Diabetes is a chronic disease marked by the body’s struggle to optimally use insulin and manage elevated blood sugar levels. According to the Centers for Disease Control and Prevention (CDC), in 2021, roughly 1 in 10 people in the United States had diabetes with over 90% suffering from type 2 diabetes.

Diabetes is a progressive disease that can lead to further health complications such as hypertension, stroke, heart disease, kidney failure, and retinopathy. 

Research in recent decades continues to shed light on the intrinsic connection between gut health and metabolic conditions such as diabetes and obesity. Keep reading to learn more about the various possible connections between the gut microbiome and blood sugar. 

Insulin is one of the most important pieces of the diabetes puzzle. To understand the hows and whys of persistent high blood sugar, let’s quickly look into how insulin works to modulate blood sugar in a typical individual and the role insulin resistance might play in the development of prediabetes and type 2 diabetes.

What is insulin?

Insulin is a hormone produced in the pancreas that signals to glucose storage sites — cells, liver, and skeletal muscle — to absorb excess blood sugar for later use.  

Your body wants to maintain an optimum level of glucose in your blood at all times. As your cells absorb and use up existing blood sugar, your blood sugar level starts to drop. Your liver responds by releasing stored glycogen (a form of glucose) to continue to maintain blood sugar levels between meals.

In a typical person, the relationship between blood sugar and insulin works like a turnstile on a need-and-response basis. It goes like this:

• After a meal, the blood sugar goes up, insulin gets released and excess glucose is stored for later use. 
• As blood sugar goes down, the insulin in the blood drops. 
• The lowered insulin in the blood triggers the liver to release stored glucose to maintain the optimum sugar level in the blood. 

The problem occurs when either the pancreas stops producing insulin altogether or glucose storage sites stop responding to the insulin. These phenomena are diagnosed as Type 1 and Type 2 diabetes.

What is insulin resistance?

Insulin resistance occurs when the cells, muscles, and liver stop responding to insulin. In response to this resistance and to maintain the optimum blood sugar level, the pancreas has to release more and more insulin into the blood over time to lower blood sugar. 

Over months and years, the pancreas gets exhausted and cannot keep up with the body's demand for more insulin to manage its blood sugar level. At this point, the blood sugar starts to rise again and if left unchecked can lead to severe health complications. 

Is gut bacteria linked to diabetes?

Your gut microbiome consists mainly of 6 types of bacterial phyla - Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, Fusobacteria, and Verrucomicrobia. Of these six phyla, Firmicutes and Bacteroidetes make up about 90% of the microbial ecosystem. The ratio between these two dominant phyla may play a crucial role in maintaining gut eubiosis.

Several studies have pointed out that there’s a difference in the gut microbiome of diabetic patients as they host a higher bacteroidetes to firmicutes ratio in their gut. 

In prediabetic patients, it’s possible that the difference in the gut microbiome may already be seen when compared to non-diabetic subjects. Patients with type 2 diabetes may have fewer butyrate (SCFA) producing bacteria when compared to non-diabetic patients. Butyrate has been associated with glucose homeostasis and increased insulin sensitivity. 

Let’s take a look at recent studies that explore the effect probiotics might have on enhancing insulin sensitivity and improving SCFA production in the gut.

Do probiotics affect serum HbA1c?

A meta-analysis of 32 randomized clinical trials conducted by Kocsis, T. et al. (2020) published in Nature studied the effect of probiotic supplements on cardiovascular and metabolic health markers such as BMI, total cholesterol levels, LDL, triglycerides, HDL, CRP (C-reactive protein, an inflammatory marker), HbA1c levels, fasting glucose, fasting insulin levels, systolic and diastolic blood pressure in type 2 diabetes. 

The analysis suggests a significant positive correlation between probiotic supplementation and a reduction in total cholesterol, triglyceride levels, CRP, HbA1c, fasting plasma glucose, fasting insulin levels, and both systolic and diastolic blood pressure, and an increase in HDL (good cholesterol). 

Which are the best probiotics for blood sugar?

Studies on the effect of probiotics on blood sugar have leaned towards exploring the effects of lactobacillus and bifidobacterium strains, such as Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium bifidum.

Researchers have explored various mechanisms that might explain the positive association of probiotics with improved glucose homeostasis and insulin sensitivity symptoms. The gut flora produces metabolites such as short chain fatty acids (SCFAs) and secondary bile acids (SBAs) that can either lead to homeostasis or inflammation. Let's look at how some of these metabolites might affect serum HBA1c and insulin sensitivity.

BSH activity of probiotics supports GLP-1 release

Primary bile acids (BAs) produced in the liver are released into the intestine after a meal. BAs facilitate the absorption of lipids and fat-soluble vitamins in the intestine. Probiotics break down and convert primary bile acids into secondary bile acids (SBAs) through Bile Salt Hydrolases (BSH) activity. BSH is produced by various strains of lactobacillus and bifidobacterium. 

The conversion of primary BAs into SBAs plays a vital role in regulating bile acid synthesis, and cholesterol homeostasis in the body. BAs and SBAs trigger the release of GLP-1 (glucagon-like peptide-1) which is responsible for insulin secretion and lowering blood sugar.

Different people react to different foods and supplements differently. It's best to consider some of the possible side effects of probiotics before adding a dietary supplement or any other probiotic food to your diet.

• Patients with immunodeficiency or immunocompromised disorders might be at risk of developing complications due to probiotics use.
• There’s a potential risk of antibiotic resistance transfer from probiotics to pathogens, if the organisms have not been properly screened and selected.
• Sensitive individuals might undergo an allergic response.

Our gut microbiome interacts with the body in countless ways through the production of by-products such as SCFAs or SBAs that then trigger and enhance essential processes like insulin sensitivity, glucose homeostasis, and lipid metabolism. 

Biotiquest’s probiotic supplements such as the Sugar shift are enriched with strains such as Bifidobacterium longum, Bifidobacterium bifidum, Lactobacillus plantarum, Lactobacillus casei, Lactobacillus reuteri, and more, and might just be the perfect ally you need in reaching your health goals.