Publications - Gunter G. C. Kuhnle

Ottaviani, Javier I; Sagi-Kiss, Virag; Schroeter, Hagen; Kuhnle, Gunter GC

Reliance on self-reports and estimated food composition data in nutrition research introduces significant bias that can only be addressed with biomarkers Journal Article

In: eLife, vol. 13, pp. RP92941, 2024.

Abstract | Links | BibTeX | Tags: biomarkers, dietary assessment, epicatechin, flavanols, nitrate

@article{ottaviani2024reliance,

title = {Reliance on self-reports and estimated food composition data in nutrition research introduces significant bias that can only be addressed with biomarkers},

author = {Javier I Ottaviani and Virag Sagi-Kiss and Hagen Schroeter and Gunter GC Kuhnle},

url = {https://elifesciences.org/articles/92941},

doi = {10.7554/eLife.92941.3},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {eLife},

volume = {13},

pages = {RP92941},

publisher = {eLife Sciences Publications Limited},

abstract = {The chemical composition of foods is complex, variable, and dependent on many factors. This has a major impact on nutrition research as it foundationally affects our ability to adequately assess the actual intake of nutrients and other compounds. In spite of this, accurate data on nutrient intake are key for investigating the associations and causal relationships between intake, health, and disease risk at the service of developing evidence-based dietary guidance that enables improvements in population health. Here, we exemplify the importance of this challenge by investigating the impact of food content variability on nutrition research using three bioactives as model: flavan-3-ols, (–)-epicatechin, and nitrate. Our results show that common approaches aimed at addressing the high compositional variability of even the same foods impede the accurate assessment of nutrient intake generally. This suggests that the results of many nutrition studies using food composition data are potentially unreliable and carry greater limitations than commonly appreciated, consequently resulting in dietary recommendations with significant limitations and unreliable impact on public health. Thus, current challenges related to nutrient intake assessments need to be addressed and mitigated by the development of improved dietary assessment methods involving the use of nutritional biomarkers.},

keywords = {biomarkers, dietary assessment, epicatechin, flavanols, nitrate},

pubstate = {published},

tppubtype = {article}

}

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Ottaviani, Javier I; Schroeter, Hagen; Kuhnle, Gunter GC

Measuring the intake of dietary bioactives: Pitfalls and how to avoid them Journal Article

In: Molecular Aspects of Medicine, vol. 89, pp. 101139, 2023.

BibTeX | Tags: biomarkers, flavanols

Kuhnle, Gunter GC

Time to wake up sleeping beauty: stable isotope ratios Journal Article

In: The Journal of Nutrition, vol. 153, no. 7, pp. 1848–1849, 2023.

BibTeX | Tags: biomarkers, stable isotope ratios

Ottaviani, Javier I; Ensunsa, Jodi L; Fong, Reedmond Y; Kimball, Jennifer; Medici, Valentina; Kuhnle, Gunter GC; Crozier, Alan; Schroeter, Hagen; Kwik-Uribe, Catherine

Impact of polyphenol oxidase on the bioavailability of flavan-3-ols in fruit smoothies: a controlled, single blinded, cross-over study Journal Article

In: Food & Function, vol. 14, no. 18, pp. 8217–8228, 2023.

Abstract | Links | BibTeX | Tags: biomarkers, epicatechin, flavanols, polyphenol oxidase

@article{ottaviani2023impact,

title = {Impact of polyphenol oxidase on the bioavailability of flavan-3-ols in fruit smoothies: a controlled, single blinded, cross-over study},

author = {Javier I Ottaviani and Jodi L Ensunsa and Reedmond Y Fong and Jennifer Kimball and Valentina Medici and Gunter GC Kuhnle and Alan Crozier and Hagen Schroeter and Catherine Kwik-Uribe},

url = {https://pubmed.ncbi.nlm.nih.gov/37615673/},

doi = {10.1039/d3fo01599h},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Food & Function},

volume = {14},

number = {18},

pages = {8217–8228},

publisher = {Royal Society of Chemistry},

abstract = {Flavan-3-ols are bioactive compounds found in a variety of fruits and vegetables (F&V) that have been linked to positive health benefits. Increasing habitual flavan-3-ol intake is challenged by the generally low consumption of F&V. While smoothies are a commonly endorsed, consumer-accepted means to increase the daily intake of these important foods, fruits used for smoothie preparation can have a high polyphenol oxidase (PPO) activity and thus potentially affect the content and bioavailability of flavan-3-ols. To assess whether or not consuming freshly prepared smoothies made with different PPO-containing fruit impacts the bioavailability of the flavan-3-ols, a controlled, single blinded and cross-over study was conducted in healthy men (n = 8) who consumed a flavan-3-ol-containing banana-based smoothie (high-PPO drink), a flavan-3-ol-containing mixed berry smoothie (low-PPO drink) and flavan-3-ols in a capsule format (control). The peak plasma concentration (Cmax) of flavan-3-ol metabolites after capsule intake was 680 $±$ 78 nmol L-1, which was similar to the levels detected after the intake of the low PPO drink. In contrast, the intake of the high PPO drink resulted in a Cmax of 96 $±$ 47 nmol L-1, 84% lower than that obtained after capsule intake. In a subsequent study (n = 11), flavan-3-ols were co-ingested with a high-PPO banana drink but contact prior to intake was prevented. In this context, plasma flavan-3-ol levels were still reduced, suggesting an effect possibly related to post-ingestion PPO activity degrading flavan-3-ols in the stomach. There was a substantial range in the PPO activity detected in 18 different fruits, vegetables and plant-derived dietary products. In conclusion, bioavailability of flavan-3-ols, and most likely other dietary polyphenol bioactives, can be reduced substantially by the co-ingestion of high PPO-containing products, the implications of which are of importance for dietary advice and food preparation both at home and in industrial settings.},

keywords = {biomarkers, epicatechin, flavanols, polyphenol oxidase},

pubstate = {published},

tppubtype = {article}

}

Close

Flavan-3-ols are bioactive compounds found in a variety of fruits and vegetables (F&V) that have been linked to positive health benefits. Increasing habitual flavan-3-ol intake is challenged by the generally low consumption of F&V. While smoothies are a commonly endorsed, consumer-accepted means to increase the daily intake of these important foods, fruits used for smoothie preparation can have a high polyphenol oxidase (PPO) activity and thus potentially affect the content and bioavailability of flavan-3-ols. To assess whether or not consuming freshly prepared smoothies made with different PPO-containing fruit impacts the bioavailability of the flavan-3-ols, a controlled, single blinded and cross-over study was conducted in healthy men (n = 8) who consumed a flavan-3-ol-containing banana-based smoothie (high-PPO drink), a flavan-3-ol-containing mixed berry smoothie (low-PPO drink) and flavan-3-ols in a capsule format (control). The peak plasma concentration (Cmax) of flavan-3-ol metabolites after capsule intake was 680 $±$ 78 nmol L-1, which was similar to the levels detected after the intake of the low PPO drink. In contrast, the intake of the high PPO drink resulted in a Cmax of 96 $±$ 47 nmol L-1, 84% lower than that obtained after capsule intake. In a subsequent study (n = 11), flavan-3-ols were co-ingested with a high-PPO banana drink but contact prior to intake was prevented. In this context, plasma flavan-3-ol levels were still reduced, suggesting an effect possibly related to post-ingestion PPO activity degrading flavan-3-ols in the stomach. There was a substantial range in the PPO activity detected in 18 different fruits, vegetables and plant-derived dietary products. In conclusion, bioavailability of flavan-3-ols, and most likely other dietary polyphenol bioactives, can be reduced substantially by the co-ingestion of high PPO-containing products, the implications of which are of importance for dietary advice and food preparation both at home and in industrial settings.

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Lang, Alexander; Kuss, Oliver; Filla, Tim; Kuhnle, Gunter; Schlesinger, Sabrina

The mediating role of obesity on the prospective association between urinary sucrose and diabetes incidence in a sub-cohort of the EPIC-Norfolk Journal Article

In: Nutrition & Diabetes, vol. 13, no. 1, pp. 14, 2023.

BibTeX | Tags: biomarkers, obestity, sucrose

Cheeseman, Jack; Badia, Concepcion; Elgood-Hunt, Georgia; Gardner, Richard A; Trinh, Duong N; Monopoli, Marco P; Kuhnle, Gunter; Spencer, Daniel IR; Osborn, Helen MI

Elevated concentrations of Neu5Ac and Neu5, 9Ac2 in human plasma: potential biomarkers of cardiovascular disease Journal Article

In: Glycoconjugate Journal, vol. 40, no. 6, pp. 645–654, 2023.

Abstract | Links | BibTeX | Tags: biomarkers, sialic acid

@article{cheeseman2023elevated,

title = {Elevated concentrations of Neu5Ac and Neu5, 9Ac2 in human plasma: potential biomarkers of cardiovascular disease},

author = {Jack Cheeseman and Concepcion Badia and Georgia Elgood-Hunt and Richard A Gardner and Duong N Trinh and Marco P Monopoli and Gunter Kuhnle and Daniel IR Spencer and Helen MI Osborn},

url = {https://pubmed.ncbi.nlm.nih.gov/37991561/},

doi = {10.1007/s10719-023-10138-3},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Glycoconjugate Journal},

volume = {40},

number = {6},

pages = {645–654},

publisher = {Springer US New York},

abstract = {Cardiovascular disease (CVD) is a group of health conditions affecting the heart and vascular system with very high prevalence and mortality rates. The presence of CVD is characterised by high levels of inflammation which have previously been associated with increased plasma concentrations of N-acetyl neuraminic acid (Neu5Ac). While Neu5Ac has been studied in the context of CVD, Neu5,9Ac2 has not, despite being the second most abundant sialic acid in human plasma. A small-scale pilot study of thirty plasma samples from patients with diagnosed CVD, and thirty age and sex-matched healthy controls, was designed to gain insight into sialic acids as biomarkers for CVD and potential future areas of study. Each sample was assayed for Neu5Ac and Neu5,9Ac2 concentrations. Mean Neu5Ac and Neu5,9Ac2 concentrations were significantly elevated in patients with CVD compared to healthy controls (Neu5Ac: P < 0.001; Neu5,9Ac2: P < 0.04). Receiver operator curve (ROC) analysis indicated that both Neu5Ac and Neu5,9Ac2 have reasonable predictive power for the presence of CVD (Neu5Ac AUC: 0.86; Neu5,9Ac2 AUC: 0.71). However, while Neu5Ac had both good sensitivity (0.82) and specificity (0.81), Neu5,9Ac2 had equivalent specificity (0.81) but very poor sensitivity (0.44). A combination marker of Neu5Ac + Neu5,9Ac2 showed improvement over Neu5Ac alone in terms of predictive power (AUC: 0.93), sensitivity (0.87), and specificity (0.90). Comparison to a known inflammatory marker, high sensitivity c-reactive protein (hs-CRP: P-value: NS, ROC:0.50) was carried out, showing that both Neu5Ac and Neu5,9Ac2 outperformed this marker. Further to this, hs-CRP values were combined with the three different sialic acid markers to determine any effect on the AUC values. A slight improvement in AUC was noted for each of the combinations, with Neu5Ac + Neu5,9Ac2 + hs-CRP giving the best AUC of 0.97 overall. Thus, Neu5Ac would appear to offer good potential as a predictive marker for the presence of CVD, which the addition of Neu5,9Ac2 predictive power improves, with further improvement seen by the addition of hs-CRP.},

keywords = {biomarkers, sialic acid},

pubstate = {published},

tppubtype = {article}

}

Close

Cardiovascular disease (CVD) is a group of health conditions affecting the heart and vascular system with very high prevalence and mortality rates. The presence of CVD is characterised by high levels of inflammation which have previously been associated with increased plasma concentrations of N-acetyl neuraminic acid (Neu5Ac). While Neu5Ac has been studied in the context of CVD, Neu5,9Ac2 has not, despite being the second most abundant sialic acid in human plasma. A small-scale pilot study of thirty plasma samples from patients with diagnosed CVD, and thirty age and sex-matched healthy controls, was designed to gain insight into sialic acids as biomarkers for CVD and potential future areas of study. Each sample was assayed for Neu5Ac and Neu5,9Ac2 concentrations. Mean Neu5Ac and Neu5,9Ac2 concentrations were significantly elevated in patients with CVD compared to healthy controls (Neu5Ac: P < 0.001; Neu5,9Ac2: P < 0.04). Receiver operator curve (ROC) analysis indicated that both Neu5Ac and Neu5,9Ac2 have reasonable predictive power for the presence of CVD (Neu5Ac AUC: 0.86; Neu5,9Ac2 AUC: 0.71). However, while Neu5Ac had both good sensitivity (0.82) and specificity (0.81), Neu5,9Ac2 had equivalent specificity (0.81) but very poor sensitivity (0.44). A combination marker of Neu5Ac + Neu5,9Ac2 showed improvement over Neu5Ac alone in terms of predictive power (AUC: 0.93), sensitivity (0.87), and specificity (0.90). Comparison to a known inflammatory marker, high sensitivity c-reactive protein (hs-CRP: P-value: NS, ROC:0.50) was carried out, showing that both Neu5Ac and Neu5,9Ac2 outperformed this marker. Further to this, hs-CRP values were combined with the three different sialic acid markers to determine any effect on the AUC values. A slight improvement in AUC was noted for each of the combinations, with Neu5Ac + Neu5,9Ac2 + hs-CRP giving the best AUC of 0.97 overall. Thus, Neu5Ac would appear to offer good potential as a predictive marker for the presence of CVD, which the addition of Neu5,9Ac2 predictive power improves, with further improvement seen by the addition of hs-CRP.

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Trinh, Duong N; Radlinskaite, Meda; Cheeseman, Jack; Kuhnle, Gunter; Osborn, Helen MI; Meleady, Paula; Spencer, Daniel IR; Monopoli, Marco P

Biomolecular corona stability in association with plasma cholesterol level Journal Article

In: Nanomaterials, vol. 12, no. 15, pp. 2661, 2022.

BibTeX | Tags: biomarkers, sialic acid

Kuhnle, Gunter GC

From rough diamond to polished gem Journal Article

In: The Journal of Nutrition, vol. 152, no. 9, pp. 2009–2010, 2022.

BibTeX | Tags: biomarkers, stable isotope ratios

Cheeseman, Jack; Badia, Concepcion; Thomson, Rebecca; Elgood-Hunt, Georgia; Trinh, Duong; Gardner, Richard; Spencer, Daniel; Kuhnle, Gunter; Monopoli, Marco; Osborn, Helen

Neu5Ac and Neu5, 9Ac2 in Human Plasma: Potential Biomarkers of Cardiovascular Disease Proceedings Article

In: GLYCOBIOLOGY, pp. 1036–1036, OXFORD UNIV PRESS INC JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA 2022.

BibTeX | Tags: biomarkers, sialic acid

Ottaviani, Javier I; Fong, Reedmond; Kimball, Jennifer; Ensunsa, Jodi L; Gray, Nicola; Vogiatzoglou, Anna; Britten, Abigail; Lucarelli, Debora; Luben, Robert; Grace, Philip B; others,

Evaluation of (-)-epicatechin metabolites as recovery biomarker of dietary flavan-3-ol intake Journal Article

In: Scientific reports, vol. 9, no. 1, pp. 13108, 2019.

BibTeX | Tags: biomarkers, dietary assessment, epicatechin, flavanols