Lactulose and renal failure

Assessment of the pharmacokinetics, removal rate of hemodialysis, and safety of lactulose in hemodialysis patients

Lactulose is often used to treat hepatic encephalopathy or constipation, and also exhibits benefits to chronic renal insufficiency due to reduce nitrogen-related products in serum. The present study investigated the pharmacokinetics of lactulose, its removal rate through dialysis, and safety by administering lactulose 6.5 g (Lagnos Jelly Divided Pack 16.05 g) orally to six hemodialysis patients who resided in Taiwan. As a result, the means of maximum plasma concentrations (C_max) and Time to reach C_max (Tmax) were 3090 ± 970 ng/mL and 6.5 ± 2.3 hours, respectively. The mean plasma concentration was 2220 ± 986 ng/mL after administration for 24 hours. Sequentially, the mean plasma concentration reduced to 307 ± 117 ng/mL after the application of 4-hour dialysis. Area under the plasma concentration-time curve from zero to 24 h post-dose (AUC_0–24h) were 56,200 ± 21,300 ng h/mL and the AUC_0–28h was 61,200 ± 23,300 ng h/mL. The rate of lactulose removal by dialysis was 83.6 ± 8.9%. In addition, the multiple doses of lactulose using a simulated model suggested that no plasma accumulation would be expected while coordinating with dialysis. Good tolerability was confirmed, while the mild adverse effect of diarrhea was observed in one case during the study period. No death or serious adverse effect was reported. Based on the present study, we demonstrated the pharmacokinetic transition with respect to plasma levels of lactulose in patients with impaired renal excretion treated with hemodialysis.

The effect of lactulose supplementation on fecal microflora of patients with chronic kidney disease; a randomized clinical trial

Introduction: Lactulose is a prebiotic with bifidogenic and urea reduction effects. It can improve Bifidobacteria and Lactobacilli counts in healthy humans and it may possibly have similar effects in chronic kidney disease (CKD) patients.

Objectives: To investigate the effect of lactulose on fecal microflora of patients with CKD.

Patients and Methods: Thirty-two patients with stages 3 and 4 of CKD (43.8% male with mean age of 58.09±12.75 years) were randomly assigned to intervention (n=16) and control (n=16) groups. Patients in intervention group received 30 mm lactulose syrup three times a day for an 8-week period. Control group received placebo 30 mm three times a day. A fecal sample was obtained from all patients at the beginning and at the end of the study and Bifidobacteria and Lactobacilli was counted.

Results: Creatinine (Cr) significantly decreased in intervention group (3.90±1.43 to 3.60±1.44, P=0.003) and increased in control group (3.87±2.08 to 4.11±1.99, P=0.03). Although Bifidobacterial and Lactobacilli counts were similar before intervention, they were significantly higher at the end of the study in lactulose group (P=0.01 and P=0.04, respectively). Lactulose led to significant increase in fecal Bifidobacterial counts (3.61±0.54 to 4.90±0.96, P<0.001) and Lactobacilli counts (2.79±1.00 to 3.87±1.13, P<0.001), while the change in placebo group was not significant.

Conclusion: Lactulose administration will increase Bifidobacteria and Lactobacillus counts in patients with CKD.

In vitro influence of dietary protein and fructooligosaccharides on metabolism of canine fecal microbiota

Background

The present in vitro study investigated whether the utilization of fructooligosaccharides (FOS) may influence canine fecal microbial population in presence of diets differing in their protein content and digestibility. Fresh fecal samples were collected from five adult dogs, pooled, and incubated for 24 h with the undigested residue of three diets: 1, Low protein high digestibility diet (LP HD, crude protein (CP) 229 g/kg); 2, High protein high digestibility diet (HP HD, CP 304 g/kg); 3, High protein low digestibility diet (HP LD, CP 303 g/kg) that had been previously subjected to enzymatic digestion. In the in vitro fermentation study, there were six treatments: 1) LP HD; 2) HP HD 3) HP LD; 4) LP HD + FOS; 5) HP HD + FOS; 6) HP LD + FOS. Fructooligosaccharides were added at the final concentration of 1.5 g/L. Samples of fermentation fluid were collected at 6 and 24 h of incubation.

Results

Values of pH were reduced by FOS at 6 and 24 h (P < 0.001); conversely, low protein digestibility and high dietary protein level resulted in higher pH at both sampling times (P < 0.001). At 24 h, FOS lowered ammonia (−10 %; P < 0.001) and resulted (P < 0.05) in higher concentrations of total volatile fatty acids (VFA) (+43 %), acetic acid (+14 %), propionic acid (+75 %) and n-butyric acid (+372 %). Conversely, at 24 h, low protein digestibility resulted (P < 0.01) in lower concentrations of acetic acid (−26 %), propionic acid (−37 %) and total VFA (−21 %). Putrescine concentrations were increased at 6 and 24 h of fermentation by low protein digestibility (+21 and 22 %, respectively; P < 0.05) and FOS (+18 and 24 %, respectively; P < 0.01). After 24 h of fermentation, high dietary protein level resulted in lower counts of lactobacilli and enterococci (−0.5 and −0.7 log cells/mL, respectively; P < 0.05) whereas low protein digestibility tended to increase counts of C. perfringens (+0.2 log cells/mL; P = 0.07).

Conclusions

Results from the present study showed that diets rich in protein may exert negative influences on the canine intestinal ecosystem, slightly increasing the presence of ammonia and reducing counts of lactobacilli and enterococci. Moreover, the presence of poorly digestible protein resulted in lower concentrations of VFA. Conversely, administration of FOS may improve metabolism of canine intestinal microbiota, reducing ammonia concentrations and enhancing VFA production.

In vitro effect of dietary protein level and nondigestible oligosaccharides on feline fecal microbiota

The aim of the present study was to evaluate in vitro the effect of some prebiotic substances and 2 dietary protein levels on the composition and activity of feline fecal microbiota. Two in vitro studies were conducted. First, 6 nondigestible oligosaccharides were studied; treatments were control diet (CTRL), gluconic acid (GA), carrot fiber (CF), fructooligosaccharides (FOS), galactooligosaccharides (GOS), lactitol (LAC), and pectins from citrus fruit (PEC). Substrates were added to feline fecal cultures at 2 g/L for 24 h incubation. Compared with the CTRL, ammonia had been reduced (P<0.05) by GOS (-9%) after 6 h and by GA (-14%), LAC (-12%), and PEC (-10%) after 24 h. After 24 h, all treatments had resulted in a lower pH versus the CTRL. Putrescine concentrations at 24 h were greater (P<0.05) in cultures treated with FOS (+90%), GOS (+96%), and LAC (+87%). Compared with the CTRL, total VFA were higher (P<0.05) in bottles containing CF (+41%), whereas the acetic to propionic acid ratio was reduced by LAC (-51%; P<0.05). After 24 h, Enterobacteriaceae had been reduced (P<0.05) by LAC and PEC. In a second study, LAC and FOS were selected to be tested in the presence of 2 diets differing in their protein content. There were 6 treatments: low-protein (LP) CTRL with no addition of prebiotics (CTRL-LP), high-protein (HP) CTRL with no addition of prebiotics (CTRL-HP), LP diet plus FOS, CTRL-HP plus FOS, LP diet plus LAC, and CTRL-HP plus LAC. Both FOS and LAC were added to feline fecal cultures at 2 g/L for 24 h incubation. Ammonia at 24 h was affected (P<0.05) by the protein level (36.2 vs. 50.2 mmol/L for LP and HP, respectively). The CTRL-HPs resulted in a higher pH and increased concentrations of biogenic amines were found after 6 and 24 h of incubation (P<0.05); putrescine at 24 h showed an increase (P<0.05) in cultures treated with FOS. Total VFA were influenced (P<0.05) by the protein level (40.9 vs. 32.6 mmol/L for LP and HP, respectively). At 24 h, the CTRL-HPs were associated with increased Clostridium perfringens and reduced Lactobacillus spp. and enterococci counts (P<0.05). The results from the present study show that different prebiotics exert different effects on the composition and activity of feline intestinal microbiota and that high dietary protein levels in a cat's diet can have negative effects on the animal intestinal environment.

Nightly high dose lactulose infusion could be a cost-effective treatment for hepatic encephalopathy, renal insufficiency and heart failure

Lactulose is an established remedy for hepatic encephalopathy and shows efficacy for chronic renal insufficiency, reducing volume overload, uremia and hyperkalemia. Potentially lactulose could also be used for non-diuretic treatment of congestive heart failure. However, use of lactulose is limited by diarrhea and flatulence. Chronic lactulose administration might be tolerable if it was accomplished by nocturnal infusion through a percutaneous duodenostomy tube, also placing a rectal foley each night following a clearing enema so that large volumes of liquid stool could be passed while patients sleep. Each morning the duodenostomy would be clamped and the foley removed. For acute patients without duodenostomies, a temporary dobhoff feeding tube with accompanying rectal foley could be employed. Patients who did not want a rectal foley could elect to have a permanent colostomy. Clinical trials could establish the relationship between lactulose infusion and clearance of water, salt, potassium, hydrogen, urea and other wastes, and compare efficacy, cost and tolerability with that of peritoneal dialysis and ultrafiltration. Lactulose could potentially allow inexpensive home-based therapy for hepatic encephalopathy, chronic renal failure and congestive heart failure, and might be life-saving in countries where renal replacement in any form is currently unavailable.