A carbohydrate-restricted diet for patients with irritable bowel syndrome lowers serum C-peptide, insulin, and leptin without any correlation with symptom reduction.

Alterations in gut endocrine cells and hormone levels have been measured in patients with irritable bowel syndrome (IBS). The hypothesis of the present study was that hormone levels would change after 4 weeks of a starch- and sucrose-reduced diet (SSRD) intervention corresponding to decreased carbohydrate intake and symptoms. Among 105 IBS patients from primary and tertiary healthcare, 80 were randomized to SSRD, while 25 followed their ordinary diet. Food diaries, Rome IV, and IBS-symptom severity score (IBS-SSS) questionnaires were completed, and blood samples were collected at baseline and after the intervention. Serum C-peptide, gastric inhibitory peptide, glucagon, glucagon-like peptide-1, insulin, leptin, luteinizing hormone, polypeptide YY, and glucose were measured, along with the prevalence of autoantibodies against gonadotropin-releasing hormone; its precursor, progonadoliberin-2, and receptor; and tenascin C. Carbohydrate intake was lower in the intervention group than in controls at week 4 (median: 88 [66-128] g vs 182 [89-224] g; P < .001). The change in carbohydrate intake, adjusted for weight, was associated with a decrease in C-peptide (ß: 14.43; 95% confidence interval [CI]: 4.12-24.75) and insulin (ß: 0.18; 95% CI: 0.04-0.32) levels. Glucose levels remained unchanged. The IBS-SSS scores were lower in the intervention group but not in controls (P < .001), without any association with changes in hormone concentrations. There was no difference in autoantibody prevalence between patients and healthy controls. In conclusion, the hypothesis that reduced carbohydrate intake corresponded to altered hormonal levels in IBS was accepted; however, there was no relationship between hormonal concentrations and symptoms.

A systematic review and meta-analysis of the associations between endometriosis and irritable bowel syndrome.

Endometriosis and Irritable Bowel Syndrome (IBS) are common conditions among young women of reproductive age. The etiologies to the diseases are uncertain, but multifactorial pathophysiology has been proposed for each of them. Many studies have examined the two conditions separately, but the literature on the associations between endometriosis and IBS is sparse. However, there is an increasing amount of research on how endometriosis patients are likely to also have a diagnosis of IBS. Furthermore, endometriosis shares several features with IBS, such as low-grade inflammation and visceral hypersensitivity. This systematic review summarized published original articles in English that have compared associations between endometriosis and IBS. The inclusion criteria for articles in the review were: i) endometriosis was diagnosed by surgical methods, ii) gastrointestinal symptoms were examined in a structured manner and iii) IBS was diagnosed by Rome criteria. From the initial 254 publications identified on PubMed, Web of Science and EMBASE, 13 fulfilled the criteria and could finally be included in the summary. The findings from the review showed that women diagnosed with endometriosis seem to have a twofold or threefold risk to also fulfill the criteria for IBS. The summary risk estimate of the four studies included in the meta-analysis was 2.39 (95 % confidence interval: 1.83-3.11). In women initially diagnosed with IBS, some studies reported a threefold risk of having an endometriosis diagnosis. Despite the strong associations reported between the two conditions, this review also revealed a gap in adjusting for factors that may have affected the expression of gastrointestinal symptoms, e.g., phases of the menstrual cycle, medication and psychological aspects, which may have interpretation of the reviewed articles' results. The conclusion of this review is that there is a coexistence of gastrointestinal symptoms fulfilling the Rome criteria in patients with endometriosis, but it is uncertain whether there is a true comorbidity between endometriosis and IBS, or whether the gastrointestinal symptomatology in endometriosis depends on medication. Additionally, the adequacy of the Rome criteria to differentiate IBS from the shared symptomatology of other diseases with visceral hypersensitivity must be further evaluated.