AIMTo determine the effects of Lactobacillus acidophilus NCFM on irritable bowel syndrome (IBS) symptoms and quality of life (QoL).METHODSIn this randomized triple-blind trial, adult IBS volunteers who were recruited according to Rome III criteria received 109 or 1010 colony-forming units of NCFM or placebo daily for 12 wk. IBS Symptom Severity Score (IBS-SSS), which constituted the primary outcome, and secondary outcomes, including individual IBS symptoms, IBS-related QoL questionnaire, anxiety and depression, defecation frequency, and stool consistency, were assessed at baseline at the end of the 8-wk run-in period, after 4 and 12 wk of intervention, and after a 4-wk washout.RESULTSA total of 340 of 391 randomized volunteers completed the trial. IBS-SSS improved over 12 wk of treatment in all treatment groups, decreasing by a mean ± SD of 44.0 ± 80.2, 50.8 ± 82.4, and 48.3 ± 72.2 in the placebo, active low-dose, and active high-dose groups, respectively. Similarly, secondary outcomes did not differ between treatment groups. However, in a post hoc analysis of volunteers with moderate to severe abdominal pain at baseline (VAS > 35/100), the treatment significantly reduced the sensation of abdominal pain. Pain scores fell by 20.8 ± 22.8, 29.4 ± 17.9, and 31.2 ± 21.9 in the placebo, active low-dose, and active high-dose groups, respectively (P value for placebo vs combined active doses = 0.0460).CONCLUSIONNCFM alleviates moderate to severe abdominal pain, consistent with earlier observations of this strain mitigating visceral pain through increased analgesic receptor expression.

Commercial probiotic strains for food or supplement use can be altered in different ways for a variety of purposes. Production conditions for the strain or final product may be changed to address probiotic yield, functionality, or stability. Final food products may be modified to improve flavor and other sensory properties, provide new product formats, or respond to market opportunities. Such changes can alter the expression of physiological traits owing to the live nature of probiotics. In addition, genetic approaches may be used to improve strain attributes. This review explores whether genetic or phenotypic changes, by accident or design, might affect the efficacy or safety of commercial probiotics. We highlight key issues important to determining the need to re-confirm efficacy or safety after strain improvement, process optimization, or product formulation changes. Research pinpointing the mechanisms of action for probiotic function and the development of assays to measure them are greatly needed to better understand if such changes have a substantive impact on probiotic efficacy.

BackgroundConstipation is a common complaint in adults. Lactitol is an osmotic disaccharide laxative that increases fecal volume and stimulates peristalsis. In this paper, we present the first meta-analysis on the efficacy and tolerance of lactitol for adult constipation.MethodsWe searched MEDLINE® and Embase, with no date or language restrictions, for studies of lactitol supplementation on adult constipation. A random-effects meta-analysis was performed on pre- to posttreatment changes in stool frequency and consistency with lactitol among all studies, as well as a comparison of efficacy and tolerance outcomes in randomized controlled trials (RCTs) of lactitol versus lactulose.ResultsA total of eleven studies representing 663 distinct patients were included in the final analysis, including five single-arm studies, four RCTs comparing lactitol with lactulose, one RCT comparing lactitol with placebo, and one nonrandomized controlled trial comparing lactitol with stimulant laxatives. Weekly stool frequency was significantly increased with lactitol compared with baseline (standardized mean difference [SMD]: 1.56, P<0.001). Stool consistency also improved over the supplementation period with lactitol (SMD: 1.04, P<0.001). Approximately one-third of patients experienced an adverse event; however, symptoms were generally mild and rarely (5%) resulted in study withdrawal. In RCTs of lactitol versus lactulose, lactitol was slightly more effective than lactulose in increasing weekly stool frequency (SMD: 0.19, P=0.06). No statistically significant differences between lactitol and lactulose were identified in any other efficacy or tolerance outcome. Lactitol demonstrated favorable efficacy and tolerance in individual studies when compared to stimulant laxatives and placebo.ConclusionLactitol supplementation is well tolerated and improves symptoms of adult constipation. The efficacy and tolerance of lactitol and lactulose are similar, with a trend for more frequent stools with lactitol. Limited evidence suggests lactitol is superior to stimulant laxatives and placebo for relieving constipation symptoms.

Psyllium and lactitol have been reported to increase fecal volume, moisture content and bowel movement frequency (BMF). However, the benefits of their combined use on constipation has not been examined. The aim of this study was to evaluate the effects of a 4-week intervention with lactitol and/or psyllium on bowel function in constipated volunteers. Adults (N = 172) who were diagnosed with functional constipation per Rome III criteria were randomized to four treatment groups: 10 g lactitol, 3.5 g psyllium, a combination of 10 g lactitol and 3.5 g psyllium, or placebo. The primary endpoint was change in BMF from Day 0 to 28 as compared to placebo. Secondary endpoints were assessed by inventories, including stool consistency, patient assessment of constipation symptoms and quality of life, relief of constipation, 24-h food recall, physical activity, product satisfaction and adverse events (AE). BMF increased by 3.0 BMs with lactitol, by 2.9 with psyllium, and by 3.1 with the combination, but was not different from placebo (3.7 BMs). Other clinical endpoints were similar between treatments. No serious AEs were reported. In conclusion, this study showed a similar effect on relief of constipation in all treatment groups. The treatments that were administered to the volunteers were well tolerated.

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