The Study
Hydrolysis of Casein Accelerates Gastrointestinal Transit via Reduction of Opioid Receptor Agonists Released from Casein in Rats
This study showed that when baby rats eat a special kind of milk protein that's been broken down, their guts move food faster. They also gave the rats a drug that blocks a certain chemical, and that stopped the faster movement — so they think the broken-down protein works by stopping that chemical. But this only happened in rats, not people.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Some milk proteins release sleepy-time chemicals that slow down digestion. Breaking those proteins apart stops the sleepy chemicals, so food moves faster.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 518 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This effect was seen in baby rats — it’s not proven to work the same way in human babies.
- 2Hydrolyzed casein: 77.4% of colon covered by dye.
- 3Native casein: 51.2%.
- 4After naloxone: both at ~77%.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Neonatology
Year
2005
Authors
W. Mihatsch, A. Franz, B. Kuhnt, J. Högel, F. Pohlandt
Related Content
Claims (6)
In rat pups, hydrolyzed casein speeds up the movement of food through the gut by about 51% compared to unmodified casein, due to lower levels of opioid peptides released during digestion.
In rat pups, blocking opioid receptors with naloxone removes the difference in how fast food moves through the gut when comparing hydrolyzed casein to native casein, showing that opioid receptor activity causes native casein to slow gut transit.
When native casein is digested, it produces peptides that slow down the movement of material through the gastrointestinal tract of rat pups by about 26 percentage points compared to hydrolyzed casein, as measured by colonic carmine red movement.
In rat pups, undigested casein protein slows gut movement through opioid receptor activation, and breaking down casein into smaller pieces reduces this slowing by stopping opioid peptides from being released.
Gastrointestinal responses to casein hydrolysis in rat pups cannot be used to predict how preterm human infants will respond without direct clinical studies in infants.
Casomorphins from dairy proteins bind to opioid receptors in the body and lead to reduced feelings of fullness and increased food intake.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.