Your body hosts trillions of bacteria, viruses, and fungi, collectively known as the microbiome. While some bacteria are linked to disease, many play essential roles in supporting your immune system, heart health, weight management, and overall well-being. This article delves into the significance of the gut microbiome and its impact on health.

What Is Gut Microbiome?

Interestingly, bacterial cells outnumber human cells in the body, with approximately 40 trillion bacterial cells compared to 30 trillion human cells. With up to 1,000 species of bacteria present in the gut, each plays a distinct role. While most bacteria contribute positively to health, some can be harmful. Together, these microbes weigh around 1–2 kilograms, functioning almost like an additional organ essential for overall well-being.

How Does Gut Microbiome Influence Your Health?

The relationship between humans and microbes has evolved over millions of years, with the gut microbiome playing a crucial role from birth. Initial exposure to microbes occurs during birth, and some evidence suggests that exposure begins in the womb. As the microbiome diversifies, it starts influencing key bodily functions:

Digestion of breast milk: Beneficial bacteria like Bifidobacteria help break down essential sugars in breast milk, supporting infant growth.

Fiber digestion: Some bacteria process fiber into short-chain fatty acids, which contribute to gut health and reduce risks of obesity, diabetes, and heart disease.

Immune system regulation: The gut microbiome interacts with immune cells, influencing how the body responds to infections.

Brain health: Emerging research suggests a link between the gut microbiome and brain function, potentially affecting mental health and neurological processes.

Gut Microbiome And Weight Management

An imbalance between beneficial and harmful microbes, known as gut dysbiosis, may contribute to weight gain. Studies on identical twins—one with obesity and the other without—suggest that microbiome composition plays a role in body weight independent of genetics. Additionally, animal studies indicate that gut bacteria can influence weight gain, even when calorie intake remains constant.

Probiotics, beneficial bacteria found in supplements and certain foods, can help restore gut balance and support weight loss, though their effects may be modest.

Gut Health And Disease Prevention

The gut microbiome plays a vital role in preventing and managing conditions like irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Imbalances in gut bacteria may lead to bloating, cramps, and digestive issues. On the other hand, beneficial bacteria like Bifidobacteria and Lactobacilli help strengthen the intestinal lining, reducing the risk of gut-related disorders.

Impact On Heart Health

Research suggests that the gut microbiome influences heart health by affecting cholesterol levels and blood pressure. Certain harmful bacteria produce trimethylamine N-oxide (TMAO), a compound linked to blocked arteries and heart disease. However, probiotics, particularly those containing Lactobacilli, may help reduce cholesterol levels and promote cardiovascular health.

Blood Sugar Regulation And Diabetes Risk

The gut microbiome also plays a role in regulating blood sugar levels. Research on infants genetically predisposed to type 1 diabetes indicates that gut microbiome diversity declines before disease onset. Furthermore, individual variations in gut bacteria may explain why people experience different blood sugar responses to the same foods.

Connection Between Gut And Brain

The gut is physically connected to the brain through nerves, and certain bacteria help produce neurotransmitters like serotonin, which influence mood and mental health. Studies indicate that people with mental health disorders often have different gut bacteria compared to those without such conditions. Additionally, some probiotics have shown promise in alleviating symptoms of depression and anxiety.

Tips For Healthier Gut Microbiome

Maintaining a balanced gut microbiome is crucial for overall health. Here are some strategies to support gut health:

• Eat a diverse range of foods: A varied diet rich in fiber, legumes, and fruits promotes microbial diversity.
• Consume fermented foods: Yogurt, kefir, and sauerkraut contain probiotics that enhance gut health.
• Limit artificial sweeteners: Some artificial sweeteners can encourage the growth of harmful bacteria.
• Include prebiotic foods: Bananas, oats, and asparagus contain fibers that nourish beneficial bacteria.
• Breastfeed infants when possible: Breastfeeding promotes a healthier gut microbiome in babies.
• Choose whole grains: Whole grains contain fiber and beneficial compounds that support digestive health.
• Opt for a plant-based diet: Vegetarian diets may reduce inflammation and support a healthier gut microbiome.
• Consume polyphenol-rich foods: Green tea, dark chocolate, and olive oil contain compounds that foster beneficial bacteria.
• Take probiotics if needed: Probiotic supplements can help restore gut balance after disruptions, such as antibiotic use.
• Use antibiotics cautiously: While antibiotics can be life-saving, overuse can harm beneficial gut bacteria.

A cigarette after stress. Chewing tobacco during the day. Smoking to “calm the nerves”

But modern science is forcing us to confront the difficult truth; Tobacco does not treat mental health symptoms, in fact it quietly deepens it.

As Oncologists and physicians, we often see patients who say, “smoking makes them feel normal.” However, in reality, what they are experiencing is nothing more than the temporary relief from nicotine withdrawal not genuine emotional regulation.

Nicotine Creates A Cycle of Temporary Relief And Dependence

When we smoke or chew tobacco, nicotine stimulates dopamine release in the brain, creating a short-lived sense of relaxation or control. But overtime it leads to brain depending on nicotine to achieve the same baseline feeling again and again. The result is a vicious cycle of dependence, irritability, anxiety, and worsening emotional resilience.

Several large studies now show that long-term tobacco use is associated with higher rates of anxiety, depression, sleep issues and substance dependence. A 2023 review published in BMJ found that smoking cessation will result in improvements in both anxiety and depression and an improved mood with benefits comparable to antidepressant treatment in some individuals.

Also read: Lung Health After 40: Natural Changes, Warning Signs And Ways To Protect Your Lungs

Tobacco May Worsen Anxiety, Depression And Sleep Problems

This has serious implications for the urban Indian population in regard to the increasing prevalence of mental exhaustion, lack of social support, digital overload, work-related stress and lack of sleep. Tobacco often enters quietly during vulnerable moments of college pressure, workplace stress, loneliness, grief and gradually shifts from “social habit” to psychological crutch.

Although they think they believe in tobacco, many of them use it, thinking that they are using it to cope with their emotional symptoms, when in fact they are making the symptoms worse.

Also, recognize the biology of tobacco use. For example, the use of nicotine will result in long-term changes in how well your body handles emotional stress because of the role of long-term nicotine exposure in altering the system of cortisol regulation and the stress response pathways in neurons. So, with time, it will become harder and harder for a person to control his/her emotional response to stress because his/her body will not be able to do it. Thus, tobacco has a negative influence on the recovery process from emotional responses to stress, rather than a beneficial one.

Also read: Air Pollution May Increase The Risk Of Painful Rheumatoid Arthritis Flares, Study Finds

How Nicotine Alters The Body’s Stress Response?

Tobacco is a significant preventable risk factor for oral, head and neck, lung, oesophageal, pancreatic and bladder cancers. When many patients arrive at cancer centres, the addiction to tobacco is already set, and it is even more difficult to quit while receiving cancer treatment.

This is why it is important to help move the conversation on tobacco beyond cancer. Now, it's more than just a public health issue; it also includes issues of mental health. Individuals experiencing emotional difficulties should not think that they are being judged. They have to learn to find alternative coping strategies, get psychological support early on in their lives, sleep well, exercise, be part of the community, and access timely medical support. The goal of this care is not just to support someone in quitting tobacco, but to provide support for them to stop needing tobacco in order to feel good.

By Dr Amit Chakraborty, Consultant Oncologist, Saifee Hospital, Mumbai

India is facing a growing burden of non-communicable diseases (NCDs), with hypertension and diabetes among the major health concerns.

Experts warned that the risk of both conditions rises after 40, often without noticeable symptoms. Increasing age, weight gain, reduced physical activity, stress, dietary habits, and metabolic changes can all contribute to the risk.

Having hypertension and diabetes together is particularly concerning, as their coexistence can increase the risk of heart disease, stroke, kidney damage, retinopathy, and other complications.

Why Risk Rises After 40?

Dr. Santosh Gupta, Associate Director - CTVS, Paras Health Udaipur, told HealthandMe that several factors contribute to the rising risk after 40.

“After the age of 40, the risk of hypertension and diabetes increases due to factors such as changes in metabolism, reduced physical activity, weight gain, stress and dietary habits. What makes both conditions particularly concerning is that they can develop silently, without noticeable symptoms, while gradually affecting vital organs,” he said.

He added that uncontrolled hypertension can damage the heart, brain, kidneys, and blood vessels, while diabetes can affect the kidneys, eyes, nerves, and cardiovascular system.

"When both conditions occur together, the risk of heart disease, stroke and kidney complications becomes even higher,” Dr. Gupta added.

Because both conditions can remain silent for years, people may have high blood pressure or blood sugar without knowing it.

Also read: Breastfeeding Can Help Reduce Mothers' Risk of Type 2 Diabetes, Breast Cancer and More

Hypertension And Diabetes Often Coexist

A recent hospital-based analysis found that hypertension and diabetes frequently occur together, with their coexistence rising sharply from around age 40 among Indians.

The study, conducted by the Department of Clinical Research and Preventive Health Program at Max Healthcare, analyzed health records of more than 56,000 adults who underwent preventive health check-ups between January 2021 and December 2024.

Nearly 5% of adults had both conditions. Their coexistence increased rapidly from around 40, continued rising until approximately 58 and gradually reached nearly 17% by around age 70.

People with diabetes were nearly four times more likely to have hypertension, while those with hypertension were about 2.5 times more likely to have diabetes.

Dr. Abhaya Indrayan, Biostatistics Consultant, Max Healthcare, said the findings support screening for both conditions rather than assessing them separately.

Why Screening After 40 Matters

Read More: Confused By Your Cholesterol Report? Here's What LDL And ApoB Really Mean

Experts said that preventive healthcare should go beyond checking for individual diseases. Adults over 40 should routinely assess key cardiometabolic risk factors, including blood pressure and blood sugar.

Screening can help detect hypertension, diabetes or prediabetes early, when lifestyle changes and treatment can help prevent or delay complications.

“This is why regular screening after 40 is important, even for individuals who feel completely healthy. A routine blood pressure check, fasting blood glucose or HbA1c test can help identify hypertension, diabetes or prediabetes at an early stage, when timely lifestyle changes and medical intervention can prevent or delay complications,” Dr. Gupta said.

“Screening should not be viewed only as a diagnostic exercise; it is an opportunity to understand one’s health risks and take corrective measures before the disease begins to cause irreversible organ damage,” he added.

How To Lower The Risk

Preventive care also involves addressing modifiable risk factors. Regular physical activity, maintaining a healthy weight, limiting salt, sugar and highly processed foods, getting adequate sleep and avoiding tobacco can help lower the long-term risk.

For those already diagnosed with hypertension or diabetes, regular monitoring and adherence to prescribed treatment are important to reduce the risk of complications.

With the risk of both conditions rising after 40, experts recommend making routine health checks part of regular healthcare—even when there are no obvious symptoms.

Amid the ongoing monsoon season, Delhi-NCR is seeing a rise in H1N1 influenza cases, with Delhi reporting 1,344 cases so far this season.

The figure is nearly six times higher than the 229 H1N1 cases recorded during the same period last year, The Times of India reported.

According to health officials, Delhi recorded around 4,000 influenza cases last year, most of them caused by H3N2. This year, H1N1 is the dominant strain. Both H1N1 and H3N2 are subtypes of Influenza A and spread mainly through respiratory droplets.

What Is H1N1 and Why Is Testing Important?

H1N1 is a subtype of Influenza A and can cause sudden fever, cough, sore throat, headache, body aches and fatigue. These symptoms can overlap with those of other seasonal influenza strains, COVID-19 and respiratory syncytial virus (RSV), making it difficult to identify the infection based on symptoms alone.

Dr Aijaz Ilmi, Senior Consultant – Metabolic Diseases, Pacific OneHealth Hospital, told HealthandMe that testing is particularly important when fever or respiratory symptoms persist or worsen, especially among older adults, young children, pregnant women and people with diabetes, obesity, heart or lung disease, or compromised immunity.

“With the current rise in H1N1 cases in Delhi, we are also seeing other seasonal respiratory infections, including Influenza A and B, COVID-19, RSV and other respiratory viruses. At the same time, the monsoon season brings an increased risk of mosquito-borne illnesses such as dengue.

“The key message is, don’t panic, but don’t dismiss a persistent fever as ‘just a viral’. Early recognition is particularly important in vulnerable individuals.”

H1N1 vs Other Respiratory Infections: How Are They Different?

H1N1 can be difficult to distinguish from other respiratory infections because many of them cause similar symptoms.

• H1N1 and other seasonal influenza strains: Both can cause sudden fever, cough, sore throat, headache, body aches and fatigue. Symptoms alone generally cannot determine whether the infection is H1N1 or another influenza strain.

• COVID-19: COVID-19 can cause fever, cough, sore throat, congestion and fatigue. Some people may also experience changes in or loss of taste or smell, while gastrointestinal symptoms can occur.
• RSV: RSV commonly causes a runny nose, cough and wheezing. It can be more severe in infants, older adults and people with certain underlying conditions. In young children, it can cause bronchiolitis and breathing difficulties.
• Dengue: During the monsoon, dengue can also cause fever, headache, body aches and fatigue, which may initially resemble a viral respiratory infection. However, dengue is spread by mosquitoes rather than respiratory droplets and does not typically cause cough or sore throat.

How Can H1N1 and Other Infections Be Prevented?

Dr Sharwari Sudhir Dabhade, Consultant - Internal Medicine, Diabetology & Endocrinology, Madhukar Rainbow Children's Hospital, told HealthandMe that prevention should focus on reducing exposure and maintaining good hygiene. Other measures to reduce transmission include:

• Washing hands frequently.
• Covering mouth and nose while coughing or sneezing.
• Maintaining good indoor ventilation.
• Avoiding crowded or poorly ventilated places when respiratory infections are circulating.
• If you have respiratory symptoms, limit close contact with others and wear a mask.
• Getting vaccinated against influenza, particularly if you are an older adult, young child or have an underlying health condition.
• Prevent mosquito breeding and take precautions to avoid mosquito bites to reduce risk of dengue.

When Should You Seek Medical Help?

Most viral respiratory infections recover with supportive care. However, should seek prompt immediate medical assessment in cases of

• breathlessness
• persistent high fever,
• chest pain,
• confusion,
• dehydration,
• falling oxygen saturation
• significant worsening of weakness.