Supplementation with inulin-type fructans affects gut microbiota and attenuates some of the cardiometabolic benefits of a plant-based diet in individuals with overweight or obesity.
Study Goal
The researchers aimed to investigate the impact of adding inulin-type fructans (ITF) to a high-fiber plant-based diet on gut microbiota composition and cardiometabolic outcomes in individuals with obesity, and whether baseline Prevotella/Bacteroides ratio predicts weight loss.
Results Summary
Adding ITF to a plant-based diet reduced microbial diversity, increased Bifidobacterium and Faecalibacterium, but was associated with higher insulin, HOMA-IR, LDL:HDL ratio, and inflammatory markers, attenuating some cardiometabolic benefits. No relationship was found between baseline P/B ratio and weight loss.
Population
Adults aged 18-65 with obesity (BMI 27-40 kg/m²).
Effective Dosage
20 g/day ITF-prebiotics.
Duration
10 weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
high fiber (∼38 g/d) plant-based diet | decrease | weight | subjects with obesity | -3.2 [95% CI -3.9, -2.5] kg | lost | #1 |
high fiber (∼38 g/d) plant-based diet | increase | body composition | subjects with obesity | - | experienced significant improvements in | #2 |
high fiber (∼38 g/d) plant-based diet | increase | cardiometabolic health indices | subjects with obesity | - | experienced significant improvements in | #3 |
addition of ITF to the plant-based diet | decrease | microbial diversity (Shannon index) | subjects with obesity | - | reduced | #4 |
addition of ITF to the plant-based diet | increase | Bifidobacterium | subjects with obesity | - | selectively increased | #5 |
addition of ITF to the plant-based diet | increase | Faecalibacterium | subjects with obesity | - | selectively increased | #6 |
addition of ITF to the plant-based diet | increase | LDL:HDL ratio | ITF-subgroup | - | were significantly elevated | #7 |
addition of ITF to the plant-based diet | increase | concentrations of IL-10 | ITF-subgroup | - | were significantly elevated | #8 |
addition of ITF to the plant-based diet | increase | concentrations of MCP-1 | ITF-subgroup | - | were significantly elevated | #9 |
addition of ITF to the plant-based diet | increase | concentrations of TNFα | ITF-subgroup | - | were significantly elevated | #10 |
- | no change | body weight | - | - | There was no relationship between | #11 |
plant-based diet | decrease | body weight | individuals with obesity | - | modestly decreases | #12 |
plant-based diet | increase | - | individuals with obesity | - | has multiple health benefits in | #13 |
addition of ITF-prebiotics | change | gut microbiota composition | - | - | selectively changes | #14 |
addition of ITF-prebiotics | decrease | some of the realized cardiometabolic benefits | - | - | attenuates | #15 |
BACKGROUND: The gut microbiota has emerged as a potential therapeutic target to improve the management of obesity and its comorbidities. OBJECTIVE: We investigated the impact of a high fiber (∼38 g/d) plant-based diet, consumed ad libitum, with or without added inulin-type fructans (ITF), on the gut microbiota composition and cardiometabolic outcomes in subjects with obesity. We also tested if baseline Prevotella/Bacteroides (P/B) ratio predicts weight loss outcomes. METHODS: This is a secondary exploratory analysis from the PREVENTOMICS study, in which 100 subjects (82 completers) aged 18-65 years with body mass index 27-40 kg/m2 were randomized to 10 weeks of double-blinded treatment with a personalized or a generic plant-based diet. Changes from baseline to end-of-trial in gut microbiota composition (16S rRNA gene amplicon sequencing), body composition, cardiometabolic health and inflammatory markers were evaluated in the whole cohort (n = 82), and also compared in the subgroup of subjects who were supplemented with an additional 20 g/d ITF-prebiotics (n = 21) or their controls (n = 22). RESULTS: In response to the plant-based diet, all subjects lost weight (-3.2 [95% CI -3.9, -2.5] kg) and experienced significant improvements in body composition and cardiometabolic health indices. Addition of ITF to the plant-based diet reduced microbial diversity (Shannon index) and selectively increased Bifidobacterium and Faecalibacterium (q < 0.05). The change in the latter was significantly associated with higher values of insulin and HOMA-IR and lower HDL cholesterol. In addition, the LDL:HDL ratio and the concentrations of IL-10, MCP-1 and TNFα were significantly elevated in the ITF-subgroup. There was no relationship between baseline P/B ratio and changes in body weight (r = -0.07, p = 0.53). CONCLUSION: A plant-based diet consumed ad libitum modestly decreases body weight and has multiple health benefits in individuals with obesity. Addition of ITF-prebiotics on top this naturally fiber-rich background selectively changes gut microbiota composition and attenuates some of the realized cardiometabolic benefits. CLINICAL TRIAL REGISTRATION: [https://clinicaltrials.gov/ct2/show/NCT04590989], identifier [NCT04590989].