. In parallel with sex differences in passive avoidance behavior, PrRP+ neurons were less activated in female vs. male rats after chamber exposure. GLP1+ neurons were not activated in either sex. In both sexes, overnight food deprivation before chamber re-exposure reduced activation of PrRP+ neurons, and also reduced vlBNST activation. Our results support the view that PrRP+ noradrenergic neurons and their inputs to the vlBNST contribute to the expression of passive avoidance memory, and that this contribution is modulated by metabolic state.
Objective: Habitual diet impacts mood and the human gastrointestinal (GI) microbiota. Yet, studies infrequently control for diet when evaluating associations between mood and GI microbiota. ...Accordingly, we aimed to investigate relationships among diet, GI microbiota, and mood in adults without mood disorders by conducting a cross-sectional examination of dietary intake, subjective emotional state, and fecal microbial taxa abundances.
Methods: Adults (N = 133; 25-45 years of age) without physician-diagnosed mood disorders were studied. Fecal DNA was extracted, and the V4 region of the 16S rRNA gene was sequenced. Sequences were analyzed using QIIME2. Subjective mood state was assessed using the 42-item Depression, Anxiety, and Stress Scale (DASS-42). Habitual dietary intake was measured with the National Cancer Institute's Diet History Questionnaire II, and diet quality was evaluated with the 2010 Healthy Eating Index (HEI).
Results: Relationships were observed between 28 bacterial taxa and DASS-42 scores. Sex-dependent associations were observed among 21 bacterial taxa and DASS-42 scores, including an inverse relationship between Anxiety scale scores and Bifidobacterium in females and an inverse relationship between Depression scale scores and Lactobacillus in males. HEI total fruit and dairy components were inversely associated with Depression and Stress scales, respectively.
Conclusions: These results suggest GI microbes are related to mood in adults without diagnosed mood disorders and that these relationships differ by sex and are influenced by dietary fiber intake. Incorporating dietary intake data in gut-microbiota-brain studies may help clarify the roles of specific microbes and dietary components in mental health symptoms.
Interoceptive feedback to the brain regarding the body's physiological state plays an important role in guiding motivated behaviors. For example, a state of negative energy balance tends to increase ...exploratory/food-seeking behaviors while reducing avoidance behaviors. We recently reported that overnight food deprivation reduces conditioned passive avoidance behavior in male (but not female) rats. Since fasting increases circulating levels of ghrelin, we hypothesized that ghrelin signaling contributes to the ability of fasting to reduce conditioned avoidance.
Ad libitum-fed male rats were trained in a passive avoidance procedure using mild footshock. Later, following overnight food deprivation, the same rats were pretreated with ghrelin receptor antagonist (GRA) or saline vehicle 30 min before avoidance testing.
GRA restored passive avoidance in fasted rats as measured by both latency to enter and time spent in the shock-paired context. In addition, compared to vehicle-injected fasted rats, fasted rats that received GRA before reexposure to the shock-paired context displayed more cFos activation of prolactin-releasing peptide (PrRP)-positive noradrenergic (NA) neurons in the caudal nucleus of the solitary tract, accompanied by more cFos activation in downstream target sites of PrRP neurons (i.e., bed nucleus of the stria terminalis and paraventricular nucleus of the hypothalamus).
These results support the view that ghrelin signaling contributes to the inhibitory effect of fasting on learned passive avoidance behavior, perhaps by suppressing recruitment of PrRP-positive NA neurons and their downstream hypothalamic and limbic forebrain targets.
In rats, overnight fasting reduces the ability of systemic cholecystokinin-8 (CCK) to suppress food intake and to activate cFos in the caudal nucleus of the solitary tract (cNTS), specifically within ...glucagon-like peptide-1 (GLP-1) and noradrenergic (NA) neurons of the A2 cell group. Systemic CCK increases vagal sensory signaling to the cNTS, an effect that is amplified by leptin and reduced by ghrelin. Since fasting reduces plasma leptin and increases plasma ghrelin levels, we hypothesized that peripheral leptin administration and/or antagonism of ghrelin receptors in fasted rats would rescue the ability of CCK to activate GLP-1 neurons and a caudal subset of A2 neurons that coexpress prolactin-releasing peptide (PrRP). To test this, cFos expression was examined in ad libitum-fed and overnight food-deprived (DEP) rats after intraperitoneal CCK, after coadministration of leptin and CCK, or after intraperitoneal injection of a ghrelin receptor antagonist (GRA) before CCK. In fed rats, CCK activated cFos in ~60% of GLP-1 and PrRP neurons. Few or no GLP-1 or PrRP neurons expressed cFos in DEP rats treated with CCK alone, CCK combined with leptin, or GRA alone. However, GRA pretreatment increased the ability of CCK to activate GLP-1 and PrRP neurons and also enhanced the hypophagic effect of CCK in DEP rats. Considered together, these new findings suggest that reduced behavioral sensitivity to CCK in fasted rats is at least partially due to ghrelin-mediated suppression of hindbrain GLP-1 and PrRP neural responsiveness to CCK.
To assess viewer engagement of a food advertising campaign on the live streaming platform Twitch.tv, a social media platform that allows creators to live stream content and communicate with their ...audience in real time.
Observational analysis of chat comments across the Twitch platform containing the word 'Wendy's' or 'Wendys' during a 5-day ad campaign compared with two 5-day non-campaign time periods. Comments were categorised as positive, negative or neutral in how their sentiment pertained to the brand Wendy's.
Twitch chatrooms.
None.
There were significantly more chatroom messages related to the Wendy's brand during the campaign period. When considering all messages, the proportion of messages was statistically different (x
= 1417·41,
< 0·001) across time periods, with a higher proportion of neutral and positive messages and a lower proportion of negative messages during the campaign compared with the comparison periods. Additionally, the proportion of negative messages following the campaign was lower than before the campaign. When considering only positive and negative messages, the proportion of messages was statistically different (x
= 366·38,
< 0·001) across each time period with a higher proportion of positive messages and a lower proportion of negative messages during the campaign when compared with the other time periods. Additionally, there was a higher proportion of positive messages and a lower portion of negative messages following the campaign when compared with before the campaign.
This study demonstrates the impact and sustained impact of a fast-food brand ad campaign on brand engagement on the live streaming platform Twitch.
Despite generally being a reinforcing drug of abuse, amphetamine (amph) also produces effects such as hypophagia and conditioned taste avoidance (CTA), which may indicate that amph acts as an ...aversive homeostatic stressor. Stress-responsive prolactin-releasing peptide (PrRP)-positive noradrenergic and glucagon-like peptide-1 (GLP-1)-positive neurons in the caudal nucleus of the solitary tract (cNTS) are modulated by metabolic state, and are prime candidates for mediating amph-induced hypophagia and CTA. The present study used dual immunolabeling and fluorescent in situ hybridization (RNAscope) to examine acute amph-induced activation of cFos expression in phenotypically-identified cNTS neurons in ad lib-fed vs. overnight-fasted male Sprague Dawley rats. We also examined the impact of food deprivation on amph-induced CTA. Compared to control saline treatment, amph activated significantly more cNTS neurons, including PrRP-negative noradrenergic (NA) neurons, GABAergic neurons, and glutamatergic neurons, but not PrRP or GLP-1 neurons. Amph also increased neural activation within a subset of central cNTS projection targets, including the lateral parabrachial nucleus and central amygdala, but not the paraventricular hypothalamus. Food deprivation did not alter amph-induced neural activation or impact the ability of amph to support CTA. These findings indicate that PrRP-negative NA and other cNTS neurons are recruited by acute amph treatment regardless of metabolic state, and may participate in amph-induced hypophagia and CTA.
•Amph activates noradrenergic, GABAergic, and glutamatergic cNTS neurons.•Amph does not activate GLP-1, PrRP, or CCK neurons in the cNTS.•Food deprivation does not alter the ability of amph to activate cNTS cFos, or to support CTA.
Avocados are rich in dietary fiber and monounsaturated fatty acids (MUFAs), nutrients that have been independently connected to metabolic health benefits and the gastrointestinal microbiota.
We aimed ...to evaluate the impact of avocado consumption on the gastrointestinal microbiota and microbial metabolites, secondary outcomes of the Persea americana for Total Health (PATH) study, and conduct exploratory analyses to assess relations between the fecal microbiota, fecal metabolites, and health markers.
Adults n= 163, 25–45 y, BMI (kg/m2) ≥ 25.0 were enrolled in the PATH study, a 12-wk investigator-blinded trial where participants were batch randomized to match the 2 groups by age, sex, visceral adiposity, and fasting glucose concentrations. Participants consumed isocaloric meals with or without avocado (175 g, men; 140 g, women) once daily for 12 wk. The fecal microbiota was assessed with 16S ribosomal RNA gene (V4 region) sequencing and analysis using DADA2 and QIIME2. Fecal fatty acid and bile acid concentrations were quantified using GC and LC-MS. Per-protocol (≥80% meal consumption) and intent-to-treat analyses were conducted using univariate ANOVA and Mann-Whitney U tests. Bivariate correlations were conducted between fecal microbiota, fecal metabolites, and health measures.
The avocado treatment increased ɑ diversity and enriched Faecalibacterium, Lachnospira, and Alistipes between 26% and 65% compared with the control group. The avocado group had 18% greater fecal acetate, 70% greater stearic acid, and 98% greater palmitic acid concentrations than the control group, while the concentrations of the bile acids cholic and chenodeoxycholic acid were 91% and 57% lower, respectively.
Daily avocado consumption resulted in lower fecal bile acid concentrations, greater fecal fatty acid and SCFAs, and greater relative abundances of bacteria capable of fiber fermentation, providing evidence that this nutrient-dense food affects digestive physiology, as well as the composition and metabolic functions of the intestinal microbiota. This trial was registered at www.clinicaltrials.gov as NCT02740439.
To compare and evaluate the prevalence of food and beverage marketing on the livestreaming platforms Twitch, Facebook Gaming and YouTube Gaming, as well as examine growth of food and beverage ...marketing on these platforms over a 17-month period of data collection.
Cross-sectional data were analysed across three livestreaming platforms and six food and beverage categories: alcohol, candy, energy drinks, snacks, sodas and restaurants.
Stream titles of livestreamed events as well as corresponding hours watched on Twitch, Facebook Gaming and YouTube Gaming.
None.
There were significant differences between the use of food and beverage brand mentions in stream titles across all three studied platforms (P < 0·05), as well as hours watched across platforms (P < 0·05). Energy drinks dominated food and beverage brand mentions across platforms, followed by restaurants, soda and snacks. All platforms demonstrated growth over the 17-month data collection period. Post-hoc analyses revealed that the COVID-19 pandemic impacted both immediate and sustained growth across all platforms, with the greatest impact observed on the Twitch platform.
Food and beverage marketing as measured through stream titles is widely prevalent across the three most popular livestreaming platforms, particularly for energy drinks. Food marketing on these platforms experienced growth over the past 17 months which was accelerated substantially by the COVID-19 pandemic. Future work should assess the sustained impact this growth may have on marketing practices and eating behaviour.
Higher protein and fiber diets promote weight management and metabolic health.
This study aimed to determine if greater weight loss and positive changes in metabolic outcomes could be achieved with ...twice-daily consumption of a high-protein and fiber-based multi-ingredient nutritional shake (HPF) compared with an isocaloric low-protein, lower fiber-based placebo (LPF).
Study procedures were conducted by an independent research organization under clinicaltrials.gov registration NCT03057873. Healthy overweight and obese adults n = 206; BMI (kg/m2): 27–35; 70% female were randomly assigned to HPF or LPF. All participants were prescribed an energy-restricted diet (500 kcal/d less than energy needs) and consumed a HPF (17 g protein, 6 g fiber) or LPF (1 g protein, 3 g fiber) shake 30 min before breakfast and lunch for 12 wk. Primary outcomes included body weight and total body fat percentage. Blood samples were collected at days (D) 0, 28, 56, and 84 for secondary analyses related to metabolic markers of health.
Although weight loss occurred in both groups, HPF had greater weight loss at D84 compared with LPF (–3.3 kg vs. –1.8 kg, P < 0.05). Percentage body fat decreased in both groups (HPF: –1.33%, LPF: –1.09%; P < 0.001) with no differences between groups. Serum total cholesterol, LDL cholesterol, and oxidized LDL decreased between –5.1% to –8.3%, whereas adiponectin increased over time in both groups; these changes occurred to a greater extent in HPF compared with LPF (all P < 0.05).
A multi-ingredient HPF nutritional supplement shake consumed as a preload before breakfast and lunch positively influenced weight management and metabolic outcomes in overweight adults compared with an LPF placebo. These findings suggest that specific nutrient factors (i.e., potentially including protein, fiber, and bioactive content) other than calorie reduction alone influence the success of a weight-loss regimen. This trial was registered at www.clinicaltrials.gov as NCT03057873,
Parental feeding practices in childhood have been shown to contribute to childhood eating habits, behaviors, and weight status. Less understood is the longitudinal impact of parental feeding ...practices on these variables in adulthood. Therefore, the aim of the present work was to validate a modified, brief, Comprehensive Feeding Practices Questionnaire (CFPQ) reformatted to account for retrospective recollections of parental feeding practices experienced in childhood among a sample of adults with obesity. Adults (n = 719, mean age = 44.3 years, mean BMI = 47.1 kg/m2) completed a modified, brief, retrospective CFPQ containing seven pre-defined subscales of the original CFPQ. Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) procedures were used to evaluate survey factor structure and associations with gender, BMI, and self-reported race. An EFA derived six-factor model demonstrated better model fit and reliability than the originally proposed seven-factor model. Gender and self-reported race were not correlated with subscales of the brief, retrospective, CFPQ, while BMI was positively correlated with the Food as Reward subscale. This six-factor, brief, retrospective, CFPQ can be used to provide insight into the potential origins of individual eating behaviors, and warrants use in future work attempting to clarify the relationships between parental feeding practices and eating behaviors in adulthood.
•Parental feeding practices contribute to childhood eating habits and behaviors.•Recollections of parental feeding practices may inform eating behavior in adulthood.•A brief, retrospective CFPQ can be used to assess recollections of parental feeding practices.