Variability in nitrate-reducing oral bacteria and nitric oxide metabolites in biological fluids following dietary nitrate administration: an assessment of the critical difference

Luke Liddle, Mia C. Burleigh, Chris Monaghan, David J. Muggeridge, Nicholas Sculthorpe, Charles R. Pedlar, John Butcher, Fiona L. Henriquez, Chris Easton

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Abstract

There is conflicting evidence on whether dietary nitrate supplementation can improve exercise performance. This may arise from the complex nature of nitric oxide (NO) metabolism which causes substantial inter-individual variability, within-person biological variation (CVB), and analytical imprecision (CVA) in experimental endpoints. However, no study has quantified the CVA and CVB of NO metabolites or the factors that influence their production. These data are important to calculate the critical difference (CD), defined as the smallest difference between sequential measurements required to signify a true change. The main aim of the study was to evaluate the CVB, CVA, and CD for markers of NO availability (nitrate and nitrite) in plasma and saliva before and after the ingestion of nitrate-rich beetroot juice (BR). We also assessed the CVB of nitrate-reducing bacteria from the dorsal surface of the tongue. It was hypothesised that there would be substantial CVB in markers of NO availability and the abundance of nitrate-reducing bacteria. Ten healthy male participants (age 25 ± 5 years) completed three identical trials at least 6 days apart. Blood and saliva were collected before and after (2, 2.5 and 3 h) ingestion of 140 ml of BR (~12.4 mmol nitrate) and analysed for [nitrate] and [nitrite]. The tongue was scraped and the abundance of nitrate-reducing bacterial species were analysed using 16S rRNA next generation sequencing. There was substantial CVB for baseline concentrations of plasma (nitrate 11.9%, nitrite 9.0%) and salivary (nitrate 15.3%, nitrite 32.5%) NO markers. Following BR ingestion, the CVB for nitrate (plasma 3.8%, saliva 12.0%) and salivary nitrite (24.5%) were lower than baseline, but higher for plasma nitrite (18.6%). The CD thresholds that need to be exceeded to ensure a meaningful change from baseline are 25, 19, 37, and 87% for plasma nitrate, plasma nitrite, salivary nitrate, and salivary nitrite, respectively. The CVB for selected nitrate-reducing bacteria detected were: Prevotella melaninogenica (37%), Veillonella dispar (35%), Haemophilus parainfluenzae (79%), Neisseria subflava (70%), Veillonella parvula (43%), Rothia mucilaginosa (60%), and Rothia dentocariosa (132%). There is profound CVB in the abundance of nitrate-reducing bacteria on the tongue and the concentration of NO markers in human saliva and plasma. Where these parameters are of interest following experimental intervention, the CD values presented in this study will allow researchers to interpret the meaningfulness of the magnitude of the change from baseline.
Original languageEnglish
Pages (from-to)1-10
Number of pages10
JournalNitric Oxide
Volume83
Early online date5 Dec 2018
DOIs
Publication statusE-pub ahead of print - 5 Dec 2018

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Metabolites
Nitrates
Bacteria
Nitric Oxide
Fluids
Nitrites
Plasmas
Saliva
Veillonella
Tongue
Eating
Prevotella melaninogenica
Haemophilus parainfluenzae
Availability
Neisseria
Dietary Supplements
Metabolism
Healthy Volunteers
Blood

Keywords

  • Beetroot juice
  • Nitrite
  • Microbiome

Cite this

@article{2f4f3fb192964a75b50422352cf9a1a6,
title = "Variability in nitrate-reducing oral bacteria and nitric oxide metabolites in biological fluids following dietary nitrate administration: an assessment of the critical difference",
abstract = "There is conflicting evidence on whether dietary nitrate supplementation can improve exercise performance. This may arise from the complex nature of nitric oxide (NO) metabolism which causes substantial inter-individual variability, within-person biological variation (CVB), and analytical imprecision (CVA) in experimental endpoints. However, no study has quantified the CVA and CVB of NO metabolites or the factors that influence their production. These data are important to calculate the critical difference (CD), defined as the smallest difference between sequential measurements required to signify a true change. The main aim of the study was to evaluate the CVB, CVA, and CD for markers of NO availability (nitrate and nitrite) in plasma and saliva before and after the ingestion of nitrate-rich beetroot juice (BR). We also assessed the CVB of nitrate-reducing bacteria from the dorsal surface of the tongue. It was hypothesised that there would be substantial CVB in markers of NO availability and the abundance of nitrate-reducing bacteria. Ten healthy male participants (age 25 ± 5 years) completed three identical trials at least 6 days apart. Blood and saliva were collected before and after (2, 2.5 and 3 h) ingestion of 140 ml of BR (~12.4 mmol nitrate) and analysed for [nitrate] and [nitrite]. The tongue was scraped and the abundance of nitrate-reducing bacterial species were analysed using 16S rRNA next generation sequencing. There was substantial CVB for baseline concentrations of plasma (nitrate 11.9{\%}, nitrite 9.0{\%}) and salivary (nitrate 15.3{\%}, nitrite 32.5{\%}) NO markers. Following BR ingestion, the CVB for nitrate (plasma 3.8{\%}, saliva 12.0{\%}) and salivary nitrite (24.5{\%}) were lower than baseline, but higher for plasma nitrite (18.6{\%}). The CD thresholds that need to be exceeded to ensure a meaningful change from baseline are 25, 19, 37, and 87{\%} for plasma nitrate, plasma nitrite, salivary nitrate, and salivary nitrite, respectively. The CVB for selected nitrate-reducing bacteria detected were: Prevotella melaninogenica (37{\%}), Veillonella dispar (35{\%}), Haemophilus parainfluenzae (79{\%}), Neisseria subflava (70{\%}), Veillonella parvula (43{\%}), Rothia mucilaginosa (60{\%}), and Rothia dentocariosa (132{\%}). There is profound CVB in the abundance of nitrate-reducing bacteria on the tongue and the concentration of NO markers in human saliva and plasma. Where these parameters are of interest following experimental intervention, the CD values presented in this study will allow researchers to interpret the meaningfulness of the magnitude of the change from baseline.",
keywords = "Beetroot juice, Nitrite, Microbiome",
author = "Luke Liddle and Burleigh, {Mia C.} and Chris Monaghan and Muggeridge, {David J.} and Nicholas Sculthorpe and Pedlar, {Charles R.} and John Butcher and Henriquez, {Fiona L.} and Chris Easton",
year = "2018",
month = "12",
day = "5",
doi = "10.1016/j.niox.2018.12.003",
language = "English",
volume = "83",
pages = "1--10",
journal = "Nitric Oxide",
issn = "1089-8603",
publisher = "Elsevier B.V.",

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TY - JOUR

T1 - Variability in nitrate-reducing oral bacteria and nitric oxide metabolites in biological fluids following dietary nitrate administration

T2 - an assessment of the critical difference

AU - Liddle, Luke

AU - Burleigh, Mia C.

AU - Monaghan, Chris

AU - Muggeridge, David J.

AU - Sculthorpe, Nicholas

AU - Pedlar, Charles R.

AU - Butcher, John

AU - Henriquez, Fiona L.

AU - Easton, Chris

PY - 2018/12/5

Y1 - 2018/12/5

N2 - There is conflicting evidence on whether dietary nitrate supplementation can improve exercise performance. This may arise from the complex nature of nitric oxide (NO) metabolism which causes substantial inter-individual variability, within-person biological variation (CVB), and analytical imprecision (CVA) in experimental endpoints. However, no study has quantified the CVA and CVB of NO metabolites or the factors that influence their production. These data are important to calculate the critical difference (CD), defined as the smallest difference between sequential measurements required to signify a true change. The main aim of the study was to evaluate the CVB, CVA, and CD for markers of NO availability (nitrate and nitrite) in plasma and saliva before and after the ingestion of nitrate-rich beetroot juice (BR). We also assessed the CVB of nitrate-reducing bacteria from the dorsal surface of the tongue. It was hypothesised that there would be substantial CVB in markers of NO availability and the abundance of nitrate-reducing bacteria. Ten healthy male participants (age 25 ± 5 years) completed three identical trials at least 6 days apart. Blood and saliva were collected before and after (2, 2.5 and 3 h) ingestion of 140 ml of BR (~12.4 mmol nitrate) and analysed for [nitrate] and [nitrite]. The tongue was scraped and the abundance of nitrate-reducing bacterial species were analysed using 16S rRNA next generation sequencing. There was substantial CVB for baseline concentrations of plasma (nitrate 11.9%, nitrite 9.0%) and salivary (nitrate 15.3%, nitrite 32.5%) NO markers. Following BR ingestion, the CVB for nitrate (plasma 3.8%, saliva 12.0%) and salivary nitrite (24.5%) were lower than baseline, but higher for plasma nitrite (18.6%). The CD thresholds that need to be exceeded to ensure a meaningful change from baseline are 25, 19, 37, and 87% for plasma nitrate, plasma nitrite, salivary nitrate, and salivary nitrite, respectively. The CVB for selected nitrate-reducing bacteria detected were: Prevotella melaninogenica (37%), Veillonella dispar (35%), Haemophilus parainfluenzae (79%), Neisseria subflava (70%), Veillonella parvula (43%), Rothia mucilaginosa (60%), and Rothia dentocariosa (132%). There is profound CVB in the abundance of nitrate-reducing bacteria on the tongue and the concentration of NO markers in human saliva and plasma. Where these parameters are of interest following experimental intervention, the CD values presented in this study will allow researchers to interpret the meaningfulness of the magnitude of the change from baseline.

AB - There is conflicting evidence on whether dietary nitrate supplementation can improve exercise performance. This may arise from the complex nature of nitric oxide (NO) metabolism which causes substantial inter-individual variability, within-person biological variation (CVB), and analytical imprecision (CVA) in experimental endpoints. However, no study has quantified the CVA and CVB of NO metabolites or the factors that influence their production. These data are important to calculate the critical difference (CD), defined as the smallest difference between sequential measurements required to signify a true change. The main aim of the study was to evaluate the CVB, CVA, and CD for markers of NO availability (nitrate and nitrite) in plasma and saliva before and after the ingestion of nitrate-rich beetroot juice (BR). We also assessed the CVB of nitrate-reducing bacteria from the dorsal surface of the tongue. It was hypothesised that there would be substantial CVB in markers of NO availability and the abundance of nitrate-reducing bacteria. Ten healthy male participants (age 25 ± 5 years) completed three identical trials at least 6 days apart. Blood and saliva were collected before and after (2, 2.5 and 3 h) ingestion of 140 ml of BR (~12.4 mmol nitrate) and analysed for [nitrate] and [nitrite]. The tongue was scraped and the abundance of nitrate-reducing bacterial species were analysed using 16S rRNA next generation sequencing. There was substantial CVB for baseline concentrations of plasma (nitrate 11.9%, nitrite 9.0%) and salivary (nitrate 15.3%, nitrite 32.5%) NO markers. Following BR ingestion, the CVB for nitrate (plasma 3.8%, saliva 12.0%) and salivary nitrite (24.5%) were lower than baseline, but higher for plasma nitrite (18.6%). The CD thresholds that need to be exceeded to ensure a meaningful change from baseline are 25, 19, 37, and 87% for plasma nitrate, plasma nitrite, salivary nitrate, and salivary nitrite, respectively. The CVB for selected nitrate-reducing bacteria detected were: Prevotella melaninogenica (37%), Veillonella dispar (35%), Haemophilus parainfluenzae (79%), Neisseria subflava (70%), Veillonella parvula (43%), Rothia mucilaginosa (60%), and Rothia dentocariosa (132%). There is profound CVB in the abundance of nitrate-reducing bacteria on the tongue and the concentration of NO markers in human saliva and plasma. Where these parameters are of interest following experimental intervention, the CD values presented in this study will allow researchers to interpret the meaningfulness of the magnitude of the change from baseline.

KW - Beetroot juice

KW - Nitrite

KW - Microbiome

U2 - 10.1016/j.niox.2018.12.003

DO - 10.1016/j.niox.2018.12.003

M3 - Article

VL - 83

SP - 1

EP - 10

JO - Nitric Oxide

JF - Nitric Oxide

SN - 1089-8603

ER -