Gut & Microbiome
Can a modified starch carry a healthy fat to the gut?
The claim, precisely: butyrylated high-amylose starch (HAMSB) delivers butyrate
Yes, it reliably delivers butyrate to the colon, but baking weakens this and no health benefit is proven yet.
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Human trials (RCT / n-of-1)
How the studies fall
What the evidence shows
Esterified butyrate on high-amylose starch (HAMSB) survives small-intestinal passage and releases butyrate in the human colon — a real food-grade delivery format, and inulin-propionate ester was successfully baked into a bread roll with retained effect. BUT cooking/baking degrades the butyrylation advantage, and no human glycemic-outcome RCT exists yet: delivery proven, metabolic benefit not.
The evidence (6)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Bajka BH, et al. (CSIRO) 2006 · (rat) | animal | supports | moderate | HAMSB > HAMS for portal butyrate (rat); cooking lowered caecal butyrate |
| Bajka BH, et al. (CSIRO) 2006 · (rat) | animal | supports | moderate | RAT HAMSB resists amylolysis raises colonic/portal butyrate; cooking lowers caecal butyrate. ANIMAL |
| (IPE in bread roll) 2019 · (RCT) | RCT | supports | moderate | Inulin-propionate ester baked into foods retained colonic SCFA delivery in humans n=21; bakeable ester-SCFA format |
| (IPE in bread roll) 2019 · (RCT) | RCT | supports | moderate | Inulin-propionate ester baked into a bread roll retained the appetite effect |
| Clarke JM, et al. (CSIRO) 2011 · (human ileostomy) | RCT | supports | high | HUMAN crossover n=16 cooked HAMSB delivered ~57% esterified butyrate to colon; fecal butyrate up vs HAMS |
| Clarke JM, et al. (CSIRO) 2011 · (human ileostomy) | observational | supports | moderate | Human ileostomy: esterified SCFA on starch released in the large bowel |
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.