Effects of plant food potassium salts (citrate, galacturonate or tartrate) on acid-base status and digestive fermentations in rats.
Potassium (K) organic anion salts, such as potassium citrate or potassium malate in plant foods, may counteract low-grade metabolic acidosis induced by western diets, but little is known about the effect of other minor plant anions. Effects of K salts (chloride, citrate, galacturonate or tartrate) were thus studied on the mineral balance and digestive fermentations in groups of 6-week-old rats adapted to an acidogenic/5 % inulin diet. In all diet groups, substantial amounts of lactate and succinate were present in the caecum, besides SCFA. SCFA were poorly affected by K salts conditions. The KCl-supplemented diet elicited an accumulation of lactate in the caecum; whereas the lactate caecal pool was low in rats fed the potassium tartrate-supplemented (K TAR) diet. A fraction of tartrate (around 50 %) was recovered in urine of rats fed the K TAR diet. Potassium citrate and potassium galacturonate diets exerted a marked alkalinizing effect on urine pH and promoted a notable citraturia (around 0.5 micro mol/24 h). All the K organic anion salts counteracted Ca and Mg hyperexcretion in urine, especially potassium tartrate as to magnesuria. The present findings indicate that K salts of unabsorbed organic anions exert alkalinizing effects when metabolizable in the large intestine, even if K and finally available anions (likely SCFA) are not simultaneously bioavailable. Whether this observation is also relevant for a fraction of SCFA arising from dietary fibre breakdown (which represents the major organic anions absorbed in the digestive tract in man) deserves further investigation.
Sabboh
Houda
H
INRA, UMR 1019, Unité Nutrition Humaine, Centre de Clermont-Ferrand-Theix, France.
Coxam
Véronique
V
Horcajada
Marie-Noëlle
MN
Rémésy
Christian
C
Demigné
Christian
C
D000818:Animals; D000838:Anions / Q000652:urine; D002118:Calcium / Q000652:urine; D002432:Cecum / Q000502:physiology; D019587:Dietary Supplements; D004063:Digestion / Q000502:physiology*; D005285:Fermentation / Q000502:physiology*; D006603:Hexuronic Acids / Q000008:administration & dosage; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000652:urine; D008297:Male; D009929:Organ Size / Q000502:physiology; D011189:Potassium Chloride / Q000008:administration & dosage; D019357:Potassium Citrate / Q000008:administration & dosage; D017419:Potassium, Dietary / Q000008:administration & dosage*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013644:Tartrates / Q000008:administration & dosage
D000838:Anions; D006603:Hexuronic Acids; D017419:Potassium, Dietary; D013644:Tartrates; C007819:galacturonic acid; D011189:Potassium Chloride; D019357:Potassium Citrate; D008274:Magnesium; D002118:Calcium; C029768:tartaric acid