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.

Learning a second or even a third language may do more than expand your communication skills. According to a new study presented at the Federation of European Neuroscience Societies (FENS) Forum 2026 in Barcelona, learning a new language could also help keep your brain younger as you age.

The findings of the study say that people who speak multiple languages have brains that appear biologically younger than those who speak only one language. The research added to the growing evidence that multilingualism has a beneficial effect on healthy cognitive ageing.

About The Study

To investigate how language affects the ageing brain, researchers analysed brain activity in adults living in Spain's multilingual Basque region.

They used magnetoencephalography (MEG), a non-invasive brain imaging technique that records the brain's electrical activity, along with artificial intelligence (AI) to ascertain each participant's brain age.

Rather than relying on a person's actual age, the AI model assessed how well different regions of the brain communicated with one another, a key marker that normally weakens with age.

Researchers first trained the AI using brain scans from 728 adults with varying language abilities before validating the findings in an independent group of 144 participants.

Read more: Normal Ageing or Alzheimer's? Doctors Explain Six Key Differences to Watch For

The results revealed an association between multilingualism and a younger-looking brain. Compared with people who spoke only one language, bilingual participants had brains that appeared around six years younger. Those who spoke three languages had brains that looked approximately seven years younger, while participants fluent in four languages had brains that appeared up to 13 years younger.

Researcher Lucia Amoruso, deputy scientific director at the Basque Center on Cognition, Brain and Language in San Sebastián, Spain, said, “In simple terms, people who spoke more languages tended to have brains that looked younger than expected for their chronological age.”

The researchers also found that language proficiency mattered. People who learned additional languages earlier in life and became more fluent showed even greater differences in brain age.

Is Multilingualism The Key To Keep Your Brain Younger?

Scientists believe speaking multiple languages provides the brain with a constant mental workout. Regularly switching between languages requires attention, memory, problem-solving and cognitive control, all of which strengthen the neural networks involved in thinking and decision-making.

This exercise may help maintain stronger communication between brain regions, increasing the brain's resilience against age-related decline.

While the team considered factors like age, sex, and education, multilingual individuals may also be more likely to engage in other habits that are beneficial for the brain.

Although the findings are encouraging, the researchers say that the study does not prove that learning another language directly slows brain ageing or prevents dementia. Experts say further long-term studies are needed to determine whether multilingualism can reduce the risk of neurodegenerative diseases such as Alzheimer's disease.

Despite the need for more research, scientists say the findings offer another compelling reason to learn a new language. Whether through formal classes, language-learning apps or everyday conversations, developing language skills could provide meaningful mental stimulation throughout life.

Millions of people around the world undergo blood tests every year to measure LDL, commonly known as "bad" cholesterol. But researchers now suggest that this standard test may not always provide the most accurate picture of heart disease risk.

A new study from Northwestern Medicine found that a blood test measuring apolipoprotein B (ApoB) may be better than LDL cholesterol testing for identifying people who need more intensive treatment to reduce their risk of heart attacks and strokes.

The researchers also found that using ApoB to guide treatment decisions could prevent more cardiovascular events while remaining cost-effective for healthcare systems. The findings were published in the journal JAMA.

"We found that ApoB testing to intensify cholesterol-lowering medication would prevent more heart attacks and strokes than current practice, and that these health benefits were achieved at a cost that represents good value for US healthcare payers," said study lead author Ciaran Kohli-Lynch, Assistant Professor of Preventive Medicine in the Division of Epidemiology at Northwestern University Feinberg School of Medicine.

ApoB vs LDL: What's the Difference?

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

Doctors have traditionally relied on LDL ("bad") cholesterol and non-HDL cholesterol levels to assess heart disease risk and decide when patients should begin or intensify cholesterol-lowering treatment. While these tests provide useful information, researchers say they do not tell the whole story.

The difference lies in what the two tests measure:

• LDL cholesterol test: Measures the amount of LDL cholesterol in the blood.
• ApoB test: Measures the number of cholesterol-carrying particles—including LDL and other potentially harmful particles—that can enter artery walls and contribute to plaque buildup.

"Research strongly shows that apolipoprotein B (ApoB) is better at identifying who is at risk because it counts the total number of harmful particles in the blood," Kohli-Lynch said.

According to the researchers, the number of harmful particles may provide a more accurate measure of cardiovascular risk than LDL cholesterol levels alone.

What Is ApoB?

Read More: US Cardiologist Explains Why 2026 AHA Cholesterol Guidelines Recommend Starting Young

In a post on X, Dr. Sudhir, Senior Consultant Neurologist at the Institute of Neurosciences, Apollo Hospitals, Hyderabad, explained that ApoB is a protein found on potentially harmful cholesterol-carrying particles such as LDL and VLDL (very low-density lipoprotein).

"Think of ApoB as a count of the particles capable of entering artery walls and causing plaque. One ApoB is equal to one potentially harmful particle," he said.

Dr. Sudhir explained that two people can have the same LDL cholesterol level but very different numbers of cholesterol-carrying particles. The person with more particles will usually have a higher ApoB level and, potentially, a greater risk of cardiovascular disease.

He added that ApoB often provides a more accurate assessment of heart disease risk than LDL cholesterol alone.

Despite growing evidence supporting ApoB, the test is still not widely used in routine clinical practice because it generally requires an additional blood test beyond the standard cholesterol panel, increasing both cost and inconvenience.

"Our study asked: Is it worth spending extra money to use ApoB instead of LDL to guide treatment intensification?" Kohli-Lynch said.

Dr. Sudhir suggested that ApoB testing should be considered for:

• people with diabetes,
• prediabetes,
• metabolic syndrome,
• obesity,
• elevated triglycerides,
• strong family history of heart disease.

New Cholesterol Guidelines

Earlier this year, the American Heart Association and 10 other medical organisations released updated guidelines recommending that many people begin cholesterol-lowering therapy at younger ages.

"This means it is increasingly important to accurately identify who would benefit most from intensive treatment," Kohli-Lynch said.

The updated guidelines also recommend measuring ApoB, particularly in people with high triglycerides, diabetes or in situations where LDL cholesterol levels may underestimate the number of harmful cholesterol-carrying particles.

Do you often forget where you kept your keys or glasses and worry that it could be a sign of Alzheimer's disease? While many people become more forgetful with age, doctors say that occasional memory lapses are a normal part of ageing. Alzheimer's disease, however, causes a different pattern of decline that affects memory, thinking and the ability to function in everyday life.

HealthandMe spoke to two neurologists who explained how to tell the difference between normal age-related forgetfulness and the warning signs of Alzheimer's disease.

"Many people worry when they start becoming more forgetful with age. While some changes in memory and thinking are a natural part of growing older, Alzheimer's disease causes a different pattern of decline that affects everyday life," said Dr. Rajneesh Kummar, Vice Chairman & Unit Head, Neurology, Max Super Speciality Hospital, Dwarka.

Dr. Praveen Gupta, Chairman, MAIINS, Marengo Asia Hospitals, Gurugram, added, "Alzheimer's is not a normal part of ageing. It's a neurodegenerative disease that affects memory, thinking and how you function each day. Recognising the difference can help people get medical evaluation and treatment sooner."

Also read: India Gets Its First Alzheimer’s Drug: Know All About Eli Lilly’s Lormalzi

The experts advised that persistent memory concerns should not be ignored. If symptoms become more noticeable or begin affecting day-to-day functioning, a medical assessment can help identify the cause and guide appropriate treatment and support.

They outlined six key differences that can help distinguish normal ageing from Alzheimer's disease.

1. Occasional Forgetfulness vs Repeated Memory Loss

According to the doctors, it is common to occasionally misplace items, forget a name or an appointment, and remember the information later.

However, people with Alzheimer's disease may repeatedly forget recent events, conversations, appointments or newly learned information and may not recall them even after reminders.

2. Slower Thinking vs Difficulty With Everyday Tasks

Normal ageing may mean taking longer to learn new technology or complete routine tasks.

In Alzheimer's disease, people may struggle to manage bills, prepare meals, follow directions, learn to use a new phone or remember instructions given only moments earlier.

3. Misplacing Things vs Forgetting They Were Ever There

Occasionally losing keys or glasses is considered a normal part of ageing, and most people can usually retrace their steps and find them.

By contrast, people with Alzheimer's disease may not remember putting an item down or even recall recently getting or buying it.

Read More: Anti-Inflammatory Diet May Help Lower Dementia Risk, Even In Those Who Show Early Signs Of Alzheimer’s: Study

4. Temporary Confusion vs Disorientation

Older adults may occasionally lose track of the day or date but usually remember it shortly afterwards.

According to the doctors, Alzheimer's disease can cause confusion about time, dates and places. People may repeatedly ask the same questions or become disoriented, even in familiar surroundings.

5. Searching for Words vs Difficulty Communicating

Everyone experiences occasional "tip-of-the-tongue" moments.

With Alzheimer's disease, people may frequently lose their train of thought, repeat themselves, struggle to follow conversations or have difficulty finding the right words.

6. Remaining Independent vs Needing Increasing Support

The doctors said one of the biggest differences is that normal ageing generally does not prevent a person from living independently.

Alzheimer's disease, however, gradually affects a person's ability to carry out everyday activities, adapt to changes in routine and maintain self-care without assistance.