The diabetes prone BB rat model of IDDM shows duration of breastfeeding to influence Type 1 diabetes development later in life

Prolonged exclusive breastfeeding reduces autoimmune diabetes incidence and increases regulatory T-cell frequency in bio-breeding diabetes-prone rats

BACKGROUND

Previously, we reported that exclusive breastfeeding delayed and partially protected bio-breeding diabetes-prone (BBDP) rats from spontaneous autoimmune diabetes development. To investigate whether this protection results from modulation of the (mucosal) immune system, the present study was designed to analyse the effect of nutrition early in life on the immune status of BBDP rats.

METHODS

The breastfeeding period of BBDP pups was extended or not, while allowing half of the pups to eat during that period whereas the other half received only breast milk. Cytokine profiles as well as naturally occurring regulatory T-cell frequencies were measured over time in the mesenteric lymph nodes (MLNs) and spleen.

RESULTS

Prolonged exclusive breastfeeding partially protects against autoimmune diabetes development and resulted in elevated levels of natural regulatory T cells (CD4(+) CD25(+) FoxP3(+)) in MLNs and spleen directly after weaning and throughout life. Stimulation of MLN cells from rats that ingested solid food during the nursing period showed massive secretion of interferon gamma (IFN-gamma), interleukin (IL)-4 and IL-10, whereas MLN cells from exclusive breastfed rats did not. In contrast, transforming growth factor beta (TGF-ss) was secreted equally by all groups.

CONCLUSIONS

Prolonged exclusive breastfeeding partially protects BBDP rats from autoimmune diabetes development. Interestingly, ingestion of solid food during the weaning period completely abolishes this protective effect. The protective effect of exclusive breastfeeding correlates with higher levels of naturally occurring regulatory T cells throughout life and low cytokine secretion at weaning.

Tight junctions, intestinal permeability, and autoimmunity: celiac disease and type 1 diabetes paradigms

Autoimmune diseases are characterized by tissue damage and loss of function due to an immune response that is directed against specific organs. This review is focused on celiac disease (CD), an autoimmune enteropathy, and type 1 diabetes (T1D), a hyperglycosaemia caused by a destructive autoimmune process targeting the insulin-producing pancreatic islet cells. Even if environmental factors and genetic susceptibility are clearly involved in the pathogenesis of autoimmunity, for most autoimmune disorders there is no or little knowledge about the causing agent or genetic makeup underlying the disease. In this respect, CD represents a unique autoimmune disorder because a close genetic association with HLA-DQ2 or HLA-DQ8 haplotypes and, more importantly, the environmental trigger (the gliadin fraction of gluten-containing grains wheat, barley, and rye) are known. Conversely, the trigger for autoimmune destruction of pancreatic ss cells in T1D is unclear. Interestingly, recent data suggest that gliadin is also involved in the pathogenesis of T1D. There is growing evidence that increased intestinal permeability plays a pathogenic role in various autoimmune diseases including CD and T1D. Therefore, we hypothesize that besides genetic and environmental factors, loss of intestinal barrier function is necessary to develop autoimmunity. In this review, each of these components will be briefly reviewed.