1.
Effect of Lactobacillus paracasei CNCM I-1572 on symptoms, gut microbiota, short chain fatty acids, and immune activation in patients with irritable bowel syndrome: A pilot randomized clinical trial.
Cremon, C, Guglielmetti, S, Gargari, G, Taverniti, V, Castellazzi, AM, Valsecchi, C, Tagliacarne, C, Fiore, W, Bellini, M, Bertani, L, et al
United European gastroenterology journal. 2018;6(4):604-613
-
-
-
Free full text
-
Plain language summary
Intestinal bacteria have a role to play in the development and symptoms of irritable bowel syndrome (IBS). The objective of this randomised controlled trial was to assess the effects of Lactobacillus paracasei CNCM I-1572 on clinical and gut microbiota-related factors in IBS. Forty IBS patients took part in the trial, and took either the probiotic or a placebo for four weeks. Lactobacillus paracasei CNCM I-1572 did not significantly improve IBS symptoms such as abdominal pain and discomfort. It did however induce a significant reduction in Ruminococcus, which has previously been associated with IBS. Patients taking the probiotic also showed a significant increase in the short chain fatty acids (SCFAs) acetate and butyrate, and a significant reduction in the pro-inflammatory cytokine interleukin-15. This pilot study shows that Lactobacillus paracasei CNCM I-1572 is able to modulate gut microbiota structure/function and reduce immune activation in IBS. As no statistically significant effect on IBS symptoms was found, further studies are necessary to determine the role of this probiotic in IBS.
Abstract
BACKGROUND Evidence suggests a role of intestinal microbiota-host interactions in the pathophysiology and symptoms of irritable bowel syndrome (IBS). OBJECTIVE The objective of this article is to assess the effects of Lactobacillus paracasei CNCM I-1572 on clinical and gut microbiota-related factors in IBS. METHODS We conducted a multicenter, randomized, double-blind, cross-over, 18-week, placebo-controlled, pilot trial assessing the effect of Lactobacillus paracasei CNCM I-1572 on symptoms, gut microbiota composition, fecal short chain fatty acid (SCFA), immunoglobulin A, and cytokines in IBS. The intestinal microbial ecosystem was characterized by 16S rRNA gene profiling. RESULTS Forty IBS patients were enrolled from five Italian centers. Lactobacillus paracasei CNCM I-1572 did not significantly improve IBS symptoms, including primary efficacy variables worst abdominal pain/discomfort and IBS degree of relief. Interestingly, Lactobacillus paracasei CNCM I-1572 induced a significant reduction in genus Ruminococcus, dominated by taxa related to Ruminococcus bromii and Ruminococcus callidus, a significant increase in the SCFAs acetate and butyrate, and a significant reduction in the pro-inflammatory cytokine interleukin-15. CONCLUSIONS This pilot study shows that Lactobacillus paracasei CNCM I-1572 is able to modulate gut microbiota structure/function and reduce immune activation in IBS. As no statistically significant effect on IBS-symptoms was found, further studies are necessary to determine the role of this probiotic in IBS. The study was registered at ClinicalTrials.gov registry under identifier NCT02371499.
2.
Effects of a gluten-free diet on gut microbiota and immune function in healthy adult humans.
Sanz, Y
Gut microbes. 2010;1(3):135-7
-
-
-
Free full text
-
Plain language summary
The composition of gut bacteria is greatly influenced by diet composition, particularly complex carbohydrates. Currently for patients with coeliac disease, the only therapy is to adhere to a strict gluten-free diet (GFD), which naturally reduces intake of these complex carbohydrates. The aim of this preliminary study was to assess the nutritional quality of the GFD through modifications on the composition and immune properties of the gut microbiota. 10 healthy subjects followed a GFD for one month and faecal microbiota was analysed. This study showed that inflammatory markers were significantly reduced, however the number of healthy gut bacteria also decreased. Based on these findings, the author concluded that a GFD does not lead to complete normalisation of the gut microbiota, and supports the consideration to promote polysaccharide and probiotic intake in treated coeliac disease patients.
Abstract
Diet is a major environmental factor influencing gut microbiota diversity and functionality, which might be relevant to subjects following dietary therapies. Celiac disease (CD) is an enteropathy caused by an aberrant immune response to cereal gluten proteins and the only therapy is the adherence to a gluten-free diet (GFD). In this context, a preliminary study was conducted to establish whether the GFD in itself could modify the composition and immune properties of the gut microbiota. The trial included 10 healthy subjects (30.3 years-old), which were submitted to a GFD over one month. Analysis of fecal microbiota and dietary intake indicated that numbers of healthy gut bacteria decreased, while numbers of unhealthy bacteria increased parallel to reductions in the intake of polysaccharides after following the GFD. Fecal samples of subjects under a GFD, which represent an altered microbiota, also exerted lower immune stimulatory effects on peripheral blood mononuclear cells than those of subjects on a regular gluten-containing diet. This addendum presents further discussion on the rationale behind these findings, limitations of the study and possible consequences of dietary counselling in the care process of celiac disease patients.