Diabetes has become a global concern at present, among which type 2 diabetes mellitus (T2DM) accounts for approximately 90%–95% of patients. T2DM is a type of metabolic disorder syndrome that results from a genetic defect, and it is based on insulin resistance and an insulin secretion disorder. The occurrence of T2DM is usually the outcome of both genetic and environmental factors and their interactions. The etiology and pathogenesis of diabetes have not been fully elucidated, and no radical therapeutic cure has been found. Patients with T2DM suffer from complications such as the development of a chronic hyperglycemic condition and even serious metabolic disorders and organ damage in the body and depression and dementia, in addition to other chronic complications. Many studies have suggested that diet is crucial in the development of diabetes and the control of blood glucose. Natural substances have the characteristics of low toxicity and few side effects and may be key to the development of diabetic health products and preventive treatments. This paper reviews the etiology, pathogenesis, risks, treatments and diets related to T2DM to summarize the types of recently available natural products, from both local and foreign sources, for lowering blood glucose at home and their application in supplementary hypoglycemic foods. The key findings and conclusions suggest that there are various known T2DM-inducing factors, including genetic and environmental factors and three types of hybrid factors.

The optimization of fermentation medium is important for synthetic biological secondary metabolite productions. The effect of rotation speed, inoculum amount, and medium supplements on the cell growth and Lycogen^TM secretion of photobacterium Rhodobacter sphaeroides WL-APD911 was evaluated. The results reveal that a higher rotational speed exhibit a higher cell density, and the increasing in the amount of inoculum amount show a slight augment on the growth of R. sphaeroides WL-APD911.In the case of nitrogen sources adding, Lycogen^TM production was achieved with a 0.5 mM L-lysine supplementation. Moreover, the attention of Tween 80 presented a tremendous increase in the secondary metabolite. Response surface methodology (RSM) exhibited the optimization of medium supplements for Lycogen^TM invention is accomplished at molasses concentration of 10 g/L, yeast extract concentration of 40 g/L, 0.3% Tween 80 and NaCl concentration of 5 g/L, respectively. Further, the batch fermentation is carried out in both 5 L and 20 L fermentors to study the scale-up process factors to be adopted. At a 20 L fermentor, Lycogen^TM yields under the optimal culture condition are over 2 times than in the shake flask. The present results provide the Lycogen^TM optimal culture mediums, scale-up procedures and efficient extractions from R. sphaeroides WL-APD911.