Stimulation of colonic motility by oral PEG electrolyte bowel preparation assessed by MRI : comparison of split vs single dose

Peer reviewe

Diversity of Bifidobacteria within the Infant Gut Microbiota

Background The human gastrointestinal tract (GIT) represents one of the most densely populated microbial ecosystems studied to date. Although this microbial consortium has been recognized to have a crucial impact on human health, its precise composition is still subject to intense investigation. Among the GIT microbiota, bifidobacteria represent an important commensal group, being among the first microbial colonizers of the gut. However, the prevalence and diversity of members of the genus Bifidobacterium in the infant intestinal microbiota has not yet been fully characterized, while some inconsistencies exist in literature regarding the abundance of this genus. Methods/Principal Findings In the current report, we assessed the complexity of the infant intestinal bifidobacterial population by analysis of pyrosequencing data of PCR amplicons derived from two hypervariable regions of the 16 S rRNA gene. Eleven faecal samples were collected from healthy infants of different geographical origins (Italy, Spain or Ireland), feeding type (breast milk or formula) and mode of delivery (vaginal or caesarean delivery), while in four cases, faecal samples of corresponding mothers were also analyzed. Conclusions In contrast to several previously published culture-independent studies, our analysis revealed a predominance of bifidobacteria in the infant gut as well as a profile of co-occurrence of bifidobacterial species in the infant’s intestine

Irritable bowel syndrome: the problem and the problem of treating it – is there a role for probiotics?

The aim of this review is to highlight the impact of irritable bowel syndrome (IBS) in those patients who consult the medical profession and examine the therapeutic potential of probiotics in this condition, where there is a strong need for new treatment options. Traditionally, IBS is frequently regarded as a trivial condition which is certainly not life threatening and mainly psychological in origin. However, these preconceptions are misplaced, as in some patients the condition can be devastating with the pain being as severe as that of childbirth coupled with incapacitating bowel dysfunction. In addition, patients suffer from a variety of non-colonic symptoms such as low backache, constant lethargy, nausea and genito-urinary problems, all of which lead to these patients having extremely poor quality of life. Unfortunately, the treatment of IBS is very unsatisfactory with only one new medication being developed for this condition in the last 25 years. It is now recognised that IBS is a multifactorial condition with symptoms being triggered by a variety of factors, some of which appear to be influenced by probiotics, resulting in speculation that they may have therapeutic potential in this condition. There have been over thirty controlled clinical trials of probiotics in IBS with approximately two-thirds of these studies showing evidence of an improvement in symptoms. However, not all probiotics appear to be effective with different symptoms being improved by different strains and some improving symptoms more than others. Consequently, the ideal probiotic for the treatment of IBS has yet to be defined, but the evidence is good enough to encourage further research with the aim of identifying an optimal strain or strains

Faecal microbiota composition and host-microbe cross-talk following gastroenteritis and in postinfectious irritable bowel syndrome

Background - About 10% of patients with IBS report the start of the syndrome after infectious enteritis. The clinical features of postinfectious IBS (PI-IBS) resemble those of diarrhoea-predominant IBS (IBS-D). While altered faecal microbiota has been identified in other IBS subtypes, composition of the microbiota in patients with PI-IBS remains uncharacterised. Objective - To characterise the microbial composition of patients with PI-IBS, and to examine the associations between the faecal microbiota and a patient's clinical features. Design - Using a phylogenetic microarray and selected qPCR assays, we analysed differences in the faecal microbiota of 57 subjects from five study groups: patients with diagnosed PI-IBS, patients who 6 months after gastroenteritis had either persisting bowel dysfunction or no IBS symptoms, benchmarked against patients with IBS-D and healthy controls. In addition, the associations between the faecal microbiota and health were investigated by correlating the microbial profiles to immunological markers, quality of life indicators and host gene expression in rectal biopsies. Results - Microbiota analysis revealed a bacterial profile of 27 genus-like groups, providing an Index of Microbial Dysbiosis (IMD), which significantly separated patient groups and controls. Within this profile, several members of Bacteroidetes phylum were increased 12-fold in patients, while healthy controls had 35-fold more uncultured Clostridia. We showed correlations between the IMD and expression of several host gene pathways, including amino acid synthesis, cell junction integrity and inflammatory response, suggesting an impaired epithelial barrier function in IBS. Conclusions - The faecal microbiota of patients with PI-IBS differs from that of healthy controls and resembles that of patients with IBS-D, suggesting a common pathophysiology. Moreover, our analysis suggests a variety of host–microbe associations that may underlie intestinal symptoms, initiated by gastroenteriti