Who should deliver the low FODMAP diet and what educational methods are optimal: a review.

Dietary management is being hailed as an effective strategy for the management of irritable bowel syndrome. Specifically, a diet low in fermentable carbohydrates (FODMAPs) has demonstrated efficacy in approximately 70% of patients. As evidence in support of the low FODMAP diet continues to emerge, there is increasing debate regarding implementation of the diet particularly concerning who should educate patients and how to educate them. Registered dieticians have largely pioneered the evidence that supports the effectiveness of the low FODMAP diet in irritable bowel syndrome, and the diet is recognized as a dietician-led therapy. However, there is an increasing trend for non-dietician-led implementation of the diet despite an absence of evidence on both the clinical or cost-effectiveness of such. Additionally, there is a growing requirement for dietetic services to increase capacity in response to increasing referrals, and consequently, there is a need to investigate innovative ways to educate patients whilst maintaining dietician-led intervention. Herein, we review the evidence for delivery of the low FODMAP diet and discuss potentially effective methods for service delivery.

Gut microbiota associations with diet in irritable bowel syndrome and the effect of low FODMAP diet and probiotics.

BACKGROUND AND AIMS: Diet is both a modulator of the gastrointestinal microbiota and an important therapy in irritable bowel syndrome (IBS). We aimed to comprehensively (i) identify diet-microbiota associations in adults with IBS consuming habitual diet; (ii) assess the impact of two nutritional interventions on the microbiota; and (iii) determine whether baseline microbiota can predict clinical response to diet or probiotic intervention. METHODS: Data were analyzed from 95 individuals with IBS participating in a previously published 4-week 2x2 factorial design randomized controlled trial investigating the impact of the low FODMAP diet (LFD) and co-administration of a probiotic. Diet was assessed at four hierarchical levels and partial 16S rRNA gene sequencing was used to profile the microbiota. RESULTS: There were numerous diet-microbiota associations especially at the nutrient level, including a negative association between protein and Bifidobacterium abundance (rs = -0.358, p < 0.001). After correction for multiple testing, the significance for this association (q = 0.237) and all others was lost. Low FODMAP diet led to changes in abundance of major saccharolytic genera compared with sham diet, including higher Bacteroides (LFD 34.1% (15.7%) vs sham 23.3% (15.2%), q = 0.01) and lower Bifidobacterium (0.9% (1.0%) vs 2.1%, (2.5%) q = 0.029). Compared with placebo, probiotic supplementation led to higher Lactobacillus (probiotic 0.08% (0.1%) vs placebo 0.03% (0.2%), q < 0.001), and Streptococcus abundance (2.0% (2.2%) vs 0.6% (1.2%), q = 0.001). The probiotic treatment buffered the impact of the low FODMAP diet on Bifidobacterium. Baseline microbiota did not predict clinical response to either intervention. CONCLUSIONS: Although diet modifies the gut microbiota, bivariate correlation analysis may only provide a limited explanation of the complex diet interactions with individual gut bacteria in IBS. Some diet interventions modify the microbiota in IBS. TRIAL REGISTRY: ISRCTN (http://www.isrctn.com) Registered under ISRCTN registry identifier no.ISRCTN02275221.

Iron status is inversely associated with dietary iron intakes in patients with inactive or mildly active inflammatory bowel disease.

BACKGROUND: Patients with inflammatory bowel disease (IBD) frequently appear iron deplete but whether this is a reflection of dietary iron intakes is not known. METHODS: Dietary data were collected from 29 patients with inactive or mildly-active IBD and 28 healthy controls using a validated food frequency questionnaire that measured intakes of iron and its absorption modifiers. Non-haem iron availability was estimated using a recently developed algorithm. Subjects were classified for iron status based upon data from a concomitant and separately published study of iron absorption. Absorption was used to define iron status because haematological parameters are flawed in assessing iron status in inflammatory conditions such as IBD. RESULTS: Dietary intakes of total iron, non-haem iron and vitamin C were significantly greater in IBD patients who were iron replete compared to those who were iron deplete (by 48%, 48% and 94% respectively; p≤0.05). The predicted percentage of available non-haem iron did not differ between these groups (19.7 ± 2.0% vs 19.3 ± 2.0% respectively; p=0.25). However, because of the difference in iron intake, the overall amount of absorbed iron did (2.4 ± 0.8 mg/d vs 1.7 ± 0.5 mg/d; p=0.013). No such differences were observed in the healthy control subjects. CONCLUSIONS: In IBD, iron status is more closely related to the quality and quantity of dietary iron intake than in the general healthy population.

Dietary fortificant iron intake is negatively associated with quality of life in patients with mildly active inflammatory bowel disease.

BACKGROUND: Iron deficiency anaemia and oral iron supplementation have been associated negatively with quality of life, and with adverse effects, respectively, in subjects with inflammatory bowel disease (IBD). Hence, the risk-benefit ratio of oral iron is not understood in this patient group. The present case-control study investigated whether dietary iron intake impacts on quality of life in IBD patients. METHODS: Quality of life, habitual dietary iron intakes and iron requirements were assessed in 29 patients with inactive or mildly active IBD as well as in 28 healthy control subjects. RESULTS: As expected, quality of life was worse in IBD patients as a whole in comparison to healthy controls according to EuroQol score and EuroQol VAS percentage (6.9 ± 1.6 vs 5.3 ± 0.6; p< 0.0001 and 77 ± 14% vs 88 ± 12%; p=0.004 respectively). For IBD subjects, 21/29 were iron deplete based upon serum iron responses to oral iron but, overall, were non-anaemic with mean haemoglobin of 13.3 ± 1.5 g/dL, and there was no difference in their quality of life compared to 8/29 iron replete subjects (Hb 14.0 ± 0.8 g/dL). Interestingly, total dietary iron intake was significantly negatively associated with quality of life in IBD patients, specifically for non-haem iron and, more specifically, for fortificant iron. Moreover, for total non-haem iron the negative association disappeared when fortificant iron values were subtracted. Finally, further sub-analysis indicated that the negative association between (fortificant) dietary iron intake and quality of life in IBD patients is driven by findings in patients with mildly active disease rather than in patients with quiescent disease. CONCLUSIONS: Iron deficiency per se (i.e. without concomitant anaemia) does not appear to further affect quality of life in IBD patients with inactive or mildly active disease. However, in this preliminary study, dietary iron intake, particularly fortificant iron, appears to be significantly negatively associated with quality of life in patients with mildly active disease.