Your Gut & Your Glucose
The trillions of microbes that decide how your body handles sugar
There are trillions of microbes in your gut. Most of them are bacteria. These microbes aren’t just sitting around; they’re eating, growing, producing chemicals and sending some of those chemicals off to do their jobs in the rest of your body. Some of those chemicals have a direct impact on how well your body absorbs glucose from your food. That connection is called the “gut–glucose axis”. It means the health of your gut microbes may shape how your blood sugar responds to food.
It’s another reason why two people who eat exactly the same meal may have completely different glucose absorption rates. Everyone has a unique microbiome that plays a major role in the overall health of their body, including how they process glucose.
The Gut–Glucose Axis
Your gut microbes help you digest parts of your food that your own digestive system isn't able to completely process.
Many types of fiber fall into this category. Fiber is a type of carbohydrate that your body can't completely digest. What happens instead is that it makes its way to your colon, where your bacteria eat it and produce chemical byproducts. Scientists call these byproducts "metabolites." Metabolites are basically molecules created through the metabolic processes that sustain your life.
Your gut microbes produce different types of metabolites depending on what type of bacteria they are. Some of those metabolites may actually increase insulin sensitivity (how well your cells can receive insulin and allow glucose to enter the cell). When you have high insulin sensitivity, your body tends to use glucose efficiently.
When you have low insulin sensitivity, glucose stays in the bloodstream for longer than it should.
Your gut microbes may be an important factor in maintaining that balance.
Helpful Signals: Short-Chain Fatty Acids
One of the most important metabolites produced by gut bacteria is a group called short-chain fatty acids (SCFAs). These are essentially tiny molecules that result from the fermentation of fibre by bacteria. Fermentation is the process in which microbes consume nutrients from food without using oxygen.
The three primary short chain fatty acids – acetate, propionate and butyrate – may play a significant role in supporting metabolic health.
Butyrate, in particular, has been shown to have a number of positive effects on the body. It supports a healthy gut lining, and helps reduce chronic inflammation, which is linked to metabolic issues.. Finally, butyrate has been shown to affect the signals of satiety; therefore your brain receives messages that make you feel full.
In short, your gut bacteria feed on fibre, and the resulting short chain fatty acids may assist in regulating your glucose levels more consistently.
Feeding the Good Bacteria
If your gut bacteria require fibre, then the next logical question is what foods provide fibre? These foods are commonly referred to as prebiotic foods, foods that are fermented by beneficial gut bacteria..
Common examples of prebiotic foods in many Asian cuisines include:
Garlic
Onions
Leeks
Asparagus
Slightly Green Bananas
Oats
Beans and Lentils
Another type of fibre is resistant starch. Resistant starch is not digested well in the small intestine. Instead, it ends up in the colon, where bacteria can ferment it. Examples of foods that contain resistant starch include: whole grains, cooked and cooled rice or potatoes, unripe bananas, and certain legumes like lentils, chickpeas, black beans, and kidney beans.
Additionally, a diverse range of plant-based foods will promote a more diverse range of bacterial species. Eat the rainbow!
Fermented Foods: Adding New Allies
While some foods simply provide a source of food for the bacteria you already have, others introduce entirely new allies. These foods are called probiotics or live microbes that may positively affect your health when consumed on a regular basis.
Many traditional Asian dishes contain probiotics, including:
*Kimchi in Korean dishes
*Miso and Natto in Japanese dishes
Tempeh in Indonesian and Malaysian dishes
Fermented Tofu and *Pickled Vegetables in Chinese dishes
Yoghurt and Kefir in many regions
*These food choices are also high in sodium. Try to control the portion sizes and how often you have them.
Probiotic-rich foods can support gut health. Though cooking may kill the live bacteria, they still provide dietary fibre that feed beneficial microbes. Note that health effects remain highly strain-specific, with different strains influencing digestion, immunity, and metabolism in distinct ways.
Research has demonstrated that consuming fermented foods regularly may decrease inflammatory markers within the body. Although occasional consumption of fermented foods is beneficial, long-term consumption may provide even greater benefits.
Antibiotics and Gut Disruption
Sometimes your microbiome needs medical help.
Antibiotics are used to fight bacterial infections in the human body. However, antibiotics also can negatively affect beneficial gut bacteria.
Taking broad-spectrum antibiotics, which can kill multiple types of bacteria, can reduce overall microbiome diversity. Microbiome diversity is defined by how many different types of microorganisms exist within an individual's system. Studies have shown that it can take days, weeks or even months for an individual's microbiome to recover from a broad-spectrum antibiotic regimen.
A good way to aid in your microbiome's recovery is to gradually increase fibre and fermented food intake as these serve as a source of nutrients and help restore balance to your microbiome.
What This Means for Your CGM Data
Blood glucose responses vary between individuals, and one reason may be differences in the gut microbiome. Each person’s unique microbial ecosystem can influence digestion, metabolism, and glucose levels, highlighting the importance of tailoring nutritional plans to the individual.
