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Intestinal fermentation in patients with self-reported food hypersensitivity: painful, but protective?

Valeur J, Morken MH, Norin E, Midtvedt T, Berstad A - Clin Exp Gastroenterol (2010)

Bottom Line: Concentrations and excretions (output) of SCFAs in patients and controls were compared and related to gastrointestinal symptoms.Despite nonsignificant differences between patients and controls for both total and individual SCFA concentrations and excretions, n-butyric acid comprised a higher (P = 0.035) and acetic acid a lower (P = 0.012) proportion of total SCFA in patients compared to controls.There were no significant correlations between symptom scores and concentrations or excretions of individual or total SCFAs, but the proportion of n-butyric acid was significantly higher in patients with severe symptoms compared to patients with moderate symptoms (P = 0.016).

View Article: PubMed Central - PubMed

Affiliation: Institute of Medicine, University of Bergen, Bergen, Norway;

ABSTRACT

Purpose: Enterometabolic disturbances may cause meal-related symptoms. We performed a functional evaluation of the intestinal microflora in patients with unexplained, self-reported food hypersensitivity by measuring fecal short-chain fatty acids (SCFAs).

Patients and methods: Thirty-five consecutive patients with self-reported food hypersensitivity and 15 healthy volunteers of similar age, gender, and body mass index collected all feces for 72 hours. Fecal concentrations of acetic, propionic, n-butyric, i-butyric, n-valeric, i-valeric, n-caproic, and i-caproic acids were analyzed by gas-liquid chromatography. Concentrations and excretions (output) of SCFAs in patients and controls were compared and related to gastrointestinal symptoms.

Results: Despite nonsignificant differences between patients and controls for both total and individual SCFA concentrations and excretions, n-butyric acid comprised a higher (P = 0.035) and acetic acid a lower (P = 0.012) proportion of total SCFA in patients compared to controls. There were no significant correlations between symptom scores and concentrations or excretions of individual or total SCFAs, but the proportion of n-butyric acid was significantly higher in patients with severe symptoms compared to patients with moderate symptoms (P = 0.016).

Conclusion: The results indicate an enterometabolic disturbance in patients with self-reported food hypersensitivity. Higher proportions of n-butyric acid may be related to abdominal symptom generation, but may also protect against organic bowel disease. Further studies are needed to clarify these aspects.

No MeSH data available.


Related in: MedlinePlus

SCFA distribution in fecal samples from patients classified as moderate cases (n = 19) and patients classified as severe cases (n = 16). Individual SCFA are shown as mean percentages of total SCFA concentration. Note, the proportion of n-butyric acid is higher in severe cases versus moderate cases (P = 0.016). Minor SCFAs = sum of percentages of i-butyric, i-valeric, n-valeric, i-caproic, and n-caproic acids.
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f1-ceg-3-065: SCFA distribution in fecal samples from patients classified as moderate cases (n = 19) and patients classified as severe cases (n = 16). Individual SCFA are shown as mean percentages of total SCFA concentration. Note, the proportion of n-butyric acid is higher in severe cases versus moderate cases (P = 0.016). Minor SCFAs = sum of percentages of i-butyric, i-valeric, n-valeric, i-caproic, and n-caproic acids.

Mentions: Total SCFA concentration in feces varied considerably from day to day within individuals, with estimated intra-individual coefficients of variation being 22.6% and 20.6% for patients and controls respectively. Inter-individual coefficients of variation were even greater; 56.2% and 42.2% for patients and controls respectively. Acetic, propionic, and n-butyric acids were the dominating SCFAs in all subjects. Iso-caproic acid was detectable in 11 patients and five controls, whereas n-caproic acid was absent in one patient and one control. There were no significant differences in either concentrations or excretions (output) between patients and controls (Table 1). There were several significant correlations between the individual SCFA concentrations (data not shown), similar to what has been reported previously.11,12 Neither BMI nor fecal wet weight was significantly correlated to SCFA concentrations, and there was no difference between males and females. There was no difference in SCFA concentrations or excretions between patients complaining of predominant constipation and patients complaining of predominant diarrhea. There was no correlation between individual or total SCFA concentrations or excretions and symptom scores in the patient group. Interestingly, the proportional distribution of individual SCFA to total SCFA was different between patients and controls, with a significantly lower percentage of acetic acid (P = 0.012) and higher percentage of n-butyric acid in the patients (P = 0.035). Although there was no correlation between the percentage of acetic acid or n-butyric acid and symptom scores, the proportion of n-butyric acid was higher in patients classified as severe cases according to IBS-SSS than in patients classified as moderate cases (P = 0.016) (Figure 1).


Intestinal fermentation in patients with self-reported food hypersensitivity: painful, but protective?

Valeur J, Morken MH, Norin E, Midtvedt T, Berstad A - Clin Exp Gastroenterol (2010)

SCFA distribution in fecal samples from patients classified as moderate cases (n = 19) and patients classified as severe cases (n = 16). Individual SCFA are shown as mean percentages of total SCFA concentration. Note, the proportion of n-butyric acid is higher in severe cases versus moderate cases (P = 0.016). Minor SCFAs = sum of percentages of i-butyric, i-valeric, n-valeric, i-caproic, and n-caproic acids.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3108650&req=5

f1-ceg-3-065: SCFA distribution in fecal samples from patients classified as moderate cases (n = 19) and patients classified as severe cases (n = 16). Individual SCFA are shown as mean percentages of total SCFA concentration. Note, the proportion of n-butyric acid is higher in severe cases versus moderate cases (P = 0.016). Minor SCFAs = sum of percentages of i-butyric, i-valeric, n-valeric, i-caproic, and n-caproic acids.
Mentions: Total SCFA concentration in feces varied considerably from day to day within individuals, with estimated intra-individual coefficients of variation being 22.6% and 20.6% for patients and controls respectively. Inter-individual coefficients of variation were even greater; 56.2% and 42.2% for patients and controls respectively. Acetic, propionic, and n-butyric acids were the dominating SCFAs in all subjects. Iso-caproic acid was detectable in 11 patients and five controls, whereas n-caproic acid was absent in one patient and one control. There were no significant differences in either concentrations or excretions (output) between patients and controls (Table 1). There were several significant correlations between the individual SCFA concentrations (data not shown), similar to what has been reported previously.11,12 Neither BMI nor fecal wet weight was significantly correlated to SCFA concentrations, and there was no difference between males and females. There was no difference in SCFA concentrations or excretions between patients complaining of predominant constipation and patients complaining of predominant diarrhea. There was no correlation between individual or total SCFA concentrations or excretions and symptom scores in the patient group. Interestingly, the proportional distribution of individual SCFA to total SCFA was different between patients and controls, with a significantly lower percentage of acetic acid (P = 0.012) and higher percentage of n-butyric acid in the patients (P = 0.035). Although there was no correlation between the percentage of acetic acid or n-butyric acid and symptom scores, the proportion of n-butyric acid was higher in patients classified as severe cases according to IBS-SSS than in patients classified as moderate cases (P = 0.016) (Figure 1).

Bottom Line: Concentrations and excretions (output) of SCFAs in patients and controls were compared and related to gastrointestinal symptoms.Despite nonsignificant differences between patients and controls for both total and individual SCFA concentrations and excretions, n-butyric acid comprised a higher (P = 0.035) and acetic acid a lower (P = 0.012) proportion of total SCFA in patients compared to controls.There were no significant correlations between symptom scores and concentrations or excretions of individual or total SCFAs, but the proportion of n-butyric acid was significantly higher in patients with severe symptoms compared to patients with moderate symptoms (P = 0.016).

View Article: PubMed Central - PubMed

Affiliation: Institute of Medicine, University of Bergen, Bergen, Norway;

ABSTRACT

Purpose: Enterometabolic disturbances may cause meal-related symptoms. We performed a functional evaluation of the intestinal microflora in patients with unexplained, self-reported food hypersensitivity by measuring fecal short-chain fatty acids (SCFAs).

Patients and methods: Thirty-five consecutive patients with self-reported food hypersensitivity and 15 healthy volunteers of similar age, gender, and body mass index collected all feces for 72 hours. Fecal concentrations of acetic, propionic, n-butyric, i-butyric, n-valeric, i-valeric, n-caproic, and i-caproic acids were analyzed by gas-liquid chromatography. Concentrations and excretions (output) of SCFAs in patients and controls were compared and related to gastrointestinal symptoms.

Results: Despite nonsignificant differences between patients and controls for both total and individual SCFA concentrations and excretions, n-butyric acid comprised a higher (P = 0.035) and acetic acid a lower (P = 0.012) proportion of total SCFA in patients compared to controls. There were no significant correlations between symptom scores and concentrations or excretions of individual or total SCFAs, but the proportion of n-butyric acid was significantly higher in patients with severe symptoms compared to patients with moderate symptoms (P = 0.016).

Conclusion: The results indicate an enterometabolic disturbance in patients with self-reported food hypersensitivity. Higher proportions of n-butyric acid may be related to abdominal symptom generation, but may also protect against organic bowel disease. Further studies are needed to clarify these aspects.

No MeSH data available.


Related in: MedlinePlus