Nutrition Reviews · Nov 5, 2026

How Plants Feed Our Microbes: Plant-Based Diets and Gut Microbiota Modulation-A Systematic Review

By Kozłowska P, Borowiecka A, Strzemkowska M et al.

CONTEXT: Diet is a key factor shaping gut microbiota composition and function, with important implications for human health. The growing popularity of plant-based dietary patterns has increased interest in their effects on the gut microbiota. OBJECTIVE: This systematic review examines specific changes in gut microbiota among individuals following a plant-based diet (PBD), as well as shifts occurring after transitioning from an omnivorous diet. DATA SOURCES: PubMed and Google Scholar were searched for articles reporting original English-language human and animal studies investigating the effects of PBDs on gut microbiota composition or function. Studies published from 2015 onward were primarily considered, with most included articles published during 2020-2024. DATA EXTRACTION: Four reviewers independently screened records according to eligibility criteria and extracted data on study characteristics, populations, dietary patterns, and outcomes related to gut microbiota composition and function. DATA ANALYSIS: A total of 37 studies met the inclusion criteria. A PBD appeared to promote the growth of short-chain fatty acid-producing and probiotic bacteria, which help maintain intestinal integrity and support carbohydrate metabolism and may offer protection against certain diseases. A PBD was also reported to encourage the growth of beneficial taxa such as Roseburia spp., Akkermansia muciniphila, Clostridium symbiosum, and Faecalibacterium prausnitzii, which are considered indicators of a healthy microbiome. An increased Bacteroidetes/Firmicutes ratio, which was found to be a common occurrence in study participants following a PBD, correlated with a lower body mass index (BMI) and a more favorable metabolic profile, supporting healthy weight maintenance. In addition, PBDs were also associated with improvements in alpha- and beta-diversity compared with omnivorous diets. CONCLUSIONS: This review indicates that PBDs appear to beneficially influence the gut microbiota and may have positive effects on human health. Nonetheless, not all studies agree on the extent or direction of microbiota changes associated with dietary patterns. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration No. [CRD420251229407]; link: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251229407.

doi.org/10.1093/nutrit/nuag157 Open access PubMed 42986715 Interventions