# Gut microbiota and metabolic responses to a 12-week caloric restriction combined with strength and HIIT training in patients with obesity: a randomized trial

PMID: 39639405
Journal: BMC sports science, medicine & rehabilitation
Published: 2024 Dec 5
Authors: Nechalová L, Bielik V, Hric I, Babicová M, Baranovičová E, Grendár M, Koška J, Penesová A

## Question

How does a 12-week calorie-restriction program combined with strength and HIIT training affect gut microbiota and metabolic health in adults with obesity?

## Summary

In adults with obesity, a 12-week program combining calorie restriction, supervised strength training, and HIIT improved body composition and liver enzymes and changed gut-microbiota measures compared with baseline and non-intervention controls. Because diet, strength training, and HIIT were bundled together, the study cannot show what HIIT alone caused.

## Population

- Adults with obesity
- Sample size: 23
- Age: Intervention 47.08 +/- 10.48 years; control 41.27 +/- 10.04 years
- Sex: Men and women
- Health status: BMI >=30 kg/m2; several clinical exclusions

## Methodology

- Randomized controlled trial with bundled diet and exercise intervention
- 12 weeks
- Outpatient obesity-care and supervised exercise setting
- Randomized and controlled study design.

## Protocol

- Caloric restriction plus strength and HIIT training.
- Modality: Strength training and HIIT circuits.
- Work intervals: 30-45 seconds during HIIT exercises.
- Recovery: 15-30 seconds during HIIT circuits.
- Sets or repetitions: 5-7 HIIT exercises in 3 circuits; strength training 2-3 exercises, 2-3 sets of 8-12 repetitions.
- Session duration: 60 minutes.
- Frequency: 2 guided sessions/week.
- Program length: 12 weeks.
- Non-intervention control.
- Program length: 12 weeks.

## Outcomes

### Body composition
Status: improved
Intervention participants reduced BMI, body weight, body-fat percentage, waist, hip, and visceral fat.

The paper reported significant within-intervention changes; waist circumference had a significant group interaction (p=0.018).

### Liver enzymes
Status: improved
AST, ALT, and GMT decreased in the intervention group.

Reported as significant in the full text.

### Microbiota
Status: mixed
Some taxa associated with obesity-related research increased, while several SCFA-producing bacteria decreased.

Specific taxa reported as significantly changed; alpha diversity did not significantly differ.

### Lipids
Status: no clear change
Lipid-profile group interaction was not significant in the extracted text, with baseline values described as near optimal.

## Practical Insights

- Do not attribute this study's benefits to HIIT alone because calorie restriction and strength training were co-delivered.
- Circuit-style 30-45 second intervals are translatable as a format, but the missing intensity target limits workout-generation precision.
- Retention and medical exclusions matter for obesity-focused programs.

## Limitations

- Small sample
- High dropout
- Bundled diet, strength, and HIIT intervention
- No detailed control diet/activity data
- No stool consistency data
- No direct adverse-event reporting

## Safety And Adherence

- No adverse events were directly reported in the extracted text.
- Dropouts were mainly due to antibiotic treatment for common infections or non-compliance.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/39639405/) (pubmed)
- [DOI](https://doi.org/10.1186/s13102-024-01029-7) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11619444/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.