Opinion

The gut matters: More than you think

Curd, or dahi, is a widely consumed probiotic in Nepal, especially after a heavy meal to help digestion. The bacteria present in curd produce lactic acid, which helps break down the lactose in it, support digestion, and reduce bloating

By Dr Sachin Aryal

Human internal organ with intestine illustration. Phopto: Freepik

A lot of people in Nepal are suffering from conditions such as diabetes, heart disease, kidney problems, and mental disorders. The focus on the prevention and treatment has always been on different medications, changes in lifestyle, and easy access to health care. But we hear very little about the importance of gut or intestinal health. Gut health simply refers to the proper functioning and well-being of our intestines. Our gut is inhabited by trillions of microbes – tiny, microscopic organisms such as bacteria, viruses, and fungi. They outnumber the cells in our body. The diverse community of microbes is termed the 'microbiome,' whereas the total population of microbes is known as the 'microbiota.' Our gut is home to a mix of both beneficial and harmful microbes. The beneficial microbes produce compounds such as essential vitamins and short-chain fatty acids. These short-chain fatty acids are produced when the gut microbiota breaks down the dietary indigestible carbohydrate and help nourish the intestinal cells to maintain the intestinal barrier. It also helps to support the metabolism and immune function. On the other hand, the harmful microbes can interfere with these processes and therefore pose a threat to the overall health of the body. Various factors, such as diet, genetics, age, antibiotics, environmental factors, disease conditions, physical activity, stress, smoking, and alcohol consumption, shape the diversity of gut microbiota. In Nepal, these factors are important to address, as the cases of malnutrition, growing preference for processed foods, unregulated use of antibiotics, and changing lifestyle patterns are rising. And along with that, the risk of altering the gut microbiota composition and the associated health outcome is also increasing, which is alarming. The impact of these factors is reflected in the public health data shown in Noncommunicable Diseases Risk Factors: STEPS Survey Nepal 2019. According to this survey, which involved Nepalis aged 15-69 years, 'unhealthy behavior' tops the list. The survey also found that 50% of men use smoked or smokeless tobacco. Those who did not smoke were also affected, as the study found that one-third of the population was exposed to secondhand smoke at home. The survey also found that Nepali people consume approximately 10 grams of salt, which is nearly twice the World Health Organisation's (WHO) recommended daily limit. Regarding the consumption of fruits and vegetables, only 3% of people meet the WHO guideline of eating at least five servings daily. Also, one in four adults has higher blood pressure, and a similar proportion of overweight ones. Drinking water is another factor that can change the gut microbiota composition. Leaching of arsenic from the Earth's crust into the groundwater contaminates the water sources, and drinking the same water for a long time disturbs the body's metabolic functions while increasing the risk of getting hepatitis, type 2 diabetes, and cancer. A now- published study, conducted in southern Nepal, found that people exposed to arsenic via well water and other sources have higher levels of potentially harmful microbiota and reduced levels of commonly inhabiting beneficial microbiota. When the number of harmful microbiota is higher than the beneficial ones, the balance is lost, a condition termed 'gut dysbiosis.' This loss in balance results in the poor absorption of nutrients, damages the gut cells, creates pores in the gut, allows the toxins produced by microbiota to enter the system, and increases the risk of infections. It may result in chronic inflammation, diabetes, anxiety, metabolic disorders, heart disease, and inflammatory bowel disease. Gut microbiota do not act in isolation. They have been found to form communication networks with other organs, including the liver, heart, lungs, muscle, and brain, through gut-liver, gut-heart, gut-lung, gut-muscle, and gut-brain axes, respectively. This two-way communication shapes metabolism, guides immune responses, and influences brain activity. This also means that these communications can influence how the heart works, how we experience emotions, and how our lungs cope with infections. Curd, or dahi, is a widely consumed probiotic in Nepal, especially after a heavy meal to help digestion. Lactobacillus spp. and Lactococcus spp. produce lactic acid and are present in the curd. These bacteria help break down the lactose in the curd, support digestion, and reduce bloating. One particular species, Lactobacillus paracasei, has been genetically engineered with the potential to even lower blood pressure in animal models. Another gut microbiota, Faecalibacterium prausnitzii, has been found to lower the risk of chronic kidney disease. Trimethylamine produced by gut microbiota can reduce insulin resistance and exhibit anti-diabetic properties. Gut microbiota can also modify bile acids (produced by the liver to aid in fat digestion) and generate compounds that can increase the ability of immune cells to fight tumors. While future clinical trials are needed to confirm these findings and strengthen their clinical relevance, the preliminary evidence already shows that gut microbiota have a pivotal role in maintaining overall health. It also provides a strong foundation for considering gut microbiota as a target for prevention and therapy against various disease conditions. As Nepal struggles with rising rates of chronic diseases, paying close attention to gut health has never been so important. As we cannot control the gut microbiota-changing factors such as age and genetics, other factors remain in our control. Staying physically active, consuming a balanced diet, incorporating probiotics (live beneficial microbiota) and prebiotics (food that feeds good microbiota), avoiding use of tobacco and alcohol, lowering daily salt intake, using antibiotics responsibly, consuming safe drinking water, and taking care of the gut can support a healthy gut and lay the foundation for a longer, healthier life.