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

Abstract

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.), the three spectral methods (MALDI-TOF, SELDI-TOF, 1 H NMR) allowed discriminating ED and controls, confirming that oral stimulation by food intake plays a role in shaping the composition of saliva. Saliva of ED patients exhibited a lower antioxidant status and lower levels of the salivary protease inhibitors cystatins. Other discriminant features (IgA1, dimethylamine) may relate to modified oral and/or intestinal microbial ecology. Finally, salivary profiles of ED patients were partly comparable to those of subjects with exacerbated gustatory sensitivities, in particular with reduced abundance of cystatin SN and higher abundance of zinc-alpha-2-glycoprotein. Whether this translates taste hypersensitivity and contributes to the eating difficulties deserves further attention.

Unstimulated saliva: Background noise in taste molecules

“…Metabolomics studies have revealed that saliva contains more than 800 inorganic and organic compounds, some of which are able to affect taste perception, as described above (Dame et al, 2015;Takeda et al, 2009). For instance, organic acids such as propionic, acetic or butyric acids, which are known to possess sensory attributes (Van Gemert, 2003), have been detected in the unstimulated saliva of both infants and adults (Morzel et al, 2015;Morzel et al, 2017;Mounayar et al, 2013Mounayar et al, , 2014. Although quantitative data on their salivary concentrations are available in metabolomics studies, with ranges from 0.14 AE 0.15 mM for butyric acid, to 4.8 AE 5.33 mM for acetic acid (Dame et al, 2015;Figueira et al, 2016;Park, Jang, Oh, & Kwon, 2014), their corresponding thresholds have essentially been measured as nasal perception.…”

Chewing bread: impact on alpha-amylase secretion and oral digestion

“…25,27,28 Total protein concentration (mg mL −1 ) was measured with a Bradford Quick Start protein assay (Bio-Rad, Hercules, CA, USA, ref: 500-0205), and bovine serum albumin (Sigma-Aldrich, Saint-Quentin Fallavier, France) was used as the calibration standard (0.1 to 1 g L −1 ). Saliva amylase activity was determined using the amylase CNPG3 assay kit (Biolabo, Maizy, France ref: 99123) after the samples were diluted by 1000.…”

A secret of salivary secretions: Multimodal effect of saliva in sensory perception of food

“…However, only few of the salivary proteins with their peculiar function contribute to the impact of saliva on food perception (Table 1). In addition to proteins, saliva contains a variety of low-molecular-weight compounds, such as ions (sodium, potassium, calcium, magnesium, chloride, bicarbonate, phosphate, fluoride), glucose, amino and fatty acids [5,64], as well as some organic acids, such as propionic, acetic, or butyric [60,65,66]. These compounds appear to regulate the sensitivity of taste receptors in the oral cavity and are thereby essential for the sensation of taste.…”