Evidence map›Paper›PMID 40220249›Full record

SynthesisIndian journal of gastroenterology : official journal of the Indian Society of Gastroenterology2025

Impact of bariatric surgery on gut microbiota in obese patients: A systematic review.

Nima Mohammadzadeh, Shabnam Razavi, Mahla Shahriari, Gholamhossein Ebrahimipour

Abstract readSystematic Review
PubMed Publisher
In one paragraph

Synthesis in Indian journal of gastroenterology : official journal of the Indian Society of Gastroenterology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

  1. Review
  2. Article
  3. Review
  4. Gut-Adipose Tissue Axis and Metabolic Health.Current issues in molecular biology · 2025
    Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Nima MohammadzadehDepartment of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.
Shabnam RazaviDepartment of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Mahla ShahriariBacteriology Department, Faculty of Medicine, Tarbiat Modares University, Tehran, Iran.
Gholamhossein EbrahimipourDepartment of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran. g-ebrahimi@sbu.ac.ir.ORCID 0000-0002-0699-3010

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundObesity is a multi-factorial disease linked to various metabolic disorders, including insulin resistance, type-2 diabetes (T2D) and cardiovascular diseases. Traditional treatments often show limited long-term success, while bariatric surgery has emerged as the most effective intervention for sustained weight loss and comorbidity improvement. Alterations in gut microbiota may significantly contribute to these metabolic improvements.

objectiveThis systematic review was aimed at evaluating changes in gut microbiota composition before and after bariatric surgery and their association with clinical outcomes, including weight loss, insulin sensitivity and lipid metabolism.

methodsFollowing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search of PubMed, Scopus, Web of Science and clinicaltrials.gov databases was conducted for studies published between 2004 and 2024. Keywords included "bariatric surgery," "gut microbiota" and "obesity." Inclusion criteria focused on human studies with pre and post-surgical microbiota analysis. Non-human studies, pediatric populations and studies without microbiota assessment were excluded. Data extraction covered microbiota profiles, metabolic outcomes and clinical markers.

resultsTotal 27 articles and 28 clinical trials met the inclusion criteria. Pre-surgery, obese patients exhibited dysbiosis characterized by reduced microbial diversity and imbalances in key bacterial phyla. Post-surgery, especially after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), patients showed increased microbial diversity, reduced Firmicutes and elevated beneficial bacteria such as Akkermansia muciniphila and short-chain fatty acid (SCFA) producing bacteria. These microbiota changes were correlated with significant improvements in weight loss, insulin sensitivity and lipid profiles. However, some studies reported inconsistent or modest microbiota changes.

conclusionBariatric surgery leads to significant gut microbiota alterations that are closely linked to metabolic improvements, including enhanced glucose control and lipid metabolism. However, the long-term sustainability of these microbial changes remains unclear. Longitudinal studies are essential to determine whether these alterations persist over time and how they continuously impact metabolic health. Further research should explore targeted microbiota interventions to maintain beneficial microbial profiles post-surgery.

Indexed as

Bariatric SurgeryGastrointestinal MicrobiomeObesityDysbiosisHumansInsulin ResistanceLipid MetabolismTreatment OutcomeWeight LossBariatric surgeryGut microbiotaMicrobial diversityObesityRoux-en-Y gastric bypassSleeve gastrectomy

Identifiers

What Socratic holds

Textmetadata
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.