HIGH LEVELS OF FAECAL p-CRESOL IN A GROUP OF HYPERACTIVE CHILDREN

Adams, R F; Murray, Keith E.; Earl, J W

doi:10.1016/s0140-6736(85)91603-4

Cited by 10 publications

(5 citation statements)

References 3 publications

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“…As a further example, sulfonation phenotype could potentially influence both the efficacy and side-effects of apomorphine, for which sulfonation is the major metabolic pathway in humans (57). As regards known associations with disease, hyperactivity in children provides one example of a condition that has been associated with increased p-cresol levels and where the involvement of dietary factors is also suspected (58). Furthermore, an increased urinary level of PCS has been associated with the progression of multiple sclerosis (59,60).…”

Section: Resultsmentioning

confidence: 99%

Pharmacometabonomic identification of a significant host-microbiome metabolic interaction affecting human drug metabolism

Clayton

Baker

Lindon

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

697

573

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We provide a demonstration in humans of the principle of pharmacometabonomics by showing a clear connection between an individual's metabolic phenotype, in the form of a predose urinary metabolite profile, and the metabolic fate of a standard dose of the widely used analgesic acetaminophen. Predose and postdose urinary metabolite profiles were determined by 1 H NMR spectroscopy. The predose spectra were statistically analyzed in relation to drug metabolite excretion to detect predose biomarkers of drug fate and a human-gut microbiome cometabolite predictor was identified. Thus, we found that individuals having high predose urinary levels of p-cresol sulfate had low postdose urinary ratios of acetaminophen sulfate to acetaminophen glucuronide. We conclude that, in individuals with high bacterially mediated p-cresol generation, competitive O-sulfonation of p-cresol reduces the effective systemic capacity to sulfonate acetaminophen. Given that acetaminophen is such a widely used and seemingly well-understood drug, this finding provides a clear demonstration of the immense potential and power of the pharmacometabonomic approach. However, we expect many other sulfonation reactions to be similarly affected by competition with p-cresol and our finding also has important implications for certain diseases as well as for the variable responses induced by many different drugs and xenobiotics. We propose that assessing the effects of microbiome activity should be an integral part of pharmaceutical development and of personalized health care. Furthermore, we envisage that gut bacterial populations might be deliberately manipulated to improve drug efficacy and to reduce adverse drug reactions.T he effects of drug treatments can vary greatly between different individuals, and pharmacogenomics has been widely advocated as a potential means of personalizing human drug treatments to increase drug efficacy and to decrease adverse reactions (1-6). However, environmental factors (such as nutritional status, gut bacterial activities, age, disease, and other drug use) are also important determinants of individual metabolic phenotypes, which modulate drug metabolism, efficacy, and toxicity. Such environmental complications, which may also alter gene expression, will tend to limit the usefulness of predictions of drug-induced responses that are based only on genomic differences (7,8). For instance, for many classes of compound, enzyme induction state, which is environmentally determined, influences drug metabolism and toxicity and this is not captured in genomic data. Recognizing this important limitation of pharmacogenomics, a different approach to personalized drug treatment has recently been proposed wherein predose metabolite profiling would instead be used to predict a subject's responses to potential drug interventions (9). This ''pharmacometabonomic'' approach has a number of major advantages, which include the ready availability and relative ease of analysis of biofluids, such as urine and blood plasma, as well as the fact that ...

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Section: Resultsmentioning

confidence: 99%

Pharmacometabonomic identification of a significant host-microbiome metabolic interaction affecting human drug metabolism

Clayton

Baker

Lindon

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

697

573

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“…Faecal excretion of phenolic compounds is not often reported, but in available studies amounts of 5–8 mg/d for p -cresol and 0·25–0·66 mg/d for phenol have been found. Interestingly, faecal excretion of p -cresol was 4-fold higher in a group of hyperactive children as compared with control children ( 119 ) .…”

Section: Beneficial and Harmful Effects Of Relevant Metabolitesmentioning

confidence: 89%

Towards microbial fermentation metabolites as markers for health benefits of prebiotics

et al. 2015

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Available evidence on the bioactive, nutritional and putative detrimental properties of gut microbial metabolites has been evaluated to support a more integrated view of how prebiotics might affect host health throughout life. The present literature inventory targeted evidence for the physiological and nutritional effects of metabolites, for example, SCFA, the potential toxicity of other metabolites and attempted to determine normal concentration ranges. Furthermore, the biological relevance of more holistic approaches like faecal water toxicity assays and metabolomics and the limitations of faecal measurements were addressed. Existing literature indicates that protein fermentation metabolites (phenol, p-cresol, indole, ammonia), typically considered as potentially harmful, occur at concentration ranges in the colon such that no toxic effects are expected either locally or following systemic absorption. The endproducts of saccharolytic fermentation, SCFA, may have effects on colonic health, host physiology, immunity, lipid and protein metabolism and appetite control. However, measuring SCFA concentrations in faeces is insufficient to assess the dynamic processes of their nutrikinetics. Existing literature on the usefulness of faecal water toxicity measures as indicators of cancer risk seems limited. In conclusion, at present there is insufficient evidence to use changes in faecal bacterial metabolite concentrations as markers of prebiotic effectiveness. Integration of results from metabolomics and metagenomics holds promise for understanding the health implications of prebiotic microbiome modulation but adequate tools for data integration and interpretation are currently lacking. Similarly, studies measuring metabolite fluxes in different body compartments to provide a more accurate picture of their nutrikinetics are needed.

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“…1 Outline of pathways of dissimilatory metabolism of aromatic amino acids in the human large intestine in young pigs (Yokoyama et al 1982). Other physiological manifestations include hyperactivity in children, where high levels of p-cresol are excreted in faeces (Adams et al 1985).…”

Section: Introductionmentioning

confidence: 99%

“…For example, phenols have been implicated in schizophrenia (Dalgliesh et al 1958) and are believed to act as co-carcinogens (Bone et al 1976 (Yokoyama et al 1982). Other physiological manifestations include hyperactivity in children, where high levels of p-cresol are excreted in faeces (Adams et al 1985).…”

Section: Introductionmentioning

confidence: 99%

Enumeration of human colonic bacteria producing phenolic and indolic compounds: effects of pH, carbohydrate availability and retention time on dissimilatory aromatic amino acid metabolism

Smith

Macfarlane

1996

Journal of Applied Bacteriology

415

295

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Concentrations of phenolic compounds in human gut contents were more than fourfold higher in the distal colon (6.2 mmol kg-1) compared to the proximal bowel (1.4 mmol kg-1). Tryptophan metabolites were never found in more than trace amounts in large intestinal contents and phenol substituted fatty acids were the major products of aromatic amino acid fermentation that accumulated in the proximal colon, whereas phenol and p-cresol were more important in the distal gut, accounting for 70% of all products of dissimilatory aromatic amino acid metabolism. In vitro incubations of colonic material showed that phenol was produced most rapidly (1.0 mumol g-1 h-1), whereas indole was formed comparatively slowly (0.06 mumol g-1 h-1). Most probable number (MPN) estimations demonstrated that large populations of phenol and indole producing bacteria occur in the large intestine (range log10 9.8-11.5 (g dry wt faeces)-1, mean 10.6, N = 7). With respect to phenolic compounds, phenylacetate and phenylpropionate producers predominated, while indoleacetate-forming bacteria were the major tryptophan-utilizing organisms. Quantitation of products of dissimilatory aromatic amino acid metabolism in MPN tubes showed that phenol and phenylpropionate mainly accumulated at low sample dilutions, whereas phenylacetate, p-cresol, indoleacetate and indolepropionate were formed in greatest amounts at high sample dilutions. The significance of pH and carbohydrate availability with respect to aromatic amino acid metabolism was shown in batch culture fermentation studies, where net production of phenolic compounds by mixed populations of intestinal bacteria was reduced by approximately 33% during growth at pH 5.5 compared to pH 6.8, and by 60% in the presence of a fermentable carbohydrate. Experiments with 16 species of intestinal bacteria belonging to six different genera showed that environmental factors such as low pH and high carbohydrate availability markedly reduced dissimilatory aromatic amino acid metabolism in some organisms, but stimulated this process in others. A three-stage continuous culture model of the colon was used to investigate the effect of system retention time (27.1 or 66.7 h) on aromatic amino acid fermentation. Qualitative and quantitative increases in phenol production occurred from vessel 1 to vessel 3 in this model. Concentrations of phenolic compounds in vessel 3 were three times greater at R = 66.7 h compared to R = 27.1 h. Phenol and p-cresol were not detected in vessel 1, though formation of these metabolites increased from vessel 2 to vessel 3, in a pattern similar to that observed in the distal colon.

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HIGH LEVELS OF FAECAL p-CRESOL IN A GROUP OF HYPERACTIVE CHILDREN

Cited by 10 publications

References 3 publications

Pharmacometabonomic identification of a significant host-microbiome metabolic interaction affecting human drug metabolism

Pharmacometabonomic identification of a significant host-microbiome metabolic interaction affecting human drug metabolism

Towards microbial fermentation metabolites as markers for health benefits of prebiotics

Enumeration of human colonic bacteria producing phenolic and indolic compounds: effects of pH, carbohydrate availability and retention time on dissimilatory aromatic amino acid metabolism

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