**6. Other microbiomes**

The gut microbiome is by far the most important when it comes to diabetes and obesity, but it is becoming clear that other microbiomes may have effects as well. Small intestinal bacterial overgrowth syndrome (SIBO), *Heliobacter pylori*, and the oral microbiome are now thought to contribute as well. SIBO and H. pylori are often comorbidities for diabetic patients.

SIBO is an upset of the natural balance of microbiota in the small intestine. It can be the result of enteric nervous system disorders such as IBS and because of nausea and abdominal pain usually result in weight loss, loss of appetite, bloating and diarrhea, and malnutrition. SIBO causes increased blood glucose levels and insulin resistance and worsening glycemic control [95]. Other investigators though believe that it is diabetes that causes SIBO. About a third of diabetic patients also have SIBO. [96] and is diagnosed by a simple hydrogen breath test. However, unless the SIBO can be controlled, these patients will have greater difficulty in controlling their diabetes and will have a higher risk of foot ulcers [96].

*Heliobacter pylori* infections in the stomach also increase the likelihood of TTDM. Causal contact and contaminated food or water can transmit the disease. It is believed

#### *Diabetic Foot - Recent Advances*

that the infections cause the release of gastric hormones and gastrointestinal inflammation that leads eventually to insulin resistance and diabetes [97].

Oral microbiomes are now being examined and studies show that this microbiome is also involved in the progression of diabetes and obesity. *Actinobacteria* levels are seriously depressed in diabetic patients and *Firmicute/Bacteroidetes* ratios have increased just as in gut microbiota in TTDM patients [89, 98, 99].
