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.

While doctors across the world recommend ensuring that fluoride and other protective minerals make up your toothpaste, your body produces its very own amino acid that protect your entire dental cavity.

Arginine, an amino acid that is already present in saliva, can turn bacteria from damaging to protective in your mouth, a study has found.

When sugars from food are broken down by the many bacteria living in the mouth, acids are produced that gradually damage tooth enamel and lead to cavities. This is known as dental caries. Over time, this acid dissolves tooth enamel and causes cavities.

However, researchers at Aarhus University in Denmark have discovered that regular arginine treatment can significantly reduced the overall acidity levels in the mouth and prevent tooth decay.

Yumi Del Rey, microbiologist at Aarhus, said: ""Our results revealed differences in acidity of the biofilms, with the ones treated with arginine being significantly more protected against acidification caused by sugar metabolism."

How Did The Study Take Place?

Volunteers were then asked to instructed to dip the dentures in a sugar solution for 5 minutes, immediately followed by distilled water (as placebo) or arginine for 30 minutes, one on each side. This was to be repeated three times a day, with arginine treatment done on the same side each time.

Sebastian Schlafer, professor at the Department of Dentistry and Oral Health, explained: "The aim was to investigate the impact of arginine treatment on the acidity, type of bacteria, and the carbohydrate matrix of biofilms from patients with active caries."

After 4 days of this process, the biofilms were developed and the dentures were removed for detailed analysis. The researchers compared dental plaques grown on customized dentures on both sides of each participant's mouth using a special pH-sensitive dye called C-SNARF-4.

How Does Arginine Work?

Additionally, the team also began to look into how arginine might be reducing acidity, by taking stock of which bacteria and sugars were present in each sample.

Biofilms treated with arginine showed lower levels of a sugar called fucose, while another sugar, galactose, was concentrated towards the outer surface of the biofilm, meaning both sugars were away from the tooth enamel.

After analyzing the DNA of bacteria present, the researchers found that arginine treatment significantly reduced a specific population of Streptococcus bacteria known to produce acid, while slightly increasing other bacterial strains that can metabolize arginine.

The scientists noted that while more research is needed into the arginine's effectiveness, the amino acid could be a promising new addition to oral hygiene products such as toothpaste or mouthwash.

Covid is returning, as the National Health Service, NHS UK warned that there has been a "bounce back" in respiratory viruses this winter, along with COVID too on the rise. While UK was already struggling with flu and norovirus on the rise, cases of COVID have also risen. The latest data from the UK Health and Security Agency (UKHSA) show that the number of patients in hospital beds with COVID per day has risen from 0.87 per 100,000, as compared with 0.77 per 100,000 the previous week.

NHS national medical director Professor Meghana Pandit said: “It’s clear that the worst is far from over for the NHS this winter, with hospitals again experiencing a rise in patients admitted with flu and other respiratory virus cases last week.”

What New COVID Variants Are We Dealing With In 2026?

Since the pandemic, there have been many variants of COVID. The virus has continued to evolve. Two new variants that caused the spike in cases in autumn were XFG, known as Stratus, and NB.1.1, known as Nimbus.

Stratus: It is a subvariant of Omicron variant and made of previous variants LF.7 and LP.8.1.2. It was first detected in a sample on January 27, 2025. Whereas, Nimbus was first detected on January 22, 2025. It also originated from the same omicron variant, which was the reason for spike in 2023.

The World Health Organization (WHO) describes stratus as a "variant under monitoring" after several countries in South East Asia reported a rise in new cases and hospitalizations with this variant being detected.

COVID Symptoms 2026: Fatigue Emerges As The Most Common Symptom

Among studies that focused on how symptoms appear together, fatigue stood out as the most consistently reported issue. It often occurred alone or alongside problems such as muscle and joint pain, brain fog, or breathlessness. Other symptom pairings that appeared frequently included loss of smell and taste, anxiety with depression, and various forms of musculoskeletal pain.

When researchers classified patients based on affected organ systems, respiratory problems were the most widespread, seen in about 47% of long COVID patients. Neurological symptoms followed at 31%, while gastrointestinal issues were reported by 28%. The authors stressed that these percentages reflect how often these clusters appeared within long COVID cases studied, not how common they are in the general population.

A smaller number of studies sorted patients by how severe their symptoms were, dividing them into mild, moderate, or severe categories using symptom scores, symptom counts, or quality-of-life measures. Three studies used clinical indicators for classification, including abnormal triglyceride levels and signs of restricted lung function on imaging.

As per the Centers for Disease Control and Prevention (CDC), here are the common COVID symptoms:

• Fever or chills
• Cough
• Shortness of breath or difficulty breathing
• Sore throat
• Congestion or runny nose
• New loss of taste or smell
• Fatigue
• Muscle or body aches
• Headache
• Nausea or vomiting
• Diarrhea

How To Know If You Have COVID?

CDC says, look out for these signs:

• Trouble breathing
• Persistent pain or pressure in the chest
• New confusion
• Inability to wake or stay awake
• Lips and nail beds may appear pale, grey or blue

While the National Capital is dealing with cold wave, the air quality also continues to worsen. In several parts of Delhi, the air quality reached severe category. The Indian Meteorological Department (IMD) also issued an Orange alert on Tuesday for cold wave. Dense fog also engulfed the city, with air pollution or the particulate matter being trapped in the air, turning the fog into smog.

The condition of air pollution in Delhi has remained concerning and the levels have spiked to 20 to 30 times above the safety levels recommended by the World Health Organization or the WHO. Many studies, including the official website of the Environmental Protection Agency (EPA), US notes that the small particulate matter found in the air pollution is directly linked to health problems. "Small particles less than 10 micrometers in diameter pose the greatest problems, because they can get deep into your lungs, and some may even get into your bloodstream," notes EPA.

The particulate matter could lead to:

• premature death in people with heart or lung disease
• nonfatal heart attacks
• aggravated asthma
• irregular heartbeat
• decreased lung function
• increases respiratory symptoms like irritation of the airways, coughing, or difficulty breathing

What Are Smog-Eating Surfaces And How Do They Help?

The government is pursuing "smog eating" surfaces to deal with the pollution problem in Delhi. While it may sound like a strange thing in India, not to the world. In fact, in the Netherlands these were used to reduce local nitrogen oxide or the NO concentrations in the air, rather than greenhouse gas concentrations.

Smog usually contains a mixture of hydrocarbons, ozone, oxides of nitrogen and sulphur, and particulates. The pollution is caused by both photochemical reactions that involve sunlight, unburned hydrocarbons and nitrogen oxides, along with high concentrations of particulate matter, especially from vehicle exhaust, construction dust and biomass burning.

Environment Minister Manjinder Singh Sirsa announced "smog eating" surface as part of its pollution control plan, for which the government has also signed an MoU with IIT Madras.

The smog eating surfaces will be public surfaces coated with photocatalytic materials like titanium dioxide or TiO2 that is used to degrade pollutants.

The Deccan Herald quoted Dr Pradeep Singh, professor and head at the School of Advanced Chemical Sciences, Shoolini University, who explained: Photocatalytic materials are basically semiconductors. Substances like TiO2₂or zinc oxide are typically used as photocatalysts. When light falls on these semiconductor catalysts, electrons within them jump from one energy level to another, creating a hole. These photocatalytic holes and electrons subsequently form free radicals, which have strong oxidizing properties and can break down certain air pollutants with which they interact."

How Do Smog Eating Surfaces Work?

Smog contains mainly nitric oxide, nitrogen dioxide, sulphur dioxide, ozone, and particulate matter. When all of these interact with photocatalytic materials, gaseous pollutants convert into less harmful compounds, such as nitrogen oxides become nitrates or decompose into ions. This process is also known as pollutant mineralization.

Fun Fact: It was in 2017, when scientists in Italy developed a type of photocatalytic cement that could absorb pollutants and convert it into harmless salts. Palazzo Italia in Milan, opened in 2015, was the first building to use the cement.

How Effective Are These Smog Eating Surfaces?

As per Dr Ashish Moon, Head of the Civil Department at Smt Radhikatai Pandav College of Engineering, Nagpur, the impact depends on environmental conditions. He explained that titanium dioxide can locally reduce certain gaseous pollutants like nitrogen oxides under ideal conditions, rather than absorbing up to 50 percent of all harmful gases.

He also co-authored a paper in 2021, titled: Detailed Case Study on Smog Eating Tile, where he noted, "It is better to use it in liquid form than a powder. I have not come across any harmful interactions between TiO2 and particles or gases in the air." However, he also points out that how it will work in Delhi will depend on its weather conditions and atmosphere. "There should be enough UV light for the nanoparticles to activate," he said.

Will this arrangement really work? That is yet to see, although a 2023 Spanish study found that although this measure showed some improvement, but it only yielded a modest reduction in ambient NO2. We are yet to see how well it will work in Delhi and its neighboring city's pollution problem.