Intestinal microbiota is involved in metabolic processes and the pathophysiology of various gastrointestinal disorders. We aimed to characterize the microbiome of the appendix in acute pediatric appendicitis comparing extraluminal and intraluminal samples. Between January and June 2015, 29 children (3–17 years, mean age 10.7±3.4 years, sex M:F=2.6:1) undergoing laparoscopic appendectomy for acute appendicitis were prospectively included in the study. Samples for bacterial cultures (n=29) and 16S ribosomal desoxyribonucleic acid (rDNA) sequencing (randomly chosen n=16/29) were taken intracorporeally from the appendiceal surface before preparation (“extraluminal”) and from the appendiceal lumen after removal (“intraluminal”). The degree of inflammation was histologically classified into catarrhal, phlegmonous, and gangrenous appendicitis. Seventeen bacterial species were cultivated in 28 of 29 intraluminal samples and 4 species were cultivated in 2 of 29 extraluminal samples. Using 16S rDNA sequencing, 267 species were detected in intraluminal but none in extraluminal samples. Abundance and diversity of detected species differed significantly between histological groups of acute appendicitis in bacterial cultures (P=.001), but not after 16S rDNA sequencing. The appendiceal microbiome showed a high diversity in acute pediatric appendicitis. The intraluminal microbial composition differed significantly depending on the degree of inflammation. As bacteria were rarely found extraluminally by culture and not at all by sequencing, the inflammation in acute appendicitis may start inside the appendix and spread transmurally.

<p>  Fetal Alcohol Syndrome (FAS) is the most serious form of Fetal Alcohol Spectrum Disorders (FASD) and the most prevalent neurodevelopmental disorder in North America. Patients with FAS may exhibit cognitive problems with working memory, manipulating information, and reduced executive functioning. Additionally, previous studies exhibited that stress responses are affected by prenatal alcohol consumption Gut microbiota compositions can also influence stress responses and memory, as several studies have shown strong relationships between the enteric gut system and the brain. However, few studies have examined how prenatal alcohol exposure’s effects on the gut microbiome and neuroinflammatory responses. For this study, pregnant HsdBlu:LE Long Evans rats were treated with either a dry diet, liquid diet, or liquid diet with alcohol. On day 28 and 42 after birth, three male and three female adolescent pups from each treatment group had their gut microbiome (fecal samples) analyzed through 16S rRNA amplicon sequencing. Brain histology staining of the cortex and hippocampus regions was also done to evaluate changes in the CNS through microglial counts and morphology analysis. There were no significant differences in alpha diversity of the fecal microbiome between groups of pups based on prenatal alcohol exposure (PAE), sex, age, the interaction of PAE and sex, or in the morphology of cortex microglia. However, analysis of beta diversity using Bray-Curtis dissimilarity and weighted UniFrac suggested distinct microbial communities between the treatment groups based on PAE and the interaction of PAE, sex, and the interaction between PAE and sex. Microglial count comparisons by PAE or sex were only statistically different in the cortex (p ≤ 0.005). The significance of this study suggests that there are some associations between the gut microbiome and CNS inflammation in rats with PAE. Based on these findings, 11 future studies may implement therapeutics such as antibiotics or probiotics to mitigate cognitive or neural symptoms of FASD affected individuals. </p>