More varied gut bacteria
- Published in
- Am J Clin Nutr 2024
- People studied
- 400
In a trial of 400 older adults, a lower-calorie Mediterranean diet with more activity meant more weight lost. The variety of gut bacteria in that group rose over a year.
- Checked against
- PubMed 38428742
- Published in
- Am J Clin Nutr 2024
- Last checked
- 30 October 2026
Key takeaway
In this randomised trial, 400 adults aged 55 to 75 at high risk of heart disease were followed for a year. One group ate a lower-calorie Mediterranean diet with more physical activity. The other ate a Mediterranean diet without calorie limits. Compared with the other group, the weight-loss group lost more weight and improved more on several heart risk factors, and the variety of its gut bacteria rose over the year. Some of the gut changes went with changes in heart risk factors.
At a glance
- Type of study
- randomised trial (part of PREDIMED-Plus)
- People studied
- 400
- How long
- 1 year
- Compared with
- a Mediterranean diet without calorie limits
- Main result
- More weight lost, and gut bacteria variety rose over one year.
- Strength of evidence
- Randomised trials
What this study does not show
The comparison group also ate a Mediterranean diet, so the study tests calorie cuts and activity on top of it. A more varied gut mix is a marker; the study does not show it leads to better health later on.
Results from studies in groups of people, mostly in diet and movement programmes. They cannot be promised to any one person. This information is educational and does not replace a consultation with a doctor.
More on gut
- Richer gut bacteriaSmall or uncontrolled studies · Cotillard et al., Nature 2013
- Less heartburnSmall or uncontrolled studies · Singh et al., Obesity 2013
- Better odds of reflux easingLong-term or observational studies · Ness-Jensen et al., Am J Gastroenterol 2013
- More varied gut bacteriaRandomised trials · García-Gavilán et al., Am J Clin Nutr 2024
- Fewer bowel leaksLong-term or observational studies · Markland et al., Int Urogynecol J 2011
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