Gut microbiota modulation accounts for the neuroprotective properties of anthocyanins

High-fat (HF) diets are thought to disrupt the profile of the gut microbiota in a manner that may contribute to the neuroinflammation and neurobehavioral changes observed in obesity. Accordingly, we hypothesize that by preventing HF-diet induced dysbiosis it is possible to prevent neuroinflammation and the consequent neurological disorders. Anthocyanins are flavonoids found in berries that exhibit anti-neuroinflammatory properties in the context of obesity. Here, we demonstrate that the blackberry anthocyanin-rich extract (BE) can modulate gut microbiota composition and counteract some of the features of HF-diet induced dysbiosis. In addition, we show that the modifications in gut microbial environment are partially linked with the anti-neuroinflammatory properties of BE. Through fecal metabolome analysis, we unravel the mechanism by which BE participates in the bilateral communication between the gut and the brain. BE alters host tryptophan metabolism, increasing the production of the neuroprotective metabolite kynurenic acid. These findings strongly suggest that dietary manipulation of the gut microbiota with anthocyanins can attenuate the neurologic complications of obesity, thus expanding the classification of psychobiotics to anthocyanins

Biology and taxonomy of crAss-like Bacteriophages, the most abundant virus in the human gut

CrAssphages represent the most abundant virus in the human gut microbiota, but the lack of available genome sequences for comparison has kept them enigmatic. Recently, sequence-based classification of distantly related crAss-like phages from multiple environments was reported, leading to a proposed familial-level taxonomic group. Here, we assembled the metagenomic sequencing reads from 702 human fecal virome/phageome samples and analyzed 99 complete circular crAss-like phage genomes and 150 contigs ≥70 kb. In silico comparative genomics and taxonomic analysis enabled a classification scheme of crAss-like phages from human fecal microbiomes into four candidate subfamilies composed of ten candidate genera. Laboratory analysis was performed on fecal samples from an individual harboring seven distinct crAss-like phages. We achieved crAss-like phage propagation in ex vivo human fecal fermentations and visualized short-tailed podoviruses by electron microscopy. Mass spectrometry of a crAss-like phage capsid protein could be linked to metagenomic sequencing data, confirming crAss-like phage structural annotations

Characterization of intestinal microbiota in alcoholic patients with and without alcoholic hepatitis or chronic alcoholic pancreatitis

Abstract Excessive alcohol consumption leads to severe alcoholic hepatitis (sAH) or chronic alcoholic pancreatitis (CAP) only in a subset of patients. We aimed to characterize the intestinal microbiota profiles of alcoholic patients according to the presence and nature of the complications observed: sAH or CAP. Eighty two alcoholic patients were included according to their complications: CAP (N = 24), sAH (N = 13) or no complications (alcoholic controls, AC, N = 45). We analyzed the intestinal microbiota by high-throughput sequencing. Bacterial diversity was lower in patients with CAP, who had a global intestinal microbiota composition different from that of AC. The intestinal microbiota composition of these two groups differed for 17 genera, eight of which were more frequent in patients with CAP (e.g. Klebsiella, Enterococcus and Sphingomonas). There was no significant difference in bacterial diversity between the sAH and CAP groups. However, 16 taxa were more frequent in sAH patients, and 10 were more frequent in CAP patients. After adjustment for confounding factors sAH patients were found to have higher levels of Haemophilus. For alcoholic patients, specific intestinal microbiota signatures are associated with different complications. Patients with CAP and sAH also display specific dysbiosis relative to AC

Influence of 16S rRNA target region on the outcome of microbiome studies in soil and saliva samples

This work was financially supported by the Ministry of Economy and Competitiveness of Spain co-financed with European Regional Development Funds (References: CGL2015-71709-R and SAF2015-71714-R) and the fellowship PEJ2018-004702-A. The European Union also collaborated in the funding of this study (Euronanomed programme, Reference: TARBRAINFECT, and Innovative Medicines Initiative IMI2, Reference: 3TR-831434), as well as the Health Institute Carlos III as the local management institution (Reference: AC18/00008). A.S.L. and V.S.M. were supported by a fellowship from the Ministry of Education, Culture and Sport (FPU 17/05413 and FPU 16/05822), and the results presented in this article are part of A.S.L's doctoral thesis. M.O.G acknowledges for the funds received by the F.P.U. fellowship provided by University of Almeria.Next generation sequencing methods are widely used in evaluating the structure and functioning of microbial communities, especially those centered on 16S rRNA subunit. Since Illumina Miseq, the most used sequencing platform, does not allow the full sequencing of 16S rRNA gene, this study aims to evaluate whether the choice of different target regions might affect the outcome of microbiome studies regarding soil and saliva samples. V1V3, V3V4, V4V5 and V6V8 domains were studied, finding that while some regions showed differences in the detection of certain bacterial taxa and in the calculation of alpha diversity, especially in soil samples, the overall effect did not compromise the differentiation of any sample type in terms of taxonomic analysis at the genus level. 16S rRNA target regions did affect the detection of specific bacteria related to soil quality and development, and microbial genera used as health biomarkers in saliva. V1V3 region showed the closest similarity to internal sequencing control mock community B, suggesting it might be the most preferable choice regarding data reliability.European Union (EU) 3TR-831434Instituto de Salud Carlos III AC18/00008Ministry of Education, Culture and Sport FPU 17/05413 FPU 16/05822University of AlmeriaMinistry of Economy and Competitiveness of SpainEuropean Union (EU) CGL2015-71709-R SAF2015-71714-R PEJ2018-004702-