Lactose intolerance but not lactose maldigestion is more frequent in patients with irritable bowel syndrome than in healthy controls: A meta‐analysis

Abstract

Background and Purpose Irritable bowel syndrome (IBS) affects 10%‐20% of the adult population and is characterized by abdominal symptoms without relevant organic disease. There are numerous clinical trials available investigating the relationship between IBS, lactose maldigestion (LM), and lactose intolerance (LI), but there have been no meta‐analyses on this topic yet. We aimed to assess the prevalence of LM, objective and subjective (self‐reported) LI in IBS patients compared to healthy controls (HC) without IBS. Methods A systematic literature search was conducted up to 24 April 2018 in PubMed, Embase, and Cochrane Library. Adult IBS patients had to be diagnosed according to the Rome criteria or other well‐defined criteria system. We enrolled controlled studies including healthy adult participants without IBS, as control group. Odds ratios with 95% confidence intervals were calculated. Key Results Altogether 14 articles were suitable for statistical analyses. IBS patients reported themselves significantly more frequently lactose intolerant than HCs (odds ratio [OR] = 3.499; 95% confidence interval [CI] = 1.622‐7.551). Generally, there was no significant difference in the prevalence of LM based on ingested lactose dose (OR = 1.122; 95% CI = 0.929‐1.356) and test type (OR = 1.156; 95% CI = 0.985‐1.356). However, significantly more IBS patients had objective LI (OR = 2.521; 95% CI = 1.280‐4.965). Conclusions and Inferences Lactose intolerance, but not LM is more frequent among patients with IBS compared to HCs. According to our results, IBS among other functional bowel disorders is a possible contributing factor of LI in people with LM.

Does Irritable Bowel Syndrome Exist? Identifiable and Treatable Causes of Associated Symptoms Suggest It May Not

“…A higher prevalence of lactose intolerance, but not lactose malabsorption, has generally been reported in patients fulfilling criteria of IBS [67][68][69]. This observation was confirmed by a meta-analysis of 14 clinical trials in which lactose intolerance, but not lactose malabsorption, was found to be significantly more frequent in patients with IBS when compared to controls [70].…”

Rational investigations in irritable bowel syndrome

“…Only three studies provided data for objective lactose intolerance, whereby symptoms were reported during or shortly after the test in patients with confirmed lactose malabsorption. 62 Those with IBS were significantly more likely to have objective lactose intolerance than healthy controls, but this analysis should be interpreted with caution, as there was significant heterogeneity between studies.…”

“…A recent meta-analysis of 14 case-control studies, the majority of which diagnosed lactose malabsorption using a HBT, reported that prevalence of lactose malabsorption was not significantly higher among those with IBS. 62 This remained the case when data were analysed according to the test used, as well as the dose of lactose ingested.…”

“…Four of the included studies presented data relating to the subjective assessment of lactose intolerance, 62 with patients with IBS being significantly more likely than controls to report the occurrence of symptoms when eating lactose-containing foods. Only three studies provided data for objective lactose intolerance, whereby symptoms were reported during or shortly after the test in patients with confirmed lactose malabsorption.…”

Reply to “A Gluten Reduction Is the Patients’ Choice for a Dietary ‘Bottom Up’ Approach in IBS—A Comment on “A 5Ad Dietary Protocol for Functional Bowel Disorders” Nutrients 2019, 11, 1938”

“…Firstly, we need to portray our view that FBDs are a spectrum of food intolerances caused by intrinsic (genetic or post-disease) factors and extrinsic dietary factors [7][8][9]. Unfortunately, all current dietary therapies originate from a symptom-based approach owing to the lack of reliable diagnostic biomarkers, apart from lactose intolerance and some rare genetic diseases (e.g., sucrose-isomaltase deficiency) [9][10][11][12].…”