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?

Microorganisms, or microbes, reside in various parts of your body, but the majority are concentrated in the intestines, particularly in the cecum, a part of the large intestine. This collection of microbes is referred to as the 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.

Metformin is a safe and effective drug used by type 2 patients for the last six decades to control their blood sugar levels and improve the way the body handles insulin.

A recent study showed that metformin can also be crucial in reducing the risk of vision loss in people over the age of 50, known as age-related macular degeneration (AMD).

The observational study, published in the BMJ Open Ophthalmology, showed that metformin can cut down the cases of AMD by nearly 40 percent in people with Type 2 diabetes over five years.

“We have found a significant association between metformin use and a reduction in the incidence of intermediate AMD by 37 percent in people with diabetes over 5 years. Previous epidemiological studies of metformin and AMD have used secondary data on AMD,” said corresponding author Nicholas A. V. Beare, from the University of Liverpool, UK.

“Given metformin’s anti-aging therapeutic effects, the reduction in risk is plausible and warrants prospective clinical trials,” he added.

Also read: Metformin Controls Blood Sugar With Help From Brain Neurons, Finds Study

Metformin And AMD

While currently there is no specific treatment option for AMD — a common cause of blindness in high-income countries — scientists have shown interest in metformin as a candidate drug for treating AMD and reducing its progression.

It is because of metformin's antioxidant, anti-inflammatory, antiangiogenic, and antifibrotic effects. Metformin is also postulated to delay ageing and ageing-related diseases.

Previous research has also identified metformin as a potential treatment for all stages of AMD. Researchers also noted that the common diabetes drug is readily accessible and has a strong safety profile.

How Metformin Improves AMD

The BMJ study analyzed more than 2,500 participants aged 50 or above who attended retinopathy screening in 2011.

All participants had Type 2 diabetes and gradable fundus photographs — high-quality retinal images.

Individuals prescribed oral metformin had a 37 percent lower risk of intermediate AMD by five years. The results are consistent with known biological mechanisms, given metformin’s potential favourable effects on AMD progression, researchers reported, the researchers said.

The team, however, acknowledged limitations such as a lack of proper data regarding the dose, duration of prior use, or compliance with metformin use.

Further, there were only a relatively small number of participants developing advanced AMD – an inevitability in population-based studies. They urged for a clinical trail to prove metformin's potential in treating AMD.

Also read: World Sight Day: 10 Tips To Help Prevent Vision Loss In Elderly

What Is AMD?

Age-related macular degeneration (AMD) is a disease of the retina. It happens when a part of the retina called the macula is damaged. It results in the loss of sharp, straight-ahead vision.

The condition commonly affects adults over 50, and causes

• blurry vision,
• dark spots,
• distorted straight lines.

While AMD rarely causes total blindness but affects central vision, making reading and driving difficult. It is of two types:

• Dry Age-Related Macular Degeneration
• Wet Age-Related Macular Degeneration

Globally, AMD is a top-five cause of vision loss. As the aging population increases, the number of people with AMD in the world is also estimated to increase by 50 percent to 288 million in 2040, with the highest burden in Asia.

Harry Potter star Daniel Radcliffe has quit smoking after 20 long years. The reason: his two–year–old son with girlfriend Erin Darke.

Speaking to media outlet Vulture, the 36-year-old English actor shared that after becoming a father, he was inspired by intrusive thoughts about his mortality, which enabled him to quit the deadly habit after two decades.

"I smoked for 20 years pretty heavily, and I was never even thinking about quitting, and then shortly after having my son, the intrusive thoughts of my own death really helped as an incentive to quit," Radcliffe was quoted as saying.

Radcliffe also shared how a book -- The Easy Way to Quit Smoking, by Alan Carr -- helped him decide to quit smoking.

"It may not work for everybody, but it really worked for me," noted the star, currently starring in the Broadway play Every Brilliant Thing.

Earlier this month, the actor spoke with WSJ Magazine and shared that from being on “cigarettes all day”, he's transformed into a fitness freak.

How Does Smoking Affect Our Body?

Smoking can affect all organs in our body. While lung cancer and tuberculosis are the most prominent ones, smoking can seriously increase the risk of several chronic diseases. These include:

• Heart Disease
• Asthma
• Reproductive Health
• Vision Loss
• Chronic Obstructive Pulmonary Disease
• Cancers of the liver, stomach, and colon.

While quitting tobacco is important, it is a difficult task, with some people finding it harder to quit than others. It may be important to seek help quitting.

Also read: Cigarettes And The Female Body: The Hormonal Toll We Don’t Talk About

What Happens When You Stop Smoking?

• In just 20 minutes of stopping, your blood pressure and heart rate begin to normalize.
• Within a few weeks, your lung function improves.
• Over time, the risk of heart disease and cancer also decreases dramatically.

A recent study published in the journal Addiction emphasizes three primary methods proven effective for quitting smoking: behavioral support, prescription medications, and nicotine replacement therapy (NRT).

These strategies have shown varying levels of success in aiding smokers to quit permanently. In addition, alternative methods like e-cigarettes and mindfulness-based techniques have gained traction in helping reduce smoking addiction.

Science-backed Methods To Help You Quit Smoking

Behavioral Support

Quitting smoking isn’t just about resisting cravings. Often, behavioral support through counseling or therapy is crucial for tackling the psychological aspects of addiction. Behavioral therapy involves working with a trained professional to identify triggers, develop coping strategies, and create a tailored quit plan. Research shows that combining counseling with other quit methods can significantly increase success rates.

Prescription Medications

Some medications, such as varenicline (Chantix) and bupropion (Zyban), have been shown to help people quit smoking by reducing cravings and withdrawal symptoms. Experts suggest that varenicline works by blocking the effects of nicotine in the brain, while bupropion is an antidepressant that helps manage withdrawal symptoms. Both medications are generally more effective when combined with behavioral therapy.

Nicotine Replacement Therapy (NRT)

Nicotine replacement products, such as nicotine patches, gums, lozenges, and nasal sprays, deliver controlled amounts of nicotine to ease withdrawal symptoms. According to experts at Harvard Health, NRT can double the chances of quitting by alleviating physical cravings while the person works on overcoming the psychological addiction.

About 10.6 percent –15 percent of India's population suffers from some form of mental health conditions, with 15 percent of the adult population also requiring active intervention.

To enable researchers to gather as well as systematically document data on patients with major forms of mental illness, neuroscientists in India have developed CALM-Brain — a digital repository of data on brain structure and function from a range of psychiatric disorders.

CALM-Brain contains data from over 2,000 participants from 900 families across the country.

CALM-Brain will help clinicians and researchers

• to understand the onset of neuropsychiatric disease
• check progression
• decode underlying biological changes
• provide better diagnosis
• plan personalized treatments for patients.

“CALM-Brain was conceived as a method to assemble data from multiple scales of analysis of brain structure and function on a single platform. We believe that the application of modern methods of data analysis to this dataset will help bridge the gap between these scales of analysis,” said Prof. Raghu Padinjat, CBM co-ordinator at CBM-NCBS, in a statement.

Also read: World Happiness Report 2026 Flags Social Media Harms On Adolescents' Mental Well-being

What Is CALM-Brain?

CALM-Brain is the result of collaborative efforts of researchers at the Rohini Nilekani Centre for Brain and Mind (CBM) — a partnership between the National Institute of Mental Health and Neuro Sciences (NIMHANS) and the National Centre for Biological Sciences (NCBS) - TIFR.

CALM-Brain is India’s first-of-its-kind repository of clinical, neuroimaging, behavioral, genetic, and other datasets on disorders such as:

• addiction,
• bipolar disorder,
• dementia,
• obsessive compulsive disorder (OCD)
• schizophrenia.

This longitudinal data incorporates multiple modes of studying brain function in neuropsychiatric diseases:

• Functional Magnetic Resonance Imaging (fMRI)
• Near Infrared Spectroscopy (NIRS)
• electroencephalogram (EEG)
• observations of cognition
• eye-tracking
• genetic analyses of blood samples
• clinical assessments.

The dataset is also linked to a biorepository of stem cells, which can be used to perform biological research in psychiatry to understand the origins of such severe mental illnesses.

“The primary goals of the project are to identify biological markers of severe psychiatric illnesses, which cut across traditional diagnostic frameworks. In addition, we will try to identify fundamental biological mechanisms of the disease and medication response,” said Prof. Y.C. Janardhan Reddy, CBM coordinator at CBM-NIMHANS.

Burden Of Mental Illnesses In India

Mental wellness is a major health and economic concern in India. The World Health Organization (WHO) estimates India’s economic loss due to mental health conditions to be USD 1.03 trillion (2012-2030).

Recently, health experts and policymakers, as part of the government-led Post-Budget Webinar series, highlighted the growing burden of mental and neurological disorders in India and also stressed the urgent need to strengthen institutional capacity to meet emerging healthcare demands.

"One in seven Indians is affected by mental health disorders, while several states continue to face a treatment gap ranging from 70 to 90 percent," the experts said.

They added that "neurological and mental health conditions are among the leading contributors to disability-adjusted life years (DALYs)" among citizens.

To address the rising burden, the government aims to launch NIMHANS-2 — first announced by Finance Minister Nirmala Sitharaman during the Union Budget 2026-27 — to deliver specialized care for mental health and neurological disorders in north India.

"In addition, the Central Institute of Psychiatry, Ranchi, and the Lokopriya Gopinath Bordoloi Regional Institute of Mental Health, Tezpur, will be upgraded as regional apex institutions to strengthen mental healthcare services in the eastern and north-eastern regions," FM Sitharaman said.