Research

Mixed

Dietary resistant starch (RS) selectively increases the abundance of Ruminococcus bromii relatives (R-ruminococci) and Eubacterium rectale in the human gut, but this response is strictly dependent on the individual's baseline microbiota composition.

If you are adding resistant starch to your diet, expect different results based on your current gut bacteria. For most people, it boosts beneficial starch-digesting bacteria. However, if you have a gut microbiome lacking these specific bacteria, resistant starch may not ferment efficiently, leading to gastrointestinal discomfort without the metabolic benefits. Personalization of fiber type is key.

GoodQualifiesHIGH confidence
Relatives of Ruminococcus bromii ('R-ruminococci') increased in most volunteers on the RS diet, accounting for a mean of 17% of total bacteria compared with 3.8% on the NSP diet... Dietary non-digestible carbohydrate can produce marked changes in the gut microbiota, but these depend on the initial composition of an individual’s gut microbiota.
Alan W. Walker et al. · The ISME Journal · 2010

Why this rating

Controlled crossover trial with qPCR validation, but small sample size (n=14) and clustering by individual reduce generalizability.

Source

Dominant and diet-responsive groups of bacteria within the human colonic microbiota

Alan W. Walker et al. · The ISME Journal · 2010

DOI 10.1038/ismej.2010.118

crossover · n=14Cited 1,617×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →