Engineering the gut for insulin replacement to treat diabetes

Role of the gut-brain axis in energy and glucose metabolism

The gastrointestinal tract plays a role in the development and treatment of metabolic diseases. During a meal, the gut provides crucial information to the brain regarding incoming nutrients to allow proper maintenance of energy and glucose homeostasis. This gut-brain communication is regulated by various peptides or hormones that are secreted from the gut in response to nutrients; these signaling molecules can enter the circulation and act directly on the brain, or they can act indirectly via paracrine action on local vagal and spinal afferent neurons that innervate the gut. In addition, the enteric nervous system can act as a relay from the gut to the brain. The current review will outline the different gut-brain signaling mechanisms that contribute to metabolic homeostasis, highlighting the recent advances in understanding these complex hormonal and neural pathways. Furthermore, the impact of the gut microbiota on various components of the gut-brain axis that regulates energy and glucose homeostasis will be discussed. A better understanding of the gut-brain axis and its complex relationship with the gut microbiome is crucial for the development of successful pharmacological therapies to combat obesity and diabetes.

Epigenetic Effects of Gut Metabolites: Exploring the Path of Dietary Prevention of Type 1 Diabetes

Type 1 diabetes (T1D) has increased over the past half century and has now become the second most frequent autoimmune disease in childhood and one of major public health concern worldwide. Evidence suggests that modern lifestyles and rapid environmental changes are driving factors that underlie this increase. The integration of these two factors brings about changes in food intake. This, in turn, alters epigenetic regulations of the genome and intestinal microbiota composition, which may ultimately play a role in pathogenesis of T1D. Recent evidence shows that dysbiosis of the gut microbiota is closely associated with T1D and that a dietary intervention can influence epigenetic changes associated with this disease and may modify gene expression patterns through epigenetic mechanisms. In this review focus on how a diet can shape the gut microbiome, its effect on the epigenome in T1D, and the future of T1D management by microbiome therapy.

GLP 1 Regulated Intestinal Cell's Insulin Expression and Selfadaptation before the Onset of Type 2 Diabetes

Purpose: Basically insulin is known to be secreted by β cells of the pancreas. Recently, it has also been found to be produced and expressed by intestinal epithelial cells with the help of L cells secreting glucagon like peptide 1 (GLP 1). Here, we have studied the same intestinal insulin expression property in T2D rats.

Methods: Following 2 weeks of high fat diet (HFD) consumption, we have been given a single dose of streptozotocin (STZ) (35 mg/kg bw). Rats were then sacrificed after 1, 7 and 21 days. The GLP 1 analogue, liraglutide was also given to one group of diabetic rats, upto their respective durations. Intestinal cells apoptosis were checked by tunnel assay, Incretin hormones secretion and dipeptidyl peptidase 4 (DPP-IV) activity were analyzed through ELISA and immunohistochemistry was used to determine the insulin expression of intestine at different time interval during diabetes progression.

Results: As compared to 1 and 21 days, we have found minor cells apoptosis in 7 days group along with high level of GLP 1 in diabetic model. Further, these effects were enhanced by liraglutide. In response to these we have found, decreased insulin expression after 21 days and with no significant effect upto 7 days in diabetic control groups. In contrast to this, GLP-1 level and insulin expression enhances prominently after 7 days of liraglutide treatment.

Conclusion: These results explain the self-adapting approach of intestinal cells against diabetes onset and insulin expression enhancing property of liraglutide under stressful conditions. This study should be continued in future for the development of intestinal insulin producing drugs, to control diabetes under irreversible β cells damage.