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.

Someone who is dying may start to their loved ones who passed away years ago. This could be unsettling and confusing for families and relatives who may assume that the person is just hallucinating or undergoing a deeper neurological issue.

But hospice physician Dr Christopher Kerr says such experiences are a known phenomenon called end-of-life dreams and visions (ELDVs). Kerr, chief medical officer of Hospice Buffalo, has spent decades studying these experiences in dying patients extensively.

Appearing on The Oprah Podcast, he told Oprah Winfrey that many patients near death describe seeing deceased relatives or people who cared for them during their lives. The experiences can feel completely real to them.

Why Do People Near Death See Deceased Loved Ones?

Also read: Ebola Bundibugyo Virus: Kenya Confirms First Death In Case Imported From Congo

One of the possibilities is that the brain experiences significant changes as the body starts to shut down.

Alterations in sleep, consciousness, metabolism, oxygen levels, medications, and brain chemistry can all affect perception during the final stages of life.

Dr. Rakesh Lalla, Additional Director - Neurology, Fortis Hospital, Mumbai, told HealthandMe, " These visions could be explained by the alterations that occur within the brain as the body starts to close down. Due to oxygen deprivation and altered brain activity, the brain would process memories, feelings, and stimuli differently. The areas responsible for memory processing and vision could become stimulated or disrupted, which could result in some vivid visions or experiences."

The expert also said that these visions do not mean that the person has a neurological or psychiatric issue.

Dr. Lalla said, "They do not necessarily mean that the person is confused or suffering from a psychiatric condition. In many cases, they are brief, peaceful, and emotionally meaningful to the individual. We still do not fully understand why particular people or memories appear."

The neurologist also advised families to stay supportive and calm during such situations.

He added, "The brain’s complex relationship between memory, emotion and perception is likely to play an important role. For families, the key is to remain calm, listen without dismissing the experience, and provide reassurance and comfort."

Also read: Global Life Expectancy Returns To Pre-Pandemic Levels, But NCDs Resulted In 8 Out 10 Deaths: WHO

Hallucinations Or Part Of The Dying Process?

Experts who have been studying ELDVs have also found that these experiences have some distinctive patterns that do not resemble random hallucinations.

In a 2014 longitudinal study led by Kerr, most of the 59 hospice patients who completed the study reported at least one dream or vision. Almost half occurred during sleep, and nearly all patients said the experiences felt real. The most common involved deceased friends or relatives or other loved ones. In fact, comforting visions of deceased people became more common as patients moved closer to death.

A 2026 systematic review of 13 studies similarly found that ELDVs occurred in at least one in five dying adults.

The National Institute on Aging also states that dying people may appear to see or talk to someone who is not present and may report dreams involving deceased relatives or friends. Such experiences are often comforting, and caregivers are generally advised not to immediately correct or challenge the person.

Seeing Loved Ones Could Be A Comforting End

Kerr said that patients seeing deceased loved ones in their visions appeared calmer afterward. His research suggests that these experiences may carry deep emotional meaning for patients.

“Very little is said between the person in the dream and the dreamer, but everything seems to be understood,” Kerr told Oprah.

Scientists still cannot say exactly what produces these experiences or whether they represent anything beyond changes occurring in the dying brain.

India accounts for one-fifth of global deaths due to cardiovascular diseases (CVDs) or complications related to the heart and blood vessels. Moreover, women are more vulnerable to these complications. Recent data show that women (14%) have a higher prevalence of CVD than men (12%), making preventive care very important for all.

When Should A Heart Check-up Be Done?

The human heart works constantly and efficiently and can compensate for metabolic stress and narrowing of blood vessels without showing any obvious symptoms. Hence, a heart health evaluation should ideally take place when the person is feeling completely well, long before any warning signs appear.

While acute symptoms, such as chest pressure or tightness, unexplained breathlessness, fainting, or unusual fatigue on effort, demand immediate attention, true heart protection occurs through early and planned tests. While heart check-ups are routinely recommended starting at age 40, screening should ideally begin earlier, around ages 30 to 35, especially if risk factors are present.

Starting check-ups at age 30 is important because certain congenital and structural heart conditions remain completely silent for years, and early screening ensures timely, targeted treatment when it is most effective.

Regular screening helps detect and rule out underlying issues early, including congenital heart defects (commonly known as holes in the heart) and conditions such as Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), or Patent Ductus Arteriosus (PDA). Structural and muscle diseases, on the other hand, include valve disorders, heart muscle weakness, or abnormal thickening of the heart walls (e.g., Hypertrophic Obstructive Cardiomyopathy (HOCM)).

Key Risk Factors

In addition to age, patients should seek a heart check-up sooner if they have any of the following risk factors:

• Strong family history of premature heart disease in immediate relatives.
• History of active or past smoking and tobacco use.
• Metabolic conditions such as diabetes, hypertension, or elevated blood cholesterol.

Excess body weight, especially central or abdominal obesity. Excess body weight damages the kidneys, leads to fat deposits in the liver and increases the risk of developing diabetes, and ultimately increases the strain on the heart and blood vessels (cardiovascular system). These interconnected conditions are known as Cardiovascular-Kidney-Metabolic (CKM) syndrome and include heart disease, kidney disease, diabetes, stetotic (fatty) liver disease, and obesity.

Effective weight and metabolic management, through modern options such as oral or injectable GLP1 therapies, can improve long-term heart health.

Tailoring care

A heart check-up can involve several tests, from blood tests to invasive or non-invasive ones (with/without needles, catheters, or probes entering the body). The most common blood tests include fasting and post-prandial or after-meal blood sugar (FBG/PPBG), HbA1c (glycated haemoglobin), lipid and thyroid profile, and kidney function tests. Non-invasive cardiac tests include electrocardiogram (ECG), 2D echocardiogram, and ultrasound. However, not everyone needs all of them.

Diagnostic tests should be customized based on the person’s age, symptoms, and individual risk score. Hence, skip the urge to self-order commercial diagnostic packages online. Instead, take the most important step towards protecting your heart by talking to your doctor. A personalized assessment can help determine which tests, if any, are appropriate for you, so that you can focus on the right steps to keep your heart healthy.

Gut chemicals may play a role in influencing the likelihood of someone developing Alzheimer's disease. A new study has a chemical produced by certain gut bacteria in focus that may affect Alzheimer’s disease risk, cognitive decline, and other changes related to the disease.

Published in Nature Communications, the study focused on imidazole propionate (ImP), a metabolite produced by some gut bacteria when they break down the amino acid histidine.

Researchers found that people with higher levels of ImP in their blood had lower cognitive scores and higher levels of biomarkers that indicate the likelihood of Alzheimer’s disease and neurodegeneration.

How Was The Study Conducted?

Also read: Global Life Expectancy Returns To Pre-Pandemic Levels, But NCDs Resulted In 8 Out 10 Deaths: WHO

The researchers studied health data from 1,196 adults who were cognitively unimpaired, with an average age of about 61 years. Higher blood levels of ImP were associated with poorer cognitive performance and faster age-related decline.

Higher ImP was also linked to increased levels of p-tau217, a key biomarker in Alzheimer’s pathology, and neurofilament light chain, a marker of nerve-cell damage.

The finding builds on earlier work from the University of Wisconsin-Madison team showing differences in gut microbes between people with Alzheimer’s and those without the disease.

“Since then, we've been trying to figure out how this difference in the gut perhaps leads to changes in the brain,” said Barbara Bendlin, professor of medicine at the University of Wisconsin-Madison.

But ImP itself may be more relevant than simply having a particular type of gut bacteria.

“ImP-producing bacteria are present in a large fraction of people, but they're not very abundant in most people,” said Federico Rey, professor of bacteriology at the University of Wisconsin-Madison. “But something we have learned over the years is that a microbe doesn't have to be abundant to have an impact on the host.”

Also read: Could This Popular Joint Supplement Turn Mild Cognitive Impairment Into Dementia? New Study Finds Link

Could Changing Your Diet Prevent Dementia Risk?

The researchers also found genetic evidence that linked higher ImP levels with an increased risk of Alzheimer’s. In experiments on mice, long-term exposure to ImP increased amyloid-beta plaques and signs of brain inflammation.

Laboratory experiments further suggested that ImP could affect the blood-brain barrier and promote tau hyperphosphorylation, a process involved in nerve damage that occurs in Alzheimer’s.

Researchers also caution against making changes to diet to alter gut bacteria. They say ImP is produced when bacteria metabolise histidine, an amino acid that the body needs and that is found in many protein-rich foods.

“Generally improving your diet would probably help,” Bendlin said. “But it's not as easy as saying, 'Stop eating eggs' or 'Don't eat so much red meat.' Because you need histidine, and it's all over the place.”

Instead, the researchers are looking at whether ImP itself could eventually be targeted.

“It could be just like cholesterol, where people with elevated cholesterol take a drug, a statin, that reduces their risk for heart disease,” Bendlin said. “If we can find an inhibitor that can help decrease the levels of ImP in the blood, that could hopefully reduce the risk of Alzheimer's and the speed of cognitive decline for a significant number of people.”

Researchers also say that the findings do not show that ImP causes Alzheimer’s in humans, nor do they suggest that probiotics or dietary changes can prevent dementia.

But they strengthen growing evidence that suggest chemicals produced by gut microbes may affect brain health years before symptoms surface.