Strong relation between probiotics, immunity during COVID-19 pandemic: Gut Microbiota and Probiotic Science Foundation insights

The insights were shared by Prof NK Ganguly and Dr Neerja Hajela

With a view to channelise international knowledge, the Gut Microbiota and Probiotic Science Foundation (India) shared latest insights on the strong relation between probiotics and immunity during the COVID-19 pandemic. These insights were shared by Prof NK Ganguly, President, Gut Microbiota and Probiotic Science Foundation (India) and Former Director General, Indian Council of Medical Research and Dr Neerja Hajela, Secretary, Gut Microbiota and Probiotic Science Foundation (India).

As we navigate through the most difficult times of our lives, we must remember that behind every cloud there is a silver lining. While the dreaded COVID-19 disease continues to threaten us, the good news is that it does not affect everyone and some people are actually symptomatic while others recover very quickly.

So why do people respond differently. An interesting study published recently in Nature Medicine by researchers at the Peter Doherty Institute in Australia showed that the secret lies in your very own natural immunity. A strong immune system can actually fight the virus and divert the course of the disease.

We have heard of various ways of boosting immunity – in fact it is the buzzword today especially with no defined treatment or vaccine available to fight the disease. We all know that the gold standard for a strong immune system remains a healthy well – balanced diet with immune boosting nutrients, regular physical activity, adequate hydration and good quality sleep for a well-rested mind.

More recently, however, scientific data suggests that improving intestinal health with probiotics could be another effective way of building immunity. The rationale is simple – about 70 per cent of the body’s immunity is found in the intestine which in turn depends on bacteria to shape the immunity. Although this may sound like stuff that science fiction is made of, our intestine is home to 100 trillion bacteria of 1000 different types which work together to build our immunity. The beneficial ones which are also called probiotics train the immune system, reduce inflammation and ward off harmful disease-causing bacteria and viruses. They also prevent metabolic disorders like obesity by producing metabolites like short chain fatty acids especially butyrate. They also protect the intestinal lining and prevent harmful pathogens and their toxins from entering the blood.

Probiotics are particularly useful in preventing respiratory infections because of their ability to increase activity of natural killer cells and levels of antibodies like secretory IgA in the mucosal linings, which are our first line of defence against viral infections.

Given that probiotics shape our immunity, is there enough scientific data that suggests their value in the current COVID-19 pandemic?

A Cochrane review of 12 studies that included 3720 children, adults and elderly suggested that probiotic use may be associated with fewer people suffering from upper respiratory tract infections and lower incidence of the infection. Dr Irene Lenoir-Wijnkoop, Utrecht University, Netherlands observed that probiotic use could save healthcare costs and lost productivity due to acute respiratory tract infections.

The link between the intestine and COVID-19 becomes apparent from the fact that some patients who suffered the infection in China showed symptoms of poor intestinal health and suffered from loss of taste and diarrhoea. This prompted China’s National Health Commission to use probiotics along with conventional treatment in patients with COVID-19 infection for improving the balance of the intestinal flora and preventing secondary bacterial infections.

However, probiotic benefits are strain-specific, and it is important to identify the strain of bacteria that is scientifically proven for the benefit. Some strains of Lactobacillus gasseri, Bifidobacterium longum and Lactobacillus casei strain Shirota have shown to boost immunity and reduce the incidence of upper respiratory tract infections or common cold and flu.

Although we are at a stage where we are still not sure of a clear benefit of probiotics in COVID-19 patients but given the fact that most of our immunity resides in the intestine which is determined by the kind of bacteria present there, it may be worthwhile to ensure a balanced intestinal flora with more beneficial probiotic microbes and a stronger immune system that could help in the fight against COVID-19.