Browsing by Author "Stevenson, Cheryl"

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    Food avoidance in irritable bowel syndrome leads to a nutrition-deficient diet
    (MedPharm Publications, 2014-08) Stevenson, Cheryl; Blaauw, Renee; Fredericks, Ernst; Visser, Janicke; Roux, Saartjie
    Objective: The objective was to assess the dietary intake of subjects with irritable bowel syndrome (IBS) and to compare it to that of international recommendations. The hypothesising assumption of this study was that a situation in which subjects insist that diet or trigger foods play a part in symptom generation may lead to an unbalanced dietary intake. Design: This was a descriptive observational study, with an analytical component. Setting: A private, secondary care-level clinic in South Africa. Subjects: The study population comprised 122 participants. Each subject completed an estimated, three-day dietary record. The data were analysed using a computerised food analysis programme. The fructose intake was analysed semi-quantitatively. IBS subjects’ protein and carbohydrate intake were significantly higher than the recommended dietary allowance for protein and carbohydrate (p-values < 0.000 and < 0.000, respectively). Outcome measures: The identification of dietary risk factors that affect IBS. Results: The IBS subjects’ daily total dietary fibre (15.13 g ± 13.11) was significantly lower (p-value < 0.000) than the dietary reference intake (DRI) target intake of 24.76 g/day, and the intake of micronutrients, calcium, iron and folate) was significantly less than the DRI. There was no significant difference in macronutrient intake between the diarrhoea-predominant IBS (D-IBS), constipation-predominant IBS (C-IBS) and the control groups. The total number of fructose serves per day was not statistically significant between the three groups (C-IBS 2.68 ± 1.68, D-IBS 2.15 ± 1.86, and controls 3.17 ± 2.39, p-value = 0.157). Conclusion: The IBS subjects in this study consumed diets that were deficient in key micronutrients and total fibre when judged against the recommended DRIs. Dietary adjustments may have been tailored by subjects to minimise symptom development and this led to nutritionally deficient diets.
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    Nutrient intake, gastrointestinal microbiota and the effect of Lactobacillus plantarum 299V in irritable bowel syndrome patients
    (Stellenbosch : Stellenbosch University, 2014-12) Stevenson, Cheryl; Roux, Saartjie; Blaauw, Renee; Visser, Janicke; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Interdisciplinary Health Sciences:. Division of Human Nutrition.
    ENGLISH ABSTRACT: Background: Irritable bowel syndrome (IBS) is a common gastrointestinal (GI) disorder. GI symptoms and impaired quality of life affect between 10-20% of all adults, corresponding to about 25-50% of all patients who visit a gastroenterologist’s clinic. In recent years, several novel mechanisms of IBS that likely relate to previously established theories have been identified. Inflammation, postinfectious low-grade inflammation, immunological and genetic predisposition along with altered microbiota are critical in IBS development, while several dietary factors may also play a role in this syndrome. However, none of these factors accounts for the full repertoire of IBS symptoms, and the pathophysiology of this condition is not fully understood. The overarching aim of this study was to investigate the nutrient intakes, GI microbiota and the effect of Lactobacillus plantarum (L.plantarum) 299v in IBS patients. Sub-aims: 1) Update healthcare professionals on current probiotic information and provide an overview of probiotic treatment approaches, with special emphasis on IBS, 2) conduct a well designed randomised, double blind, placebo-controlled trial (RCT) with L. plantarum 299v as part of an intervention and establish whether a course of probiotics may alleviate undesirable symptoms of IBS and improve quality of life, 3) assess nutrient intake in patients with irritable bowel syndrome (IBS) compared to dietary recommendations, 4) validate and assess the reproducibility of food records and 5) identify possible nutrient risk components for establishing GI microbiota involved in IBS and as part of an intervention, determine whether a course of probiotics may alter stool microbiota. Results: 1) A review article published by the author provides an overview of current probiotic treatment options to health care professionals and indicates certain probiotics are a promising therapeutic treatment option for management of IBS symtpoms, 2) the effects of the single strain probiotic, L. plantarum 299v, supplementation was evaluated in a RCT. Compared to placebo, the probiotic supplementation showed no significant reduction in GI symptom severity scores, particularly abdominal pain relief. Quality of life was also not improved in the treatment versus control group. Both the treatment and placebo groups improved significantly over the trial period, indicating a large placebo effect, 3) nutrient intakes of the IBS patients compared to current dietary reference recommendations indicates that this group of patients are at risk for nutrient inadequacies in key macro and micronutrients, 4) the validity and reliability of the dietary data showed good reliability but poor validity as measured by plasma fatty acids and 5) the GI microbiota composition in the phenotypically different diarrhoea-predominant IBS (D-IBS) vs. constipation-predominant IBS (C-IBS) showed that D-IBS patients had significantly lower counts of Lactobacillus plantarum compared to C-IBS patients. The probiotic had no significant effects on the GI microbiota as measured by quantitative polymerase chain reaction (qPCR). It was found that nutrient intakes had a significant impact on the microbiota. Lower fibre intakes were associated with higher Bacteroides spp., lower Bifidobacteria bifidum and Lactobacillus plantarum counts in both IBS groups. Conclusion: Taken together, L.plantarum 299v did not alleviate the GI symptoms of IBS, nor was it associated with significant changes in the GI microbiota. IBS patients may be at risk of key nutrient inadequacies. The influence of nutrient intakes on the GI microbiota provides an attractive explanation as a potential pathophysiological factor for IBS.
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    Probiotic effect and dietary correlations on faecal microbiota profiles in irritable bowel syndrome
    (Medpharm Publications, 2019) Stevenson, Cheryl; Blaauw, Renee; Fredericks, Ernst; Visser, Janicke; Roux, Saartjie
    Objective: Probiotics and nutrient intakes modulate gastrointestinal (GIT) microbiota and symptoms of irritable bowel syndrome (IBS). The extent to which these factors influence the microbiota is relatively unknown. The primary objective of this paper was to investigate the effect of a probiotic on gut microbiota and IBS symptoms. The secondary objective was exploring correlations between dietary intake and gut microbiota. Design: This study was an extension of a randomised clinical trial (Clinical Trials Registry NCT018867810). Dietary intake was recorded by three-day estimated food records. Faecal samples were collected at three time points: (1) baseline (A), (2) after eight weeks’ probiotic supplementation (Lactobacillus plantarum 299v) (B) and (3) following a two-week washout period (C). Total Bacteroides spp., Bifidobacteria bifidum and Lactobacillus plantarum were quantified by quantitative real-time polymerase chain reaction (qPCR). Results: Twenty-eight diarrhoea-predominant IBS (D-IBS) and 24 constipation-predominant IBS (C-IBS) patients participated. Lactobacillus plantarum profiles at baseline (A) were significantly different between C-IBS and D-IBS (−0.956 ± 1.239 vs. −1.700 ± 1.239; p = 0.024). There was no significant change in bacterial counts after completion of the trial (B) and following the washout period (C) between groups. In both groups there were significant direct correlations between fibre and Lactobacillus plantarum and inverse correlations between fibre and Bacteroides spp. There was no difference in symptom severity scores between treatment and placebo groups during the study. Conclusion: The probiotic had no effect on symptoms and GIT microbiota. Certain nutrients strongly correlate to certain bacterial profiles, suggesting that nutrients can significantly influence gastrointestinal microbiota composition.