Olfaction in the Multisensory Processing of Faces: A Narrative Review of the Influence of Human Body Odors

A recent body of research has emerged regarding the interactions between olfaction and other sensory channels to process social information. The current review examines the influence of body odors on face perception, a core component of human social cognition. First, we review studies reporting how body odors interact with the perception of invariant facial information (i.e., identity, sex, attractiveness, trustworthiness, and dominance). Although we mainly focus on the influence of body odors based on axillary odor, we also review findings about specific steroids present in axillary sweat (i.e., androstenone, androstenol, androstadienone, and estratetraenol). We next survey the literature showing body odor influences on the perception of transient face properties, notably in discussing the role of body odors in facilitating or hindering the perception of emotional facial expression, in relation to competing frameworks of emotions. Finally, we discuss the developmental origins of these olfaction-to-vision influences, as an emerging literature indicates that odor cues strongly influence face perception in infants. Body odors with a high social relevance such as the odor emanating from the mother have a widespread influence on various aspects of face perception in infancy, including categorization of faces among other objects, face scanning behavior, or facial expression perception. We conclude by suggesting that the weight of olfaction might be especially strong in infancy, shaping social perception, especially in slow-maturing senses such as vision, and that this early tutoring function of olfaction spans all developmental stages to disambiguate a complex social environment by conveying key information for social interactions until adulthood.

Dynamics of the Gut Microbiota in MEBO and PATM conditions: Protocol of a fully remote clinical study

Human odor-prints, mostly owing to the microbiome, have proven their value as biomarkers of health and environmental exposures. In recent years, microbial networks responsible for localized malodors - such as intra-oral halitosis, neck, foot and axillary odor - have been mapped by using next generation sequencing approaches. Intestinal microbes responsible for psychologically debilitating systemic malodor (whole-body including extraoral halitosis), however, remain to be identified. Even a relatively straightforward disorder of choline metabolism trimethylaminuria (TMAU) is thought to exhibit complex host-gene microbiome interactions and its microbial dynamics has not been sufficiently studied. Mapping gut microbiome is needed to understand human metabolic disfunction, make proper dietary recommendations and develop targeted treatments such as microbial therapies. Our preliminary analysis of culture-, PCR- and 16S-RNA-based data found several Operational Taxonomic Units (OTUs) potentially linked to systemic malodor. Proposed controlled pilot study will provide a more comprehensive evaluation and, combined with our prior data, will help to develop new therapies and treatments.

Comparison of the Effect of Combined Cardiovascular Dexmedetomidine and Propofol in Minimally Invasive axillary Odor Surgery with Tumescent Anesthesia

Objective: The effects of combined dexmedetomidine hydrochloride and propofol in minimally invasive axillary odor surgery with tumescent anesthesia. Methods: A total of 46 patients underwent minimally invasive axillary odor surgery by tumescent anesthesia received in the hospital from May 2017 to January 2019 were divided into observation group (23 cases) and control group (23 cases) according to the random number table method. The control group used propofol, and the observation group underwent minimally invasive axillary odor combined with dexmedetomidine hydrochloride by tumescent anesthesia. The changes of arterial blood pressure (MAP), heart rate (HR) and postoperative complications before and after anesthesia were compared and analyzed between the two groups. Results: After anesthesia, MAP and HR in both groups were lower than before anesthesia, and the observation group was lower than the control group, the difference was statistically significant (P<0.05). Compared with the control group, the postoperative complications were less in the observation group, but the difference was not statistically significant (P>0.05). Conclusion: Compared with the use of propofol, the effect of dexmedetomidine hydrochloride combined with minimally invasive axillary odor surgery by tumescent anesthesia is more obvious, and the postoperative recovery is faster with fewer complications.

Consumer Safety Considerations of Skin and Oral Microbiome Perturbation

SUMMARY Microbiomes associated with human skin and the oral cavity are uniquely exposed to personal care regimes. Changes in the composition and activities of the microbial communities in these environments can be utilized to promote consumer health benefits, for example, by reducing the numbers, composition, or activities of microbes implicated in conditions such as acne, axillary odor, dandruff, and oral diseases. It is, however, important to ensure that innovative approaches for microbiome manipulation do not unsafely disrupt the microbiome or compromise health, and where major changes in the composition or activities of the microbiome may occur, these require evaluation to ensure that critical biological functions are unaffected. This article is based on a 2-day workshop held at SEAC Unilever, Sharnbrook, United Kingdom, involving 31 specialists in microbial risk assessment, skin and oral microbiome research, microbial ecology, bioinformatics, mathematical modeling, and immunology. The first day focused on understanding the potential implications of skin and oral microbiome perturbation, while approaches to characterize those perturbations were discussed during the second day. This article discusses the factors that the panel recommends be considered for personal care products that target the microbiomes of the skin and the oral cavity.