The Claim
In healthy adults, a high-fiber diet providing 45 grams of fiber per day for 10 weeks increases microbial carbohydrate-degrading enzymes (CAZymes) and stool microbial protein density without increasing overall microbiota diversity.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
In healthy adults, consuming 45 grams of fiber daily for 10 weeks increases the activity of gut microbes that break down carbohydrates and raises the amount of microbial protein in stool, without increasing the number of different microbial species.
See the scientific wording
In healthy adults, a high-fiber diet (45 g/day) for 10 weeks increases microbial carbohydrate-degrading enzymes (CAZymes) and stool microbial protein density without increasing overall microbiota diversity, indicating that fiber enhances functional capacity rather than taxonomic richness.
When a person eats a lot of fiber, gut bacteria break it down using special enzymes that digest plant material. This causes the bacteria to make more of these enzymes and produce more bacterial protein, but it doesn't bring in new types of bacteria — the same types just work harder.
What the research says
1 studyStudy: Gut-microbiota-targeted diets modulate human immune status
Eating 45 grams of fiber a day for weeks makes gut bacteria better at digesting plant material and increases their total amount, but doesn’t make more types of bacteria show up — just the same ones working harder.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.