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 new review of studies has found that people living with type 2 diabetes have a significantly higher risk of developing Alzheimer's disease.

Researchers from Curtin University conducted a systematic review and meta-analysis of 40 studies. They estimated that if 1,000 people with type 2 diabetes were followed for a year, an average of 4.7 would develop Alzheimer's disease.

Published in Alzheimer's Research & Therapy, a separate analysis found that type 2 diabetes was associated with a 53% higher adjusted relative risk of Alzheimer's disease compared with people without the condition.

How Does Blood Sugar Affect Memory?

Ahead of World Diabetes Day, Dr Sudhir Kumar, neurologist at Apollo Hospitals, Hyderabad, in a post on X, explained that several overlapping mechanisms may link type 2 diabetes to Alzheimer's disease. These include:

• Brain insulin resistance: Brain cells become less responsive to insulin, potentially impairing their ability to use glucose for energy and clear amyloid and tau proteins.
• Vascular damage: High blood sugar can damage large and small blood vessels in the brain, increasing the risk of strokes and vascular dementia.
• Chronic inflammation: Peripheral inflammation and lipid abnormalities can weaken the blood-brain barrier and trigger neuroinflammation.

How Does Diabetes Increase The Risk Of Dementia?

According to Alzheimer's Society UK, diabetes is an established risk factor for dementia. The risk also increases with the duration and severity of diabetes. However, having diabetes does not mean a person will necessarily develop dementia.

With diabetes and Alzheimer's disease cases rising globally, understanding the link between the two conditions is becoming increasingly important.

Insulin helps regulate blood sugar by enabling the body's cells to use glucose for energy. In people with diabetes, the body either does not produce enough insulin or cannot use it effectively, causing blood sugar levels to rise.

Studies have linked type 2 diabetes to an increased risk of dementia. In people with type 1 diabetes, severe and repeated episodes of high or low blood sugar have also been associated with a higher risk.

Diabetes and Alzheimer's disease may share certain underlying mechanisms. In both conditions, brain cells can become less responsive to insulin, potentially affecting brain function and contributing to the accumulation of amyloid and tau proteins associated with Alzheimer's disease.

How Can People With Diabetes Protect Their Brain Health?

Dr Kumar recommended the following measures for people living with type 2 diabetes:

• Maintain blood sugar levels: Aim to keep glucose within your target range.
• Avoid extreme fluctuations: Prevent prolonged high blood sugar (HbA1c of 7% or higher) and severe, repeated episodes of low blood sugar (hypoglycemia).
• Manage other health conditions: Keep blood pressure and cholesterol under control.
• Prioritise a healthy lifestyle: Eat whole foods, including vegetables, fruits and whole grains, and engage in regular physical activity to improve insulin sensitivity.

"Early detection, consistent blood sugar management, and working closely with your healthcare team can help safeguard your cognitive future," he said.

Four-year-old Deborah started school this year full of excitement. But she is struggling to understand why she now has to attend classes on a screen. The nursery student misses the school bus, chatting with friends and running around the classroom. Despite the appeal of screens, she finds it difficult to sit still for online lessons.

Coughing badly, she asks what pollution is and pleads with her family to let her play in the park.

Deborah is not alone. Across Delhi-NCR, children are facing similar disruptions as schools shift classes online amid deteriorating air quality, keeping them indoors for longer.

Air pollution in India is no longer just a winter problem. Although levels peak during the colder months, poor air quality has increasingly become a year-round concern, with Delhi-NCR experiencing severe pollution episodes.

Beyond its well-documented respiratory and developmental effects, pollution and the disruption it brings to children's daily lives may also affect their emotional well-being. HealthandMe spoke to health experts, who warned that reduced outdoor play, disrupted social interactions and increased screen time could add to children's psychological stress.

How Air Pollution Can Affect Children's Mental Health

Air pollution should not be viewed as an isolated exposure when examining its impact on children's mental health, said Dr. Pradeep B.S., a Professor of Epidemiology and Deputy Medical Superintendent at the National Institute of Mental Health and Neuro Sciences (NIMHANS) in Bengaluru.

"Air pollution is a macro-level effect. If we reduce it to individual-level effects, we are scientifically wrong," he told HealthandMe on the sidelines of the 11th Together Against Stigma (TAS) Conference, held in the national capital.

He said air pollution is associated with several broader changes, including increased traffic, population growth, climate disturbances and unpredictable weather patterns. Together, these can have a silent effect on people's psychological well-being, including that of children and adolescents.

The effects may not always be direct. Respiratory and gastrointestinal problems, for instance, can prevent children from going outdoors and participating in activities. Losing the opportunity to play can itself become a source of distress.

He also pointed to urbanisation and road expansion, which not only contribute to pollution but also reduce green spaces, playgrounds and community recreational areas. The combination can limit children's opportunities to play, interact and socialise.

Environmental Stress Can Also Affect Children's Emotional Well-Being

Dr. Pallab K. Maulik, the Director of Research at The George Institute for Global Health India said air pollution is one of the contributors to mental health concerns, with both Indian and international research examining the association.

He told HealthandMe that pollution and environmental disasters can create anxiety and stress among children, particularly those whose everyday lives are disrupted by these conditions.

Citing an example from one of his study sites, he recalled speaking to a child living in a slum area whose home gets flooded whenever municipal tankers wash the streets. The child has to spend two days drying her books after the water enters the house.

Dr Pallab also referred to children in the Sundarbans who regularly experience flooding and salinity-related problems.

He said some adolescents are now using platforms such as adolescent parliaments to bring their concerns to local administrators. While children are becoming more aware of environmental challenges, he said, much more needs to be done to understand how environmental changes affect their mental health.

Staying Indoors, Screen Addiction And Anxiety

Dr Syed Hubbe Ali - Health Specialist (RMNCHA) at UNICEF highlighted another possible consequence of pollution-related restrictions on outdoor activities: increased screen exposure among children and adolescents.

When children cannot go outside, they tend to spend more time indoors, often turning to mobile phones, social media and online content. This can create a cycle of screen dependence, he explained.

He described how the pursuit of dopamine, associated with the brain's reward system, can encourage children to keep scrolling through social media content.

The cycle can become more complicated when children begin posting content and seeking validation through likes and engagement.

"Once you start developing your roles, the next stage comes when you see how many likes I got. I got the likes, I don't get the likes. Then the anxiety, you know, it starts," Dr Ali told HealthandMe.

He explained that not receiving the expected engagement can cause distress and, in some cases, contribute to depressive feelings and risky behaviour.

Dr Ali also raised concerns about children spending more time on screens for online learning. Referring to an NCERT survey conducted after the COVID-19 pandemic among 3.7 lakh children, he said only 51% were able to understand online content.

He suggested that learning methods need to move beyond conventional online teaching and incorporate more games and interactive approaches to improve children's engagement.

Why Outdoor Play And Social Spaces Matter

Dr Pradeep emphasised that the impact of pollution cannot be separated from the wider changes taking place in children's surroundings.

Reduced access to green spaces and recreational areas can affect opportunities for physical activity, social interaction and play. When children are unable to participate in these activities, the effects can extend beyond physical health.

Dr Ali also highlighted the importance of outdoor activities and sunlight exposure in children's everyday lives. He said keeping children indoors for prolonged periods can increase their dependence on digital platforms as a source of entertainment and stimulation.

Gait, or an individual's walking pattern, is an important marker of overall health, reflecting neurological integrity, musculoskeletal function and cognitive status. Although walking may seem effortless, people often dismiss changes in their gait as signs of tiredness or ageing.

Losing balance while walking can sometimes be attributed to fatigue, dehydration or a momentary lapse in attention. However, recurrent or unexplained balance problems can also indicate an underlying neurological condition and should not be ignored, experts warned.

Dr Gaurav Batra, Principal Consultant, Neurosurgery, Yashoda Super Speciality, said individuals experiencing instability, changes in their walking pattern or more frequent tripping than usual should seek medical evaluation.

"Walking seems so natural that it is often taken for granted. However, it involves the brain, nerves, muscles, eyes and the balance system in the inner ear working in unison," he told HealthandMe.

"When there is a disorder in one of these systems, the way a person walks can be affected, which is exactly why the type of imbalance becomes an important consideration. One person may feel like they are being dragged in a particular direction," the expert added.

When Is Loss Of Balance A Neurological Warning Sign?

New, persistent or worsening balance problems warrant attention, Dr Batra said. Changes in walking patterns or deteriorating balance could sometimes indicate an underlying problem affecting the brain or spinal cord.

Certain conditions can cause pressure on the brain or spinal cord in the neck, resulting in subtle changes in walking patterns and the ability to maintain balance.

Dr Batra advised against dismissing increasingly abnormal changes in walking, particularly when they affect daily activities or occur alongside stiffness, tremors, weakness, numbness or difficulty with coordination.

Neurological Conditions That Can Affect Balance

Dr Atampreet Singh, Senior Director and Head, Institute of Neurosciences, ShardaCare - Healthcity, explained that disruptions in the systems responsible for maintaining balance can cause unsteadiness, difficulty walking in a straight line, frequent stumbling and an increased tendency to fall.

Recurrent balance problems may be associated with several neurological conditions, including:

• Parkinson's disease: Can affect movement and coordination, making walking and maintaining balance difficult.
• Cerebellar disorders: Can interfere with coordination and the ability to maintain a steady gait.
• Peripheral neuropathy: Damage to peripheral nerves can affect sensation and balance.
• Multiple sclerosis: Can disrupt communication between the brain and the rest of the body, affecting coordination and walking.

In older adults, recurrent or unexplained falls may sometimes be an early indication of an underlying neurological or sensory deficit, Dr Singh told HealthandMe.

Sudden Loss Of Balance Could Indicate A Stroke

A sudden loss of balance, particularly when accompanied by other neurological symptoms, can be a warning sign of stroke and requires immediate medical attention.

Dr Singh highlighted the following symptoms to watch for:

• Weakness or numbness on one side of the body
• Facial weakness
• Difficulty speaking
• Severe dizziness
• Visual disturbances
• A sudden, severe headache

Such symptoms require immediate medical assessment, the expert noted.

When Should You See A Doctor?

Seek medical attention if unsteadiness persists or worsens, particularly when accompanied by weakness or numbness in the arms or legs, frequent falls, severe headache, vomiting, changes in vision or speech, or loss of bladder or bowel control.

A doctor may conduct a neurological examination and recommend brain or spinal imaging, if necessary, to determine the cause.

The doctors noted that early diagnosis is important because some underlying conditions are treatable, and timely intervention may help prevent permanent neurological problems.

They advised patients to pay attention to when the imbalance began, whether it appeared suddenly or developed gradually, and whether it is accompanied by tremors, dizziness, numbness, weakness, speech changes or difficulty with coordination.