The bacterial species profiles of the lingual and salivary microbiota differ with basic tastes sensitivity in human.

Taste perception is crucial and impairments, which can be linked to pathologies, can lead to eating disorders. It is triggered by taste compounds stimulating receptors located on the tongue. However, the tongue is covered by a film containing saliva and microorganisms suspected to modulate the taste receptor environment.

Alterations in the Oral Microbiome Associated With Diabetes, Overweight, and Dietary Components.

The Mediterranean diet (MedDiet) represents the traditional food consumption patterns of people living in countries bordering the Mediterranean Sea and is associated with a reduced incidence of obesity and type-2 diabetes mellitus (T2DM). The objective of this study was to examine differences in the composition of the oral microbiome in older adults with T2DM and/or high body mass index (BMI) and whether the microbiome was influenced by elements of a MedDiet. Using a nested case-control design individuals affected by T2DM were selected from the Seniors-ENRICA-2 cohort concurrently with non-diabetic controls.

Impact of Very Hot Drink Consumption Habits, Age, and Sex, on Taste Sensitivity.

The temperature range for consuming hot drinks includes temperatures that can damage cells on the tongue. We hypothesized that the consumption of very hot drinks can lead to a decrease in the ability to perceive low concentrations of tastants. We evaluated the ability to perceive low concentrations of five prototypical sapid compounds in 42 women and 40 men aged 18-65.

The salivary proteome reflects some traits of dietary habits in diabetic and non-diabetic older adults.

Purpose: Objective markers of usual diet are of interest as alternative or validating tools in nutritional epidemiology research. The main purpose of the work was to assess whether saliva protein composition can reflect dietary habits in older adults, and how type 2 diabetes impacted on the saliva-diet correlates.

Methods: 214 participants were selected from 2 European cohorts of community-dwelling older adults (3C-Bordeaux and Seniors-ENRICA-2), using a case-control design nested in each cohort.

The role of overweight in the association between the Mediterranean diet and the risk of type 2 diabetes mellitus: a mediation analysis among 21 585 UK biobank participants.

Background: There is growing evidence that the Mediterranean (Medi) diet may lower the risk of type 2 diabetes mellitus (T2DM). Whether this association is due to the Medi diet by itself or is mediated by a diet-associated lower rate of overweight is uncertain. Our aim was to disentangle these relationships among UK adults.

Longitudinal analysis of the salivary metabolome of breast-fed and formula-fed infants over the first year of life.

Introduction: The salivary metabolome has been increasingly studied over the past ten years due to the potential of saliva as a non-invasive source of biomarkers. However, although saliva has been studied in relation to various diseases, its dynamic evolution during life is not known. This is particularly true for the first months of life.

Biological films adhering to the oral soft tissues: Structure, composition, and potential impact on taste perception.

The role of free-flowing saliva in taste perception is increasingly recognized, but saliva is also present in the mouth as films intimately associated to soft or hard tissues. On mucosal surfaces, particularly on the tongue, the structure and composition of such films (including its microbial constitutive part) may play a particular role in the sense of taste due to their proximity with the taste anatomical structures. This review compiles the current knowledge on the structure of biological films adhering to oral mucosae and on their biochemical and microbiological composition, before presenting possible implications for taste perception.

How are macronutrient intake, BMI, ethnicity, age, and gender related to the composition of unstimulated saliva? A case study.

This study investigated how macronutrient intake, BMI, ethnicity, age, and gender are related to the composition of unstimulated saliva. First, two groups of Caucasian, Dutch subjects varying in daily intake of carbohydrate, fat, and protein were selected. The daily intake of macronutrients differed by two- to threefold between the low (n = 14) and high (n = 16) macronutrient intake groups.

The Associations between Biochemical and Microbiological Variables and Taste Differ in Whole Saliva and in the Film Lining the Tongue.

The objective of this work was to investigate whether the biological film lining the tongue may play a role in taste perception. For that purpose, the tongue film and saliva of 21 healthy subjects were characterized, focusing on microorganisms and their main metabolic substrates and products. In parallel, taste sensitivity was evaluated using a test recently developed by our group, and the links between biological and sensory data were explored by a correlative approach.

The basal free fatty acid concentration in human saliva is related to salivary lipolytic activity.

Fat perception during eating is a complex sensation that involves various sensory modalities, such as texture, aroma and taste. Taste is supported by the discovery of fatty acid receptors in the tongue papillae. Dietary fat is mainly composed of esterified fatty acids, whereas only free fatty acids can bind to taste receptors.

Associations between food consumption patterns and saliva composition: Specificities of eating difficulties children.

Identifying objective markers of diet would be beneficial to research fields such as nutritional epidemiology. As a preliminary study on the validity of using saliva for this purpose, and in order to explore the relationship between saliva and diet, we focused on clearly contrasted groups of children: children with eating difficulties (ED) receiving at least 50% of their energy intake through artificial nutrition vs healthy controls (C). Saliva of ED and C children was analyzed by various methods (targeted biochemical analyses, 2-D electrophoresis coupled to MS, H NMR) and their diet was characterized using food frequency questionnaires, considering 148 food items grouped into 13 categories.

Salivary Composition Is Associated with Liking and Usual Nutrient Intake.

Salivary flow and composition have an impact on flavor perception. However, very few studies have explored the relationship between saliva, individual liking and usual dietary intake. The aim of our study was to evaluate the association of salivary flow and composition with both a liking for fat, saltiness and sweetness and the usual nutrient intake in an adult French population.

Multi-omics profiling reveals that eating difficulties developed consecutively to artificial nutrition in the neonatal period are associated to specific saliva composition.

Prolonged enteral or parenteral nutrition in neonatal periods sometimes results in eating difficulties persisting for years, with reduced food intake through the oral route and thereby reduced stimulation of the oral cavity. Aiming at describing the consequences on oral physiology, saliva of 21 children with eating difficulties (ED) was compared to that of 23 healthy controls, using various omics and targeted methods. Overall, despite heterogeneity within the groups (age, medication etc.

Nutri-metabolomics applied to taste perception phenotype: human subjects with high and low sensitivity to taste of fat differ in salivary response to oleic acid.

Saliva has different functions in the mouth and is involved, for example, in taste perception. Saliva composition can also be modified rapidly by taste stimulation. It remains unclear, however, whether the perceived intensity of a tastant may modulate this response.

Role of saliva in oral food perception.

Saliva is the first fluid that comes into contact with food during oral processing. Because saliva is the medium that bathes the taste receptors, is the fluid through which taste and aroma compounds are released into the oral cavity and is mixed continuously with food during bolus formation, it is an essential actor in oral chemosensory perception. The complexity of saliva composition, with compounds originating from different salivary glands, from gingival crevicular fluid, from micro-organisms and from food debris, together with its variable nature increases the possibilities for interactions with food compounds and for different roles in perception.

Variability of human saliva composition: possible relationships with fat perception and liking.

Saliva is the medium that bathes the taste receptors in the oral cavity and in which aroma and taste compounds are released when food is eaten. Moreover saliva contains enzymes and molecules that can interact with food. To date, little research has been devoted to the intra- and inter-individual variabilities of these components and their inter-relationships.

Effects of sucrose on salivary flow and composition: differences between real and sham intake.

Human saliva contains numerous salivary components that are fundamental for a healthy oral environment and the oral processing of foods. To study a possible differential influence of orosensory stimulation and metabolic activation on salivary composition, human parotid salivary flow, pH, A(280), and alpha-amylase activity were measured before, during and after real or sham (sip-and-spit) sucrose intakes. Variations in these salivary characteristics were related to perceived satiety.

Proteomic analysis of human whole and parotid salivas following stimulation by different tastes.

Whole and parotid salivas, collected after stimulation with tastants, were analyzed by 2D electrophoresis and mass spectrometry. In whole saliva, the number of proteins affected by taste stimulation increased in the order sweet < umami < bitter < acid. Annexin A1 and calgranulin A, involved in inflammation, were over-represented after umami, bitter, and sour stimulations.

Relating ionisation of calcium chloride in saliva to bitterness perception.

Saliva plays a role in the perception of bitter, sour and salty tastes that are presumed to be derived from the concentration of free cations or anions ions dissolved in saliva. The role of ionisation of calcium in bitter taste was studied by determining binding in vitro mixture of saliva and protein solutions and in spit. In vitro, the addition of whey to calcium chloride solutions increased the calcium binding, pH and viscosity.

NaCl and sugar release, salivation and taste during mastication of salted chewing gum.

Salt perception impacts on food acceptability and nutrition and depends upon salt release from foods that was determined in situ during mastication of chewing gum with up to 10% (1800 mmol/kg) added NaCl. The mechanical action of chewing increased salivation, which was further increased by the presence of salt, particularly above 180 mmol NaCl/kg gum or above 100 mM NaCl in saliva. The average resting salivary flow rate was 1 ml/min, increasing to 4 and 6 ml/min with gums containing low and high salt, respectively.