Serum vitamin A and total carotene concentrations in well-nourished children with Helicobacter pylori infection

Colitis-Mediated Dysbiosis of the Intestinal Flora and Impaired Vitamin A Absorption Reduce Ovarian Function in Mice

Changes in the composition and ratio of the flora during colitis have been found to potentially affect ovarian function through nutrient absorption. However, the mechanisms have not been fully explored. To investigate whether colitis-induced dysbacteriosis of the intestinal flora affects ovarian function, mice were given dextran sodium sulfate (DSS) through drinking water. High-throughput sequencing technology was used to clarify the composition and proportion of bacterial flora as well as gene expression changes in the colon. Changes in follicle type, number, and hormone secretion in the ovary were detected. The results showed that 2.5% DSS could induce severe colitis symptoms, including increased inflammatory cell infiltration, severe damage to the crypt, and high expression of inflammatory factors. Moreover, vitamin A synthesis metabolism-related genes Rdh10, Aldh1a1, Cyp26a1, Cyp26b1, and Rarβ were significantly decreased, as well as the levels of the steroid hormone synthase-related proteins STAR and CYP11A1. The levels of estradiol, progesterone, and Anti-Mullerian hormone as well as the quality of oocytes decreased significantly. The significantly changed abundances of Alistipes, Helicobacter, Bacteroides, and some other flora had potentially important roles. DSS-induced colitis and impaired vitamin A absorption reduced ovarian function.

Human gastric epithelial cells contribute to gastric immune regulation by providing retinoic acid to dendritic cells

Despite the high prevalence of chronic gastritis caused by Helicobacter pylori, the gastric mucosa has received little investigative attention as a unique immune environment. Here, we analyzed whether retinoic acid (RA), an important homeostatic factor in the small intestinal mucosa, also contributes to gastric immune regulation. We report that human gastric tissue contains high levels of the RA precursor molecule retinol (ROL), and that gastric epithelial cells express both RA biosynthesis genes and RA response genes, indicative of active RA biosynthesis. Moreover, primary gastric epithelial cells cultured in the presence of ROL synthesized RA in vitro and induced RA biosynthesis in co-cultured monocytes through an RA-dependent mechanism, suggesting that gastric epithelial cells may also confer the ability to generate RA on gastric dendritic cells (DCs). Indeed, DCs purified from gastric mucosa had similar levels of aldehyde dehydrogenase activity and RA biosynthesis gene expression as small intestinal DCs, although gastric DCs lacked CD103. In H. pylori-infected gastric mucosa, gastric RA biosynthesis gene expression was severely disrupted, which may lead to reduced RA signaling and thus contribute to disease progression. Collectively, our results support a critical role for RA in human gastric immune regulation.

Helicobacter pylori prevalence and circulating micronutrient levels in a low-income United States population

High prevalence of Helicobacter pylori (H. pylori), the leading cause of gastric cancer, and low levels of micronutrients have been observed in many developing countries, and the question remains as to the whether an association between the 2 exists. The present study seeks to further our understanding of this potential connection in the Southern Community Cohort Study, representing a low-income population in the United States. Blood levels of antibodies to H. pylori proteins were assessed by multiplex serology for a sample of 310 African American and white participants, ages 40 to 79 years. Blood collected at baseline was also assayed for levels of carotenoids, tocopherols, retinol, and folate. Multivariate linear regression was used to calculate least-squares mean micronutrient levels within groups defined by H. pylori status. The mean serum levels of all micronutrients assayed were lower among H. pylori + individuals than H. pylori - individuals, significantly for β-carotene, folate, and retinol (decreases of 27.6%, 18.6%, and 9.7%, respectively). Individuals who were seropositive to the virulent CagA+ H. pylori strains had even lower mean levels of micronutrients, particularly β-carotene, folate, total carotenoids, and retinol (decreases of 38.9%, 19.1%, 17.0%, and 11.7%, respectively, compared with H. pylori - individuals). However, dietary micronutrient levels as derived from a food frequency questionnaire did not vary between groups defined by H. pylori status. These results provide support for the hypothesis that H. pylori infection impairs nutrient absorption and suggest a need for future studies to explore the role of H. pylori infection on nutrition and gastric cancer risk in this high-risk population.

Helicobacter pylori and extragastric diseases--other Helicobacters

Reports on Helicobacter pylori and extragastric diseases have almost doubled this year compared with last year, bearing witness to the persistent scientific interest in this branch of Helicobacter-related pathology. Data belong increasingly to the area of vascular medicine, as well as hematology, dermatology, pediatrics and other fields. Unfortunately, these studies show overall controversial results, due to the impact of several confounding factors, and to the difficulty of recruiting homogeneous patient populations. Furthermore, many studies continue to be conducted on Helicobacter species other than H. pylori, focusing on animal models of gastroenterological illnesses which may retain strong similarities with human diseases. In this paper, taxonomy, detection and characterisation of Helicobacter spp. will be reviewed, together with the most important data issued this year on other Helicobacters and animal models.