Roundup: Changes in ‘Gut Microbiome’ Linked to Risk of Type 2 Diabetes; and More News

Largest Study Yet of ‘Gut Microbiome’ Finds Possible Link to Higher Risk of Type 2 Diabetes

The composition of a person’s vital “gut microbiome” may create the likelihood of developing type 2 diabetes, according to the largest study of its kind conducted by researchers at Brigham and Women’s Hospital in Boston, the Broad Institute of MIT, and Harvard T.H. Chan School of Public Health.

The researchers analyzed the gut microbiome of people with type 2 diabetes, prediabetes, or healthy blood glucose levels. They found that “specific viruses and genetic variants within bacteria” correspond with changes in gut microbiome function that increases the risk of type 2 diabetes.

Several factors may cause a person to develop type 2 diabetes, including family history, age and ethnicity, along with modifiable risk factors such as obesity, poor diet and a sedentary lifestyle. The new research, published in Nature Medicine, could add the gut microbiome as a factor that can be potentially treated to prevent diabetes in the future.

Varies types of bacteria, viruses, fungi, and other microorganisms — collectively known as the gut microbiome — play a key role in maintaining overall health by helping to digest food and make nutrients. They also support the body’s immune system and produce chemicals that affect brain function. When the microbiome gets out of balance, it can contribute to disease.

“The gut microbiome's relationship to complex, chronic, heterogeneous diseases like type 2 diabetes is quite subtle,” said co-corresponding author Curtis Huttenhower, professor of computational biology and bioinformatics at the Harvard T.H. Chan School of Public Health, the Broad Institute of MIT, and Harvard, in a statement. “Large and diverse populations are necessary — and increasingly feasible — for detailed microbiome variation studies.”

In type 2 diabetes, a person’s body gradually loses its ability to effectively regulate blood sugar. Although prior research has connected changes in the gut microbiome to type 2 diabetes, a diverse large-scale study has been lacking.

Researchers analyzed data from the newly established Microbiome and Cardiometabolic Disease Consortium (MicroCardio). The dataset included genomic information from the gut microbiomes of 8,117 people who were ethnically and geographically diverse, hailing from the United States, Israel, Sweden, Finland, Denmark, Germany, France, and China.

“The researchers found a consistent set of microbial species that were linked to type 2 diabetes across their study populations, including many that had never been reported before,” states a Harvard news release.

Explains co-corresponding author Daniel (Dong) Wang, of the Channing Division of Network Medicine at Brigham and Women’s Hospital, MIT, and Harvard, in a statement: “We believe that changes in the gut microbiome cause type 2 diabetes. The changes to the microbiome may happen first, and diabetes develops later, not the other way around—although future prospective or interventional studies are needed to prove this relation firmly.”

Study: Smoking is Major Risk Factor in Accelerated Cognitive Decline

Smoking may be the most important – and modifiable -- lifestyle factors affecting how quickly a person’s cognitive skills decline as they age, indicates a new study from researchers at University College London (UCL).

The study, published in Nature Communications, analyzed data from 32,000 adults aged 50 or over from 14 European countries who responded to surveys over 10 years.

The researchers examined how rates of cognitive decline differ in cognitively-healthy older adults with different combinations of health-related behaviors, including smoking, physical activity, alcohol consumption and social contact.

“Participants were grouped into lifestyles based on whether they smoked or not, whether they did both moderate and vigorous physical activity at least once per week, whether they saw friends and family at least weekly, and whether they drank more or the same/less than two alcoholic drinks per day (men) or one drink per day (women),” states a news release from UCL.

Cognitive function was assessed according to participants’ performance in memory and verbal fluency tests.

The study’s results: Cognitive decline was faster for lifestyles that included smoking, while cognitive decline was generally similar for all non-smoking lifestyles. “Smoking lifestyles had cognitive scores that declined up to 85 percent or more over 10 years than non-smoking lifestyles,” UCL states.

Lead author, Dr. Mikaela Bloomberg, UCL Behavioural Science & Health, said in a statement: “Our study is observational so it cannot definitively establish cause and effect, but it suggests smoking might be a particularly important factor influencing the rate of cognitive ageing.

“Previous evidence suggests individuals who engage in more healthy behaviors have slower cognitive decline; however, it was unclear whether all behaviors contributed equally to cognitive decline, or if there were specific behaviors driving these results.”

Smoking tobacco remains the single largest preventable cause of death and illness in the world. Tobacco smoke is made up of thousands of chemicals, including at least 70 known to cause cancer, states the American Cancer Society. Smoking causes an estimated 480,000 deaths every year, or about 1 in 5 deaths, according to the U.S. Centers for Disease Control and Prevention (CDC). It is, by far, the single, largest cause of lung cancer.

NIH Launches Clinical Trial of Nasal COVID-19 Vaccine to Slow Spread of Emerging Variants

The National Institutes of Health (NIH) is sponsoring the first human trial of an investigational nasal vaccine with the goal of reducing infections of emerging COVID-19 variants.

The vaccine was “designed and tested in pre-clinical studies” by scientists from NIH’s National Institute of Allergy and Infectious Diseases (NIAID) Laboratory of Infectious Diseases, states the NIH in a news release. The clinical trial is now enrolling healthy adults at three sites in the U.S.

“While first-generation COVID-19 vaccines continue to be effective at preventing severe illness, hospitalizations, and death, they are less successful at preventing infection and milder forms of disease,” explains NIAID Director Jeanne M. Marrazzo, M.D., M.P.H., in a statement. “With the continual emergence of new virus variants, there is a critical need to develop next-generation COVID-19 vaccines, including nasal vaccines, that could reduce SARS-CoV-2 infections and transmission.”

Researchers hope to enroll 60 adult participants, ages 18 to 64 years old, who previously received at least three prior doses of an FDA-approved or -authorized mRNA COVID-19 vaccine. The trial sites are Baylor College of Medicine, Houston; The Hope Clinic of Emory University, Decatur, Georgia; and New York University, Long Island.

Previous studies indicate that “mucosal immunity is more effective than systemic immunity” in controlling replication of respiratory viruses, the NIH said.

“In pre-clinical non-human primate studies, the investigational vaccine MPV/S-2P was safe and well tolerated,” said the NIH. “It produced robust systemic immune responses, including SARS-CoV-2 (COVID-19)-directed antibodies, as well as local immunity in cells in the mucosal tissues lining the nose and respiratory tract.”

The NIAID states it supports research — at NIH, throughout the U.S. and worldwide — to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses.