Individuals with diabetes have to be fairly cautious with what they are consuming and how they are consuming. Their blood sugar levels tend to fluctuate often. For instance, if a diabetic person consumes a piece of cake in a party, his blood sugar levels might shoot up overnight. While diet, exercise, and medications have their own significance in the management of diabetes, the drastic increase in the rates of diabetes has led scientists to explore alternative therapies. One of these therapies includes the use of probiotics in diabetes. Luckily, probiotics have been so far shown to regulate the blood glucose levels and benefit people with diabetes.
Probiotics raise insulin and incretin and lower blood sugar levels
Insulin is a hormone released by pancreas (a gut organ) that functions to move the ingested glucose into the target cells, thereby lowering the blood glucose levels. In individuals with diabetes, insulin is either completely absent (such as in type 1 diabetes) or the target organs are unresponsive (like in type 2 diabetes). Probiotics can raise the levels of insulin as well as another intestinal hormone called incretin that works to increase insulin levels in the body after a meal, allowing the blood glucose levels to drop.
German experts conducted a study to determine the antidiabetic potential of the probiotic, Lactobacillus reuteri.  What did they discover? After daily administration of L. reuteri for a month, the subjects were found to have raised insulin and incretin levels.
Probiotics reduce oxidative stress and glucose levels
Oxidative stress or damage is a state in which excess of oxidants or highly reactive and damaging molecules (called free radicals) overcome the body’s natural antioxidant potential. This oxidative stress plays a vital role in triggering the dysfunction of the pancreas, impairment of insulin action, impaired glucose control, and the onset of diabetes mellitus. 
Certain probiotics strains have been demonstrated to scavenge the reactive radicals, which eventually limit the oxidative damage in diabetes and the rise in blood sugar levels. 
Probiotics can augment the body’s natural antioxidant capabilities
While these beneficial bacteria minimize the oxidative molecules, they tend to boost the function and levels of natural antioxidants produced within the body.  These antioxidants, in turn, minimize the inflammatory oxidative damage, blood sugar fluctuations, and the impending complications in diabetes.
Probiotics restore the balance of the gut microbiota in diabetes
An altered gut flora in diabetics also contributes to disease. Moreover, type 2 diabetics are frequently obese that promotes inflammation and impairs the insulin action, driving the blood glucose levels to the higher side. By curbing the inflammation, controlling the body weight, and fixing the imbalance of the gut microbiome in diabetes, probiotics can help with optimal blood glucose control. 
Probiotics strengthen the weakened gut lining in diabetics
Diabetics have a leaky gut barrier that is easily invaded by inflammatory substances that promote the destruction of the pancreas and impairment of insulin secretion.  Owing to their gut lining-reparative potential, probiotics can prevent these damaging triggers from crossing the gut lining and inducing pancreatic destruction.
Probiotics can also prevent diabetes-related complications: An insight into the role of nitric oxide in diabetes
Diabetes tends to severely damage the blood vessels. One of the key factors identified in promoting this blood vessel damage is lower nitric oxide levels. Nitric oxide is a molecule that functions to repair the damaged cells and is a potent blood vessel relaxer, i.e. it widens the blood vessels facilitating easier blood flow. However, nitric oxide production is impaired in diabetics, which contributes to the poor circulation.
Brazilian scientists illustrated the blood sugar-lowering effect of kefir, which is a probiotic-enriched food.  Although conducted on rats, this study showed that other than controlling the blood sugar spikes, the probiotic can also reduce or delay diabetes-related complications by restoring the nitric oxide levels in the blood vessels.
Dr. Rasheed Huma
- Simon MC, Strassburger K, Nowotny B et al. Intake of Lactobacillus reuteri improves incretin and insulin secretion in glucose-tolerant humans: a proof of concept. Diabetes Care. 2015;38(10):1827-34. doi: 10.2337/dc14-2690.
- Wright E, Scism-Bacon J, Glass L. Oxidative stress in type 2 diabetes: the role of fasting and postprandial glycaemia. International Journal of Clinical Practice. 2006;60(3):308-314. doi:10.1111/j.1368-5031.2006.00825.x.
- Mishra V, Shah C, Mokashe N et al. Probiotics as potential antioxidants: a systematic review. J Agric Food Chem. 2015 Apr 15;63(14):3615-26. doi: 10.1021/jf506326t.
- Boulangé CL, Neves AL, Chilloux J, Nicholson JK, Dumas M-E. Impact of the gut microbiota on inflammation, obesity, and metabolic disease. Genome Medicine. 2016;8:42. doi:10.1186/s13073-016-0303-2.
- Brown CT, Davis-Richardson AG, Giongo A, et al. Gut Microbiome Metagenomics Analysis Suggests a Functional Model for the Development of Autoimmunity for Type 1 Diabetes. Roop RM, ed. PLoS ONE. 2011;6(10):e25792. doi:10.1371/journal.pone.0025792.
- Maciel FR, Punaro GR, Rodrigues AM et al. Immunomodulation and nitric oxide restoration by a probiotic and its activity in gut and peritoneal macrophages in diabetic rats. Clin Nutr. 2016;35(5):1066-72. doi: 10.1016/j.clnu.2015.07.018.