FODMAP-free diet: not for all patients
Its use remains questionable in FGIDs, but a possible correlation between bacterial populations and response to the FODMAP-free diet could help refine the therapeutic choice.18, 19
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TREATMENT OF IBS
The FODMAP-free diet (Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols) seems to represent an appropriate therapeutic response to IBS. The incriminated foods in fact cause intestinal disruption when they are fermented by bacteria via the production of gas and shortchain fatty acids. Restricting their intake provides benefits that are confirmed by the literature, but which must be weighed against potential negative effects to confirm the value of this type of diet as a first- line therapeutic option. The absence of FODMAPs can in fact cause eating disorders, deficiencies and biological disruption, directly or following dysbiosis of the intestinal microbiota. They should also not be used as a diagnostic test for IBS in place of recognized symptomatic criteria (those of Rome IV), note the experts, who also recall the importance of the gradual reintroduction of excluded foods, after checking that the organism will tolerate them.
THERAPEUTIC EFFICACY AND BACTERIAL PROFILE
A FODMAP-free diet could therefore be appropriate for some types of disorders or individuals, but not for others. This research area has been explored by a Norwegian team, who compared the composition of the intestinal microbiota of IBS patients with response to treatment. In this study, a patient was judged responsive if they showed a reduction of symptoms of at least 50% at 4 weeks on an IBS-SSS score. Out of 61 subjects, 32 (29 women, 3 men) were considered as respondents and 29 (25 women, 4 men) as non-respondents. The analysis of 54 bacterial markers by means of a specific test demonstrated significant differences between the two groups for 10 of these markers. From the data collected, a response index (RI) graduated from 0 to 10 and based on the median values of 10 bacterial markers of the responsive patients was created. Result: subjects with an RI higher than 3 were five times more likely to respond to treatment. A possible innovative therapeutic approach for the treatment of FGIDs.
AN ALTERNATIVE THERAPY, AMONG OTHERS
These reservations have led to the study of other non-pharmacological alternatives in FGIDs (hypnotherapy, gluten-free diet etc..). The literature tends to demonstrate that the conventional dietary advice given by health professionals provides less benefit: list of products to be avoided (fatty or spicy foods, coffee, alcohol, onions…) and eating habits to be adopted (eating at regular intervals, in reasonable quantities, chewing thoroughly…). On the contrary, hypnotherapy might offer the same physiological advantages as the low-FODMAP diet and a better psychological impact in patients suffering from IBS. Regarding the gluten-free diet, there is no comparative study with the low-FODMAP diet, but drawing comparisons between similar studies holds out the prospect of similar results.
18 Hill P, Muir JG, Gibson PR. Controversies and Recent Developments of the Low-FODMAP Diet. Gastroenterol Hepatol (N Y). 2017;13(1):36-45.
19 Valeur J, Småstuen MC, Knudsen T, et al. Exploring Gut Microbiota Composition as an Indicator of Clinical Response to Dietary FODMAP Restriction in Patients with Irritable Bowel Syndrome. Dig Dis Sci. 2018;63(2):429-436.