Table 2.

Studies with human models of inflammation and their taste consequences from 2016 to 2020

Reference	Study objective	Study design	Model	Measures	Results	Conclusions
Kaufman et al. (2020) [7]	Investigating changes in human taste bud abundance in increased bodyweight individuals non-invasively.	Taste buds counting from humans enrolled in a longitudinal study designed to measure college weight gain were counted	n = 49 (39 F, 10 M) subjects originally aged 17–18. Measurements obtained during freshman year and again 4 years later	Neck circumference measured as a proxy for bodyweight along with BMI, fungiform TBs counted..	Change in fungiform density inversely correlated with neck circumference. R = −0.374, p = 0.008	Although not a direct measure of taste buds per se`, taste papillae were diminished with increasing neck circumference, an accepted measure of adiposity.
Schalk et al. (2018) [15]	Investigating the contribution of cancer, its treatment, inflammation resulting from either, and concomitant taste-dysfunction on malnutrition	Measure taste, inflammation and effect of chemotherapy on each in patients with cancer.	138 patients, mean age 65.2 in three groups. Group 1: 42 patients hospitalized due to cancer undergoing chemotherapy Group 2: 57 patients hospitalized for an acute inflammatory disease without malignancy Group 3: 39 healthy study participants	Sniffin’ Sticks for olfaction, recognition taste test for 5 basic tastes. Detection and recognition threshold recorded.	No significant difference between patients with or without chemotherapeutical treatment. Recognition and detection thresholds were significantly different between hospitalized patients and healthy controls. Cancer patients and hospitalized patients with inflammatory disease both exhibited taste dysfunction versus healthy controls. Inflammatory status as measured by CRP and leukocyte count did not directly associated with changes in taste	Inflammation, not chemotherapy, impacted taste function. As specific measures of inflammation did not correlate with taste dysfunction, mechanism is likely mediated through other proinflammatory cytokines (not CRP/leukocytes).
Archer et al. (2018) [5]	Determine whether there is a difference in molecular makeup of taste tissue in lean and obese individuals.	RNA transcript analysis of fungiform TB biopsies	Human Female Caucasians, lean (n = 23) and obese (n = 13) BMI >30	Fungiform papillae counting, RNA-seq	No difference in papillae count. Highly divergent gene expression: PLCβ2& Sonic Hedge Hog (SHH) ↓in obese vs lean Top ↑pathways associated with immune and inflammatory response. Generally ↓ expression of taste genes in obese, mostly type II.	Evidence in humans that immune and taste gene expression is altered in obese vs lean individuals.
Noel et al. (2017) [16]	Investigate relationship between reduced sweet taste function and sweet solution intake	Participants had sweet taste inhibited and performed ad-libitum mixing task to an optimal sweetness level, along with tasting various sweet foods	Repeated session with Gymnema sylvestre(GS) to inhibit sweet taste function to varying levels versus blank in 51 participants	gLMS ratings of sweetness with various levels of GS, compared with liking of sweet foods, plus ideal concentration of sugar in beverage from ad lib mixing task.	GS reduced sweet taste significantly vs control. Reduction in intensity perception was associated with an increase in desired sucrose in the ad-libitum mixing task. An incremental 1% reduction in rated sweetness intensity corresponded to a 0.4 g/L increase in desired sucrose.	Weakened sense of sweet taste was associated with an increased desire for sweeter beverages. Taste damage may thus lead to the desire for more energy dense foods.
Adappa et al. (2016) [17]	Investigate T2R38 phenotype status on biofilm formation in patients with chronic rhinosinusitis (CRS)	Recruit CRS positive patients with evidence of immune activation, genotype, taste tests, and biofilm assay.	Human subjects >18 yrs (M and F), immune competent CRS patients with evidence of sinonasal inflammation. 59 subjects	13 point PTC taste test, biofilm formation assay, T2R38 genotyping	PTC taste score correlates with biofilm formation in patients without polyps (p = 0026). Increasing PTC taste score was inversely correlated with biofilm formation in nonpolyploid patients.	Increased T2R38 expression in the airway may be associated with a reduction in biofilm formation.