The latest roundup of scientific studies on the novel coronavirus, and efforts to find treatments and vaccines for Covid-19, puts the spotlight on an under-recognized concept, the microbiome. And this is of special interest to people with diabetes.
Your own ecosystem
Just as the planet is an ecosystem of which you are a part, your body contains an ecosystem of tiny living things: trillions of bacteria, viruses, fungi and other microbes, that live in and on you—skin, mouth, gut, everywhere. This is your microbiome. It can affect nearly every aspect of your life: mood, stress, energy, sleep, skin, appetite, digestion, the immune system, and so much more. Your microbiome helps in supplying nutrients to your cells and fighting invasive bad pathogens, too.
With the rise of “next-generation” gene sequencing technology, a growing body of research now suggests that gut bacteria play a key role in your physical and mental health. Research in the last decade has shown that many of the microbes provide benefits to you in many ways, including, but not limited to, digestion, production of nutrients, detoxification, protection against pathogens and regulation of your immune system. You need the microbes to stay healthy, while they need your body to thrive and survive. And now, scientists, are saying that your microbiome is your clue to how vulnerable you are to Covid-19, especially if you have an underlying chronic condition like diabetes.
Covid and diabetes
Through 2020, scientists have repeatedly reported that people with “comorbidities”—diabetes, high blood pressure, heart diseases, arthritis, stroke to cancer and auto-immune diseases—are more vulnerable to Covid-19, along with obesity and old age. An intense debate is playing out between scientists, administrators and vaccine-makers: should people with these underlying medical conditions be on the priority list of immunisation.
A bunch of new reports now add another layer to the lengthening list of unanswered questions and unsettled-issues on Covid-19 and diabetes. Most noteworthy is a study conducted by the scientists of The Chinese University of Hong Kong. Published online in the journal Gut in January, the study shows that bacteria in our digestive tract may play a role in the severity of Covid-19 infection and the strength of our immune system response.
In the last few years, a substantial body of literature has provided evidence on the role of gut microbes in a range of metabolic diseases, including obesity, diabetes (type 2), depression and heart disease. It has also been found that breastfeeding impacts gut bacteria and could be a possible factor in type 1 diabetes. Scientists are working on the combined effects of gut bacteria and Covid-19 to explain why some people seem to be at increased risk of Covid-19. A definitive answer awaits future research.
The gut microbiome
When we talk about the human body, we focus on the 30 trillion cells that make it and forget the microbes. In fact, most people–even some doctors–are unaware of the critical role the microbiome plays in serving as a foundation for lifelong health. In 2016, a review of more than four decades of research into the human microbiome found that the average human contains about around 100 trillion microbes, give or take, of which 40 trillion are bacteria. Most of these reside in the digestive tract and are commonly referred to as the gut microbiome.
In scientific terms, microbiome refers to all the genes and DNA of the microorganisms. Loosely, and in lay terms, it is used to describe the entire population of microorganisms. In the most common usage, however, of microbiome stands for the largest colonies of microbes that live in your digestive tract, or the gut microbiome. Remember, your microbiome is unique to you. For every person, the microbiome is determined by their genes (DNA), gender, age, diet, personal hygiene, level of activity, the environment they live in, and even life experiences. While most of the microbes in your body are symbiotic–meaning both you and the microbes benefit from the relationship–some can promote diseases.
Changes in the microbiome
In healthy people, there is a balance between microbes and human cells. But this balance can get disturbed. In fact, your gut microbiome can get altered—for better or worse—by new foods and diet you eat, the medicines (like antibiotics) you take, the amount of sleep you get, the environment you live and work in and even an infectious disease.
Called “gut dysbiosis,” an unbalanced gut microbiome has been shown to cause an abnormal immune response and a range of chronic diseases: Irritable Bowel Disorder, type 2 diabetes, depression to heart disease. Several studies have reported how hyperglycaemia (excessive sugar levels in the blood) associated with type 2 diabetes changes the gut microbiome and how dysbiosis can become a factor in rapid progression of insulin resistance. Dysbiosis has especially been reported in old age. The human body needs a healthy and diverse microbiome to properly function, which comes down with age.
The leaky gut
Emerging evidence supports the hypothesis that an altered gut microbiome, especially from chronic conditions and old age, enhances the risk of a leaky gut. This allows the SARS-CoV-2 virus (which causes Covid-19) to escape the gut lining, enter the bloodstream and access various organs throughout the body.
Countless researchers are working on the gut microbiome. Here are some of their key messages: some microbes make the gut more permeable (increasingly leaky guts are observed in people with type 2 diabetes); some work to reduce leaks in the gut; some influence blood glucose levels and digestion of sugars; some affect the production and release of gut hormones; some affect insulin sensitivity.
The study reported in the journal Gut shows how the gut microbiome differs significantly between patients with and without Covid-19. The analysis of stool in patients with Covid-19 has shown a higher number of bacteria linked to gastrointestinal disease (R. gnavus, R. torques and B. dorei species) than people without the infection. The former also seems to have far fewer of those microbes that can influence the immune system response positively (such as B. adolescentis, F. prausnitzii and E. rectale).
To the scientists of the Indian Institute of Public Health Gandhinagar, the difference in microbiome from person-to-person explains why everybody is not equally susceptible to coronavirus infection. Even those living in the same household where a member is diagnosed with Covid-19 do not always get the disease. Differences in microbiome give people different immunity to the virus, they believe.
Support your microbiome
Personal medicine based on the individual microbiome is the road ahead, especially for diabetes. Because people with different microbiomes respond to treatments differently, doctors and scientists are working on specific strategies to treat each patient.
In the meantime, here are some proactive steps you can take to support the health of your microbiome:
- Eat plenty of fruits and vegetables, especially a fiber-rich diet
- Reduce sugars and artificial sweeteners
- Avoid taking antibiotics when not medically necessary, since this can damage your gut bacteria
- Try to reduce stress, exercise, get good quality sleep, don’t smoke