Sucrose Taste Research Articles

Neural processing of sweet taste in reward regions is reduced following bariatric surgery.

Bariatric surgery reduces sweet-liking, but mechanisms remain unclear. We examined related brain responses. A total of 24 nondiabetic bariatric surgery and 21 control participants with normal weight to overweight were recruited for an observational controlled cohort study. They underwent sucrose taste testing outside the scanner followed by stimulation with 0.40M and 0.10M sucrose compared with water during functional magnetic resonance imaging. A total of 21 bariatric participants repeated these procedures after surgery. Perceived sweet intensity was not different among the control, presurgery, or postsurgery groups. Bariatric participants' preferred sweet concentration decreased after surgery (0.52M to 0.29M; p = 0.008). Brain reward system (ventral tegmental area, ventral striatum, and orbitofrontal cortex) region of interest analysis showed that 0.40M sucrose activation (but not 0.10M) decreased after surgery. Sensory region (primary somatosensory and primary taste cortex) 0.40M sucrose activation was unchanged by surgery and did not differ between control and bariatric participants. Primary taste cortex activation to 0.10M sucrose solution was greater in postsurgical bariatric participants compared with control participants. Bariatric surgery reduces the reward system response to sweet taste in women with obesity without affecting activity in sensory regions, which is consistent with reduced drive to consume sweet foods.

Optogenetic hedonic hotspots in orbitofrontal cortex and insula: causing enhancement of sweetness 'liking'.

Hedonic hotspots are brain subregions that causally amplify the hedonic impact of palatable tastes, measured as increases in affective orofacial 'liking' reactions to sweetness. Previously, two cortical hedonic hotspots in orbitofrontal cortex and insula were identified by neurochemical stimulation using opioid or orexin microinjections. Here we used optogenetic stimulation in rats as an independent neurobiological technique for activating cortical hedonic hotspots to identify hedonic functions and map boundaries. We report that channelrhodopsin stimulations within rostral orbitofrontal and caudal insula hotspots doubled the number of hedonic 'liking' reactions elicited by sucrose taste. This independently confirms their robust functional identity as causal amplifiers of hedonic 'liking' and confirms their anatomical boundaries. Additionally, we confirmed an intervening suppressive hedonic coldstrip, to stretching from caudal orbitofrontal cortex to rostral insula. By contrast to localized hedonic hotspots for 'liking' enhancement, motivational 'wanting' for reward, measured as laser self-stimulation, was mediated by more widely distributed anatomical sites.

Taste Changes and Salivary Flow Rate Disparities in Premenopausal and Postmenopausal Women: Exploring the Zinc Connection.

Menopause triggers hormonal changes that can manifest in oral symptoms like dysgeusia, xerostomia, and burning sensations, substantially impacting daily life, including chewing, swallowing, and taste perception. Menopausal women are particularly susceptible to nutritional fluctuations, including variations in zinc levels, which are believed to be linked to taste perception. Taste alterations can render food unappetizing, leading to malnutrition and diminished quality of life. The study aims to assess taste alterations, salivary flow rate, and zinc levels in premenopausal and postmenopausal women, investigating the correlation between these factors. This research involved 30 premenopausal and 30 postmenopausal women randomly selected from outpatients at the Department of Oral Medicine and Radiology, Panineeya Institute of Dental Sciences and Research Centre, Hyderabad, India. Saliva samples were collected, unstimulated salivary flow rates were measured, taste perception was evaluated using a whole mouth threshold taste test, and serum zinc levels were assessed. The study revealed that a significantly higher percentage of postmenopausal women could not identify sucrose taste at concentrations 1 (76.7%, p = 0.017) and concentrations 2 (56.7%, p = 0.007) compared to premenopausal women (43.3%, 20%, respectively). A statistically significant number of postmenopausal women also couldn't identify the bitter taste at concentration 1 (43.3%, p=0.047) compared to premenopausal women. No significant difference in taste perception of salt and sour was observed between both groups at all tested concentrations. In both groups, mean taste perception rankings were similar, with salt being most perceived, followed by sour bitter, and at least with sucrose. Salivary flow rates and zinc levels did not significantly differ between premenopausal and postmenopausal women. The correlation between zinc levels and taste perception was weak and non-significant, indicating that zinc levels were not significant predictors of taste perception in either group. Postmenopausal women exhibited reduced perceptions of sucrose and quinine hydrochloride, potentially impacting eating habits, while taste perception of sodium chloride and citric acid remained relatively consistent. Salivary flow rates and zinc levels were within the normal range for postmenopausal women up to 60 years of age included in the study. The study demonstrated that zinc levels did not significantly influence perception among postmenopausal women, suggesting that taste impairment is a multifactorial phenomenon.

Change in taste sensation after orthognathic surgery

ObjectiveThe objective of this study was to evaluate the effect of orthognathic surgery on taste sensation.Materials and methodsThirty-five patients scheduled to undergo Le Fort I osteotomy (LFIO), sagittal split ramus osteotomy (SSRO), and bimaxillary surgery (BMS) were evaluated by administering localized and whole-mouth taste tests preoperatively and postoperatively at months 1, 3, and 6. The patients were asked to identify the quality of four basic tastes applied to six locations on the palate and tongue and to rate the taste intensities they perceived. Taste recognition thresholds and taste intesity scores were evaluted according to operation groups and follow-ups.ResultsThere were significant decreases in the quinine HCl recognition thresholds at the postoperative follow-ups compared to the preoperative in LFIO patients (p = 0.043). There were significant decreases in sucrose taste intensity scores in the right posterolateral part of the tongue at months 3 and 6 compared to preoperative in SSRO patients (p = 0.046), and significant increases in quinine HCL taste intensity scores in the right and left anterior parts of the tongue at month 6 compared to preoperative in LFIO patients (p < 0.05).ConclusionTaste perception is affected due to potential damage to the chemosensory nerves during orthognathic surgical procedures. Generally, non-significant alterations have been observed in taste perception after orthognathic surgery, except for significant alterations in bitter and sweet taste perceptions.Clinical relevanceMaxillofacial surgeons should be aware of taste perception change after orthognathic surgery procedures and patients should be informed accordingly.The trial registration number (TRN)NCT06103422/Date of registration: 10.17.2023 (retrospectively registered).

Glutamine enhances sucrose taste through a gut microbiota-gut-brain axis in Drosophila

AimsAmino acids (AAs) are known to play important roles in various physiological functions. However, their effect on sweet taste perception remains largely unknown. Main methodsWe used Drosophila to evaluate the effect of each AA on sucrose taste perception. Individual AA was supplemented into diets and male flies were fed on these diets for 6 days. The proboscis extension response (PER) assay was applied to assess the sucrose taste sensitivity of treated flies. We further utilized the RNA-seq and germ-free (GF) flies to reveal the underlying mechanisms of sucrose taste sensitization induced by glutamine (Gln). Key findingsWe found that supplementation of Gln into diets significantly enhances sucrose taste sensitivity. This sucrose taste sensitization is dependent on gut microbiota and requires a specific gut bacterium Acetobacter tropicalis (A. tropicalis). We further found that CNMamide (CNMa) in the gut and CNMa receptor (CNMaR) in dopaminergic neurons are required for increased sucrose taste sensitivity by Gln diet. Finally, we demonstrated that a gut microbiota-gut-brain axis is required for Gln-induced sucrose taste sensitization. SignificanceThese findings can advance understanding of the complex interplay between host physiology, dietary factors, and gut microbiota.

Reducing sugar intake through chronic swimming training: Exploring palatability changes and central vasopressin mechanisms

Excessive sugar intake has been associated with the onset of several non-communicable chronic diseases seen in humans. Physical activity could affect sweet taste perception which may affect sugar intake. Therefore, it was investigated the chronic effects of swimming training on sucrose intake/preference, reactivity to sucrose taste, self-care in neurobehavioral stress, and the possible involvement of the vasopressin type V1 receptor in sucrose solution intake. Male Wistar rats, of from different cohorts were used, subjected to a sedentary lifestyle (SED) or swimming training (TR - 1 h/day, 5×/week, for 8 weeks, with no added load). Weekly intake was verified in SED and TR rats after access to a sucrose solution 1×/week, 2 h/day, for eight weeks. Chronic effects of swimming and/or a sedentary lifestyle were carried out three days after the end of the physical exercise protocol. Swimming training reduced the intake of sucrose solution from the third week onwards in the two-bottle test measured once a week for 8 weeks. After the ending of the swimming protocol, sucrose intake was also reduced as per its preference. This reduced intake is probably correlated with the carbohydrate aspect of sucrose since saccharin intake was not affected. In addition, chronic swimming training was shown to reduce ingestive responses, increase neutral responses, without interfering with aversive, in the sucrose solution taste reactivity test. In addition, these results are not related to a depressive-like behavior, nor to neurobehavioral stress. Furthermore, treatment with vasopressin V1 receptor antagonist abolished the reduced sucrose intake in trained rats. The results suggest that swimming performed chronically is capable of reducing intake and preference for sucrose by decreasing the palatability of sucrose without causing depressive-type behavior or stress. In addition, the results also suggest that central V1 vasopressin receptors are part of the mechanisms activated to reduce sucrose intake in trained rats.

High-intensity sweet taste as a predictor of subjective alcohol responses to the ascending limb of an intravenous alcohol prime: an fMRI study.

High-intensity sweet-liking has been linked to alcohol use disorder (AUD) risk. However, the neural underpinning of this association is poorly understood. To find a biomarker predictive of AUD, 140 participants (social and heavy drinkers, ages 21-26) underwent functional magnetic resonance imaging (fMRI) during a monetary incentive delay (MID) task and stimulation with high (SucroseHigh)- and low-concentration sucrose, as well as viscosity-matched water. On another day after imaging, and just before free-access intravenous alcohol self-administration, participants experienced a 30 mg% alcohol prime (10 min ascent) using the Computerized Alcohol Infusion System. Principal component analysis (PCA) of subjective responses (SR) to the prime's ascending limb generated enjoyable (SRenjoy) and sedative (SRsed) intoxication components. Another PCA created one component reflective of self-administered alcohol exposure (AE) over 90 min. Component loadings were entered as regressors in a voxel-wise general linear fMRI model, with reward type as a fixed factor. By design, peak prime breath alcohol concentration was similar across participants (29 ± 3.4 mg%). SRenjoy on the prime's ascending limb correlated positively with [SucroseHigh > Water] in the supplementary motor area and right dorsal anterior insula, implicating the salience network. Neither SR component correlated with the brain's response to MID. AE was unrelated to brain reward activation. While these findings do not support a relationship between alcohol self-administration and (1) subjective liking of or (2) regional brain response to an intensely sweet taste, they show that alcohol's enjoyable intoxicating effects on the rising limb correspond with anterior insular and supplementary motor area responses to high-concentration sucrose taste. No such associations were observed with MID despite robust activation in those regions. Insula and supplementary motor area responses to intense sensations relate to a known risk factor for AUD in a way that is not apparent with a secondary (monetary) reward.

Nutritional geometry framework of sucrose taste in Drosophila

Dietary protein (P) and carbohydrate (C) have a major impact on the sweet taste sensation. However, it remains unclear whether the balance of P and C influences the sweet taste sensitivity. Here, we use the nutritional geometry framework (NGF) to address the interaction of protein and carbohydrates on sweet taste using Drosophila as a model. Our results reveal that high-protein, low-carbohydrate (HPLC) diets sensitize to sweet taste and low-protein, high-carbohydrate (LPHC) diets desensitize sweet taste in both male and female flies. We further investigate the underlying mechanisms of the effects of two diets on sweet taste using RNA sequencing. When compared to the LPHC diet, the mRNA expression of genes involved in the metabolism of glycine, serine, and threonine is significantly upregulated in the HPLC diet group, suggesting these amino acids may mediate sweet taste perception. We further find that sweet sensitization occurs in flies fed with the LPHC diet supplemented with serine and threonine. Our study demonstrates that sucrose taste sensitivity is affected by the balance of dietary protein and carbohydrates possibly through changes in serine and threonine.

A putative biological adsorption process of binary mixture taste of sucrose and caffeine on human neuroreceptor site by the use of statistical physics modeling

This work represents a contribution in the comprehension of a racimic mixture of caffeine-sucrose molecules and their taste-taste interaction, by the use of a binary model expression of non-exclusive competitive extended Hill model. This extended model is deduced by statistical physics treatment. The simulation results suggested that the sucrose molecule formed an aggregate of two molecules and anchored with a non-parallel position onto the human neuroreceptor taste sites. Contrary to the sucrose molecule, the molecule of caffeine is anchored in a parallel position with the human neuroreceptor taste sites. The pore size distribution (PSD) and the adsorption energy distribution (AED) of human neuroreceptor sites are derived through the selected model to describe porosity and energitical homogeneity of taste adsorbent surface. So, the mutual interaction between molecules of racemic mixture dose-response curves of caffeine and sucrose on human neuroreceptor sites. Firstly, this model is used to analyze the taste-taste interaction mechanism of the mixture of bitter caffeine-sweet sucrose taste. Secondly, all these stereo and energetical parameters will be used for an objective description of the taste of the mixture of caffeine-sucrose molecules in the intense and qualitative aspects of the taste of the mixture.

Investigating the temporality of binary taste interactions in blends of sweeteners and citric acid in solution

AbstractThis study investigated sweet–sour taste interactions in novel sweeteners using a 3 × 2 factorial design consisting of Sweetening System (three levels: sucrose; d‐allulose; and a blend of d‐allulose and Monk fruit extract) and Acidity (two levels: with or without citric acid). 110 untrained Chinese subjects participated using the temporal check‐all‐that‐apply (TCATA) method. Mixed‐model ANOVA was conducted to investigate the effect of Sweetening System, Acidity, and their interactions on the fractional Area Under the Curve within three 20 s time intervals (attack, evolution, finish). Treatments were compared using Dunnett's test with sucrose as control. Citric acid suppressed the sweet taste of both sucrose and d‐allulose more than the blend of d‐allulose and Monk fruit extract throughout attack and evolution time intervals. This finding was confirmed by a significant interaction between Sweetening System and Acidity for sweet taste. Sour taste was not affected differently by different Sweetening Systems or the difference in sweetener concentration.Practical ApplicationsThis study showed that the sweet taste of a blend of sweeteners could be altered by citric acid to have a similar temporal profile as sucrose in most of the evaluation time. This emphasizes the importance of not only conducting evaluations of novel sweeteners in aqueous solutions but also considering studies in more complex matrices and the choice of the methodology used to measure the sensory profile.

The effect of concurrent use of swaddle and sucrose on the intensity of pain during venous blood sampling in neonate: a clinical trial study

Background & objectiveInfants undergo painful procedures while receiving care and treatment. Blood sampling is the most common painful procedure for infants. Pain control plays a significant role in preventing unwanted physical and psychological effects. Therefore, this study aimed to investigate the effect of concurrent use of swaddle and sucrose taste on the pain intensity during venous blood sampling in neonates.MethodsIn this clinical trial study, 60 infants admitted to the neonatal ward of Amirkola Hospital were randomly divided into four groups of 15 patients. In the first group, the infants were swaddled before blood sampling. In the second group, sucrose was administered to infants. In the third group, the neonates were swaddled and given sucrose simultaneously, and in the fourth group (control), blood sampling was performed routinely. PIPP pain scale and demographic questionnaire were used to collect the data. Data analysis was performed using SPSS23.ResultsThe results showed a significant difference between the mean pain intensity in neonates in the sucrose-swaddle group (4.53 ± 1.30) and the sucrose (7.73 ± 2.73), swaddle (9.86 ± 33.33), and control (12.13 ± 2.06) groups during blood sampling (P < 0.001). Besides, after blood sampling, there was a significant difference between the mean pain intensity in neonates in the sucrose-swaddle group (4.33 ± 1.23) and the sucrose (8.13 ± 2.66), swaddle (7.73 ± 2.78), and control (10.00. ± 1.96) groups (P < 0.001).ConclusionThe present study showed that pain severity during and after venous blood sampling was lower in the swaddle-sucrose group than in other groups. Therefore, it is recommended that the combined method of swaddle-sucrose be used in infants as a better pain reliever when intravenous blood sampling is performed.

The Influence of Roux-en-Y Gastric Bypass and Diet on NaCl and Sucrose Taste Detection Thresholds and Number of Circumvallate and Fungiform Taste Buds in Female Rats.

Roux-en-Y gastric bypass (RYGB) in rats attenuates preference for, and intake of, sugar solutions. Additionally, maintenance on a high-fat diet (HFD) reportedly alters behavioral responsiveness to sucrose in rodents in short-term drinking tests. Due to the fact that the behavioral tests to date rely on the hedonic value of the stimulus to drive responsiveness, we sought to determine whether taste detection thresholds to sucrose and NaCl are affected by these manipulations as measured in an operant two-response signal detection paradigm. Female rats were maintained on HFD or chow for 10 weeks, at which point animals received either RYGB or SHAM surgery followed by a gel-based diet and then powdered chow. Upon recovery, half of the rats that were previously on HFD were switched permanently to chow, and the other rats were maintained on their presurgical diets (n = 5–9/diet condition × surgery group for behavioral testing). The rats were then trained and tested in a gustometer. There was a significant interaction between diet condition and surgery on NaCl threshold that was attributable to a lower value in RYGB vs. SHAM rats in the HFD condition, but this failed to survive a Bonferroni correction. Importantly, there were no effects of diet condition or surgery on sucrose thresholds. Additionally, although recent evidence suggests that maintenance on HFD alters taste bud number in the circumvallate papillae (CV) of mice, in a subset of rats, we did not find that diet significantly influenced taste pores in the anterior tongue or CV of female rats. These results suggest that any changes in sucrose responsiveness in intake/preference or hedonically oriented tests in rats as a function of HFD maintenance or RYGB are not attributable to alterations in taste sensitivity.

Impact of aerobic exercises on taste perception for sucrose in patients with type 2 diabetes mellitus; A randomized controlled trial

BackgroundRegular exercise is a key element in the management of type 2 diabetes mellitus (T2DM). Although the importance of regular exercises on glycemic control in people with diabetes is studied extensively, evidence is lacking on its impact on sweet taste perception. Thus, the aim of this study was to determine the impact of aerobic exercises on taste perception for sucrose in people with diabetes.MethodsA sample of 225 people with diabetes aged 35-60 years was assigned randomly into 3 groups; aerobic exercise, combined exercise and a control group. The outcomes of the combined exercise group is not reported. The aerobic exercise group performed brisk walking 30min/day, 4-5days/week for 6 months. The primary outcome measures were supra-threshold intensity ratings and preference for sucrose assessed at baseline, at 3 and 6 months using ‘general Labeled Magnitude Scale’ and ‘Monell 2-series-forced choice method’ respectively. Glycated haemoglobin (HbA1c) level was assessed at baseline and at 6 months to determine glycemic control.ResultsAerobic exercise group showed significantly increased ratings (mm) for higher sucrose concentrations at 3 months (mean difference for 2.02M; +6.63±2.50, p=0.048 and for 0.64M; +7.26±2.76, p=0.026) and at 6 months (mean difference for 0.64M; +7.79±4.49, p= 0.044) compared to baseline and also when compared to controls (mean difference for 2.02M between baseline and 3 months; intervention: +6.63±2.50, control: -4.01±1.79, p=0.02 and between baseline and 6 months for 2.02M; intervention: +3.15±0.57, control: -7.96±0.40, p=0.022 and for 0.64M; intervention: +7.79±4.49, control: -8.98±0.99, p=0.003). A significantly reduced preference (mol/L) was seen both at 3 (mean difference; -0.03±0.02, p= 0.037) and at 6 months (mean difference; -0.05±0.12, p=0.011) compared to baseline within the intervention group. Also, a significant reduction was seen in the intervention group compared to controls at 6 months (mean difference; intervention: -0.05±0.12, control: 0.01±0.03, p=0.044). HbA1c was significantly reduced in the intervention group compared to controls at 6 months (mean difference; intervention -0.43±1.6%, control +0.33±1.8%, p=0.018).ConclusionRegular aerobic exercises increase the sweet taste sensitivity, especially for higher concentrations of sucrose and decrease sweet taste preference in people with diabetes . These alterations in sweet taste perception, are likely to contribute to a better glycemic control in people with diabetes.Trial registrationThis trial was registered at the Sri Lanka Clinical Trial registry on 16/12/2015. (Trial registration number- SLCTR/2015/029, https://slctr.lk/trials/slctr-2015-029).

Differences in the Liking of Sweet Tastes of Different Sources (Natural and Artificial) among Older Adolescents in Slovenia

The aim of this research paper is to investigate the recognition and liking of sweet tastes among older adolescents (19–21 years), and in doing so determine whether any differences exist in the liking of sweet tastes with respect to their differing sources (i.e. either of natural or artificial origin). With this aim in mind, data was obtained from sensory testing performed on a total of 101 participants between 19 and 21 years of age, of whom 60 were female and 41 male. Recognition of the basic tastes (i.e. sweet, salty, sour and bitter) was found to be good among most respondents and its success unrelated to gender. Furthermore, participants were found to demonstrate no difficulties with respect to the correct ordering of solutions of different intensities of sweetness (or, rather, of different concentrations of sucrose in water), regardless of gender. The most liked concentration among both men and women was 4.3%. Also established were differences in the liking of sweet tastes of different sources (i.e. natural and artificial). Participants were offered the most generally liked solution of sucrose in water (4.3%) as well as a number of table-top sweeteners prepared, in accordance with their packaging instructions, to be of comparable gustatory sweetness to the sucrose solution. In this endeavour, the selection of solutes was informed by the availability of table-top sweeteners among the five largest commercial producers, and involved those commercially sold under the names stevia, birch sugar, liquid sweetener (Na cyclamate, Na saccharin, thaumatin), sucralose, erythrol, fructose, Streusüße (sorbitol and saccharin). It was found that the most liked sweet tastes were those of sucrose and sucralose, while the taste of fructose was in third place albeit statistically significantly less liked than the tastes of sucrose and sucralose. Although the results of average values indicate that all kinds of sweet tastes are moderately liked, the liking of stevia and erythrol was found to be statistically significantly lower than the liking of sucrose and sucralose. From this, we conclude that artificial sweeteners are gaining in likeability, but even so, of the three most generally liked sources of sweet taste, two are natural sugars.

Mucin1 expression and gustatory function in postmenopausal females: A case-control observational study.

Investigating possible relationship between Mucin1 expression levels in saliva, gustatory function, and taste perception in postmenopausal females. Using whole mouth taste test, twenty-five post-menopausal females (51.35 ± 5.22 years) and twenty-five premenopausal females (39.65 ± 6.46 years) were prospectively evaluated for gustatory function. The expression of mucin1 was investigated; RNA was isolated from stimulated whole saliva samples and real-time PCR was used to determine mucin1 mRNA levels relative to bactin and GAPDH mRNA levels. Significant difference was observed between postmenopausal and premenopausal women regarding intensity judgments of all tastants. The difference was more evident for sucrose taste perception (p<0.00001). Mucin1 expression levels were significantly decreased in postmenopausal females compared with premenopausal ones (p<0.00001). Mucin1 expression level had significant negative correlation with the salt taste sensitivity but did not correlate significantly with intensity judgments of the other tastants. Postmenopausal women have a reduced gustatory function, especially sucrose. Mucin1 expression was significantly decreased in postmenopausal females and had a significant negative correlation with the salt taste sensitivity. However, no correlation was found between mucin1 expression level and taste sensitivity of other tastants. Key words:Gustatory function, MUC1, taste, postmenopausal.

Association of Brain Reward Response With Body Mass Index and Ventral Striatal-Hypothalamic Circuitry Among Young Women With Eating Disorders

Eating disorders are severe psychiatric disorders; however, disease models that cross subtypes and integrate behavior and neurobiologic factors are lacking. To assess brain response during unexpected receipt or omission of a salient sweet stimulus across a large sample of individuals with eating disorders and healthy controls and test for evidence of whether this brain response is associated with the ventral striatal-hypothalamic circuitry, which has been associated with food intake control, and whether salient stimulus response and eating disorder related behaviors are associated. In this cross-sectional functional brain imaging study, young adults across the eating disorder spectrum were matched with healthy controls at a university brain imaging facility and eating disorder treatment program. During a sucrose taste classic conditioning paradigm, violations of learned associations between conditioned visual and unconditioned taste stimuli evoked the dopamine-related prediction error. Dynamic effective connectivity during expected sweet taste receipt was studied to investigate hierarchical brain activation between food intake relevant brain regions. The study was conducted from June 2014 to November 2019. Data were analyzed from December 2019 to February 2020. Prediction error brain reward response across insula and striatum; dynamic effective connectivity between hypothalamus and ventral striatum; and demographic and behavior variables and their correlations with prediction error brain response and connectivity edge coefficients. Of 317 female participants (197 with eating disorders and 120 healthy controls), the mean (SD) age was 23.8 (5.6) years and mean (SD) body mass index was 20.8 (5.4). Prediction error response was elevated in participants with anorexia nervosa (Wilks λ, 0.843; P = .001) and in participants with eating disorders inversely correlated with body mass index (left nucleus accumbens: r = -0.291; 95% CI, -0.413 to -0.167; P < .001; right dorsal anterior insula: r = -0.228; 95% CI, -0.366 to -0.089; P = .001), eating disorder inventory-3 binge eating tendency (left nucleus accumbens: r = -0.207; 95% CI, -0.333 to -0.073; P = .004; right dorsal anterior insula: r = -0.220; 95% CI, -0.354 to -0.073; P = .002), and trait anxiety (left nucleus accumbens: r = -0.148; 95% CI, -0.288 to -0.003; P = .04; right dorsal anterior insula: r = -0.221; 95% CI, -0.357 to -0.076; P = .002). Ventral striatal to hypothalamus directed connectivity was positively correlated with ventral striatal prediction error in eating disorders (r = 0.189; 95% CI, 0.045-0.324; P = .01) and negatively correlated with feeling out of control after eating (right side: r = -0.328; 95% CI, -0.480 to -0.164; P < .001; left side: r = -0.297; 95% CI, -0.439 to -0.142; P = .001). The results of this cross-sectional imaging study support that body mass index modulates prediction error and food intake control circuitry in the brain. Once altered, this circuitry may reinforce eating disorder behaviors when paired with behavioral traits associated with overeating or undereating.

Effects of Sweet-Liking on Body Composition Depend on Age and Lifestyle: A Challenge to the Simple Sweet-Liking-Obesity Hypothesis.

Taste hedonics drive food choices, and food choices affect weight maintenance. Despite this, the idea that hyper-palatability of sweet foods is linked to obesity development has been controversial for decades. Here, we investigate whether interpersonal differences in sweet-liking are related to body composition. Healthy adults aged 18–34 years from the UK (n = 148) and the US (n = 126) completed laboratory-based sensory tests (sucrose taste tests) and anthropometric measures (body mass index; BMI, body fat; fat-free mass; FFM, waist/hips circumferences). Habitual beverage intake and lifestyle and behavioural characteristics were also assessed. Using hierarchical cluster analysis, we classified participants into three phenotypes: sweet liker (SL), sweet disliker (SD), and inverted-U (liking for moderate sweetness). Being a SD was linked to higher body fat among those younger than 21 years old, while in the older group, SLs had the highest BMI and FFM; age groups reflected different levels of exposure to the obesogenic environment. FFM emerged as a better predictor of sweet-liking than BMI and body fat. In the older group, sweetened beverage intake partially explained the phenotype–anthropometry associations. Collectively, our findings implicate underlying energy needs as an explanation for the variation in sweet-liking; the moderating roles of age and obesogenic environment require additional consideration.

Differences in Sweet Taste Perception and Its Association with the Streptococcus mutans Cariogenic Profile in Preschool Children with Caries.

The aim of the study was to verify the hypothesis about differences in sweet taste perception in the group of preschool children with and without caries, and to determine its relationship with cariogenic microbiota and the frequency of sweets consumption in children. The study group included of 63 children aged 2–6 years: 32 with caries and 31 without caries. The study consisted of collecting questionnaire data and assessment of dental status using the decayed, missing, filled in primary teeth index (dmft) and the International Caries Detection and Assessment System (ICDAS II). The evaluation of sweet taste perception was carried out using a specific method that simultaneously assessed the level of taste preferences and the sensitivity threshold for a given taste. The microbiological analysis consisted of the assessment of the quantitative and qualitative compositions of the oral microbiota of the examined children. The sweet taste perception of children with caries was characterized by a lower susceptibility to sucrose (the preferred sucrose solution concentration was >4 g/L) compared to children without caries (in the range ≤ 4 g/L, p = 0.0015, chi-square test). A similar relationship was also observed for frequent snacking between meals (p = 0.0038, chi-square test). The analysis of studied variables showed the existence of a strong positive correlation between the perception of sweet taste and the occurrence and intensity of the cariogenic process (p = 0.007 for dmft; and p = 0.012 for ICDAS II), as well as the frequency of consuming sweets (p ≤ 0.001 for frequent and repeated consumption of sweets during the day, Spearman test) in children with caries. Additionally, children with an elevated sucrose taste threshold were more than 10-times more likely to develop S. mutans presence (OR = 10.21; 95% CI 3.11–33.44). The results of this study suggest the future use of taste preferences in children as a diagnostic tool for the early detection of increased susceptibility to caries through microbial dysbiosis towards specific species of microorganisms.

Relationship between Sucrose Taste Detection Thresholds and Preferences in Children, Adolescents, and Adults.

To address gaps in knowledge, our objectives were to (1) to determine whether there are age-related changes in sweet taste detection thresholds, as has been observed for sweet taste preferences, and (2) determine whether detection thresholds and taste preferences were significantly related to each other from childhood to adulthood. We combined data from studies that used the same validated psychophysical techniques to measure sucrose taste detection threshold and the most preferred sucrose concentration in children (n = 108), adolescents (n = 172), and adults (n = 205). There were significant effects of age group on both sucrose detection thresholds (p < 0.001) and most preferred sucrose concentration (p < 0.001). While children had higher sucrose detection thresholds than adolescents, who in turn tended to have higher detection thresholds than adults, both children and adolescent most preferred sucrose concentrations were higher than that of adults (all p < 0.05). Among each age group, and when combined, the lowest sucrose concentration detected was not significantly correlated with the most preferred sucrose concentration (all p > 0.18). These data provide further evidence that age-related changes in sucrose taste preferences that occur during adolescence cannot be explained by changes in taste sensitivity and that these two dimensions of sweet taste undergo distinct developmental trajectories from childhood to adulthood.

Rapid Throughput Operant Taste Discrimination: Signal Detection Theory (SDT) and Concentration‐Response (CR) Analyses for Quantifying Sucrose Taste Sensitivities in Individual Human Subjects

Most human taste discrimination experiments have focused on determination of detection thresholds, which are taken as indications of the sensitivity of the taste sensory system. However, detection thresholds reported in the literature can vary substantially across and within studies, and there is little evidence to support repeatability of the values obtained. Two factors that likely contribute to the observed variability are 1) inherent low throughput, which would impact assay robustness, and 2) insufficient accounting for subject bias in the analysis. Low throughput capacity of traditional taste discrimination methods all but precludes quantification by the more broadly applicable measures of discriminability (d′) and subject bias (β) obtained by SDT, as well as the ability to conduct CR analyses. We previously have reported a novel technology for automated rapid throughput operant taste discrimination using human subjects, called the TāStation®. We applied this technology to compare sensitivities to low “threshold” concentrations of sucrose determined by SDT with EC50s obtained by CR analysis in the same subjects. Small volumes (200 μl) of sucrose solutions or water, distributed in replicate wells of a 96‐well plate, were automatically drawn by an electronic pipette from single randomly selected wells on each trial. Subjects then removed the pipette and self‐administered the stimuli to the tongue. Subjects were trained through an interactive game‐like algorithm to associate the taste of sucrose with coordinates on the right sided of a touch‐sensitive display (TSD), and water on corresponding coordinates reflected to the opposite side. Correct responses on control trials were reinforced by the appearance of a virtual poker chip carrying remunerative value (which accumulated across the 96 trials); incorrect responses were penalized by a reduction in the cumulative score. The rapid generation of large robust data sets enabled an assessment of repeatability for SDT values of d′ and β, and EC50s derived from CR functions. We found that d′ and β were relatively stable across tests for some individuals but varied for other subjects. Less variability was observed in the EC50s for all subjects. For example, in three tests each occurring on separate days, 5 mM sucrose d′ values for subject M1200 were 1.18, 1.07, 0.94; those for subject M1194 were 0.56, −0.08, and 1.29. EC50s obtained for subject M1200 were 22, 27, and 24 mM, and for subject M1194 were 16, 20, and 27 mM. The repeatability of the EC50s within subjects revealed two distinct phenotypes for sucrose potency across subjects, with one group exhibiting EC50s that ranged narrowly around 25 mM, and a second group around 60 mM. These differences in sucrose potencies across subjects suggest the possibility of alternative structural features in the sucrose binding site of the T1R2/R3 receptor. Our results further imply that EC50 values, obtained from quantitative characterization of the entire concentrations‐response function for taste, are more reliable and more informative than measures of discriminability at the lowest taste‐active concentrations (i.e., “thresholds”).Support or Funding InformationEntirely funded by Opertech Bio