Cronkhite-Canada syndrome (CCS) is a very rare gastrointestinal disorder with ectodermal abnormalities. Taste abnormalities appear in more than 80% of cases. Our objective was to investigate the characteristics of CCS. Ten patients with taste abnormalities who were diagnosed with CCS were included. A medical interview, examination of the tongue findings, and blood tests were performed, and taste functions were assessed using an electrogustometry (EGM) and a filter paper disc (FPD) before and after treatment. There was nail atrophy in all cases, weight loss in 8 cases, hair loss in 6 cases, skin hyperpigmentation in 5 cases, gastrointestinal symptoms in 4 cases, and atrophy of the lingual papillae in at least 8 cases. Zinc therapy for taste disorders by the previous physicians was ineffective in all cases. The results of the FPD at the first examination showed a severe decrease in taste function of the anterior tongue, whereas taste function tended to be preserved in the posterior tongue (P < 0.01, Wilcoxon). In all cases, subjective symptoms improved within 3 mo after treatment of CCS. Taste function improved significantly after treatment (FPD in anterior tongue, P < 0.05, EGM in posterior tongue, P < 0.01, Wilcoxon). Taste disorder in CCS tended to be severe in the anterior tongue with findings of tongue papillary atrophy, which appears to be an ectodermal abnormality. Their taste function improved along with symptoms after treatment. The taste tests were useful for determining the effect of treatment for CCS.

Taste buds are commonly studied in rodent models, but some differences exist between mice and humans in terms of gustatory mechanisms and sensitivities. Whether these functional differences are reflected in structural differences between species is unclear. Using immunofluorescent image stacks, we compared morphological and molecular characteristics of mouse and human fungiform taste buds. The results suggest that while the general features of fungiform taste buds are similar between mice and humans, several characteristics differ significantly. Human taste buds are larger and taller than those of mice, yet they contain similar numbers of taste cells. Taste buds in humans are more heavily innervated by gustatory nerve fibers expressing the purinergic receptor P2X3 showing a 40% higher innervation density than in mice. Like Type II cells of mice, a subset (about 30%) of cells in human taste buds is immunoreactive for PLCβ2. These PLCβ2-immunoreactive cells display CALHM1-immunoreactive puncta closely apposed to gustatory nerve fibers suggestive of channel-type synapses in Type II cells in mice. These puncta, used as a measure of synaptic contact, are significantly larger in humans compared to mice suggesting a higher efflux of ATP neurotransmitter in humans. Altogether these findings suggest that while many similarities exist in the organization of murine and human fungiform taste buds, significant differences do exist in taste bud size, innervation density, and size of synaptic contacts that may impact gustatory signal transmission.

Gustatory dysfunction is an often overlooked symptom in people with multiple sclerosis (PwMS), potentially leading to poor appetite, malnutrition, weight loss, and decreased quality of life. This systematic review and meta-analysis aimed to assess the pooled prevalence of gustatory dysfunction in PwMS and compare their gustatory test scores with healthy controls. An online database search of PubMed, Embase, Scopus, and Web of Science was conducted on 2024 June 29. Observational studies reporting gustatory dysfunction or gustatory test scores in PwMS were included. Pooled prevalence rates were calculated using a random-effects model, with subgroup analyses based on the type of gustatory test used. Standardized mean differences (SMD) were calculated for comparisons between PwMS and healthy controls. A total of 9 studies encompassing 1385 PwMS were included. The pooled prevalence of gustatory dysfunction among PwMS was 16.4% (95% confidence intervals [95% CI]: 8.7% to 24.1%, I² = 90%, P < 0.01). Subgroup analysis showed a prevalence of 18.8% (95% CI: 10.5% to 27.2%, I² = 0%) in 4 studies using the Taste Strip Test (TST), while 3 non-TST studies using liquid tastants or self-reports reported a prevalence of 20.2% (95% CI: 7.2% to 33.3%, I² = 86%). PwMS had significantly lower gustatory test scores compared to healthy controls (SMD: -0.93, 95% CI: -1.20 to -0.65, I² = 0%, P = 0.48). Gustatory dysfunction affects a notable proportion of PwMS, with prevalence rates varying by assessment method. Future studies should assess the possible causes of gustatory dysfunction in PwMS using validated gustatory assessment scales.

Although animals can reliably locate and recognize odorants embedded in complex environments, the neural circuits for accomplishing these tasks remain incompletely understood. Adaptation is likely to be important as it could allow neurons in a brain area to adjust to the broader sensory environment. Adaptive processes must be flexible enough to allow the brain to make dynamic adjustments, while maintaining sufficient stability so that organisms do not forget important olfactory associations. Processing within the mouse olfactory bulb is likely involved in generating adaptation, although there are conflicting models of how it transforms the glomerular output of the mouse olfactory bulb. Here we performed 2-photon Ca2+ imaging from mitral/tufted glomeruli in awake mice to determine the time course of recovery from adaptation, and whether it acts broadly or selectively across the glomerular population. Individual glomerular responses, as well as the overall population odor representation were similar across imaging sessions. However, odor-concentration pairings presented with interstimulus intervals upwards of 30-s evoked heterogeneous adaptation that was concentration-dependent. We demonstrate that this form of adaptation is unrelated to variations in respiration, and olfactory receptor neuron glomerular measurements indicate that it is unlikely to be inherited from the periphery. Our results indicate that the olfactory bulb output can reliably transmit stable odor representations, but recent odor experiences can selectively shape neural responsiveness for upwards of 30 seconds. We propose that neural circuits that allow for non-uniform adaptation across mitral/tufted glomeruli could be important for making dynamic adjustments in complex odor environments.

A common tool to measure olfactory function is the Sniffin' Sticks Test extended version (SSET). The SSET evaluates olfactory ability by summing the scores of three subtests: Threshold, Discrimination, and Identification. Recent meta-scientific literature revealed that many psychometric instruments currently in use have not been adequately validated, leading to a measurement crisis that raises concerns about the validity of the conclusions drawn with these instruments. Two examples of the measurement crisis are (i) the use of sum scores without testing their assumptions (e.g. unidimensionality and tau-equivalence), which indicate that all subtests have the same, stable relationship with their underlying construct, and (ii) the lack of assessment of measurement invariance across groups. Here, we aim to investigate the unidimensionality and tau-equivalence assumptions, internal consistency, and measurement invariance of sex and age groups of the SSET. We tested 988 (555 females, mean ± SD: 39.75 ± 18.60 years) participants with the Italian version of the SSET. The tau-equivalent model demonstrated excellent fit indices (CFI robust = 1, TLI robust = 1, RMSEA robust = 0, SRMR = 0.013), which best explain the data, indicating that all subtests are equally important in measuring olfactory function, but not necessarily equally precise. The results also revealed full measurement invariance across age groups and configural, partial metric, and scalar invariance across sexes, indicating that the use of latent means to compare sex groups should be chosen over raw scores. However, the SSET demonstrated moderate internal consistency. Future studies should clarify whether the reliability of the SSET can be increased.

Astringency, commonly described as a drying, roughening, and/or puckering sensation associated with polyphenol-rich foods affects their palatability. While the compounds eliciting astringency are known, its mechanism of action is debated. This study investigated the role of transient receptor potential (TRP) channels A1 and V1 in astringency perception. If TRP A1 or V1 have a functional role in astringency perception, then desensitizing these receptors should decrease perceived astringency. Thirty-seven panelists underwent unilateral lingual desensitization of TRP A1 and V1 channels using mustard oil and capsaicin, respectively. Panelists then evaluated four astringent stimuli: epicatechin (EC), epigallocatechin gallate (EGCG), tannic acid (TA), and potassium alum (Alum), via 2-AFC and intensity ratings. When TRPA1 receptors were desensitized on one half of the tongue via mustard oil, no significant differences were observed between the treated and untreated sides for both 2-AFC and intensity ratings. Similarly, when TRPV1 receptors were desensitized on one half of the tongue via capsaicin, no significant differences were observed between the treated and untreated sides for both 2-AFC and intensity ratings. These findings challenge the notion that TRP channels play a pivotal role in astringency perception.

Most patients report "taste" changes after undergoing metabolic surgeries. Yet, most studies that used validated sensory evaluation techniques, including ours, found no changes in perceived taste intensity from before to after surgery. However, we assessed participants with pure gustatory stimuli and after an overnight fast, which raises questions about whether patients' self-reported "taste" changes are due to conflating changes in retronasal smell/"flavor" with taste changes or whether they only manifest during the fed state. To investigate this, we conducted a cross-sectional study comparing sensory responses in women who underwent metabolic surgery 2 to 6 yr ago (n = 15) with 2 nonoperated control groups: one with a body mass index (BMI) equivalent (n = 15) and one with a healthy BMI (n = 15). Participants attended 2 sessions, one fed and one fasted. Using a sip-and-spit method, women tasted liquid samples containing gustatory and olfactory stimuli and puddings with varying fat content with and without nose clips. They used separate general labeled magnitude scales to rate their perceived intensity of taste, smell, flavor, and liking. Mixed ANOVAs indicated that the surgery and BMI equivalent groups rated retronasal smell intensity of coffee stronger than the healthy BMI group (P ≤ 0.015). However, there were no differences in taste/flavor intensity or liking ratings among groups. Additionally, feeding conditions did not significantly affect perceived intensity ratings. Our findings suggest that changes in the sensory-discriminatory component of taste or taste-odor interactions are not significant contributors to dietary modifications following metabolic surgery.

Self-reported measures emerge as potential indicators for early detection of dementia and mortality. We investigated the predictive value of different self-reported measures, including subjective cognitive decline (SCD), subjective olfactory impairment (SOI), subjective taste impairment (STI), and self-reported poor health (SPH), in order to determine the risk of progressing to Alzheimer's disease (AD) dementia, Parkinson's disease (PD) dementia, or any-other-cause dementia. A total of 6,028 cognitively unimpaired individuals from the 8th wave of the English Longitudinal Study of Ageing (ELSA) were included as the baseline sample and 5,297 individuals from the 9th wave were included as 2-year follow-up sample. Self-rated measures were assessed using questions from the ELSA structured interview. Three logistic regression models were fitted to predict different the dementia outcomes. SCD based on memory complaints (OR = 11.145; P < 0.001), and older age (OR = 1.108, P < 0.001) significantly predicted the progression to AD dementia at follow-up. SOI (OR = 7.440; P < 0.001) and older age (OR = 1.065, P = 0.035) significantly predicted the progression to PD dementia at follow-up. Furthermore, SCD based on memory complaints (OR = 4.448; P < 0.001) jointly with complaints in other (non-memory) mental abilities (OR = 6.662; P < 0.001), and older age (OR = 1.147, P < 0.001) significantly predicted the progression to dementia of any other cause. Different types of complaints are specifically associated with different dementia outcomes. Our study demonstrates that self-reported measures are a useful and accessible tool when screening for individuals at risk of dementia in the general population.

Postprandial regulation of the gastric emptying (GE) rate plays an important role in food intake. Although oral sweetening with glucose may accelerate GE, the effects of different sweetness intensities of glucose (10% and 20%, w/v) and other energy sweeteners (e.g. fructose and sucrose) remain uncertain. The purpose of this study was to determine the effects of different glucose concentrations (Experiment 1) and different sugars with the same sweet taste intensity (Experiment 2) on postprandial GE. In both experiments, after ingesting a 200 kcal carbohydrate solution containing 50 g of maltodextrin, participants repeatedly sipped, but did not swallow, one of three (water, 10% and 20%, w/v glucose) or four (water and equally sweet 20%, w/v glucose, 12%, w/v fructose, and 14%, w/v sucrose) solutions for 1 min every 5 min over a 30 min period. GE was evaluated by measuring the temporal change in the cross-sectional area of the gastric antrum using ultrasound. In Experiment 1, oral stimulation with 20% (w/v) glucose resulted in greater GE than the control stimulus (i.e. water), but the effect of stimulation with 10% (w/v) glucose on GE was not different from that of the control stimulus. In Experiment 2, stimulation with 20% (w/v) glucose or 12% (w/v) fructose resulted in greater GE than the control stimulus. However, the effect of stimulation with 14% (w/v) sucrose on GE did not differ from that of the control stimulus. Consequently, oral stimulation with glucose or fructose solutions of moderate to high sweetness following a meal facilitates postprandial GE.

Olfactory perception begins when odorous substances interact with specialized receptors located on the surface of dedicated sensory neurons. The recognition of smells depends on a complex mechanism involving a combination of interactions between an odorant and a set of odorant receptors (ORs), where molecules are recognized according to a combinatorial activation code of ORs. Although these interactions have been studied for decades, the rules governing this ligand recognition remain poorly understood, and the complete combinatorial code is only known for a handful of odorants. We have carefully analyzed experimental results regarding the interactions between ORs and molecules to provide a status report on the deorphanization of ORs, i.e. the identification of the first agonist for a given sequence. This meticulous analysis highlights the influence of experimental methodology (cell line or readout) on molecule-receptor association results and shows that 83% of the results are conserved regardless of experimental conditions. The distribution of another key parameter, EC50, indicates that most OR ligand activities are in the micromolar range and that impurities could lead to erroneous conclusions. Focusing on the human ORs, our study shows that 88% of the documented sequences still need to be deorphanized. Finally, we also estimate the size of the ORs' recognition range, or broadness, as the number of odorants activating a given OR. By analogously estimating molecular broadness and combining the two estimates we propose a basic framework that can serve as a comparison point for future machine learning algorithms predicting OR-molecule activity.

Transient or persistent hypo-anosmia is common in SARS‑CoV‑2 infection but olfactory pathway late-term morphometric changes are still under investigation. We evaluated late olfactory bulb (OB) imaging changes and their correlates with the olfactory function in otherwise neurologically asymptomatic COVID-19 patients. Eighty-three subjects (mean-age 43 ± 14 yr; 54 females; time-interval infection/MRI: 129±68 d) were affected by asymptomatic to mild COVID-19 in 2020 and 25 healthy controls (mean-age 40 ± 13 yr; 9 females) underwent 3T-MRI and olfactory function evaluation through anamnestic questionnaire and Sniffin' Sticks. Exclusion criteria were intensive care treatment or neurological involvement other than olfaction. Maximal OB area was measured blindly on high-resolution coronal T2w images by 2 observers. Patients were subdivided into (i) persistently hypo/anosmic, (ii) recovered normosmic, and (iii) never complaining smell dysfunction with proven normal olfactory function. No significant differences were observed among patients' subgroups (P = 0.76). Intraobserver and interobserver reliability were high (r = 0.96 and 0.86). Former COronaVIrus Disease 19 (COVID-19) patients had decreased mean maximal OB area than controls (6.52 ± 1.11 mm2 vs. 7.26 ± 1.17 mm2, P = 0.008) even when considering persistently hypo-anosmic (6.46 ± 0.90, P = 0.006) or normosmic patients at MRI (6.57 ± 1.25, P = 0.04). SARS-CoV-2 infection is associated with mid/late-term morphological changes in the OB, regardless of presence or persistence of olfactory dysfunction. The long-term consequences on olfactory aging need to be further investigated including possible links with neurodegenerative disorders.

Sweeteners are used in the food industry to provide sweetness similar to sugar and to decrease the caloric intake and risks associated with obesity. However, some sweeteners are characterized by bitter, metallic and other off-tastes. Sensory and cellular studies have demonstrated synergies between sweetener blends, which are responsible for enhancing sweetness. This study aimed to identify new sweetener blends that are able to enhance sweetness intensity without causing bitter off-taste using in vitro functional expression of taste receptors. The dose-response of the sweet taste receptor (TAS1R2/TAS1R3) was determined for sucrose and 9 sweeteners and was consistent with their sweetness potency. Stimulation of TAS1R2/TAS1R3 by 6 binary sweetener blends confirmed 3 known synergies determined by sensory analysis, including sucralose/acesulfame-K, rebaudioside A/erythritol and rebaudioside A/thaumatin, and revealed 2 new synergies, known as, neotame/D-allulose and mogroside V/thaumatin. No synergy was observed for the rebaudioside M/mogroside V blend, probably due to their common binding sites on the sweet taste receptor. The ability of the 9 selected sweeteners to activate the 25 human bitter taste receptors (TAS2Rs) was tested. The cellular-based assay demonstrated that sucralose, acesulfame-K, rebaudioside A, mogroside V and D-allulose activated at least 2 TAS2Rs. Sucralose, acesulfame-K and rebaudioside A exhibited lower EC50 values for TAS1R2/TAS1R3 than for TAS2Rs, which may explain their absence of bitter off-taste at low concentrations, unlike mogroside V and D-allulose. Our data provide a receptor-based understanding of the complex synergies among sweetener blends and an effective approach for testing new sweeteners while avoiding the activation of TAS2Rs.

Former American football players are at risk for developing traumatic encephalopathy syndrome (TES), the clinical disorder associated with neuropathologically diagnosed chronic traumatic encephalopathy (CTE). The objective of this study was to determine whether hyposmia is present in traumatic encephalopathy syndrome. The study included 119 former professional American football players, 60 former college football players, and 58 same-age asymptomatic unexposed men from the DIAGNOSE CTE Research Project. All subjects included in the analysis had completed the Brief Smell Identification Test (B-SIT). Traumatic encephalopathy syndrome and the level of CTE certainty were diagnosed using the 2021 NINDS consensus diagnostic criteria. TES is categorized antemortem by provisional levels of increasing CTE certainty: Suggestive, Possible, and Probable. Former players who had traumatic encephalopathy syndrome and Probable CTE had lower B-SIT scores than those with TES and Suggestive CTE. Hyposmia was more likely in the former players with TES who were either CTE Possible or Probable than in those who did not have TES or had TES but were less likely to have CTE, or CTE Suggestive. There was no difference in B-SIT scores between all former players versus unexposed men nor overall between the football players with and without TES. We conclude that lower B-SIT scores may be a clinical biomarker for underlying CTE in former American football players.

In insects, olfactory receptor neurons (ORNs) are localized in sensilla. Within a sensillum, different ORN types are typically co-localized and exhibit nonsynaptic reciprocal inhibition through ephaptic coupling. This inhibition is hypothesized to aid odor source discrimination in environments where odor molecules (odorants) are dispersed by wind, resulting in turbulent plumes. Under these conditions, odorants from a single source arrive at the ORNs synchronously, while those from separate sources arrive asynchronously. Ephaptic inhibition is expected to be weaker for asynchronous arriving odorants from separate sources, thereby enhancing their discrimination. Previous studies have focused on ephaptic inhibition of sustained ORN responses to constant odor stimuli. This begs the question of whether ephaptic inhibition also affects transient ORN responses and if this inhibition is modulated by the temporal arrival patterns of different odorants. To address this, we recorded co-localized ORNs in the fruit fly Drosophila melanogaster and exposed them to dynamic odorant mixtures. We found reciprocal inhibition, strongly suggesting the presence of ephaptic coupling. This reciprocal inhibition does indeed modulate transient ORN responses and is sensitive to the relative timing of odor stimuli. Notably, the strength of inhibition decreases as the synchrony and correlation between arriving odorants decrease. These results support the hypothesis that ephaptic inhibition aids odor source discrimination.

Mammalian taste buds are highly regenerative and can restore themselves after normal wear and tear of the lingual epithelium or following physical and chemical insults, including burns, chemotherapy, and nerve injury. This is due to the continual proliferation, differentiation, and maturation of taste progenitor cells, which then must reconnect with peripheral gustatory neurons to relay taste signals to the brain. The turnover and re-establishment of peripheral taste synapses are vital to maintain this complex sensory system. Over the past several decades, the signal transduction and neurotransmitter release mechanisms within taste cells have been well delineated. However, the complex dynamics between synaptic partners in the tongue (taste cell and gustatory neuron) are only partially understood. In this review, we highlight recent findings that have improved our understanding of the mechanisms governing connectivity and signaling within the taste bud and the still-unresolved questions regarding the complex interactions between taste cells and gustatory neurons.

The olfactory nerve, also known as cranial nerve I, is known to have exclusive ipsilateral projections to primary olfactory cortical structures. However, the lateralization of olfactory processes is known to depend on the task and nature of stimuli. It still remains unclear whether olfactory system projections in humans also correspond to functional pathways during olfactory tasks without any trigeminal, perceptual, or cognitive-motor components. Twenty young healthy subjects with a normal sense of smell took part in an olfactory functional magnetic resonance imaging (fMRI) study. We used 2 types of nostril-specific stimulation, passive (no sniffing), and active (with sniffing), with phenyl ethyl alcohol, a pure olfactory stimulant, to investigate fMRI activity patterns in primary and secondary olfactory-related brain structures. Irrespective of the stimulated nostril and the type of stimulation, we detected symmetrical activity in primary and secondary olfactory-related brain structures such as the primary olfactory cortex, entorhinal cortex, and orbitofrontal cortex. In the absence of perceptual or cognitive-motor task demands, the perception of monorhinally presented pure odors is processed bilaterally in the brain.

Experience plays a pivotal role in determining our food preferences. Consuming food generates odor-taste associations that shape our perceptual judgements of chemosensory stimuli, such as their intensity, familiarity, and pleasantness. The process of making consummatory choices relies on a network of brain regions to integrate and process chemosensory information. The mediodorsal thalamus is a higher-order thalamic nucleus involved in many experience-dependent chemosensory behaviors, including olfactory attention, odor discrimination, and the hedonic perception of flavors. Recent research has shown that neurons in the mediodorsal thalamus represent the sensory and affective properties of experienced odors, tastes, and odor-taste mixtures. However, its role in guiding consummatory choices remains unclear. To investigate the influence of the mediodorsal thalamus in the consummatory choice for experienced odors, tastes, and odor-taste mixtures, we pharmacologically inactivated the mediodorsal thalamus during 2-bottle brief-access tasks. We found that inactivation altered the preference for specific odor-taste mixtures, significantly reduced consumption of the preferred taste and increased within-trial sampling of both chemosensory stimulus options. Our results show that the mediodorsal thalamus plays a crucial role in consummatory decisions related to chemosensory preference and attention.

Studies on taste bud cells and brain stem relay nuclei suggest that alternative pathways convey information regarding different taste qualities. Building on the hypothesis that amiloride (epithelial Na channel antagonist)-sensitive neurons respond to palatable salt (low-concentration) and amiloride-insensitive neurons respond to aversive salt (high-concentration), we investigated the histological distribution of taste-sensitive neurons in the rostral nucleus of the solitary tract in rats and their NaCl and amiloride sensitivities. We recorded neuronal activity in extracellular single units using multi-barrel glass micropipettes and reconstructed their locations on the rostrocaudal and mediolateral axes. Seventy-three taste-sensitive neurons were categorized into the best-taste category. The amiloride sensitivities of the 31 neurons were examined for 0.1, 0.2, 0.4, and 0.8 M NaCl. The neuronal distribution of amiloride-sensitive neurons was located in the lateral region, while amiloride-insensitive neurons were located in the medial region. The amiloride-sensitive neurons responded to low salt concentrations, signaling the NaCl levels required by body fluids. Amiloride-insensitive neurons were silent at low salt concentrations but may function as warning signals for high salt concentrations. Low-threshold and/or high-response neurons were located in the rostrolateral region. In contrast, high-threshold and/or low-response neurons were located in the caudal-medial region.

SCENTinel, a rapid smell test designed to screen for olfactory disorders, including anosmia (no ability to smell an odor) and parosmia (distorted sense of smell), measures 4 components of olfactory function: detection, intensity, identification, and pleasantness. Each test card contains one of 9 odorant mixtures. Some people born with genetic insensitivities to specific odorants (i.e. specific anosmia) may fail the test if they cannot smell an odorant but otherwise have a normal sense of smell. However, using odorant mixtures has largely been found to prevent this from happening. To better understand whether genetic differences affect SCENTinel test results, we asked genetically informative adult participants (twins or triplets, N = 630; singletons, N = 370) to complete the SCENTinel test. A subset of twins (n = 304) also provided a saliva sample for genotyping. We examined data for differences between the 9 possible SCENTinel odors; effects of age, sex, and race on SCENTinel performance, test-retest variability; and heritability using both structured equation modeling and SNP-based statistical methods. None of these strategies provided evidence for specific anosmia for any of the odors, but ratings of pleasantness were, in part, genetically determined (h2 = 0.40) and were nominally associated with alleles of odorant receptors (e.g. OR2T33 and OR1G1; P < 0.001). These results provide evidence that using odorant mixtures protected against effects of specific anosmia for ratings of intensity but that ratings of pleasantness showed effects of inheritance, possibly informed by olfactory receptor genotypes.

The Social Odor Scale (SOS) is a 12-item questionnaire initially developed and validated in Italian and German to investigate self-reported awareness of social odors, which are odors emanating from the human body that convey diverse information and evoke various emotional responses. The scale includes a total score and 3 subscales representing social odors in the respective categories: romantic partner, familiar, and strangers. Here, we aimed to (i) replicate the validation of the Italian and German versions of the SOS, (ii) translate and validate the SOS into multiple additional languages (French, English, Dutch, Swedish, Chinese), and (iii) explore whether the factor structure of each translated version aligns with the original versions. Confirmatory Factor Analysis (CFA) supported the scale's structure, yielding a good fit across all languages. Notable differences in SOS mean scores were observed among the different languages: Swedish participants exhibited lower social odor awareness compared to the other groups, whereas Chinese participants reported higher social odor awareness compared to Dutch and Swedish participants. Furthermore, SOS scores correlated with respondents' geographical location, with higher (i.e. northern) latitudes linked to lower social odor awareness. These results corroborate the SOS as a valid and reliable instrument, especially for the SOS total score and the Familiar and Partner factors, emphasizing the influence of individual and geographic factors on social odor awareness.