Microbiota-Dependent Fiber Responses: A Proof-of-Concept Study on Short-chain Fatty Acid Production in Prevotella- and Bacteroides-Dominated Healthy Individuals.

Background: Dietary fiber supports metabolic health via microbial fermentation, producing short-chain fatty acids (SCFAs). However, metabolic responses to fiber vary between individuals, potentially due to differences in gut microbiota composition. The Prevotella-to-Bacteroides (P/B) ratio has emerged as a potential biomarker for fiber responsiveness.

The effect of alcohol withdrawal therapy on gut microbiota in alcohol use disorder and its link to inflammation and craving.

Background: Alcohol use disorder (AUD) is linked to changes in the function and composition of the human gut microbiome (GM). The GM affects inflammation by producing anti-inflammatory molecules such as short-chain fatty acids (SCFA), in particular butyrate, which are linked to appetite regulation, a mechanism involved in alcohol craving. This study investigates changes in GM composition and functional capacity to produce SCFA during alcohol withdrawal and their link to inflammation and craving.

Short-term and long-term development of gut microbiota in children after liver transplantation-A prospective observational trial.

In children, little is known about gut microbiota (GM) in end-stage liver disease and its association with graft function after pediatric liver transplantation (pLT). We analyzed GM composition and function in children before pLT, longitudinally post-pLT and in long-term survivors (LT-pLT) in order to assess the impact of disease severity, treatment, and pLT on GM and delineate associations with graft and patient health. Fecal samples (FS) of 29 children [17f (female), age 2.

Distinct clusters of bacterial and fungal microbiota in end-stage liver cirrhosis correlate with antibiotic treatment, intestinal barrier impairment, and systemic inflammation.

Decompensated liver cirrhosis (dLC) is associated with intestinal dysbiosis, however, underlying reasons and clinical consequences remain largely unexplored. We investigated bacterial and fungal microbiota, their relation with gut barrier integrity, inflammation, and cirrhosis-specific complications in dLC-patients. Competing-risk analyses were performed to investigate clinical outcomes within 90 days.

Oral tributyrin treatment affects short-chain fatty acid transport, mucosal health, and microbiome in a mouse model of inflammatory diarrhea.

Butyrate may decrease intestinal inflammation and diarrhea. This study investigates the impact of oral application of sodium butyrate (NaB) and tributyrin (TB) on colonic butyrate concentration, SCFA transporter expression, colonic absorptive function, barrier properties, inflammation, and microbial composition in the colon of slc26a3 mice, a mouse model for inflammatory diarrhea. In vivo fluid absorption and bicarbonate secretory rates were evaluated in the cecum and mid-colon of slc26a3 and slc26a3 mice before and during luminal perfusion of NaB-containing saline and were significantly stimulated in both slc26a3 and slc26a3 colon by NaB.

Escherichia coli Nissle Improves Short-Chain Fatty Acid Absorption and Barrier Function in a Mouse Model for Chronic Inflammatory Diarrhea.

Background: Defects in SLC26A3, the major colonic Cl-/HCO3- exchanger, result in chloride-rich diarrhea, a reduction in short-chain fatty acid (SCFA)-producing bacteria, and a high incidence of inflammatory bowel disease in humans and in mice. Slc26a3-/- mice are, therefore, an interesting animal model for spontaneous but mild colonic inflammation and for testing strategies to reverse or prevent the inflammation. This study investigates the effect of Escherichia coli Nissle (EcN) application on the microbiome, SCFA production, barrier integrity, and mucosal inflammation in slc26a3-/- mice.

Short-chain fatty acids improve inflamm-aging and acute lung injury in old mice.

A chronic proinflammatory milieu (inflamm-aging) is observed in the elderly and associated with poorer prognosis in acute lung injury (ALI). Gut microbiome-derived short-chain fatty acids (SCFAs) are known to have immunomodulatory capabilities, but their function in the gut-lung axis in aging is poorly understood. Here, we analyzed the gut microbiome and its impact on inflammatory signaling in the aging lung and tested the effects of SCFAs in young (3 mo) and old (18 mo) mice that received either drinking water with a mixture of each 50 mM acetate, butyrate, and propionate for 2 wk or water alone.

Predicting butyrate- and propionate-forming bacteria of gut microbiota from sequencing data.

The bacteria-derived short-chain fatty acids (SCFAs) butyrate and propionate play important (distinct) roles in health and disease, and understanding the ecology of respective bacteria on a community-wide level is a top priority in microbiome research. Applying sequence data (metagenomics and 16S rRNA gene) to predict SCFAs production and , a clear split between butyrate- and propionate-forming bacteria was detected with only very few taxa exhibiting pathways for the production of both SCFAs. After growth of fecal communities from distinct donors (n = 8) on different substrates (n = 7), abundances of bacteria exhibiting pathways correlated with respective SCFA concentrations, in particular in the case of butyrate.

The Resistance Mechanism Governs Physiological Adaptation of to Growth With Sublethal Concentrations of Carbapenem.

Factors governing resistance in carbapenem-resistant are manifold. Despite ample research efforts, underlying molecular mechanisms are still only partly understood. Furthermore, little is known on (eco)physiological consequences from resistance acquisition originating from distinct mechanisms in respective bacteria.

Microbiota-dependent increase in δ-valerobetaine alters neuronal function and is responsible for age-related cognitive decline.

Understanding the physiological origins of age-related cognitive decline is of critical importance given the rising age of the world's population. Previous work in animal models has established a strong link between cognitive performance and the microbiota, and it is known that the microbiome undergoes profound remodeling in older adults. Despite growing evidence for the association between age-related cognitive decline and changes in the gut microbiome, the mechanisms underlying such interactions between the brain and the gut are poorly understood.

Molecular characterization and improved diagnostics of strains isolated over the last two decades at a German tertiary care center.

Nocardiosis is a rare but life-threatening infection caused by aerobic of the genus particularly affecting immunocompromised hosts. The identification of and antibiotic susceptibility testing by standard microbiological methods are incomplete and molecular techniques may improve diagnostics. We studied 39 strains isolated from 33 patients between 2000 and 2018.

Genome and Methylome Adaptation of -Negative Helicobacter pylori during Experimental Human Infection.

Multiple studies have demonstrated rapid bacterial genome evolution during chronic infection with In contrast, little was known about genetic changes during the first stages of infection, when selective pressure is likely to be highest. Using single-molecule, real-time (SMRT) and Illumina sequencing technologies, we analyzed genome and methylome evolution during the first 10 weeks of infection by comparing the pathogenicity island (PAI)-negative challenge strain BCS 100 with pairs of reisolates from gastric antrum and corpus biopsy specimens of 10 human volunteers who had been infected with this strain as part of a vaccine trial. Most genetic changes detected in the reisolates affected genes with a surface-related role or a predicted function in peptide uptake.

Microbiota-associated Risk Factors for Clostridioides difficile Acquisition in Hospitalized Patients: A Prospective, Multicentric Study.

Background: Asymptomatic C. difficile colonization is believed to predispose to subsequent C. difficile infection (CDI).

BaiCD gene cluster abundance is negatively correlated with Clostridium difficile infection.

Background: Clostridium difficile infection (CDI) is a major cause of hospital-acquired diarrhea. Secondary bile acids were shown to confer resistance to colonization by C. difficile.

Different gastric microbiota compositions in two human populations with high and low gastric cancer risk in Colombia.

Inhabitants of Túquerres in the Colombian Andes have a 25-fold higher risk of gastric cancer than inhabitants of the coastal town Tumaco, despite similar H. pylori prevalences. The gastric microbiota was recently shown in animal models to accelerate the development of H.

Intraclonal genome diversity of the major Pseudomonas aeruginosa clones C and PA14.

Bacterial populations differentiate at the subspecies level into clonal complexes. Intraclonal genome diversity was studied in 100 isolates of the two dominant Pseudomonas aeruginosa clones C and PA14 collected from the inanimate environment, acute and chronic infections. The core genome was highly conserved among clone members with a median pairwise within-clone single nucleotide sequence diversity of 8 × 10(-6) for clone C and 2 × 10(-5) for clone PA14.

Intestinal mucus affinity and biological activity of an orally administered antibacterial and anti-inflammatory peptide.

Objective: Antimicrobial peptides (AMP) provide protection from infection by pathogenic microorganisms and restrict bacterial growth at epithelial surfaces to maintain mucosal homeostasis. In addition, they exert a significant anti-inflammatory activity. Here we analysed the anatomical distribution and biological activity of an orally administered AMP in the context of bacterial infection and host-microbial homeostasis.

No human virus sequences detected by next-generation sequencing in benign verrucous skin tumors occurring in BRAF-inhibitor-treated patients.

Patients treated with BRAF inhibitors (e.g. vemurafenib), a novel targeted therapy for advanced melanoma harbouring certain BRAF mutations, develop numerous adverse cutaneous side effects, including skin tumors such as squamous cell carcinoma or non-malignant verruciform keratinocyte proliferations, termed 'BRAF-inhibitor-associated verrucous keratosis (BAVK) lesions'.

Intestinal microbiota composition of interleukin-10 deficient C57BL/6J mice and susceptibility to Helicobacter hepaticus-induced colitis.

The mouse pathobiont Helicobacter hepaticus can induce typhlocolitis in interleukin-10-deficient mice, and H. hepaticus infection of immunodeficient mice is widely used as a model to study the role of pathogens and commensal bacteria in the pathogenesis of inflammatory bowel disease. C57BL/6J Il10(-/-) mice kept under specific pathogen-free conditions in two different facilities (MHH and MIT), displayed strong differences with respect to their susceptibilities to H.

Genomic evolution and transmission of Helicobacter pylori in two South African families.

Helicobacter pylori infects the stomachs of one in two humans and can cause sequelae that include ulcers and cancer. Here we sequenced the genomes of 97 H. pylori isolates from 52 members of two families living in rural conditions in South Africa.

Closely related Campylobacter jejuni strains from different sources reveal a generalist rather than a specialist lifestyle.

Background: Campylobacter jejuni and Campylobacter coli are human intestinal pathogens of global importance. Zoonotic transmission from livestock animals or animal-derived food is the likely cause for most of these infections. However, little is known about their general and host-specific mechanisms of colonization, or virulence and pathogenicity factors.