Gut MicrobesNov 9, 2026, 21:54 GMT

Gut microbe score linked to diet and fitness in adults

An observational study of 893 adults found diet and lifestyle links in both disease-free participants and people with common medical conditions.

Paper by Tzipi Braun, Orli Harounian, Rotem Hadar, +13Yael Haberman · Tel Aviv University · Cincinnati Children's Hospital Medical Center

Figure 1. The study design included 893 participants undergoing annual medical checkups.The study design included 893 participants undergoing annual medical checkups.Braun et al.

Our read

Biomarkers

Studied:: Cross-sectional study of 893 adults who underwent medical check-ups
What changed:: Gut microbial health index was higher with better diet and physical fitness, and lower with ultra-processed foods
The catch:: Classifying ultra-processed foods carries uncertainty because exact processing methods are unknown
In the record:: The 101st paper on dietary fiber with results in people; 271 on record in all.

Editor of record: Boris Djordjevic · AgingResearch.News

Paper

The 893 adults in this observational study underwent annual executive medical checkups; their average age was 57, and 61% were male. Researchers combined stool samples, diet and lifestyle questionnaires, blood tests and exercise stress tests. They assessed a gut microbial health index, a score developed from studies of people with various diseases. Higher values indicate a less disease-related mix of gut microbes.

Higher scores were associated with more fiber, better exercise capacity and greater reported well-being. Lower scores were linked to more ultra-processed food and higher levels of inflammation markers, mostly within normal ranges. The diet and lifestyle links persisted among people without disease and those with common conditions, including high blood pressure and abnormal blood fat levels.

Why it matters

The authors suggest that gut microbes could serve as an indicator of overall health in aging adults, including those with common medical conditions.

Caveats

The checkup-based comparisons could not rule out existing health differences influencing both diet and gut microbes. The associations were modest, and the analysis excluded stool samples collected within four weeks of antibiotic use.

From the paper

Participants

We analyzed 893 participants who underwent annual Executive Medical Checkups (61% male, mean age 57 ± 11 y, median BMI of 25, and 10% smokers), who submitted fecal samples (,, Dataset S1).

Results, Cohort characteristics

Quoted word for word from the full text on PubMed Central.