What Are Probiotics And Why Are They Important: Experts Talk
Probiotics laden, small, pink hued bottles occupy space at many a grocery store's shelves. The shopkeepers often sell them as a delicious, healthy drink, which is ideal for daily intake by everyone in a family, and something even the kids would love. Apparently, they are a robust dose of good or essential bacteria. These are miniature bottles of Yakult, a fermented milk, originally from Japan, but now widely popular in India, too. More than 40 million bottles of Yakult were consumed every day in 40 countries and regions in 2020, as per Yakult India's website. Alternatively, foods such as curd, yogurt, dhokla, cheese, kimchi, kombucha and various other fermented foods have been consumed traditionally for the good bacteria they lend. But are they technically probiotic in nature?
We probe Dr Neerja Hajela, Assistant Vice President – Science and Regulatory Affairs, Yakult Danone India to share her insights on probiotics and how they boost our immunity, overall well-being as well as their importance in a Covid impacted world. Edited excerpts below:
Q. What are probiotics and why are they important for health?
Ans. The word probiotic means “for life”. They are beneficial bacteria, which are essential for our survival. They aid in the process of digestion, help in better absorption of nutrients, help to boost immunity and also reduce the risk of infections. Probiotics can also produce neurotransmitters like serotonin, Gamma Amino Butyric Acid (GABA) and dopamine and therefore may influence your mood including depression, stress and anxiety.
Q. How do probiotics help boost immunity?
Ans. About 70% of the body's immune system is located in the gut. Probiotic bacteria interact with the immune cells and help in boosting both the natural and acquired immunity. They help in increasing the activity of natural killer cells which play a critical role in protecting us from viral infections and some kinds of cancer. They also keep our mucosal lining (eyes, respiratory tract, digestive system) protected. Probiotics reduce inflammation by producing anti-inflammatory molecules and maintain the intestinal barrier by increasing the production of mucus and tight junction proteins which hold the intestinal cells together.
Q. How do probiotics help prevent or treat respiratory tract infections?
Ans. Probiotics help in preventing respiratory infections by increasing the production of an antibody that is found in the mucosal linings, which is the first line of defence against viruses and infections. Studies around the world have shown that improving the balance of the microbiota may help in preventing respiratory infections and viral influenza. A Cochrane review of 12 studies evaluated the benefit of probiotics in preventing upper respiratory tract infections (URTIs) like common cold in all age groups including children, adults and the elderly showed a reduction in incidence of URTIs by 30%.
Q. What impact do probiotics have on gut health? Why gut health is important and what role does it play in one's well-being?
Ans. The gut is the site for processing the nutrients from the food we consume and providing us with energy. Weak gut health results in poor absorption of nutrients and accumulation of toxins. The gut is our largest immune organ since about 70% of the body's immune system is located there. It therefore keeps us protected from infections. The gut harbours 100 trillion microbes. These microbes help in maintaining intestinal health and are indispensable for digestive function and immunity. They are our first line of defence against harmful bacteria and viruses. The gut is also the second brain of the human body because it harbours the enteric nervous system with 100 million neurons that connect with the brain. We have now learned that there is a Gut-Brain Axis and the microbes in the gut can influence the brain and vice versa. Gut health is therefore very important for long term well-being. Some probiotic bacteria can produce B group of vitamins in the gut and may help overcome nutrient deficiency. They help to maintain the integrity of the intestinal wall and prevent the entry of harmful bacteria into the blood stream.
Q. In a pandemic driven world, how important is it to include probiotics in one's daily diet and what kind of impact can that have on one's health vis-a-vis Covid?
Ans. In a pandemic driven world, immunity plays a very important role in combating infection. In fact researchers at the Peter Doherty Institute in Australia, showed that some people respond to the Covid infection like they would to flu, and recover quickly, while others succumb to the disease. According to them, this has a lot to do with the strength of the immune system and therefore immunity has taken centre stage during these times. Scientifically validated probiotic strains have shown to boost immunity by increasing the activity of immune cells.
Q. Would you particularly recommend consumption of probiotics for people suffering from Covid or for post Covid recovery?
Ans. Most people suffering from Covid or post Covid recovery require an intervention to improve both immunity and intestinal health. Probiotics could be a welcome addition to the daily diet for an improvement in overall health. There is considerable research and systematic reviews on the use of probiotics to reduce viral infections and respiratory infections. There are systematic reviews that describe the effect of probiotics on the length of hospital stay, new infections and gastrointestinal symptoms. Therefore indirectly, probiotics may help Covid recovery.
Q. How are natural probiotic foods such as curd different from probiotic supplements?
Ans. Curd, lassi and such foods which contain lactic acid bacteria are not standardised for the strain of bacteria, live number of bacteria, viability of the bacteria at the target site (intestine) and their ability to impart scientifically proven, strain-specific health benefits. Therefore, while one cannot undermine the nutritional benefit of traditional fermented foods, they cannot be classified as true probiotics. According to the definition of probiotics given by Food Agricultural Organization (FAO) and the World Health Organization (WHO), probiotics are scientifically tested bacteria that reach the intestine alive in sufficient numbers to impart a scientifically proven health benefit of better intestinal health and immunity. The two categories cannot be compared but go hand in hand for better overall health.
Q. How often should one consume these?
Ans. Only regular consumption of a probiotic will ensure a strong immune system, which is often negatively influenced by challenges such as medications, infections, ageing, lifestyle, surgery and poor nutrition.
A Nutritionist's Take
Probiotics may have live bacteria that are good for the gut and the well-being of one and all, but these supplements can be taken more mindfully to mitigate various health concerns. For instance while you'd want to take probiotics as part of your everyday diet for general upkeep, someone else might want to take them for more targeted reasons.
“Not all probiotics are equal in their action and in the benefits that they provide. The characteristics of a probiotic depend on the strain of the bacteria present in the food. Different strains support health in different ways. So, at the outset, it is important to be clear about the purpose of adding the probiotic food to the diet. It could be anything like improving overall health and reducing the risk of infections, controlling antibiotic associated diarrhoea, ameliorating constipation, or as a treatment adjunct in IBS. If, for instance, the goal is to prevent infections especially of the respiratory kind, you should choose the probiotic that offers documented evidence of achieving this,” says Neelanjana Singh, a registered dietician and wellness consultant.
As per Singh, some recent studies suggest that beneficial microbes can also be vital for managing obesity, Type 2 Diabetes and even some kinds of cancers, further elevating the importance of probiotics as well as their targeted consumption.
“Probiotic foods are certainly not a one-shot remedy but including them in the diet can effectively improve wellbeing,” Singh adds.
She, however, goes on to share a word of caution, stating that in certain specific patients with ongoing sepsis or bacteremia, people with severe immune deficiencies may not be good candidates for probiotic supplementation.