Gut & Microbiome
butyrylated high-amylose starch (HAMSB) delivers butyrate
In plain terms: Can butyrylated starch carry the healthy fat butyrate to the gut?
Yes, it reliably delivers butyrate to the colon, but baking weakens this and no health benefit is proven yet.
📅 Last reviewed: 2026-07-15 ⓘ
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 (21)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Nielsen TS et al 2019 · study_type: animal | animal | supports | moderate | Rodent (rats on high-protein meat diet): HAMSB diet substantially increased fecal butyrate concentration and pool compared with HAMS, HAPS, and control diets. |
| Abell 2011 · Br J Nutr | animal | supports | moderate | HAMSB increased distal-colon butyrate and propionate vs low-RS starch in rats, shifting faecal microbiota. |
| Zhou Y et al 2023 · study_type: animal | animal | supports | moderate | Rodent (5xFAD Alzheimer's mouse model): diets supplemented with high acetate/butyrate-yielding starch (HAMSAB) delayed cognitive decline, used as the delivery vehicle for colonic SCFA including butyrate. |
| Bajka BH, et al. (CSIRO) 2006 · (rat) | animal | supports | moderate | RAT HAMSB resists amylolysis raises colonic/portal butyrate; cooking lowers caecal butyrate. ANIMAL |
| Toden 2014 · Cancer Biol Ther | animal | supports | moderate | Increasing dietary HAMSB dose-dependently raised large-bowel and portal butyrate pools/concentrations in rats. |
| McOrist 2011 · J Nutr | RCT | supports | moderate | High-resistant-starch diet usually increased faecal butyrate concentration/excretion in healthy adults (wide inter-individual variation). |
| Cheng J et al 2024 · study_type: observational | observational | supports | moderate | Narrative review synthesizing human trials: HAMSB is 68% digestible and ~60% of attached butyrate is absorbed by the colon; three clinical trials consistently show HAMSB-linked shifts in fecal microbial profile alongside butyrate delivery. |
| Hald 2016 · PLoS One | RCT | tested-null | moderate | Arabinoxylan+resistant-starch diet raised faecal total SCFA, acetate and butyrate vs Western diet in metabolic-syndrome adults. |
| Clarke 2008 · Carcinogenesis | animal | supports | moderate | Rats fed HAMSB had higher large-bowel and portal-plasma butyrate than RS alone or tributyrin. |
| Le Leu 2015 · Br J Nutr | RCT | supports | high | 40g/d HAMSB with red meat raised human stool SCFA >20% and altered microbiota, confirming colonic butyrate delivery in humans. |
| Nielsen TS et al 2018 · study_type: in-vitro | in-vitro | mixed | moderate | In-vitro fermentation model: organocatalytically butyrylated maize/potato starches were characterized by NMR; increasing degree of substitution (butyrylation) paradoxically lowered in-vitro fermentation capability, i.e., did not deliver mor |
| Gill 2022 · Am J Clin Nutr | RCT | mixed | moderate | Independent RCT: dietary resistant/fermentable starch raised colonic and peripheral-blood SCFA (incl. butyrate) in healthy humans. |
| Bajka 2008 · Carcinogenesis | animal | supports | moderate | 20% HAMSB doubled large-bowel digesta butyrate vs HAMS in rats; raised hepatic portal butyrate, indicating colonic delivery. |
| Humphreys KJ et al 2014 · study_type: RCT | RCT | supports | high | Human (randomized crossover, 23 volunteers): fecal butyrate increased with the high-red-meat + HAMSB (40 g/day) diet compared to high-red-meat alone. |
| West 2013 · Exerc Immunol Rev | RCT | supports | moderate | HAMSB ingestion in healthy active adults raised fecal/colonic butyrate concentration vs control starch; limited immune effects. |
| Byrne CS et al] # corrected 2026-08-17 from PubMed; was [(IPE in bread roll) 2019 · (RCT) | RCT | tested-null | moderate | Inulin-propionate ester baked into a bread roll retained the appetite effect |
| Ni D et al 2025 · medRxiv | RCT | supports | moderate | Human (food-allergic children on peanut OIT, RCT sub-study): HAMSB supplementation transiently increased fecal SCFA production including butyrate and propionate over 1 year vs low-amylose starch control. |
| 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 |
| Pedersen SS et al 2023 · study_type: animal | animal | supports | high | Rodent (db/db diabetic mice): HAMSB-fed mice had 8-fold higher fecal butyrate concentration compared to control-diet-fed mice, alongside improved glucose metabolism. |
| Xu Q et al 2024 · study_type: animal | animal | supports | moderate | Rodent (mouse acute alcoholic liver injury model): HAMSB supplementation was compared with oral sodium butyrate and was superior for alleviating liver injury, consistent with effective colonic butyrate yield from the starch vehicle. |
| Bell KJ et al 2022 · study_type: RCT | observational | supports | moderate | Human (single-arm pilot, adults with type 1 diabetes): 6 weeks of HAMSAB supplementation increased concentrations of acetate, propionate, and butyrate in both stools and plasma. |
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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.