Intake of L. reuteri DSM 17938 for 12 weeks did not affect HbA1c in people with type 2 diabetes on insulin therapy; however, L. reuteri improved insulin sensitivity in a subset of participants and we propose that high diversity of the gut microbiota at baseline may be important.
1H magnetic resonance spectroscopy (1H MRS) studies exploring brain metabolites, especially glutamine + glutamate (Glx), in obsessive compulsive disorder (OCD) are of vital interest for trying to understand more about the pathophysiology of OCD. Therefore, we conducted the present 1H MRS study with the aims of (1) comparing MRS metabolites in a group of adult patients with OCD and a group of healthy controls, and (2) examining the relationship between MRS metabolite concentrations and symptom severity in the patient group. Three brain regions were studied, the right caudate nucleus, the anterior gyrus cinguli and the occipital cortex bilaterally. Since multivariate analysis is a highly useful tool for extraction of 1H MRS data, we applied principal component analysis (PCA) and partial least square projection to latent structures (PLS) to the MRS data. PLS disclosed a strong relationship between several of the metabolites and OCD symptom severity, as measured with Yale-Brown obsessive-compulsive scale (YBOCS): the YBOCS score was found to be positively correlated to caudate creatine, Glx, glutamate, and choline compounds as well as occipital cortex myoinositol, and negatively correlated to occipital cortex Glx. The negative correlation between occipital cortex Glx and YBOCS was the most impressive. PCA did not reveal any tendency for a separation between the patients with OCD and controls with respect to MRS metabolites. The results are discussed in relation to corticostriatothalamocortical feedback and previous observations of poor visuospatial ability in OCD.
Background and aimsEvidence from preclinical and clinical studies suggests that interactions among the brain, gut, and microbiota may affect the pathophysiology of irritable bowel syndrome (IBS). As disruptions in central and peripheral serotonergic signaling pathways have been found in patients with IBS, we explored the hypothesis that the abundance of serotonin-modulating microbes of the order Clostridiales is associated with functional connectivity of somatosensory brain regions and gastrointestinal (GI) sensorimotor function.MethodsWe performed a prospective study of 65 patients with IBS and 21 healthy individuals (controls) recruited from 2011 through 2013 at a secondary/tertiary care outpatient clinic in Sweden. Study participants underwent functional brain imaging, rectal balloon distension, a nutrient and lactulose challenge test, and assessment of oroanal transit time within a month. They also submitted stool samples, which were analyzed by 16S ribosomal RNA gene sequencing. A tripartite network analysis based on graph theory was used to investigate the interactions among bacteria in the order Clostridiales, connectivity of brain regions in the somatosensory network, and GI sensorimotor function.ResultsWe found associations between GI sensorimotor function and gut microbes in stool samples from controls, but not in samples from IBS patients. The largest differences between controls and patients with IBS were observed in the Lachnospiraceae incertae sedis, Clostridium XIVa, and Coprococcus subnetworks. We found connectivity of subcortical (thalamus, caudate, and putamen) and cortical (primary and secondary somatosensory cortices) regions to be involved in mediating interactions among these networks.ConclusionsIn a comparison of patients with IBS and controls, we observed disruptions in the interactions between the brain, gut, and gut microbial metabolites in patients with IBS—these involve mainly subcortical but also cortical regions of brain. These disruptions may contribute to altered perception of pain in patients with IBS and may be mediated by microbial modulation of the gut serotonergic system.Electronic supplementary materialThe online version of this article (10.1186/s40168-019-0656-z) contains supplementary material, which is available to authorized users.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.