Bacteroides uniformis CECT 7771 Modulates the Brain Reward Response to Reduce Binge Eating and Anxiety-Like Behavior in Rat

Food addiction (FA) is characterized by behavioral and neurochemical changes linked to loss of food intake control. Gut microbiota may influence appetite and food intake via endocrine and neural routes. The gut microbiota is known to impact homeostatic energy mechanisms, but its role in regulating the reward system is less certain. We show that the administration of Bacteroides uniformis CECT 7771 (B. uniformis) in a rat FA model impacts on the brain reward response, ameliorating binge eating and decreasing anxiety-like behavior. These effects are mediated, at least in part, by changes in the levels of dopamine, serotonin, and noradrenaline in the nucleus accumbens and in the expression of dopamine D1 and D2 receptors in the prefrontal cortex and intestine. B. uniformis reverses the fasting-induced microbiota changes and increases the abundance of species linked to healthy metabolotypes. Our data indicate that microbiota-based interventions might help to control compulsive overeating by modulating the reward response.

Enhanced Eye Velocity in Head Impulse Testing—A Possible Indicator of Endolymphatic Hydrops

Introduction: On video head impulse testing (vHIT) of semicircular canal function, some patients reliably show enhanced eye velocity and so VOR gains >1.0. Modeling and imaging indicate this could be due to endolymphatic hydrops. Oral glycerol reduces membranous labyrinth volume and reduces cochlear symptoms of hydrops, so we tested whether oral glycerol reduced the enhanced vHIT eye velocity.Study Design: Prospective clinical study and retrospective analysis of patient data.Methods: Patients with enhanced eye velocity during horizontal vHIT were enrolled (n = 9, 17 ears) and given orally 86% glycerol, 1.5 mL/kg of body weight, dissolved 1:1 in physiological saline. Horizontal vHIT testing was performed before glycerol intake (time 0), then at intervals of 1, 2, and 3 h after the oral glycerol intake. Control patients with enhanced eye velocity (n = 4, 6 ears) received water and were tested at the same intervals. To provide an objective index of enhanced eye velocity we used a measure of VOR gain which captures the enhanced eye velocity which is so clear on inspecting the eye velocity records. We call this measure the initial VOR gain and it is defined as: (the ratio of peak eye velocity to the value of head velocity at the time of peak eye velocity). The responses of other patients who showed enhanced eye velocity during routine clinical testing were analyzed to try to identify how the enhancement occurred.Results: We found that oral glycerol caused, on average, a significant reduction in the enhanced eye velocity response, whereas water caused no systematic change. The enhanced eye velocity during the head impulses is due in some patients to a compensatory saccade-like response during the increasing head velocity.Conclusion: The significant reduction in enhanced eye velocity during head impulse testing following oral glycerol is consistent with the hypothesis that the enhanced eye velocity in vHIT may be caused by endolymphatic hydrops.

Monitoring in vivo neural activity to understand gut-brain signaling

Appropriate food intake requires exquisite coordination between the gut and the brain. Indeed, it has long been known that gastrointestinal signals communicate with the brain to promote or inhibit feeding behavior. Recent advances in the ability to monitor and manipulate neural activity in awake, behaving rodents has facilitated important discoveries about how gut signaling influences neural activity and feeding behavior. This review emphasizes recent studies that have advanced our knowledge of gut-brain signaling and food intake control, with a focus on how gut signaling influences in vivo neural activity in animal models. Moving forward, dissecting the complex pathways and circuits that transmit nutritive signals from the gut to the brain will reveal fundamental principles of energy balance, ultimately enabling new treatment strategies for diseases rooted in body weight control.

Computations by different types of brain, and by artificial neural systems

In this Chapter a comparison is made between computations in the brain and computations performed in computers. This is intended to be helpful to those engineers, computer scientists, AI specialists et al interested in designing new computers that emulate aspects of brain function. In fact, the whole of this book is intended to be useful for this aim, by setting out what is computed by different brain systems, and what we know about how it is computed. It is essential to know this if an emulation of brain function is to be performed, and this is important to enable this group of scientists to bring their expertise to help understand brain function more. The Chapter also considers the levels of investigation, which include the computational, necessary to understand brain function; and some applications of this understanding, to for example how our developing understanding is relevant to understanding disorders, including for example of food intake control leading to obesity. Finally, Section 19.10 makes it clear why the focus of this book is on computations in primate (and that very much includes human) brains, rather than on rodent (rat and mice) brains. It is because the systems-level organization of primate including human brains is quite different from that in rodents, in many fundamental ways that are described.

Development of a Questionnaire to Assess the Relationship Between Weight Status and Sociocultural Factors

Objectives Cultural factors influence obesity risk, but this relationship has not been systematically studied due to the lack of a validated survey instrument. The objective of this project was to develop a prototype questionnaire to assess the relationship between body mass index (BMI) and sociocultural factors. Methods Interviews and focus groups were conducted in the US (N = 24) and France (N = 25). Recordings were transcribed and analyzed (NVivo), and results informed the new questionnaire. The questionnaire was administered in two pilots using Amazon Mechanical Turk (pilot 1: N = 25 adults in France and 25 in US; pilot 2: N = 120 US adults). Demographic information was also collected. Questions were grouped by theme and scores were created from response averages within each theme. The scores were analyzed in relation to BMI, age and country (ANOVA, Spearman correlation). The scores included cultural insularity (high score = greater role of cultural identity in food choices), external eating pressures (high score = stronger perceived and overt pressures), food insecurity (high score = greater food insecurity), childhood intake control (high score = stricter parental control of eating during childhood), and nutrition knowledge (high score = better discernment of healthy vs. unhealthy foods). Results In France, the cultural insularity score was higher than in the US (P = 0.01) and was correlated with BMI (r = 0.5, P = 0.03). The childhood intake control score was also inversely associated with BMI in France (r = −0.5, P = 0.03). In the US, BMI was positively associated with the external eating pressures (pilot 2: r = 0.2, P = 0.03) and nutrition knowledge (pilot 2: r = 0.2, P = 0.04) scores, and was inversely associated with the food insecurity score (pilot 2: r = −0.24, P = 0.008). In both countries, age was associated with the childhood intake control score (France: r = 0.5, P = 0.03, and US pilot 1: r = 0.4, P = 0.03, pilot 2: r = 0.4, P < .0001). Conclusions This approach and prototype questionnaire identified novel cultural factors associated with high BMI in France and the US. Additional research is needed to validate the prototype and identify core cultural factors associated with risk of obesity in different cultures. Funding Sources USDA agreement #8050–51,000-105–01S; Danone Research; Institute of Cardiometabolism and Nutrition.

PSXII-18 The influence of molybdenum in drinking water or feed on apparent absorption and retention of molybdenum and copper in beef steers

Twelve Angus steers (BW 694.1 ± 47.4 kg) fitted ruminal cannulae were used to examine the effect of molybdenum (Mo) supplemented in drinking water or feed on apparent absorption and retention of Mo and copper (Cu). Steers were fed a low-quality grass hay diet (DM basis: 6.5% CP; 0.13% S, 3.4 mg Cu/kg, 2.4 mg Mo/kg) for 14 d. Steers were then housed in individual metabolism stalls for 3 d to determine DMI. Steers were then blocked by BW and DMI and randomly assigned within block to one of three treatments (n = 4 steers per treatment). Treatments consisted of: 1) Control (no supplemental Mo); 2) 5.0 mg Mo/kg DM from sodium molybdate dihydrate (Mo-diet), and 3) 1.5 mg Mo/l from sodium molybdate dihydrate delivered in the drinking water (Mo-water). After the 3d DMI determination period, total fecal and urine output was collected for 5 d. Dry matter intake and DM digestibility were similar across treatments. Data were analyzed using a mixed effects model (PROC MIXED, SAS) for a completely randomized block design. Apparent absorption of Cu was greater (P < 0.05) in Control and Mo-water steers when compared to Mo-diet steers. Apparent retention of Cu was greater (P < 0.05) in Control steers when compared to Mo-diet steers. Steers receiving Mo-water had a similar apparent retention of Cu when compared to Control and Mo-diet steers. By design, treatment was a significant (P < 0.01) source of variation for Mo intake. Control steers had lesser (P < 0.05) Mo intake when compared to Mo-diet and Mo-water supplemented steers. Apparent absorption and retention of Mo were greater (P < 0.05) in Mo-diet steers compared to Control and Mo-water steers. These data indicate that Mo metabolism and apparent absorption of Cu are different when Mo is supplemented in water relative to feed.