Lactulose breath test results in patients with persistent abdominal symptoms followingGiardia lambliainfection

Abstract

Gastrointestinal complaints in patients with persistent or cleared giardiasis were unrelated to hydrogen breath excretion after lactulose challenge. Post-giardiasis IBS cannot be ascribed to intestinal bacterial overgrowth, as diagnosed by LBT.

Carbohydrate intolerance in patients with self-reported food hypersensitivity: Comparison of lactulose and glucose

“…Hence, intestinal hydrogen gas production as measured by hydrogen excretion in exhaled air does not explain carbohydrate-induced symptoms in our patients. This finding is in accordance with previous findings of others [18] and of our group [6][7][8]. Since only a fraction of the gas produced in the intestines is excreted via the lungs [19], it is possible that a 3-h quantification of exhaled gas post-challenge is a poor estimate of the actual gas production throughout the following day.…”

“…The main goal of the present study was to clarify whether the response to a small dose of an indigestible, but fermentable, carbohydrate, the disaccharide lactulose [6,7], is related to fermentation or merely reflects psychological factors, primarily symptom anticipation. We thus performed a randomized, double-blind, cross-over study with lactulose and the easily absorbable monosaccharide glucose as placebo in patients with self-reported food hypersensitivity.…”

Plasma glucagon-like peptide 1 and peptide YY levels are not altered in symptomatic fructose-sorbitol malabsorption

“…It could be argued that our study design was not appropriate for the exclusion of SIBO (or rapid small-intestinal transit) as a cause of false-positive results of the breath test. However, in the present as well as in a previous study [27], we found no difference in the occurrence of early positive breath tests (a widely used criterion for SIBO during lactulose breath testing) between the groups, and it thus seems unlikely that SIBO would explain the difference between asymptomatic and symptomatic malabsorbers. The role of SIBO in functional gastrointestinal disorders remains controversial [28] and there are quite convincing arguments that the symptoms of carbohydrate intolerance are related to colonic rather than small-intestinal fermentation [29].…”

Giardia

“…While chronically infected hosts may continue to have diarrhea, they may also become constipated, and symptoms may rarely be associated with signs of "microscopic duodenal infl ammation" (Hanevik et al, 2007;Morken et al, 2008). Infected hosts may present with a spectrum of symptoms ranging from asymptomatic carriage to acute or chronic symptomatic infection that manifests as diarrheal disease.…”

“…Research fi ndings indicate that acute enteric infection may result in post-infectious IBS (PI-IBS) (Thornley et al, 2001;Marshall et al, 2006). Lactulose breath tests are negative for individuals that have developed PI-IBS as a result of G. duodenalis infection (Morken et al, 2008). In affected individuals, it appears that the infection may represent a triggering factor for the development of IBS, and the presence of the parasite is not required for symptoms to persist (D'Anchino et al, 2002).…”