Invest In Your Gut Bank In Times of Covid-19 Crisis

Focus on inner microbial economy for immune fitness

Tanvi Shinde, PhD
Jul 31, 2020 · 9 min read
Image by Alexandra_Koch from Pixabay

ith no signs of abating since its start in early 2020, the COVID-19 pandemic has generated a huge chaos in our economic and health sectors. With escalating mortality rate adding to this turmoil, it is an important reminder of our vulnerability to emerging infections and their deadly outcomes.

We have seen everything from empty supermarket shelves, people fighting over toilet paper to rationing of medical supplies and equipment.

While we highly anticipate the vaccines to be developed against the novel SARS-CoV-2 virus for this pandemic to be tamed, it will be a waiting game before the right one can be made available for public use. While the scientific community around the world is racing to develop effective vaccines, what we need to acknowledge is that the vaccine alone cannot be the sole solution to this complex problem, at least not for all.

Image by Alexandra_Koch from Pixabay

Not all people who get infected with the SARS-CoV-2 fall sick and those who do, do not necessarily present similar levels of sickness.

While some people are asymptomatic or experience only mild symptoms and have a short recovery period, others, particularly those with immune-compromised health status, experience severe outcomes. Countless factors are accounted for such asymmetric severity — viral load, ACE2 receptor levels, smoking, age or medical co-morbidities (eg. heart diseases, diabetes, obesity, chronic obstructive pulmonary disease etc).

The mortality with COVID-19 is reported to be the highest amongst elderly population and/or with people with underlying health conditions. Aging and most health conditions accompany chronic inflammation that weakens the ability of our immune system to produce an effective immune response against an invading pathogen.

Such ‘at-risk’ population therefore, is rendered highly susceptible to infection and mortality. In this at-risk population, the infection can progress rapidly from mild symptoms to acute respiratory distress syndrome (ARDS), making them difficult to breathe and is often accompanied by damage to the lungs and other organs. Patients with ARDS have to rely on ventilators to breathe and have a greater risk of mortality.

Vaccines support our adaptive immunity, but some people fail to respond.

In population with sub-optimal immunity, a vaccine cannot guarantee sufficient protection or prevention. In case of influenza infection, for instance, the effectiveness of a vaccine ranges from only 40 to 60%, accounting for its high annual mortality.

A vaccine mainly works by engaging the adaptive arm of our immune system (B cells and T cells) to fight infection. But, in case of elderly and in people with co-existing medical conditions, vaccines sometimes fail to activate their adaptive immune components effectively to fight-off the pathogen and promote recovery. Moreover, rapid antigenic shifts due to mutations in SARS-CoV-2 also confronts us about the degree of vaccine precision.

How about the innate immunity, that is usually the first one to arrive at the scene of infection ?

While the vaccine development (to activate the adaptive immunity) against SARS-CoV-2 has received all the deserved attention, the role of innate immune system in COVID-19 needs careful scrutiny. In severe COVID-19 patients, the most harmful outcomes are a result of uncontrolled inflammation caused by the over-activated innate cells responsible for causing significant tissue damage and multi-organ failure leading to death in severely infected patients.

Damage and injury to the lungs owing to the acute innate immune response triggered by the “cytokine storm’ and ‘neutrophil influx’ is known to cause serious damage to the tissues and rapid progression to ARDS leading to death in critically-ill COVID-19 patients. Such ill-favored immune events are generated by the hyper-activated innate immune components and failure of the immune system to blunt the excessive inflammatory response.

To put this into perspective, at-risk population is forced to ride a penny farthing also known as high wheeler bicycle, with a big front wheel (hyper-activated innate immunity) and a small back wheel (under-activated adaptive immunity) during the COVID-19 journey. Others with mild symptoms get to ride a more classical bicycle with two wheels of the same size (balanced innate and adaptive immune functions), a ride less tricky and less difficult.

Unbalanced immunity in severe COVID-19. Image by Tanvi Shinde

So if immune fitness requires smooth functioning of both innate and adaptive immunity wheels, vaccine alone cannot be the only solution to COVID-19 severity.

Thus, for effective management of COVID-19 clinical outcomes, especially in severe cases, a balanced orchestration of both innate and adaptive arms of the immune system and at sufficient levels is necessary. The strategies that can activate adaptive immunity and at the same time can control hyper-activation of innate immune system should be projected for COVID-19.

So, how do we achieve this balanced immune fitness to ensure community-wide protection/prevention from the current as well as future biological threats.

The clue to the solution of this pressing problem lies right inside us — in our gut!

Our gut is packed with about 70 to 80% of our body’s immune cells making it a control room for immunity while also helping to digest food. Hence, it holds a strong power to keep us healthy and fight diseases. Almost all diseases either originate, affect or involve gut in some way or the other, making it a powerful organ to control our health and well-being.

The key to unleashing this power lies with the gut microbiota- a big community of tiny organisms that reside in our gastrointestinal (GI) tract. The gastrointestinal tract is known to harbor the biggest proportion of the 100 trillion microbes that a human body houses. Hence, the gut is also called as the body’s microbial bank.

This gut microbial bank consist of a variety of micro-organisms, commonly referred to as microbiota and include bacteria, fungi, archaea and even viruses. While bacteria are amongst the most studied members of the gut community, the role of other microbes in influencing health and diseases are being increasingly explored by scientists. Maintaining the diversity among the microbial community in the gut is vouched as the key to our immune fitness.

Healthy versus unhealthy gut microbiota. Image by Tanvi Shinde

The gut microbiota is known to not only help digest food, produce important vitamins and eliminate toxins from our body, but are also involved in training our immune system to detect and eliminate pathogens. Emerging evidence is supporting the role of gut microbiota in dictating our susceptibility towards certain diseases, our ability to respond to particular therapies and treatments and also influence our mood and mental health.

If taken care of correctly, these tiny microbes in our gut hold an immense power to keep us healthy and happy by keeping diseases at bay. On the other hand, when we neglect our gut health, these microbes can turn against us to make us sick and also not respond to certain treatments effectively, including vaccines.

As unbelievable as it sounds, these tiny micro-organisms control whether we will fall sick or not, and even decide whether you get to ride the challenging big wheeler or the less risky classical bicycle during the course of sickness. So these microbes in our gut are like the gate-keepers of health.

The gut microbiota is a complex network and consists of both beneficial members and opportunistic pathogens at a delicate balance. The beneficial gut bacteria, for instance, compete with the pathogens for space and nutrients to keep their population in check.

The beneficial bacteria also function by fermenting the prebiotic dietary fibres (parts of plant food that escape digestion in the small intestine and is passed on to the large intestine) to produce a variety of specific vital molecules that are known to provide significant health benefits.

Of these, short-chain fatty acids (SCFAs) such as butyrate, acetate and propionate produced by the bacterial fermentation play an important role in nourishing the intestinal cell lining and promoting immune fitness.

SCFAs are powerful bacterial by-products that can activate intricate functions of both innate and adaptive immune arms and support the immune system to present the right defense tools to fight infections.

The immune functions mediated by the SCFAs are not only restricted to the gut but also influence distant sites in our body including brain (gut-brain axis) and lungs (gut-lung axis). In addition, bacterial SCFAs and antimicrobial molecules create an unfavorable environment for the pathogens, thus reducing their chance to overpopulate. The problem begins when the balance between the beneficial and pathogenic members is disturbed. Such microbial disturbance is referred to as ‘dysbiosis’.

Production of beneficial metabolites versus toxic metabolites in healthy and dysbiotic gut. Image by Tanvi Shind

A number of factors are known to cause disturbances among the microbial community in the gut leading to immune dysfunctions. Some of these factors include exposure to antibiotics, stress, and most importantly, unhealthy dietary patterns that are associated with the reduced consumption of fruits and vegetables.

Dysbiosis and dampening of the immune functions are also common amongst the elderly, thus making them more susceptible to severe infections. Also, underlying chronic inflammatory conditions, including GI disorders, obesity, diabetes, cardiovascular conditions, cancer and even mental disorders often accompany disturbances in the gut microbiota.

In such inflammatory states, the immune system is unable to accurately use the appropriate immune defense tools against a pathogen for effective elimination and to promote recovery. Therefore, in elderly people and patients with chronic conditions, the sub-optimal immunity and associated microbial dysbiosis poses an increased risk of infection and severity as evidenced by COVID-19.

Emerging scientific evidence indicates alterations in the gut microbiota of COVID-19 patients and its association with disease severity. So if we can maintain a diverse microbiota and focus on reducing or repairing these alterations in the gut microbiota, there is a strong potential to lessen the COVID-19 severity. And the good news is, maintaining the microbial balance and/or correcting the dysbiotic microbiota in the gut is achievable.

Eating a healthy balanced diet is known to support the diversity in the gut microbiota to ensure well-balanced immunity. Getting adequate nutrients from a balanced diet is key to ensuring a healthy immune system. In contrast, excessive consumption of diet loaded with refined carbohydrates, sugar, processed fats and salts are known to cause inflammation and microbial disturbances.

The best currency to invest in your gut bank to boost your inner economy of microbiota is a diet rich in prebiotic dietary fibre and probiotic bacteria.

Feeding your gut microbiota with variety of plant-based dietary fibres (from fruits, vegetables, whole grains) is a great way to ensure gut microbial diversity and adequate production of the beneficial SCFAs. Other natural dietary sources rich in healthy fats, proteins, vitamins and minerals including fish, nuts and meat also encourage healthy immunity.

Certain bacteria in the gut metabolize the prebiotic fibres into SCFAs, while others into intermediate by-products that feed other beneficial bacteria in the gut. A variety of whole-plant dietary fibres will make sure that all types of beneficial bacteria in our gut are fed well.

In addition, fermented foods that carry probiotic bacteria (eg. yoghurt, kefir, kombucha, sauerkraut, kimchi etc) are known to add to the gut microbial diversity and promote immune defenses against infections and diseases. A combination of probiotic and prebiotic dietary fibres, which is known as synbiotic is even more powerful strategy to influence gut microbiota and produce appropriate immune fitness against viral infections.

Synbiotic is, in fact a more sensible approach that delivers both the beneficial probiotic together with the prebiotic to feed them. This is especially important in the elderly population and those with underlying medical conditions with dysbiotic gut that houses increased pathogenic bacteria and lose a considerable number of beneficial bacteria that can utilize dietary fibres.

Synbiotic is like two-point approach — The probiotic bacteria in it will reintroduce the lost beneficial bacteria in the gut and the prebiotic in it will feed the newly introduced probiotic and the microbiota. You get the SCFAs and immunity. So, everyone is happy!

Vaccines undoubtedly remain a valuable public health tool and should be encouraged to continue facilitating the prevention of diseases in the wider community, stabilize health systems and benefit national and global economy. A rich inner economy of diverse gut microbiota will ensure additional support to the immune system in building the right immune defenses for viral clearance, improve our responsiveness to vaccine and also support recovery of our health to normalcy with minimal damage to the organs.

So, feed your gut bank with the right currency and enjoy the immune fitness benefits in times of COVID-19 pandemic or otherwise.

Take care of your gut and good health will follow….!

In Fitness And In Health

Inspiring stories related to health, fitness and the pursuit of well-being.

Tanvi Shinde, PhD

Written by

. Biomedical Researcher interested in inflammation and microbiome for gut health and beyond . Published Academic author . Gut Health Evangelist . Mom . Reader .

In Fitness And In Health

A fast-growing health and fitness community dedicated to sharing knowledge, lessons, and suggestions to living happier, healthier lives.

Tanvi Shinde, PhD

Written by

. Biomedical Researcher interested in inflammation and microbiome for gut health and beyond . Published Academic author . Gut Health Evangelist . Mom . Reader .

In Fitness And In Health

A fast-growing health and fitness community dedicated to sharing knowledge, lessons, and suggestions to living happier, healthier lives.

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