Research

Mixed

Consuming high levels of resistant starch (48-66g/day) shifts the gut microbiome composition by increasing the Firmicutes-to-Bacteroidetes ratio and enriching butyrate-producing taxa such as Faecalibacterium prausnitzii, Roseburia, and Ruminococcus.

To leverage resistant starch, incorporate high-amylose cornstarch (like Hi-Maize) into your diet at doses of 48-66g daily for at least two weeks. This specific type of starch resists digestion in the small intestine, allowing it to ferment in the colon. This process enriches beneficial bacteria like Faecalibacterium and Ruminococcus, which produce butyrate, a short-chain fatty acid linked to improved gut health and insulin sensitivity. This is particularly relevant if you have insulin resistance.

GoodSupportsHIGH confidence
the HRS diet resulted in a shift in the structure of the gut microbiome... there was a consistent increase in the proportion of Firmicutes to Bacteroides following the HRS diet... These changes included increases in relative amounts of species in the genera Faecalibacterium, Roseburia, and Ruminococcus
Tanja Maier et al. · mBio · 2017

Why this rating

Multi-omics (16S, metaproteomics, metabolomics) in a controlled crossover trial with insulin-resistant subjects provides strong mechanistic evidence.

Source

Impact of Dietary Resistant Starch on the Human Gut Microbiome, Metaproteome, and Metabolome

Tanja Maier et al. · mBio · 2017

DOI 10.1128/mbio.01343-17

crossover · n=39Cited 315×
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 →