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.

Squirrels could be natural hosts of the mpox virus (MPXV) -- that causes monkeypox disease -- according to a recent study by German researchers.

The team from the Helmholtz Institute for One Health (HIOH) identified the fire-footed rope squirrel (Funisciurus pyrropus) as a likely natural reservoir of the MPXV.

The study published in the journal Nature revealed that sooty mangabeys – a primate found in West Africa -- can contract mpox by eating infected squirrels. The disease may present mild lesions, but it can also cause more severe skin lesions or even be fatal.

"Identifying the animal sources of the virus and the exposure routes that lead to inter-species transmission are key steps towards understanding spillover mechanisms and developing effective prevention measures to mitigate the risk of transmission to humans," said Livia V. Patrono, one of the senior authors at HIOH.

Squirrels Suspected MPXV Hosts

While squirrels have long been suspected as potential reservoirs for MPXV, their role was confirmed after an investigation of an mpox outbreak among wild sooty mangabeys (Cercocebus atys) in Côte d'Ivoire.

During the outbreak, reported in early 2023, nearly one-third of the primates showed clinical signs of disease, and four infants died.

The team conducted viral genome sequencing and found that the infected monkeys carried a virus that was nearly identical to an MPXV strain identified in a fire-footed rope squirrel found dead 12 weeks earlier nearby.

Further, the team analyzed fecal samples from the mangabeys. A sample collected eight weeks before the outbreak's onset contained DNA from both the virus and the rope squirrel. This provided strong evidence of interspecies transmission at that moment.

Sooty mangabeys have been previously observed catching and eating fire-footed rope squirrels, which provide a direct route for the transmission of viruses.

Mpox Continues To Spread Globally

Although mpox is no longer a public health emergency, outbreaks of clade I and clade II strains of the mpox virus are continuing in many countries around the world, especially in Africa.

Last week, Madagascar announced the country's first death from mpox, a 3-year-old girl from the island nation’s eastern city of Toamasina.

The WHO has also confirmed that two cases of the recombinant strain – combining genomic elements of clades Ib and IIb of the monkeypox virus (MPXV) – have been identified to date: one in the United Kingdom and one in India.

Mpox is an infectious disease caused by the monkeypox virus (MPXV), part of the Orthopoxvirus genus, which also includes the virus that causes smallpox.

It spreads through close physical contact, including sexual contact, and in some cases through contaminated materials or respiratory droplets.

Symptoms typically include fever, swollen lymph nodes, rash, and/or lesions.

The global health body has also urged all countries to “remain alert to the possibility of MPXV genetic recombination.” It has also urged for continued epidemiological surveillance, sequencing, vaccination of at-risk groups, and infection prevention and control measures.

An international group of scientists has created an artificial intelligence tool that can estimate a woman’s likelihood of developing breast cancer within the next four years.

The AI tool, known as the BRAIx risk score, analyzes mammogram images to generate an individualized risk assessment and flag women who may face a higher chance of developing the disease.

It may not only show the current risk but also predict the future risk, enabling early detection and treatments for a better outcome.

According to the findings published in The Lancet Digital Health journal, nearly one in 10 women ranked in the top 2 percent of risk by the AI tool were diagnosed with breast cancer within four years. This was despite previously receiving a clear screening result.

“These risk scores enable future development of personalized screening pathways to transform population breast cancer screening and save lives,” said corresponding author Helen M. L. Frazer of the University of Melbourne.

Frazer noted that identifying women who appear cancer-free but carry very high risk -- comparable to those with inherited BRCA1 or BRCA2 mutations -- will unravel both hereditary and non-hereditary causes of breast cancer.

From one-size-fits-all screening to personalization

Breast cancer screening programs have significantly lowered mortality rates -- by roughly 40-50 percent among women aged 50 to 74. However, most screening systems still apply the same approach to all women, regardless of individual risk.

Traditional screening tools use genetics, breast density, and questionnaires to estimate breast cancer risk. On the other hand, new AI-based screening tools, such as BRAIx personalizes screening by gathering information already present in breast scan images to better identify who is at higher risk.

“Our results show that conventional mammographic density is a far weaker predictor of breast cancer risk than the BRAIx risk score, even for interval cancers,” the researchers said in the paper. Interval cancers are aggressive tumors diagnosed after a negative mammogram.

The BRAIx Tool

The BRAIx risk score was developed using mammograms from nearly 400,000 women. To prove its efficacy, the AI tool was tested on data from almost 96,000 women from Australia and then confirmed in an independent Swedish population of over 4,500 women.

The findings showed that:

• The BRAIx risk score estimated breast cancer risk more accurately than the traditional risk factors, such as breast density, country of birth, and even family history.

• For the top 2 percent of women with the highest BRAIx risk score, the probability of a cancer diagnosis within 4 years was 9.7 percent -- a risk level exceeding that typically seen in women with inherited BRCA1 or BRCA2 mutations.

The BRAIx risk score can:

• Make breast screening more personalised,
• Improve early cancer detection,
• Reduce false alarms,
• Save lives without increasing costs

Global Breast Cancer Burden

Breast cancer continues to be the most common cancer among women worldwide.

A recent study published in The Lancet Oncology journal predicted that the number of new cases of the deadly disease will reach more than 3.5 million globally in 2050 -- rising by a third from 2.3 million in 2023.

Annual deaths from the disease will also rise by 44 percent -- from around 764,000 to 1.4 million.

However, not smoking, getting sufficient physical activity, lowering red meat consumption, and having a healthy weight can help prevent over a quarter of healthy years lost to illness and premature death from breast cancer.

People who survived a COVID-19 infection can be at significant risk for kidney disease, acute kidney injury, and chronic kidney disease. compared to individuals who were not infected, according to a study.

The study, published online in the journal Communications Medicine, revealed that COVID patients have

• a 2.3-times higher risk of acute kidney injury
• a 1.4-times higher risk of chronic kidney disease
• a 4.7 times higher risk of kidney failure

“While we’re in the post-pandemic era, this shows that COVID-19 history is an important variable when considering the long-term impact of the infection on kidney function and disease,” said first author Yue Zhang, who was at Pennsylvania State University, US, while conducting the study. Zhang is currently a postdoctoral scholar at Johns Hopkins Bloomberg School of Public Health.

How Was The Study Conducted?

For the study, data on over 3 million working-age adults in the United States were analyzed.

The team compared the effect of influenza, another common viral infection that affects kidney health, and people with a history of COVID infection on kidney infections.

Using a machine learning model, the individuals were followed between 180 and 540 days for the emergence of new acute or sudden kidney disease.

The results showed that:

• Both COVID and the flu can worsen kidney health
• Flu caused a mild and temporary effect
• COVID increased the risk of acute kidney injury for a longer duration
• COVID survivors developed kidney disease within a few hours to a few days
• COVID patients had a longer-term chronic and end-stage kidney disease.

How COVID Worsens Kidneys Health

The Penn State researchers explained that kidney cells express high levels of the primary protein receptors that SARS-CoV-2 uses to enter and infect cells. Kidney cells also produce specialized enzymes that help viruses enter cells.

According to Kidney Health Australia, an acute COVID infection can impact the kidneys with fevers and respiratory symptoms, and/or worsening blood sugar control.

The US National Institutes of Health stated that renal dysfunction is an increasing clinical indicator of COVID propagation.

Citing several studies, the NIH said that the most common clinical manifestation is proteinuria -- found in more than half of the COVID patients. In addition, hematuria, elevated blood urea nitrogen, and elevated serum creatinine are other common features in Covid survivors with poor kidney health.

Nasr Ghahramani, Professor of Medicine at Penn State College of Medicine, stressed the need for COVID survivors, especially those with diabetes and high blood pressure, to take "more frequent and more prolonged monitoring of their kidney function" to enable early detection and better outcomes.