Effect of protein rich versus fat rich diet on gall bladder ejection fraction

Objectives Assessment of gall bladder ejection fraction (GBEF) after a standard fatty meal using hepatobiliary scintigraphy is routinely used to study GB motility. However, amino acids also stimulate release of cholecystokinin, causing GB contraction. The effect of a protein rich diet on GBEF is not known. We studied the effect of protein rich versus fat rich diet on GBEF using cholescintigraphy.

Methods Patients with suspected GB dysfunction underwent ultrasonographic assessment of the biliary tree and GB, followed by 99mTc Mebrofenin scintigraphy. A standard fatty meal comprising high fat, low protein was used at baseline; a repeat study after one week used a low fat, high protein meal. GBEF in each study was calculated and the values compared using paired Student ‘t’ test.

Results Seven patients (4M, 3F; aged 49 ± 21 years) were evaluated in this pilot study. Gall stones were present in 5 patients (4 multiple, 1 single) and two had suspected cholecystopathy. The mean EF after a protein rich meal was significantly higher than after a fatty meal (70 ± 25% vs 52.5 ± 23%; p=0.008). The protein meal EF showed a high degree of correlation with the fat meal EF, rho=0.881, p=0.009. The mean increase in GBEF after high protein meal compared to a high fat meal was 17.5 ± 12%. The increase was noticed in all patients irrespective of their gall stone status, gender, age and their baseline GBEF.

Conclusions High protein meal elicits a better GB contraction than a standard high fat meal. Patients with GB dysmotility may be advised regular high protein meals to prevent stasis and its associated complications.