Strawberry dietary intervention influences diversity and increases abundances of SCFA-producing bacteria in healthy elderly people

Study information

Needs review

study design

randomized controlled trial

Citation

PMID PubMed identifier for scientific articles.

39772703

DOI Digital object identifier for electronic documents.

10.1128/spectrum.01913-24

URI

Authors

Meiners F, Kreikemeyer B, Newels P, Zude I, Walter M, Hartmann A, Palmer D, Fuellen G, Barrantes I

Journal

Microbiology spectrum

Year

2025

Keywords:

aging, dietary intervention, human gut microbiome

The gut microbiome is amenable to dietary interventions, and polyphenol-rich diets have been shown to enhance abundances of bacteria associated with short-chain fatty acid (SCFA) production. We examined the effects of a strawberry-based intervention on the gut microbiome of 69 healthy elderly German adults. Participants in five groups consumed varying amounts of strawberries, freeze-dried strawberries, and capers in olive oil over 10 weeks as part of a randomized controlled trial. 16S rRNA sequencing was used to analyze differences in microbial composition, diversity, phenotypes, differential abundance, and functional pathways. The intervention group featuring the highest amounts of fresh and freeze-dried strawberries without capers in olive oil (group 4) showed changes in gut microbial diversity and differential abundance that could be linked to improved health. Beta diversity, based on weighted UniFrac distances, increased significantly (P = 0.0035), potentially pathogenic bacteria decreased (P = 0.04), and abundances of SCFA-producing genera Faecalibacterium and Prevotella increased significantly. Other findings included a significant reduction of CAG-352, Preveotellaceae_NK3B31-group, and Eubacterium coprostanoligenes (group 2), and a trend of lowered Firmicutes-to-Bacteroidetes ratio (P = 0.067) and a reduction in Ruminococcaceae (group 3). Our findings suggest that a dietary intervention based on strawberries can positively alter the gut microbiota of healthy elderly people as seen in an enrichment of SCFA-producing genera, increased diversity, and a reduction in potentially pathogenic bacteria.IMPORTANCEAging is often associated with changes in the gut microbiome, including a decline in beneficial bacteria and an increase in potentially pathogenic species. Addressing these changes through lifestyle interventions is of significant interest. Our study demonstrates that a 10-week dietary intervention with strawberries can beneficially modulate gut microbial composition and diversity in healthy elderly individuals. Notably, the group consuming the highest amount of strawberries (without capers in olive oil) initially had higher abundances of potentially pathogenic bacteria. Here, the intervention led to increased abundances of the beneficial genera Faecalibacterium and Prevotella, which are linked to health benefits including reduced inflammation and improved lipid metabolism. These findings suggest that strawberry consumption can positively influence gut microbial composition, thereby contributing to overall health and disease prevention in older adults.

Experiment 1

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Curated date: 2025/02/23

Curator: Victoria

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Subjects

Location of subjects: Germany

Host species Species from which microbiome was sampled. Contact us to have more species added.: Homo sapiens

Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology: Feces Cow dung,Cow pat,Droppings,Dung,Excrement,Excreta,Faeces,Fecal material,Fecal matter,Fewmet,Frass,Guano,Matières fécales@fr,Merde@fr,Ordure,Partie de la merde@fr,Piece of shit,Porción de mierda@es,Portion of dung,Portion of excrement,Portion of faeces,Portion of fecal material,Portion of fecal matter,Portion of feces,Portion of guano,Portion of scat,Portionem cacas,Scat,Spoor,Spraint,Stool,Teil der fäkalien@de,Feces,feces

Condition The experimental condition / phenotype studied according to the Experimental Factor Ontology: Diet measurement Diet measurement,diet measurement

Group 0 name Corresponds to the control (unexposed) group for case-control studies: Group1-Visit1 (g1_vA)

Group 1 name Corresponds to the case (exposed) group for case-control studies: Group1-Visit2 (g1_vB)

Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group: The participants in this group consumed 500g of fresh strawberries every week for 10 weeks.

Group 0 sample size Number of subjects in the control (unexposed) group: 12

Group 1 sample size Number of subjects in the case (exposed) group: 12

Lab analysis

Sequencing type: 16S

16S variable region One or more hypervariable region(s) of the bacterial 16S gene: V3-V4

Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance: Illumina

Statistical Analysis

Data transformation Data transformation applied to microbial abundance measurements prior to differential abundance testing (if any).: raw counts

Statistical test: DESeq2

Significance threshold p-value or FDR threshold used for differential abundance testing (if any): 0.05

MHT correction Have statistical tests be corrected for multiple hypothesis testing (MHT)?: Yes

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness: unchanged

Signature 1

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Curated date: 2025/02/24

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Source: Table 3

Description: Taxa with significant changes in abundance after the strawberry intervention, with false discovery rate (FDR) < 0.05.

Abundance in Group 1: decreased abundance in Group1-Visit2 (g1_vB)

NCBI	Quality Control	Links
Clostridia UCG-014Clostridia UCG-014

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Experiment 2

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Curated date: 2025/02/25

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Differences from previous experiment shown

Subjects

Group 0 name Corresponds to the control (unexposed) group for case-control studies: Group2-Visit1 (g2_vA)

Group 1 name Corresponds to the case (exposed) group for case-control studies: Group2-Visit2 (g2_vB)

Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group: The participants in this group consumed 1500g of fresh strawberries in the first two weeks, 2500g from week 3 to week 9, and 3750g in week 10.

Group 0 sample size Number of subjects in the control (unexposed) group: 14

Group 1 sample size Number of subjects in the case (exposed) group: 14

Lab analysis

Statistical Analysis

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness: unchanged

Signature 1

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Curated date: 2025/02/25

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Source: Table 3

Description: Taxa with significant changes in abundance after the strawberry intervention, with false discovery rate (FDR) < 0.05.

Abundance in Group 1: decreased abundance in Group2-Visit2 (g2_vB)

NCBI	Quality Control	Links
Ruminococcaceae CAG-352Ruminococcaceae CAG-352
Prevotellaceae NK3B31_groupPrevotellaceae NK3B31_group
Eubacterium coprostanoligenes

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Experiment 3

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Curated date: 2025/02/25

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Differences from previous experiment shown

Subjects

Group 0 name Corresponds to the control (unexposed) group for case-control studies: Group3-Visit1 (g3_vA)

Group 1 name Corresponds to the case (exposed) group for case-control studies: Group3-Visit2 (g3_vB)

Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group: The participants in this group consumed 1500g of fresh strawberries and 100g of Freeze-dried strawberries in the first two weeks, 2500g of fresh strawberries from week 3 to week 9, and 3750g of fresh strawberries plus 100g of freeze-dried strawberries in week 10.

Group 0 sample size Number of subjects in the control (unexposed) group: 15

Group 1 sample size Number of subjects in the case (exposed) group: 15

Lab analysis

Statistical Analysis

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness: unchanged

Signature 1

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Mark reviewed

Your review change was submitted

Needs review

Curated date: 2025/02/26

Curator: Victoria

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Source: Table 3

Description: Taxa with significant changes in abundance after the strawberry intervention, with false discovery rate (FDR) < 0.05.

Abundance in Group 1: decreased abundance in Group3-Visit2 (g3_vB)

NCBI	Quality Control	Links
Oscillospiraceae

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Experiment 4

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Curated date: 2025/02/25

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Differences from previous experiment shown

Subjects

Group 0 name Corresponds to the control (unexposed) group for case-control studies: Group4-Visit1 (g4_vA)

Group 1 name Corresponds to the case (exposed) group for case-control studies: Group4-Visit2 (g4_vB)

Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group: The participants in this group consumed 1500g of fresh strawberries in the first two weeks, 2500g from week 3 to week 9, and 3750g in week 10. Additionally, they had 100g of Freeze-dried strawberries in week 1 and 200g in week 2 and week 10.