GI highlights from the literature
The changes in gut microbiota in pregnancy—a gateway to investigate the role of the gut microbiome in metabolic syndrome?
▸ Koren O, Goodrich JK, Cullender TC, et al. Host remodeling of the Gut microbiome and metabolic changes during pregnancy. Cell 2012;150:470–80.
Changes in the gut microbiota have been implicated in many diseases; however changes in pregnancy are rarely documented. During pregnancy significant changes occur in hormonal, immunological and metabolic status not dissimilar to metabolic syndrome. There is now a growing body of evidence that the gut microbiota are capable of causing such effects in non-pregnant hosts. The gut microbiota is reported to increase through gestation, but whether any composition remodelling occurs is unknown. The recent study by Koren and colleagues describes a dramatic perturbation of the gut microbiota through pregnancy with an increase in Proteobacteria and Actinobacteria identified in the third trimester. Furthermore, it would appear that potentially health promoting bacteria including Faecalibacteria prausnitzii reduce correspondingly to accommodate the increase in these non-commensals. These changes also persist postpartum although offspring microbiota were most similar to the mothers microbiota during the first trimester. This suggests that the microbiota in latter stages of pregnancy were potentially at a selection disadvantage in the infant gut. The microbiota profiles seen by the third trimester resembles a disease-associated dysbiosis. The underlying mechanisms resulting in the alteration of the microbiota remain to be clarified, but the authors suggest that the changes in the immune system at the mucosal surfaces in particular precipitate changes in the microbiota, although hormonal changes must also be considered. It is possible that the role of the gut microbiota in metabolic diseases and insulin resistance may be discovered through reproductive biological research.
DNA methylation patterns as predictors of hepatoma risk
▸ Nishida N, Kudo M, Nagasaka T, et al. Characteristic patterns of altered DNA methylation predict emergence of human hepatocellular carcinoma. Hepatology 2012;56:994–1003.
In hepatocellular carcinoma (HCC), common genetic alterations in specific genes …