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.

Organ donation is one of the most generous gifts a person can give. Age, diabetes, hypertension or other medical conditions do not automatically rule out organ donation, doctors said on World Organ Donation Day.

Observed on August 13 every year, World Organ Donation Day aims to raise awareness about the need for organ and tissue donation and honour donors and their families.

Organ Donation After Brain Death

Dr. Umesh Gupta, Director and HOD, Nephrology and Kidney Transplant, Aakash Healthcare Multi-Speciality Hospital, Dwarka, told HealthandMe that organ donation can be considered when brain function is permanently lost and cannot be restored.

Brain death occurs when all functions of the brain and brainstem have permanently stopped.

“Brain death is different from a coma or a prolonged unconscious state. In brain death, the person cannot regain consciousness or breathe independently. Mechanical support may continue to keep the heart beating and preserve the condition of organs for a limited period, which is why organ donation can be considered,” he said.

Depending on the donor’s medical condition, organs such as the heart, liver, kidneys, lungs and pancreas may be suitable for transplantation.

Who Can Donate Organs?

Age alone does not rule out organ donation. Eligibility is assessed individually by the transplant team.

Doctors evaluate:

• Health and functioning of individual organs
• Existing illnesses
• Infections
• Medical history
• Other factors that could affect transplant safety

Can People With Diabetes or Hypertension Donate?

People with well-controlled diabetes or hypertension may still be eligible to donate certain organs or tissues, said Dr. Shailesh Chandra Sahay, Senior Director - Urology, Kidney Transplant, Robotic Surgery, Max Super Speciality Hospital, Patparganj.

Modern transplantation practices allow doctors to assess each organ individually rather than excluding a donor solely because of age or a particular diagnosis.

Every potential donor deserves a medical evaluation. An organ that may appear unsuitable to a person could ultimately give another patient a second chance at life.

Blood Group Is Important — But Not the Only Factor

Blood group compatibility is an important consideration in organ transplantation.

“A blood group O donor typically donates to O recipients, while AB recipients can receive organs from all ABO blood groups in many transplant settings,” Dr. Saurabh said.

However, compatibility involves more than blood type. Doctors also assess:

• Tissue compatibility
• Antibodies
• Organ size
• Recipient’s overall health

World Organ Donation Day 2026: Why Donation Matters

• One deceased donor can potentially save up to eight lives through vital organ donation.
• Tissue donation can improve the lives of many more people.
• A record 173,727 solid-organ transplants were performed worldwide in 2024, but demand continues to exceed supply.
• India performed 20,019 organ transplants in 2025, nearly four times the number in 2013.
• As of March 3, 2026, 89,839 patients were on India’s national waiting list for major organs.
• Only around 18% of transplants currently involve deceased-donor organs.
• More than 4.8 lakh Indians have pledged to donate organs and tissues after death since September 2023.

Lung cancer has long been associated with smoking, but this is no longer the complete picture. While tobacco remains the leading cause, an increasing number of people who have never smoked are also being diagnosed with the disease. This changing pattern highlights the need to look beyond smoking alone when considering lung cancer risk.

In non-smokers, lung cancer is often diagnosed later because neither patients nor families may initially suspect the disease. As a result, symptoms are sometimes mistaken for common respiratory illnesses, delaying evaluation and treatment.

Why Non-Smokers Are Also at Risk

While smoking continues to account for most lung cancer cases, several other factors can also contribute. Long-term exposure to second-hand smoke, air pollution, radon gas, asbestos, diesel exhaust, and certain workplace chemicals has been linked to an increased risk. A family history of lung cancer or specific genetic mutations may also make some individuals more susceptible, even if they have never used tobacco.

In urban areas, prolonged exposure to polluted air is becoming an important concern. Fine particulate matter can enter deep into the lungs, causing long-term inflammation and damage that may increase the risk of developing lung disease, including cancer.

Symptoms That Should Not Be Ignored

Early lung cancer may not cause noticeable symptoms. When symptoms do appear, they should not be ignored, particularly if they persist for more than a few weeks. Symptoms that should be evaluated by a doctor include:

• A persistent cough that does not improve

• Coughing up blood

• Chest pain

• Shortness of breath

• Unexplained weight loss

• Repeated chest infections

• Hoarseness of voice

• Persistent fatigue

These symptoms can occur due to several conditions and do not always indicate lung cancer. However, persistent or worsening symptoms should be assessed promptly to identify the underlying cause and begin appropriate treatment if needed.

Why Early Diagnosis Makes a Difference

Finding lung cancer at an early stage improves the chances of successful treatment. Individuals with prolonged exposure to environmental or occupational risk factors, or those with a strong family history of lung cancer, should discuss their risk with a doctor. Imaging tests such as chest CT scans and, when indicated, molecular testing help identify the type of lung cancer and support treatment planning.

Looking Beyond Smoking

Not every case of lung cancer can be prevented, but reducing exposure to tobacco smoke, avoiding harmful occupational exposures, improving indoor air quality where possible, and seeking medical advice for persistent respiratory symptoms can help protect lung health. Greater awareness that lung cancer can affect both smokers and non-smokers may lead to earlier diagnosis, timely treatment, and better outcomes.

(Dr Dipanjan Panda, Senior Consultant, Medical Oncology, Indraprastha Apollo Hospital, Delhi)

Influenza strain H1N1, formerly known as swine flu, is rising significantly in India, with deaths also being reported in some states.

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.

H1N1 Cases and Deaths Reported in States

Delhi: According to official data, Delhi has reported 1,349 confirmed H1N1 infections. No official deaths have been reported.

Kerala: A total of 2,468 influenza cases were recorded in the state in July, with 24 deaths reported during the month. The total number of cases recorded in the state this year stands at 5,519, with 60 deaths reported.

Maharashtra: The state has reported 25 laboratory-confirmed H1N1 cases, including a major spike of 15 cases in July. One confirmed death was officially verified by the Nagpur Municipal Corporation (NMC) Death Audit Committee.

Gujarat: H1N1 activity is also being reported, with Ahmedabad currently seeing a rise in cases.

Although H1N1 influenza primarily affects the respiratory tract, the infection can also put additional strain on the heart in some people, particularly those with a chronic history of cardiovascular disease, experts told HealthandMe.

How H1N1 Can Strain the Heart

Fever, dehydration, increased levels of carbon dioxide in the body, decreased oxygen levels and the body’s inflammatory response can increase the workload on the heart during an H1N1 infection.

This added strain may be more concerning for people who already have cardiovascular disease, said Dr. Praveen Raman Mishra, Associate Consultant, Institute of Cardiac Sciences at ShardaCare – Healthcity.

Heart Problems Linked to H1N1

Some H1N1 influenza patients may experience cardiovascular complications, including:

• Inflammation of the heart
• Abnormal heartbeats
• Worsening of heart failure

Dr. Saurabh Gupta, Associate Director, Internal Medicine, Yashoda Medicity, added that H1N1 infection may cause fluctuations in heart rhythm or inflammation associated with the heart.

“In some circumstances when suffering from the H1N1 virus, although the initial symptoms of the virus may be those shared with the normal flu, such as temperature, aches and cough, those with pre-existing heart conditions should be more vigilant whilst they’re recuperating,” he told HealthandMe.

“As the infection puts more work on the body, you can find that previous heart problems are more noticeable,” he added.

Warning Signs to Watch For After H1N1

The experts noted that people recovering from H1N1 should seek medical attention if they develop symptoms such as:

• Severe chest pain
• Shortness of breath
• A high or fluttering pulse
• Sudden faintness
• Severe weakness

Who Should Be Particularly Careful?

People with a chronic history of cardiovascular disease may face greater strain on the heart during H1N1 infection.

Monitoring symptoms during recovery and seeking medical attention when concerning symptoms develop can help identify cardiovascular problems early.